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1.  Multicenter, Double-Blind, Randomized, Intra-individual Crossover Comparison of Gadobenate Dimeglumine and Gadopentetate Dimeglumine in MRI of Brain Tumors at 3 Tesla 
To prospectively compare 0.1 mmol/kg doses of gadobenate dimeglumine and gadopentetate dimeglumine for contrast-enhanced MRI of brain lesions at 3 Tesla (T).
Materials and Methods
Forty-six randomized patients underwent a first examination with gadobenate dimeglumine (n = 23) or gadopentetate dimeglumine (n = 23) and then, after 2–7 days, a second examination with the other agent. Contrast administration (volume, rate), sequence parameters (T1wSE; T1wGRE), and interval between injection and image acquisition were identical for examinations in each patient. Three blinded neuroradiologists evaluated images qualitatively (lesion delineation, lesion enhancement, global preference) and quantitatively (lesion-to-brain ratio [LBR], contrast-to-noise ratio [CNR],%lesion enhancement). Differences were assessed using Wilcoxon’s signed-rank test. Reader agreement was determined using kappa (κ) statistics.
There were no demographic differences between groups. The three readers preferred gadobenate dimeglumine globally in 22 (53.7%), 21 (51.2%), and 27 (65.9%) patients, respectively, compared with 0, 1, and 0 patients for gadopentetate dimeglumine. Similar significant (P < 0.001) preference was expressed for lesion border delineation and enhancement. Reader agreement was consistently good (κ = 0.48–0.64). Significantly (P < 0.05) higher LBR (+43.5–61.2%), CNR (+51.3–147.6%), and % lesion enhancement (+45.9–49.5%) was noted with gadobenate dimeglumine.
Brain lesion depiction at 3T is significantly improved with 0.1 mmol/kg gadobenate dimeglumine.
PMCID: PMC2730487  PMID: 19306364
brain tumor imaging; gadobenate dimeglumine; comparative studies; high field MRI
2.  Expectant and medical management of placenta increta in a primiparous woman presenting with postpartum haemorrhage: The role of Imaging 
We report a case of postpartum hemorrhage due to adherent placenta. A 28 year old primiparous woman who underwent manual removal of placenta for primary postpartum haemorrhage soon after delivery was referred to our Institute on her third postnatal day because of persistent tachycardia and low grade fever. Placenta accreta was suspected on initial ultrasonographic examination. MRI examination confirmed the diagnosis of placenta accreta in few areas and revealed increta in other areas. On expectant management she developed genital tract sepsis and hence she was treated with intravenous Methotrexate after controlling infection with appropriate antibiotics. Doppler Imaging showed decreased blood flow to the placental mass and increased echogenecity on gray scale USG after Methotrexate administration. She expelled the whole placental mass on 35th postnatal day and MRI performed the next day showed empty uterine cavity. Morbid adhesion of placenta should be suspected even in primiparous women without any risk factors when there is history of post-partum hemorrhage. MRI is the best modality for evaluation of adherent placenta.
PMCID: PMC3303403  PMID: 22470732
Manual removal of placenta; Placenta accreta & increta; MRI; Methotrexate
3.  Prophylactic Hypogastric Artery Ballooning in a Patient with Complete Placenta Previa and Increta 
Journal of Korean Medical Science  2010;25(4):651-655.
Abnormal attachment of the placenta (Placenta accreta, increta, and percreta) is an uncommon but potentially lethal cause of maternal mortality from massive postpartum hemorrhage. A 33-yr-old woman, who had been diagnosed with a placenta previa, was referred at 30 weeks gestation. On ultrasound, a complete type of placenta previa and multiple intraplacental lacunae, suggestive of placenta accreta, were noted. For further evaluation of the placenta, pelvis MRI was performed and revealed findings suspicious of a placenta increta. An elective cesarean delivery and subsequent hysterectomy were planned for the patient at 38 weeks gestation. On the day of delivery, endovascular catheters for balloon occlusion were placed within the hypogastric arteries, prior to the cesarean section. In the operating room, immediately after the delivery of the baby, bilateral hypogastric arteries were occluded by inflation of the balloons in the catheters previously placed within. With the placenta retained within the uterus, a total hysterectomy was performed in the usual fashion. The occluding balloons were deflated after closure of the vaginal cuff with hemostasis. The patient had stable vital signs and normal laboratory findings during the recovery period; she was discharged six days after delivery without complications. The final pathology confirmed a placenta increta.
PMCID: PMC2844598  PMID: 20358016
Placenta Increta; Hypogastric Artery; Balloon Occlusion
4.  A Case of Placenta Increta Presenting as Delayed Postabortal Intraperitoneal Bleeding in the First Trimester 
Journal of Korean Medical Science  2007;22(5):932-935.
Placenta increta is an uncommon and life-threatening complication of pregnancy characterized by complete or partial absence of the decidua basalis. Placenta increta usually presents with vaginal bleeding during difficult placental removal in the third-trimester. Although placenta increta may complicate first and early second-trimester pregnancy loss, the diagnosis can be very difficult during early pregnancy and thus the lesion is difficult to identify. We encountered with a woman who was diagnosed with placenta increta after receiving emergency hysterectomy due to intraperitoneal bleeding 2 months after an uncomplicated dilatation and curettage in the first trimester. Therefore, we report this case with a brief review of the literature.
