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1.  Multi-Detector Computed Tomography Angiography for Coronary Artery Disease 
Executive Summary
Purpose
Computed tomography (CT) scanning continues to be an important modality for the diagnosis of injury and disease, most notably for indications of the head and abdomen. (1) According to a recent report published by the Canadian Institutes of Health Information, (1) there were about 10.3 scanners per million people in Canada as of January 2004. Ontario had the fewest number of CT scanners per million compared to the other provinces (8 CT scanners per million). The wait time for CT in Ontario of 5 weeks approaches the Canadian median of 6 weeks.
This health technology and policy appraisal systematically reviews the published literature on multidetector CT (MDCT) angiography as a diagnostic tool for the newest indication for CT, coronary artery disease (CAD), and will apply the results of the review to current health care practices in Ontario. This review does not evaluate MDCT to detect coronary calcification without contrast medium for CAD screening purposes.
The Technology
Compared with conventional CT scanning, MDCT can provide smaller pieces of information and can cover a larger area faster. (2) Advancing MDCT technology (8, 16, 32, 64 slice systems) is capable of producing more images in less time. For general CT scanning, this faster capability can reduce the time that patients must stay still during the procedure, thereby reducing potential movement artefact. However, the additional clinical utility of images obtained from faster scanners compared to the images obtained from conventional CT scanners for current CT indications (i.e., non-moving body parts) is not known.
There are suggestions that the new fast scanners can reduce wait times for general CT. MDCT angiography that utilizes a contrast medium, has been proposed as a minimally invasive replacement to coronary angiography to detect coronary artery disease. MDCT may take between 15 to 45 minutes; coronary angiography may take up to 1 hour.
Although 16-slice and 32-slice CT scanners have been available for a few years, 64-slice CT scanners were released only at the end of 2004.
Review Strategy
There are many proven, evidence-based indications for conventional CT. It is not clear how MDCT will add to the clinical utility and management of patients for established CT indications. Therefore, because cardiac imaging, specifically MDCT angiography, is a new indication for CT, this literature review focused on the safety, effectiveness, and cost-effectiveness of MDCT angiography compared with coronary angiography in the diagnosis and management of people with CAD.
This review asked the following questions:
Is the most recent MDCT angiography effective in the imaging of the coronary arteries compared with conventional angiography to correctly diagnose of significant (> 50% lumen reduction) CAD?
What is the utility of MDCT angiography in the management and treatment of patients with CAD?
How does MDCT angiography in the management and treatment of patients with CAD affect longterm outcomes?
The published literature from January 2003 to January 31, 2005 was searched for articles that focused on the detection of coronary artery disease using 16-slice CT or faster, compared with coronary angiography. The search yielded 138 articles; however, 125 were excluded because they did not meet the inclusion criteria (comparison with coronary angiography, diagnostic accuracy measures calculated, and a sample size of 20 or more). As screening for CAD is not advised, studies that utilized MDCT for this purpose or studies that utilized MDCT without contrast media were also excluded. Overall, 13 studies were included in this review.
Summary of Findings
The published literature focused on 16-slice CT angiography for the detection of CAD. Two abstracts that were presented at the 2005 European Congress of Radiology meeting in Vienna compared 64-slice CT angiography with coronary angiography.
The 13 studies focussing on 16-slice CT angiography were stratified into 2 groups: Group 1 included 9 studies that focused on the detection of CAD in symptomatic patients, and Group 2 included 4 studies that examined the use of 16-slice CT angiography to detect disease progression after cardiac interventions. The 2 abstracts on 64-slice CT angiography were presented separately, but were not critically appraised due to the lack of information provided in the abstracts.
16-Slice Computed Tomography Angiography
The STARD initiative to evaluate the reporting quality of studies that focus on diagnostic tests was used. Overall the studies were relatively small (fewer than 100 people), and only about one-half recruited consecutive patients. Most studies reported inclusion criteria, but 5 did not report exclusion criteria. In these 5, the patients were highly selected; therefore, how representative they are of the general population of people with suspicion if CAD or those with disease progression after cardiac intervention is questionable. In most studies, patients were either already taking, or were given, β-blockers to reduce their heart rates to improve image quality sufficiently. Only 6 of the 13 studies reported interobserver reliability quantitatively. The studies typically assessed the quality of the images obtained from 16-slice CT angiography, excluded those of poor quality, and compared the rest with the gold standard, coronary angiography. This practice necessarily inflated the diagnostic accuracy measures. Only 3 studies reported confidence intervals around their measures.
Evaluation of the studies in Group 1 reported variable sensitivity, from just over 60% to 96%, but a more stable specificity, at more than 95%. The false positive rate ranged from 5% to 8%, but the false negative rate was at best under 10% and at worst about 30%. This means that up to one-third of patients who have disease may be missed. These patients may therefore progress to a more severe level of disease and require more invasive procedures. The calculated positive and negative likelihood ratios across the studies suggested that 16-slice CT angiography may be useful to detect disease, but it is not useful to rule out disease. The prevalence of disease, measured by conventional coronoary angiography, was from 50% to 80% across the studies in this review. Overall, 16-slice CT angiography may be useful, but there is no conclusive evidence to suggest that it is equivalent to or better than coronary angiography to detect CAD in symptomatic patients.
In the 4 studies in Group 2, sensitivity and specificity were both reported at more than 95% (except for 1 that reported sensitivity of about 80%). The positive and negative likelihood ratios suggested that the test might be useful to detect disease progression in patients who had cardiac interventions. However, 2 of the 4 studies recruited patients who had been asymptomatic since their intervention. As many of the patients studied were not symptomatic, the relevance of performing MDCT angiography in the patient population may be in question.
64-Slice Computed Tomography Angiography
An analysis from the interim results based on 2 abstracts revealed that 64-slice CT angiography was insufficient compared to coronary angiography and may not be better than 16-slice CT angiography to detect CAD.
Conclusions
Cardiac imaging is a relatively new indication for CT. A systematic review of the literature was performed from 2003 to January 2005 to determine the effectiveness of MDCT angiography (16-slice and 64-slice) compared to coronary angiography to detect CAD. At the time of this report, there was no published literature on 64-slice CT for any indications.
Based on this review, the Medical Advisory Secretariat concluded that there is insufficient evidence to suggest that 16-slice or 64-slice CT angiography is equal to or better than coronary angiography to diagnose CAD in people with symptoms or to detect disease progression in patients who had previous cardiac interventions. An analysis of the evidence suggested that in investigating suspicion of CAD, a substantial number of patients would be missed. This means that these people would not be appropriately treated. These patients might progress to more severe disease and possibly more adverse events. Overall, the clinical utility of MDCT in patient management and long-term outcomes is unknown.
Based on the current evidence, it is unlikely that CT angiography will replace coronary angiography completely, but will probably be used adjunctively with other cardiac diagnostic tests until more definitive evidence is published.
If multi-slice CT scanners are used for coronary angiography in Ontario, access to the current compliment of CT scanners will necessarily increase wait times for general CT scanning. It is unlikely that these newer-generation scanners will improve patient throughput, despite the claim that they are faster.
Screening for CAD in asymptomatic patients and who have no history of ischemic heart disease using any modality is not advised, based on the World Health Organization criteria for screening. Therefore, this review did not examine the use of multi-slice CT for this purpose.
PMCID: PMC3382628  PMID: 23074474
2.  Characterization of Incidental Liver Lesions: Comparison of Multidetector CT versus Gd-EOB-DTPA-Enhanced MR Imaging 
PLoS ONE  2013;8(6):e66141.
As a result of recent developments in imaging modalities and wide spread routine medical checkups and screening, more incidental liver lesions are found frequently on US these days. When incidental liver lesions are found on US, physicians have to make a decision whether to just follow up or to undergo additional imaging studies for lesion characterization. In order to choose the next appropriate imaging modality, the diagnostic accuracy of each imaging study needs to be considered. Therefore, we tried to compare the accuracy of contrast-enhanced multidetector CT (MDCT) and Gd-EOB-DTPA-enhanced MRI for characterization of incidental liver masses. We included 127 incidentally found focal liver lesions (94 benign and 33 malignant) from 80 patients (M∶F = 45∶35) without primary extrahepatic malignancy or chronic liver disease. Two radiologists independently reviewed Gd-EOB-DTPA-enhanced MRI and MDCT. The proportion of confident interpretations for differentiation of benign and malignant lesions and for the specific diagnosis of diseases were compared. The proportion of confident interpretations for the differentiation of benign and malignant lesions was significantly higher with EOB-MRI(94.5%–97.6%) than with MDCT (74.0%–92.9%). In terms of specific diagnosis, sensitivity and accuracy were significantly higher with EOB-MRI than with MDCT for the diagnosis of focal nodular hyperplasia (FNH) and focal eosinophilic infiltration. The diagnoses of the remaining diseases were comparable between EOB-MRI and MDCT. Hence, our results suggested that Gd-EOB-MRI may provide a higher proportion of confident interpretations than MDCT, especially for the diagnosis of incidentally found FNH and focal eosinophilic infiltration.
doi:10.1371/journal.pone.0066141
PMCID: PMC3679037  PMID: 23776623
3.  Are “Normal” Multidetector Computed Tomographic Scans Sufficient to Allow Collar Removal in the Trauma Patient? 
The Journal of Trauma  2010;68(1):103-108.
Background
Controversy continues as to the most safe and reliable method for clearing the cervical spine (C-spine) in a trauma patient who is rendered unable to participate in a clinical examination. Although magnetic resonance imaging (MRI) is the most sensitive test to detect soft-tissue injuries, it is impractical for routine use in every patient largely because of its cost and time of acquiescence. Recent studies have advocated the sole use of multidetector computed tomographic (MDCT) scans of the C-spine to decide if cervical collar immobilization can be discontinued. The current investigation retrospectively reviewed a series of MDCT scans obtained after an acute traumatic event that were used to direct treatment in the emergency department (ED) or intensive care unit.
Methods
Seven-hundred and eight trauma patients consecutively admitted to the ED between June 2001 and July 2006 underwent a computed tomographic scan of their C-spine as part of an institutional protocol. We identified 91 patients with MDCT scans that were officially recorded as adequate and negative by an attending ED radiologist who had also undergone an MRI during the same trauma admission period. Retrospectively, two fellowship-trained spine surgeons independently reviewed these MDCT studies to address the following questions: (1) Is the study adequate? (2) Is it suggestive of an acute injury? (3) Is there sufficient information to safely recommend collar removal? Institutional Review Board approval was obtained before the images were reviewed. Neither clinical examination findings nor MRI readings were made available to the surgeon evaluators.
Results
Both spine surgeons agreed that 76 of the 91 studies (84%) were adequate to evaluate for possible C-spine injuries. Seven of 91 MDCT scans (8%) were deemed inadequate by both surgeons (95% confidence interval, 2.3–13.1). Reasons for inadequacy included motion artifact, insufficient visualization of the cervical-thoracic or occipital-cervical junctions, incomplete reconstructive views, or poor quality. Three of the adequate MDCT scans had fractures that were identified by both of the spine surgeons; 4 additional fractures and 15 findings suspicious for instability were identified by at least one of the surgeons. Ultimately, 22 of 91 MDCT scans read as adequate and normal by attending radiologists were deemed suspicious for abnormality by the spine surgeons. Of these 22 cases, the official MRI reading was positive for a trauma-related abnormality in 17 cases.
Conclusions
C-spine clearance of patients without the ability participate in a clinical examination remains difficult. A multidisciplinary, algorithmic approach generally yields the most consistent results. However, our data highlight that reliance on a single imaging modality may lead to missed diagnosis of C-spine injuries. These data suggest that early involvement of the spine service for radiographic clearance may help identify occult injuries or suspicious findings necessitating further evaluation.
doi:10.1097/TA.0b013e3181b021da
PMCID: PMC3256247  PMID: 20065764
Cervical spine; Trauma; Clearance; Multidetector computed tomographic scan; Cervical collar
4.  Severe osteoporosis: diagnosis of non-hip non-vertebral (NHNV) fractures 
Osteoporotic bone, structurally altered because of reduction of bone mineral density and quality deterioration, can easily head for fracture after minimum mechanical stress.
The most common sites of fracture, other than spine and hip, are, in decreasing order: distal radius, forearm, proximal humerus, other femoral sites, ribs, pelvis, tibia and fibula, metatarsal bone and calcaneum. The role of diagnostic imaging is essential in detecting fractures for their immediate and correct assessment, which is necessary to the planning of treatment, whether conservative or surgical. Imaging is also important in fracture monitoring, evaluation of healing and relief of any complications.
Conventional radiology is the most widely used technique in the diagnosis of fracture, although its low sensitivity, mainly in anatomically complex sites; the role of radiology is undisputed in monitoring the healing bone callus formation. Multidetector Computed Tomography (MDCT) is of great help in doubtful cases, especially in locations as “critical”; its diagnostic accuracy is very elevated with 3D and multi-planar reconstructions, allowing the surgeon to implement an appropriate therapeutic strategy.
Magnetic Resonance (MR) is the most sensitive technique in the relief of minimal structural alteration of the cancellous bone, as it reveals both fracture line and surrounding bone marrow oedema.
Its specificity is higher compared to MDCT and conventional radiology in the differential diagnosis between osteoporotic and malignancy pathological fracture.
Bone scintigraphy is complementary to MRI in detecting occult fractures, crucial in finding metastatic disease in other locations.
Ultrasound is used in limited districts, and its role is confined to the relief of cortical interruption in the fractured bone segment.
In the future, technological advances with three-dimensional techniques (hr-CT, hr-MRI) may improve in vivo the diagnostic potential with an earlier detection of the ultrastructural alterations that predispose to the risk of bone fracture.
PMCID: PMC3004452  PMID: 22460010
Osteoporosis, NHNV fractures.
5.  Multidetector Computed Tomography for Coronary Artery Disease Screening in Asymptomatic Populations 
Executive Summary
Objective
This evidence-based health technology assessment systematically reviewed the published literature on multidetector computed tomography (MDCT) angiography (with contrast) as a diagnostic tool for coronary artery disease (CAD), and applied the results of the assessment to health care practices in Ontario.
Clinical Need
Coronary artery disease is the leading cause of death in the western world. Occlusion of coronary arteries reduces coronary blood flow and oxygen delivery to the myocardium (heart muscle). The rupture of an unstable atherosclerotic plaque may result in myocardial infarction. If left untreated, CAD can result in heart failure and, subsequently, death. According to the Heart and Stroke Foundation of Canada, 54% of all cardiovascular deaths are due to CAD. Patient characteristics (e.g., age, sex, and genetics), underlying clinical conditions that predispose to cardiac conditions (e.g., diabetes, hypertension, and elevated cholesterol), lifestyle characteristics, (e.g., obesity, smoking, and physical inactivity), and, more recently, determinants of health (e.g., socioeconomic status) may predict the risk of getting CAD.
In 2004/2005, The Ontario government funded approximately 15,400 percutaneous (through the skin) coronary interventions and 7,840 coronary bypass procedures for the treatment of CAD. These numbers are expected to reach 22,355 for percutaneous coronary interventions and 12,323 for coronary bypass procedures in 2006/2007. It was noted that more than one-half of all first coronary events occur in people without symptoms of CAD. In Ontario in 2000/2001, $457.9 million (Cdn) was spent on invasive ($237.4 million) and noninvasive ($220.5 million) cardiac services. The use of noninvasive cardiac tests, in particular, is rising rapidly.
The Technology
Computed tomography (CT) is a medical imaging method employing tomography where digital geometry processing is used to generate a 3-dimensional image of the internals of an object from a large series of 2-dimensional X-ray images taken around a single axis of rotation. Multidetector computed tomography is performed for noninvasive imaging of the coronary arteries. Computer software quantifies the amount of calcium within the coronary arteries and calculates a coronary artery calcium score.
Compared with conventional CT scanning, MDCT can provide smaller pieces of information and cover a larger area faster. Advanced MDCT technology (that is, 8-, 16-, 32-, and 64-slice systems) can produce more images in less time. For general CT scanning, this faster capability can reduce the length of time people are required to be still during the procedure and thereby reduce potential movement artifact. However, the additional clinical utility of images obtained from faster scanners compared with the images obtained from conventional CT scanners for current CT indications (i.e., nonmoving body parts) is unknown.
Review Strategy
The Medical Advisory Secretariat completed a computer-aided search limited to English-language studies in humans from 1998 to 2007 in multiple medical literature databases, including MEDLINE, EMBASE, The Cochrane Library, and INAHTA/CRD. Case reports, letters, editorials, nonsystematic reviews, and comments were excluded. Additional studies that met the inclusion and exclusion criteria were obtained from reference lists of included studies. Inclusion and exclusion criteria were applied to the results according to the criteria listed below.
The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to evaluate the overall quality of the body of evidence (defined as 1 or more studies) supporting the research questions explored in this systematic review.
Summary of Findings and Conclusions
Screening the asymptomatic population for CAD using MDCT does not meet World Health Organization criteria for screening; hence, it is not justifiable. Coronary artery calcification measured by MDCT is a good predictor of future cardiovascular events. However, MDCT exhibits only moderately high sensitivity and specificity for detection of CAD in an asymptomatic population. If population-based screening were implemented, a high rate of false positives would result in increased downstream costs and interventions. Additionally, some cases of CAD would be missed, as they may not be developed, or not yet have progressed to detectable levels. There is no evidence for the impact of screening on patient management. Cardiovascular risk factors are positively associated with the presence of coronary artery calcification and cardiovascular events; however, risk factor stratification to identify high-risk asymptomatic individuals is unclear given the current evidence-base.
Safety of MDCT screening is also an issue because of the introduction of increased radiation doses for the initial screening scan and possible follow-up interventions.
No large randomized controlled trials of MDCT screening have been published, which indicates an important area of future research.
Lastly, the policy implications for MDCT screening for CAD in the asymptomatic population are significant. There is no evidence on the long-term implications of screening, and the potential impact on the resources of the health care system is considerable.
PMCID: PMC3377586  PMID: 23074503
6.  Morphological and functional MDCT: problem-solving tool and surrogate biomarker for hepatic disease clinical care and drug discovery in the era of personalized medicine 
This article explains the significant role of morphological and functional multidetector computer tomography (MDCT) in combination with imaging postprocessing algorithms served as a problem-solving tool and noninvasive surrogate biomarker to effectively improve hepatic diseases characterization, detection, tumor staging and prognosis, therapy response assessment, and novel drug discovery programs, partial liver resection and transplantation, and MDCT-guided interventions in the era of personalized medicine. State-of-the-art MDCT depicts and quantifies hepatic disease over conventional CT for not only depicting lesion location, size, and extent but also detecting changes in tumor biologic behavior caused by therapy or tumor progression before morphologic changes. Color-encoded parameter display provides important functional information on blood flow, permeability, leakage space, and blood volume. Together with other relevant biomarkers and genomics, the imaging modality is being developed and validated as a biomarker to early response to novel, targeted anti-VEGF(R)/PDGFR or antivascular/angiogenesis agents as its parameters correlate with immunohistochemical surrogates of tumor angiogenesis and molecular features of malignancies. MDCT holds incremental value to World Health Organization response criteria and Response Evaluation Criteria in Solid Tumors in liver disease management. MDCT volumetric measurement of future remnant liver is the most important factor influencing the outcome of patients who underwent partial liver resection and transplantation. MDCT-guided interventional methods deliver personalized therapies locally in the human body. MDCT will hold more scientific impact when it is fused with other imaging probes to yield comprehensive information regarding changes in liver disease at different levels (anatomic, metabolic, molecular, histologic, and other levels).
doi:10.2147/HMER.S9052
PMCID: PMC3846718  PMID: 24367211
perfusion MDCT; liver nodule; angiogenesis; functional imaging; VEGF receptor
7.  Imaging investigation of pancreatic cystic lesions and proposal for therapeutic guidelines 
World Journal of Radiology  2012;4(8):372-378.
AIM: To propose a diagnostic algorithm for preoperatively predicting the need for surgical intervention.
METHODS: The study included 56 patients (27 men and 29 women) with a final diagnosis of cystic pancreatic lesions. The following materials were used: ultrasonic equipment with 3.5 and 7 MHz linear, convex and biopsical transducers. Multidetector computed tomography (MDCT) investigations were performed using a 16-slice scanner. Images were obtained following the oral administration of 200 mL water and 100 mL intravenous iopamidol (300 mg/mL) administered by pump injector at a rate of 3 mL/s (40 and 60 s post-injection, respectively) using 0.5 mm detectors, reconstructed at 1 mm (pancreatic phase) or 2 mm (portal venous phase) increments. The table feed was 10 mm per rotation. Images were acquired in the pancreatic and portal venous phases of contrast enhancement. The “Chiba” needles 18, 20, 22, 23 G and an automatic aspiration system were used in conjunction with the following methods of guiding the interventional procedures: (1)“free-hand” biopsy and puncture method under ultrasound (US) or computed tomography (CT) control; (2) guiding method using biopsical transducer.
RESULTS: All 56 patients in this study underwent at least two cuts imaging survey methods, such as US, CT or magnetic resonance imaging (MRI). The most common preoperative diagnostic examination was US scan - 56 patients (100%). MDCT studies were conducted in 49 (87.50%) and MRI in 13 (23.21%). More than half of patients surveyed (37) underwent some type of interventional procedure: 25-fine-needle aspiration and 29-fine needle aspiration biopsy (FNAB), as part of the examination. Thirty-four patients of all 56 patients underwent surgery because of histological evidence of malignancy after the FNAB for cystic lesions of the pancreas. Distal pancreatectomy with splenectomy was the most common operative approach in 13 patients, followed by Whipple resection in 11 and distal pancreatectomy without splenectomy in 7. Three patients were treated with total pancreatectomy due to the presence of a multifocal mucinous neoplasm. Comparing the diagnostic results of US examination with those of MDCT examination and histological verification true positive results were found in 31 patients, true negative in 11 patients, false positive in 5 and false negative in 9 patients. Accordingly we estimated the power of the diagnostic imaging methods for cystic lesions of the pancreas. A specificity of 68.75%, sensitivity of 79.48%, accuracy of 75.00%, positive predictive value of 86.11% and negative predictive value of 55% were obtained. The power increased after applying invasive procedures with immunohistochemical analysis of CEA and P-53 (Fig. 4). In 15 patients with cytological feature of malignant tumour cells, the tumour markers were positive. In our opinion the higher the percentage of reacting cells the higher the percent of malignancy. In patients with clear symptoms and/or clear imaging features of malignant or premalignant cystic neoplasm, the need for surgery was confirmed by histological verification in 34 (60.71%) of cases.
CONCLUSION: By using the proposed algorithm, cystic mucinous tumors of the pancreas were detected and proper operative interventions would have been rendered with fewer diagnostic examinations.
doi:10.4329/wjr.v4.i8.372
PMCID: PMC3430734  PMID: 22937216
Pancreatic cystic neoplasm; Diagnostic intervention; Fine-needle biopsy
8.  Extra cardiac findings by 64-multidetector computed tomography in patients with symptomatic atrial fibrillation prior to pulmonal vein isolation 
The aim of this study was to investigate the prevalence of extracardiac findings diagnosed by 64-multidetector computed tomography (MDCT) examinations prior to circumferential pulmonary vein (PV) ablation of atrial fibrillation (AF). A total of 158 patients (median age, 60.5 years; male 68%) underwent 64-MDCT of the chest and upper abdomen to characterize left atrial and PV anatomy prior to AF ablation. MDCT images were evaluated by a thoracic radiologist and a cardiologist. For additional scan interpretation, bone, lung, and soft tissue window settings were used. CT scans with extra-cardiac abnormalities categorized for the anatomic distribution and divided into two groups: Group 1—exhibiting clinically significant or potentially significant findings, and Group 2—patients with clinically non-significant findings. Extracardiac findings (n = 198) were observed in 113/158 (72%) patients. At least one significant finding was noted in 49/158 patients (31%). Group 1 abnormalities, such as malignancies or pneumonias, were found in 85/198 findings (43%). Group 2 findings, for example mild degenerative spine disease or pleural thickening, were observed in 113/198 findings (72%). 74/198 Extracardiac findings were located in the lung (37%), 35/198 in the mediastinum (18%), 8/198 into the liver (4%) and 81/198 were in other organs (41). There is an appreciable prevalence of prior undiagnosed extracardiac findings detected in patients with AF prior to PV-Isolation by MDCT. Clinically significant or potentially significant findings can be expected in ~40% of patients who undergo cardiac MDCT. Interdisciplinary trained personnel is required to identify and interpret both cardiac and extra cardiac findings.
doi:10.1007/s10554-010-9653-9
PMCID: PMC3035788  PMID: 20549365
Extra cardiac findings; Atrial fibrillation; 64-MDCT; Pulmonary vein ablation
9.  MDCT of small bowel tumours 
Cancer Imaging  2007;7(1):224-233.
Abstract
Primary benign and malignant neoplasm of the small bowel are rare. Malignant tumours often present late symptoms resulting in a poor prognosis. Early detection of small bowel neoplasms is desirable but challenging for both clinicians and radiologists. Conventional double contrast enteroclysis was the method of choice in small bowel imaging but is increasingly being replaced by cross-sectional imaging methods as computed tomography (CT) and magnetic resonance imaging (MRI). Multidetector CT (MDCT) produces high-resolution cross-sectional imaging of the abdomen and the small bowel. It allows multiplanar visualisation of small bowel tumours, demonstrates signs of small bowel obstruction as well as the mural and extramural extent of small bowel malignancies. This aids planning for surgical resection. In addition, liver metastases or peritoneal seeding can be detected with CT. The best visualisation of small bowel neoplasms is achieved with CT enteroclysis or enterography and this review discusses these techniques and MDCT characteristics of small bowel tumours.
doi:10.1102/1470-7330.2007.0032
PMCID: PMC2151330  PMID: 18083648
Computed tomography; small bowel tumour
10.  Multi-Detector Computed Tomography for the Evaluation of Myocardial Cell Therapy in Heart Failure:_A Comparison with Cardiac Magnetic Resonance Imaging 
JACC. Cardiovascular imaging  2011;4(12):1284-1293.
Objective
The aim of this study was to use multi-detector computed tomography (MDCT) to assess therapeutic effects of myocardial regenerative cell therapies.
Background
Cell transplantation is being widely investigated as a potential therapy in heart failure. Noninvasive imaging techniques are frequently used to investigate therapeutic effects of cell therapies in the preclinical and clinical setting. Previous studies have shown that cardiac MDCT can accurately quantify myocardial scar tissue and determine left ventricular (LV) volumes and ejection fraction (LVEF).
Methods
Twenty-two minipigs were randomized to intramyocardial injection of phosphate-buffered saline (placebo, n=9) or 200 million mesenchymal stem cells (MSCs, n=13), twelve weeks after myocardial infarction (MI). Cardiac MRI and MDCT acquisitions were performed prior to randomization 12 weeks after MI induction and at the study endpoint 24 week post-MI. None of the animals received medication to control the intrinsic heart rate during first-pass acquisitions for assessment of LV-volumes and LVEF. Delayed enhancement MDCT imaging was performed 10 min after contrast delivery. Two blinded observers analyzed MDCT acquisitions.
Results
MDCT demonstrated that MSC therapy resulted in a reduction of infarct size from 14.3±1.2% to 10.3±1.5% of LV-mass (p=0.005) while infarct size increased in non-treated animals (from 13.8±1.3% to 16.5±1.5%; p=0.02) (Placebo vs MSC; p=0.003). Both observers had excellent agreement for infarct size (r=0.96; p<0.001). LVEF increased from 32.6±2.2% to 36.9±2.7% in MSC treated animals (p=0.03) and decreased in placebo animals (from 33.3±1.4 to 29.1±1.5%; p=0.01; at week 24: placebo vs MSC p=0.02). Infarct size, end-diastolic LV volume and LVEF assessed by MDCT compared favorably with MRI acquisitions (r=0.70; r=0.82; r=0.902; respectively, p<0.001).
Conclusions
This study demonstrates that cardiac MDCT can be used to evaluate infarct size, LV-volumes, and LVEF after intramyocardial delivered MSC therapy. These findings support the use of cardiac MDCT in preclinical and clinical studies for novel myocardial therapies. (word count 299)
doi:10.1016/j.jcmg.2011.09.013
PMCID: PMC3245738  PMID: 22172785
MDCT; MRI; Delayed Contrast Enhancement; Göttingen Minipig; Mesenchymal Stem Cell; Myocardial Infarction; Heart failure
11.  Radiological diagnosis and staging of hilar cholangiocarcinoma 
Hilar cholangiocarcinoma is a rare malignant tumor arising from the epithelium of the bile ducts. Surgery is still the only chance of potentially curative treatment in patients with perihilar cholangiocarcinoma. However, radical resection requires aggressive surgical strategies that should be tailored optimally according to the location, size and vascular invasion of the tumors. Accurate diagnosis and staging of these tumors is therefore critical for optimal treatment planning and for determining a prognosis. Multidetector computed tomography (MDCT), magnetic resonance imaging (MRI) and MR cholangiography are useful tools, both to diagnose and stage hilar cholangiocarcinoma. Modern imaging techniques allow accurate detection of the level of obstruction and the longitudinal and radial spread of the tumor. In addition, high-resolution MDCT and MR provide specific radiographic features to determine vascular involvement of anatomic structures, such as the hepatic artery or the portal vein, which are critical to decide the surgical strategy. Finally, radiological staging allows detection of patients with distant metastasis in the liver or peritoneum who will not benefit from a surgical approach.
doi:10.4251/wjgo.v5.i7.115
PMCID: PMC3731524  PMID: 23919105
Cholangiocarcinoma; Radiological staging; Magnetic resonance imaging; Multidetector computed tomography; Hepatic resection
12.  Taekling the challenges of interpretation of conventional coronary angiography using multidetector CT coronary angiography 
Netherlands Heart Journal  2004;12(5):203-207.
Background
Although conventional catheter angiography is still regarded as the gold standard for anatomical visualisation of the coronary artery tree, it faces a number of challenges and pitfalls concerning the interpretation of the acquired images.
Aim
The aim of this review is to demonstrate that multidetector computed tomography (MDCT) can provide information that is not or only partially acquired by coronary angiography (CAG).
Methods
For different interpretation issues and pitfalls, we establish whether MDCT can provide better, i.e. more standardised and reproducible, information on the basis of both the properties of the technique and clinical examples.
Results
Advantages of MDCT are full three- and four-dimensional coverage of the heart and contrast enhancement of all vascular compartments together with a superior low contrast resolution. MDCT shortcomings are the low temporal resolution and related to this the lack of flow information compared with catheter coronary angiography. MDCT is shown to meet most of the blind spots and pitfalls described for catheter coronary angiography.
Conclusion
Cardiac and coronary MDCT provides diagnostic information, which equals CAG diagnosis in most cases, and in some cases even provides a better diagnosis. This could influence the value of the sensitivity and specificity numbers published comparing noninvasive techniques with catheter coronary angiography (gold standard). Due to the added advantages of CT and its continuous improvement of temporal and spatial resolution, it might eventually replace diagnostic catheter coronary angiography.
Images
PMCID: PMC2497115
coronary artery disease; coronary angiography; multidetector computed tomography
13.  Water enema multidetector CT technique and imaging of diverticulitis and chronic inflammatory bowel diseases 
Insights into Imaging  2013;4(3):309-320.
Background
Water enema multidetector computed tomography (WE-MDCT) is currently considered the most accurate imaging modality to provide high-resolution multiplanar visualisation of the colonic wall and surrounding structures.
Methods
This pictorial review presents our experience with WE-MDCT applications outside colorectal tumour staging, particularly for investigating diverticular disease and chronic inflammatory bowel diseases. A detailed explanation of the technique is provided, including patient preparation, the acquisition protocol, and study interpretation.
Results
WE-MDCT allows accurate preoperative visualisation of diverticular disease, acute and complicated diverticulitis. Ulcerative, indeterminate, or Crohn’s colitis can be assessed including longitudinal distribution, mural thickening and enhancement patterns, pseudopolyps, associated perivisceral changes, adjacent organ involvement, and features suggesting carcinoma. Elective WE-MDCT represents a useful complementary technique in patients with impossible, incomplete, or inconclusive endoscopy, can allow study of a stricture’s features and the upstream bowel, and helps planning medical, endoscopic, or surgical treatments.
Conclusion
Urgent WE-MDCT with limited or no bowel preparation may prove useful in acutely symptomatic patients, as it may obviate a risky or contraindicated endoscopy, can determine disease severity, and allows making correct therapeutic choices.
Teaching Points
• Water enema multidetector CT provides high-resolution multiplanar visualisation of the colonic wall.
• WE-MDCT allows accurate visualisation of diverticular disease, acute and complicated diverticulitis.
• In chronic inflammatory bowel diseases WE-MDCT depicts the distribution, mural and perivisceral changes.
• Elective WE-MDCT usefully complements incomplete endoscopy to assess strictures and upstream colon.
• Urgent WE-MDCT with limited or no bowel preparation in acute diseases may obviate endoscopy.
doi:10.1007/s13244-013-0239-7
PMCID: PMC3675246  PMID: 23508934
Contrast enema; Computed tomography (CT); Colonoscopy; Diverticular disease; Acute diverticulitis; Chronic inflammatory bowel diseases; Ulcerative colitis; Crohn’s disease; Indeterminate colitis
14.  Accuracy of 64-multidetector computed tomography in diagnosis of adnexal tumors 
Background
Adnexal cancers are in fifth place among the tumors with the highest mortality in the female population. The aim of the present study was to evaluate the accuracy of Multi-detector computed tomography (MDCT) on a 64-multislice CT scanner in the detection and differentiation of adnexal masses stages.
Methods
During the present prospective study, 95 women with a primary diagnosis of ovarian mass in base of clinical examination and ultrasonographic findings underwent preoperative evaluation by a 64-slice MDCT with a section thickness of 0.6 mm, 50% overlap and reconstructed images. Afterward, results of MDCT were compared with surgical and histopathological findings, and the sensitivity, specificity, positive and negative predictive value and accuracy were determined.
Results
The mean age of patients was 48.63 ± 13.93 years. MDCT diagnosed 25 (26.3%) masses to be benign and 70 (73.7%) to be malignant (sensitivity, specificity, positive and negative predictive value and accuracy were 92.8%, 88.0%, 95.5%, 81.4% and 91.5% respectively). The sensitivity and specificity of MDCT in determining local extension was 72.2% and 93.4% respectively. And the sensitivity and specificity of MDCT in determining peritoneal seeding and liver extension was 81.8% and 93% respectively. Estimated stage was significantly agreed with the surgical (Cohen's Kappa (κ) = 0.891) and histopathological findings (κ = 0.858).
Conclusion
MDCT is a highly sensitive and specific diagnostic method in evaluation of adnexal masses and successfully stage the tumor in consistent with surgery and histopathology.
doi:10.1186/1757-2215-4-15
PMCID: PMC3170630  PMID: 21846406
Adnexal diseases; diagnostic imaging; ovarian neoplasms; tomography; spiral computed
15.  Cardiac Magnetic Resonance Imaging for the Diagnosis of Coronary Artery Disease 
Executive Summary
In July 2009, the Medical Advisory Secretariat (MAS) began work on Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease (CAD), an evidence-based review of the literature surrounding different cardiac imaging modalities to ensure that appropriate technologies are accessed by patients suspected of having CAD. This project came about when the Health Services Branch at the Ministry of Health and Long-Term Care asked MAS to provide an evidentiary platform on effectiveness and cost-effectiveness of non-invasive cardiac imaging modalities.
After an initial review of the strategy and consultation with experts, MAS identified five key non-invasive cardiac imaging technologies for the diagnosis of CAD. Evidence-based analyses have been prepared for each of these five imaging modalities: cardiac magnetic resonance imaging, single photon emission computed tomography, 64-slice computed tomographic angiography, stress echocardiography, and stress echocardiography with contrast. For each technology, an economic analysis was also completed (where appropriate). A summary decision analytic model was then developed to encapsulate the data from each of these reports (available on the OHTAC and MAS website).
The Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease series is made up of the following reports, which can be publicly accessed at the MAS website at: www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.html
Single Photon Emission Computed Tomography for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis
Stress Echocardiography for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis
Stress Echocardiography with Contrast for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis
64-Slice Computed Tomographic Angiography for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis
Cardiac Magnetic Resonance Imaging for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis
Pease note that two related evidence-based analyses of non-invasive cardiac imaging technologies for the assessment of myocardial viability are also available on the MAS website:
Positron Emission Tomography for the Assessment of Myocardial Viability: An Evidence-Based Analysis
Magnetic Resonance Imaging for the Assessment of Myocardial Viability: an Evidence-Based Analysis
The Toronto Health Economics and Technology Assessment Collaborative has also produced an associated economic report entitled:
The Relative Cost-effectiveness of Five Non-invasive Cardiac Imaging Technologies for Diagnosing Coronary Artery Disease in Ontario [Internet]. Available from: http://theta.utoronto.ca/reports/?id=7
Objective
The objective of this analysis was to determine the diagnostic accuracy of cardiac magnetic resonance imaging (MRI) for the diagnosis of patients with known/suspected coronary artery disease (CAD) compared to coronary angiography.
Cardiac MRI
Stress cardiac MRI is a non-invasive, x-ray free imaging technique that takes approximately 30 to 45 minutes to complete and can be performed using to two different methods, a) perfusion imaging following a first pass of an intravenous bolus of gadolinium contrast, or b) wall motion imaging. Stress is induced pharmacologically with either dobutamine, dipyridamole, or adenosine, as physical exercise is difficult to perform within the magnet bore and often induces motion artifacts. Alternatives to stress cardiac perfusion MRI include stress single-photon emission computed tomography (SPECT) and stress echocardiography (ECHO). The advantage of cardiac MRI is that it does not pose the radiation burden associated with SPECT. During the same sitting, cardiac MRI can also assess left and right ventricular dimensions, viability, and cardiac mass. It may also mitigate the need for invasive diagnostic coronary angiography in patients with intermediate risk factors for CAD.
Evidence-Based Analysis
Literature Search
A literature search was performed on October 9, 2009 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 2005 to October 9, 2008. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist and then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology.
Given the large amount of clinical heterogeneity of the articles meeting the inclusion criteria, as well as suggestions from an Expert Advisory Panel Meeting held on October 5, 2009, the inclusion criteria were revised to examine the effectiveness of cardiac MRI for the detection of CAD.
Heath technology assessments, systematic reviews, randomized controlled trials, observational studies
≥20 adult patients enrolled.
Published 2004-2009
Licensed by Health Canada
For diagnosis of CAD:
Reference standard is coronary angiography
Significant CAD defined as ≥ 50% coronary stenosis
Patients with suspected or known CAD
Reported results by patient, not segment
Non-English studies
Grey literature
Planar imaging
MUGA
Patients with recent MI (i.e., within 1 month)
Patients with non-ischemic heart disease
Studies done exclusively in special populations (e.g., women, diabetics)
Outcomes of Interest
Sensitivity and specificity
Area under the curve (AUC)
Diagnostic odds ratio (DOR)
Summary of Findings
Stress cardiac MRI using perfusion analysis yielded a pooled sensitivity of 0.91 (95% CI: 0.89 to 0.92) and specificity of 0.79 (95% CI: 0.76 to 0.82) for the detection of CAD.
Stress cardiac MRI using wall motion analysis yielded a pooled sensitivity of 0.81 (95% CI: 0.77 to 0.84) and specificity of 0.85 (95% CI: 0.81 to 0.89) for the detection of CAD.
Based on DORs, there was no significant difference between pooled stress cardiac MRI using perfusion analysis and pooled stress cardiac MRI using wall motion analysis (P=0.26) for the detection of CAD.
Pooled subgroup analysis of stress cardiac MRI using perfusion analysis showed no significant difference in the DORs between 1.5T and 3T MRI (P=0.72) for the detection of CAD.
One study (N=60) was identified that examined stress cardiac MRI using wall motion analysis with a 3T MRI. The sensitivity and specificity of 3T MRI were 0.64 (95% CI: 0.44 to 0.81) and 1.00 (95% CI: 0.89 to 1.00), respectively, for the detection of CAD.
The effectiveness of stress cardiac MRI for the detection of CAD in unstable patients with acute coronary syndrome was reported in only one study (N=35). Using perfusion analysis, the sensitivity and specificity were 0.72 (95% CI: 0.53 to 0.87) and 1.00 (95% CI: 0.54 to 1.00), respectively, for the detection of CAD.
Ontario Health System Impact Analysis
According to an expert consultant, in Ontario:
Stress first pass perfusion is currently performed in small numbers in London (London Health Sciences Centre) and Toronto (University Health Network at the Toronto General Hospital site and Sunnybrook Health Sciences Centre).
Stress wall motion is only performed as part of research protocols and not very often.
Cardiac MRI machines use 1.5T almost exclusively, with 3T used in research for first pass perfusion.
On November 25 2009, the Cardiac Imaging Expert Advisory Panel met and made the following comments about stress cardiac MRI for perfusion analysis:
Accessibility to cardiac MRI is limited and generally used to assess structural abnormalities. Most MRIs in Ontario are already in 24–hour, constant use and it would thus be difficult to add cardiac MRI for CAD diagnosis as an additional indication.
The performance of cardiac MRI for the diagnosis of CAD can be technically challenging.
GRADE Quality of Evidence for Cardiac MRI in the Diagnosis of CAD
The quality of the body of evidence was assessed according to the GRADE Working Group criteria for diagnostic tests. For perfusion analysis, the overall quality was determined to be low and for wall motion analysis the overall quality was very low.
PMCID: PMC3377522  PMID: 23074389
16.  Three-Dimensional Volume-Rendered Series Complements 2D Orthogonal Multidetector Computed Tomography in the Evaluation of Abnormal Spinal Curvature in Patients at a Major Cancer Center: A Retrospective Review 
ISRN Orthopedics  2012;2012:639189.
Background. Abnormal spinal curvature is routinely assessed with plain radiographs, MDCT, and MRI. MDCT can provide two-dimensional (2-D) orthogonal as well as reconstructed three-dimensional volume-rendered (3-D VR) images of the spine, including the translucent display: a computer-generated image set that enables the visualization of surgical instrumentation through bony structures. We hypothesized that the 3-D VR series provides additional information beyond that of 2-D orthogonal MDCT in the evaluation of abnormal spinal curvature in patients evaluated at a major cancer center. Methods. The 3-D VR series, including the translucent display, was compared to 2-D orthogonal MDCT studies in patients with an abnormal spinal curvature greater than 25 degrees and scored as being not helpful (0) or helpful (1) in 3 categories: spinal curvature; bony definition; additional findings (mass lesions, fractures, and instrumentation). Results. In 38 of 48 (79.2%) patients assessed, the 3-D VR series were scored as helpful in 63 of 144 (43.8%) total possible categories (32 spinal curvature; 14 bony definition; 17 additional findings). Conclusion. Three-dimensional MDCT images, including the translucent display, are complementary to multiplanar 2-D orthogonal MCDT in the evaluation of abnormal spinal curvature in patients treated at a major cancer center.
doi:10.5402/2012/639189
PMCID: PMC4063197  PMID: 24977083
17.  Imaging features of intraductal papillary mucinous neoplasms of the pancreas in multi-detector row computed tomography 
AIM: To retrospectively evaluate the imaging features of pancreatic intraductal papillary mucinous neoplasms (IPMNs) in multi-detector row computed tomography (MDCT).
METHODS: A total of 20 patients with pathologically-confirmed intraductal papillary mucinous neoplasms (IPMNs) were included in this study. Axial MDCT images combined with CT angiography (CTA) and multiplanar volume reformations (MPVR) or curved reformations (CR) were preoperatively acquired. Two radiologists (Tan L and Wang DB) reviewed all the images in consensus using an interactive picture archiving and communication system. The disputes in readings were resolved through consultation with a third experienced radiologist (Chen KM). Finally, the findings and diagnoses were compared with the pathologic results.
RESULTS: The pathological study revealed 12 malignant IPMNs and eight benign IPMNs. The diameters of the cystic lesions and main pancreatic ducts (MPDs) were significantly larger in malignant IPMNs compared with those of the benign IPMNs (P < 0.05). The combined-type IPMNs had a higher rate of malignancy than the other two types of IPMNs (P < 0.05). Tumors with mural nodules and thick septa had a significantly higher incidence of malignancy than tumors without these features (P < 0.05). Communication of side-branch IPMNs with the MPD was present in nine cases at pathologic examination. Seven of them were identified from CTA and MPVR or CR images. From comparison with the pathological diagnosis, the sensitivity, specificity, and accuracy of MDCT in characterizing the malignancy of IPMN of the pancreas were determined to be 100%, 87.5% and 95%, respectively.
CONCLUSION: MDCT with CTA and MPVR or CR techniques can elucidate the imaging features of IPMNs and help predict the malignancy of these tumors.
doi:10.3748/wjg.15.4037
PMCID: PMC2731955  PMID: 19705500
Computed tomography; Diagnostic imaging; Intraductal papillary mucinous neoplasm; Pancreatic neoplasms
18.  Characterization of Peri-Infarct Zone Heterogeneity by Contrast Enhanced Multi-detector Computed Tomography: Comparison with Magnetic Resonance Imaging 
Objectives
We examined whether MDCT improves the ability to define peri-infarct zone (PIZ) heterogeneity relative to MRI.
Background
The PIZ as characterized by delayed enhanced (de) MRI identifies patients susceptible to ventricular arrhythmias and predicts outcome after myocardial infarction (MI).
Methods
Fifteen mini-pigs underwent coronary artery occlusion followed by reperfusion. MDCT and MRI were performed on the same day approximately 6 months after MI induction followed by animal sacrifice and ex-vivo MRI (n=5). Signal density threshold algorithms were applied to MRI and MDCT data sets reconstructed at various slice thicknesses (1–8mm) to define the PIZ and quantify partial volume effects.
Results
De-MDCT reconstructed at 8mm slice thickness demonstrated excellent correlation of infarct size with post mortem pathology (r2=0.97; p<0.0001) and MRI (r2=0.92; p<0.0001). De-MDCT and de-MRI were able to detect a PIZ in all animals, which correlates to a mixture of viable and non-viable myocytes at the PIZ by histology. The ex-vivo de-MRI PIZ volume decreased with slice thickness from 0.9±0.2cc at 8mm to 0.2±0.1cc at 1mm (p=0.01). PIZ volume/mass by de-MDCT increased with decreasing slice thickness due to declining partial volume averaging in the PIZ, but was susceptible to increased image noise.
Conclusion
De-MDCT provides a more detailed assessment of the PIZ in chronic MI and is less susceptible to partial volume effects than MRI. This increased resolution best reflects the extent of tissue mixture by histopathology and has the potential to further enhance the ability to define the substrate of malignant arrhythmia in ischemic heart disease non-invasively.
doi:10.1016/j.jacc.2009.01.056
PMCID: PMC3381611  PMID: 19406346
MDCT; delayed enhancement; peri-infarct zone; MRI
19.  Diagnostic imaging strategy for MDCT- or MRI-detected breast lesions: use of targeted sonography 
BMC Medical Imaging  2012;12:13.
Background
Leading-edge technology such as magnetic resonance imaging (MRI) or computed tomography (CT) often reveals mammographically and ultrasonographically occult lesions. MRI is a well-documented, effective tool to evaluate these lesions; however, the detection rate of targeted sonography varies for MRI detected lesions, and its significance is not well established in diagnostic strategy of MRI detected lesions. We assessed the utility of targeted sonography for multidetector-row CT (MDCT)- or MRI-detected lesions in practice.
Methods
We retrospectively reviewed 695 patients with newly diagnosed breast cancer who were candidates for breast conserving surgery and underwent MDCT or MRI in our hospital between January 2004 and March 2011. Targeted sonography was performed in all MDCT- or MRI-detected lesions followed by imaging-guided biopsy. Patient background, histopathology features and the sizes of the lesions were compared among benign, malignant and follow-up groups.
Results
Of the 695 patients, 61 lesions in 56 patients were detected by MDCT or MRI. The MDCT- or MRI-detected lesions were identified by targeted sonography in 58 out of 61 lesions (95.1%). Patients with pathological diagnoses were significantly older and more likely to be postmenopausal than the follow-up patients. Pathological diagnosis proved to be benign in 20 cases and malignant in 25. The remaining 16 lesions have been followed up.
Lesion size and shape were not significantly different among the benign, malignant and follow-up groups.
Conclusions
Approximately 95% of MDCT- or MRI-detected lesions were identified by targeted sonography, and nearly half of these lesions were pathologically proven malignancies in this study. Targeted sonography is a useful modality for MDCT- or MRI-detected breast lesions.
doi:10.1186/1471-2342-12-13
PMCID: PMC3427136  PMID: 22691539
20.  Multidetector-row computed tomography of thoracic aortic anomalies in dogs and cats: Patent ductus arteriosus and vascular rings 
Background
Diagnosis of extracardiac intrathoracic vascular anomalies is of clinical importance, but remains challenging. Traditional imaging modalities, such as radiography, echocardiography, and angiography, are inherently limited by the difficulties of a 2-dimensional approach to a 3-dimensional object. We postulated that accurate characterization of malformations of the aorta would benefit from 3-dimensional assessment. Therefore, multidetector-row computed tomography (MDCT) was chosen as a 3-dimensional, new, and noninvasive imaging technique. The purpose of this study was to evaluate patients with 2 common diseases of the intrathoracic aorta, either patent ductus arteriosus or vascular ring anomaly, by contrast-enhanced 64-row computed tomography.
Results
Electrocardiography (ECG)-gated and thoracic nongated MDCT images were reviewed in identified cases of either a patent ductus arteriosus or vascular ring anomaly. Ductal size and morphology were determined in 6 dogs that underwent ECG-gated MDCT. Vascular ring anomalies were characterized in 7 dogs and 3 cats by ECG-gated MDCT or by a nongated thoracic standard protocol.
Cardiac ECG-gated MDCT clearly displayed the morphology, length, and caliber of the patent ductus arteriosus in 6 affected dogs. Persistent right aortic arch was identified in 10 animals, 8 of which showed a coexisting aberrant left subclavian artery. A mild dilation of the proximal portion of the aberrant subclavian artery near its origin of the aorta was present in 4 dogs, and a diverticulum analogous to the human Kommerell's diverticulum was present in 2 cats.
Conclusions
Contrast-enhanced MDCT imaging of thoracic anomalies gives valuable information about the exact aortic arch configuration. Furthermore, MDCT was able to characterize the vascular branching patterns in dogs and cats with a persistent right aortic arch and the morphology and size of the patent ductus arteriosus in affected dogs. This additional information can be of help with regard to improved diagnoses of thoracic anomalies and the planning of surgical interventions.
doi:10.1186/1746-6148-7-57
PMCID: PMC3186751  PMID: 21943366
21.  Multiplanar and two-dimensional imaging of central airway stenting with multidetector computed tomography 
Background
Multidetector computed tomography (MDCT) provides guidance for primary screening of the central airways. The aim of our study was assessing the contribution of multidetector computed tomography- two dimensional reconstruction in the management of patients with tracheobronchial stenosis prior to the procedure and during a short follow up period of 3 months after the endobronchial treatment.
Methods
This is a retrospective study with data collected from an electronic database and from the medical records. Patients evaluated with MDCT and who had undergone a stenting procedure were included. A Philips RSGDT 07605 model MDCT was used, and slice thickness, 3 mm; overlap, 1.5 mm; matrix, 512x512; mass, 90 and kV, 120 were evaluated. The diameters of the airways 10 mm proximal and 10 mm distal to the obstruction were measured and the stent diameter (D) was determined from the average between D upper and D lower.
Results
Fifty-six patients, 14 (25%) women and 42 (75%) men, mean age 55.3 ± 13.2 years (range: 16-79 years), were assessed by MDCT and then treated with placement of an endobronchial stent. A computed tomography review was made with 6 detector Philips RSGDT 07605 multidetector computed tomography device. Endobronchial therapy was provided for the patients with endoluminal lesions. Stents were placed into the area of stenosis in patients with external compression after dilatation and debulking procedures had been carried out. In one patient the migration of a stent was detected during the follow up period by using MDCT.
Conclusions
MDCT helps to define stent size, length and type in patients who are suitable for endobronchial stinting. This is a non-invasive, reliable method that helps decisions about optimal stent size and position, thus reducing complications.
doi:10.1186/2049-6958-7-27
PMCID: PMC3492010  PMID: 22958300
Airway obstruction; Endobronchial stent; Multidetector computed tomography (MDCT)
22.  Comprehensive evaluation of preoperative patients with aortic valve stenosis: usefulness of cardiac multidetector computed tomography 
Heart  2007;93(9):1121-1125.
Background
Preoperative assessment of patients with aortic valve stenosis (AS) relies on the evaluation of AS severity (aortic valve area, AVA) and left ventricular ejection fraction (LVEF) by echocardiography, and of coronary artery anatomy by coronary angiography.
Aim
To evaluate the feasibility and accuracy of contrast‐enhanced multidetector computed tomography (MDCT), as a single non‐invasive preoperative test, for simultaneous evaluation of the AVA, LVEF and coronary status in patients with AS.
Methods
40 consecutive patients with AS scheduled for aortic valve replacement underwent transthoracic echocardiography, electrocardiogram (ECG)‐gated MDCT and coronary angiography within a time span of 1 week.
Results
MDCT measurements could be performed in all patients. A good correlation but a slight overestimation was observed between mean (SD) AVA measured by MDCT and by echocardiography (0.87 (0.22) vs 0.81 (0.20) cm2, p = 0.01; r = 0.77, p<0.001). Mean difference between methods was 0.06 (0.15) cm2. LVEF measured by MDCT correlated well with, and did not differ from, electrocardiographic measurements (59% (13%) vs 61% (10%), p = 0.34; r = 0.76, p<0.001; mean difference 1% (8%)). Coronary angiography displayed 33 lesions in 13 patients. MDCT correctly identified 26 of these 33 lesions and overestimated three <50% stenosis. On a segment‐by‐segment analysis, MDCT sensitivity, specificity, positive and negative predictive values were 79%, 99%, 90% and 98%, respectively. For each patient, MDCT had a sensitivity of 85% (11/13 patients), a specificity of 93% (25/27 patients) and positive and negative predictive values of 85% (11/13 patients) and 93% (25/27 patients), respectively.
Conclusion
MDCT can provide a simultaneous and accurate evaluation of the AVA, LVEF and coronary artery anatomy in patients with AS. In the near future, with technological improvements, MDCT could achieve an exhaustive and comprehensive preoperative assessment of patients with AS. In addition, for the assessment of AS severity in difficult cases, MDCT could be considered as an alternative to transoesophageal echocardiography or cardiac catheterisation.
doi:10.1136/hrt.2006.107284
PMCID: PMC1955027  PMID: 17483132
23.  Controversies in imaging of hepatocellular carcinoma: multidetector CT (MDCT) 
Cancer Imaging  2005;5(1):178-187.
Primary hepatocellular carcinoma (HCC) is a significant tumor worldwide and represents the most common primary hepatic neoplasm. Staging criteria are important for appreciation of timely work up of these neoplasms in contradiction with surgical colleagues. This article demonstrates the appearance of HCC on multiphasic, multidetector CT (MDCT) and relates these findings to current staging criteria. The variable appearance on different planes of contrast is critical to appreciate in staging this neoplasm. The hypervascular nature of the primary tumor makes MDCT and three-phase imaging a critical feature in the detection and characterization of this tumor. This is especially critical in the patients who are candidates for surgical resection. Additionally, MDCT has allowed arterial phase imaging to define the vascular supply of the tumor. An accurate representation of the size and number of lesions is critical in not only the initial staging but also the follow-up of hepatocellular carcinoma. The post-treatment features including the appearance post-surgically and after radiofrequency ablation can be well appreciated on MDCT.
doi:10.1102/1470-7330.2005.0105
PMCID: PMC1665245  PMID: 16361147
Hepatocellular carcinoma; liver; multidetector CT
24.  Imaging features of solid pseudopapillary tumor of the pancreas on multi-detector row computed tomography 
AIM: To retrospectively analyze the imaging features of solid-pseudopapillary tumors (SPTs) of the pancreas on multi-detector row computed tomography (MDCT) and define the imaging findings suggestive of malignant potential.
METHODS: A total of 24 consecutive cases with surgically and pathologically confirmed SPTs of the pancreas underwent preoperative abdominal MDCT studies in our hospital. All axial CT images, CT angiographic images, and coronally and sagittally reformed images were obtained. The images were retrospectively reviewed at interactive picture archiving and communication system workstations.
RESULTS: Of the 24 cases of SPTs, 11 cases (45.8%) occurred in the pancreatic head and seven (29.1%) in the tail. Eighteen were pathologically diagnosed as benign and six as malignant. MDCT diagnosis of SPTs was well correlated with the surgical and pathological results (Kappa = 0.6, P < 0.05). The size of SPTs ranged from 3 to 15 cm (mean, 5.8 cm). When the size of the tumor was greater than 6 cm (including 6 cm), the possibilities of vascular (8 vs 1) and capsular invasion (9 vs 0) increased significantly (P < 0.05). Two pathologically benign cases with vascular invasion and disrupted capsule on MDCT presented with local recurrence and hepatic metastases during follow-up about 1 year after the resection of the primary tumors.
CONCLUSION: Vascular and capsular invasion with superimposed spread into the adjacent pancreatic parenchyma and nearby structures in SPTs of the pancreas can be accurately revealed by MDCT preoperatively. These imaging findings are predictive of the malignant potential associated with the aggressive behavior of the tumor, even in the pathologically benign cases.
doi:10.3748/wjg.15.829
PMCID: PMC2653382  PMID: 19230043
Solid pseudopapillary tumor; Pancreas; Multi-detector row computed tomography; Malignant potential; Aggressive behaviors
25.  Using Multidetector-Row CT for the Diagnosis of Afferent Loop Syndrome Following Gastroenterostomy Reconstruction 
Yonsei Medical Journal  2011;52(4):574-580.
Purpose
To assess the clinical manifestations and multidetector-row computed tomography (MDCT) findings of afferent loop syndrome (ALS) and to determine the role of MDCT on treatment decisions.
Materials and Methods
From January 2004 to December 2008, 1,100 patients had undergone gastroenterostomy reconstruction in our institution. Of these, 22 (2%) patients were diagnosed as ALS after surgery that included Roux-en-Y gastroenterotomy (n=9), Billroth-II gastrojejunostomy (n=7), and Whipple's operation (n=6). Clinical manifestations and MDCT features of these patients were recorded and statistically analyzed. The presumed etiologies of obstruction shown on the MDCT were correlated with clinical information and confirmed by surgery or endoscopic biopsy.
Results
The most common clinical symptom was acute abdominal pain, presenting in 18 patients (82%). We found that a fluid-filled C-shaped afferent loop in combination with valvulae conniventes projecting into the lumen was the most common MDCT features of ALS. Malignant causes of ALS, such as local recurrence and carcinomatosis, are the most common etiologies of obstruction. These etiologies and associated complications can be predicted 100% by MDCT.
Conclusion
Our results suggest that MDCT is a reliable modality for assessing the etiologies of ALS and guiding treatment decisions.
doi:10.3349/ymj.2011.52.4.574
PMCID: PMC3104453  PMID: 21623598
Afferent loop syndrome; multidetector-row CT; Roux-en-Y gastroenterotomy; Billroth II gastrojejunostomy; Whipple's operation

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