PMCID: PMC2693868  PMID: 17982250
Placenta Increta; First Trimester; Intraperitoneal Bleeding
5.  Lack of nephrotoxicity of gadopentetate dimeglumine-enhanced non-vascular MRI and MRI without contrast agent in patients at high-risk for acute kidney injury 
Gadolinium chelates (GCs) have been traditionally considered as non-nephrotoxic magnetic resonance imaging (MRI) contrast materials. However, it has been suggested in some recent articles that GCs may have a nephrotoxic potential, but most of these reports are retrospective. However, the evaluated contrast agents, their doses, and the tests used to determine the kidney function were not consistent across studies. We aimed to investigate the effect of magnetic field and an MRI contrast agent, gadopentetate dimeglumine (GD), on renal functions in patients at high risk for acute kidney injury (AKI).
We designed a prospective case-control study with 2 age- and sex-matched groups of patients at high-risk for AKI (n=72 for each group). Patients in Group 1 received a fixed dose of (0.2 mmol/kg) GD-enhanced non-vascular MRI and patients in Group 2 received MRI without GD. Before the MRI and at 6, 24, 72, and 168 hours after the MRI, biochemical tests, estimated glomerular filtration rate (eGFR), albumin/creatinine ratio in spot urine, and early AKI biomarkers (cystatin C, N-Acetyl-Glucosaminidase [NAG], Neutrophil gelatinase-associated lipocalin [NGAL]) were measured.
Serum creatinine, albumin/creatinine ratio, and eGFR were not different between Group 1 and 2 (p>0.05). There were no significant changes in renal function tests and AKI biomarkers (Δserum creatinine, Δalbumin/creatinine ratio, ΔGFR, Δcystatin C, ΔNAG, and ΔNGAL) for either groups 6, 24, 72, and 168 hours after the procedures (p>0.05).
MRI without contrast agent and non-vascular contrast-enhanced (GD, 0.2 mmol/kg) MRI are not nephrotoxic procedures for patients at high risk for AKI.
PMCID: PMC3829701  PMID: 24193150
MRI; gadopentetate dimeglumine; contrast nephropathy; acute kidney injury; NAG; NGAL
6.  Tumor Vascularity Assessed By Magnetic Resonance Imaging and Intravital Microscopy Imaging1 
Neoplasia (New York, N.Y.)  2008;10(4):354-362.
Gadopentetate dimeglumine (Gd-DTPA)-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is considered to be a useful method for characterizing the vascularity of tumors. However, detailed studies of experimental tumors comparing DCE-MRI-derived parametric images with images of the morphology and function of the microvascular network have not been reported. In this communication, we describe a novel MR-compatible mouse dorsal window chamber and report comparative DCE-MRI and intravital microscopy studies of A-07-GFP tumors xenografted to BALB/c nu/nu mice. Blood supply time (BST) images (i.e., images of the time from when arterial blood enters a tumor through the supplying artery until it reaches a vessel segment within the tumor) and morphologic images of the microvascular network were produced by intravital microscopy. Images of E·F (E is the initial extraction fraction of Gd-DTPA and F is perfusion) were produced by subjecting DCE-MRI series to Kety analysis. The E·F images mirrored the morphology (microvascular density) and the function (BST) of the microvascular networks well. Tumor regions showing high E·F values colocalized with tumor regions showing high microvascular density and low BST values. Significant correlations were found between E·F and microvascular density and between E·F and BST, both within and among tumors.
PMCID: PMC2288537  PMID: 18392132
7.  Imaging Diagnosis of Spinal Intramedullary Tuberculoma: Case Reports and Literature Review 
Spinal intramedullary tuberculoma is rare, accounting for 2/100,000 of cases of tuberculosis and only 2% of all cases of tuberculosis of the central nervous system. Diagnostic imaging is essential to improving diagnosis and management of this disease.
The clinical profile, radiological data, and histological slides of 2 cases of intramedullary tuberculomas confirmed by pathologic examinations were reviewed.
In 2 cases, magnetic resonance imaging (MRI) showed thickening of the spinal cord and oval lesions with a low T1-weighted image signal and a typical “target sign” T2-weighted image signal. After gadopentetate dimeglumine administration, the lesion's rim shape was enhanced, showing uneven wall thickness and sharp margins.
MRI findings of spinal intramedullary tuberculoma were specific, and accurate diagnosis could be obtained. MRI is the optimal measure because it shows location, size, and number of lesions and the presence of degeneration and necrosis.
PMCID: PMC2869271  PMID: 20486535
Tuberculoma; Spinal cord; Tuberculosis, central nervous system; Magnetic resonance imaging
8.  Left Ventricular Infarct Size Assessed with 0.1 mmol/kg Gadobenate Dimeglumine (Gd-BOPTA) Correlates with 0.2 mmol/kg of Gadopentetate Dimeglumine (Gd-DTPA) 
To determine myocardial infarct (MI) size during cardiovascular magnetic resonance (CMR) at 1.5 Tesla using 0.1 mmol/kg bodyweight of gadobenate dimeglumine (Gd-BOPTA) and 0.2 mmol/kg bodyweight of gadopentetate dimeglumine (Gd-DTPA).
Twenty participants (16 men, 4 women), aged 58 ± 12 years, with a prior chronic MI were imaged in a cross-over design. Participants received 0.2 mmol/kg bodyweight of Gd-DTPA, and 0.1 mmol/kg bodyweight of Gd-BOPTA on 2 occasions separated by 3 to 7 days
The correlations were high between Gd-DTPA and Gd-BOPTA measures of infarct volume (r=0.93) and the percentage of infarct relative to LV myocardial volume (r=0.85). The size and location of the infarcts were similar (p=0.9) for the 2 contrast agents. Interobserver correlation of infarct volume (r=0.91) was high.
In chronic myocardial infarction, late gadolinium enhancement identified with a single 0.1 mmol/kg bodyweight dose of Gd-BOPTA is associated in volume and location to a double (0.2 mmol/kg body weight) dose of Gd-DTPA. Lower doses of higher relaxivity contrast agents should be considered for determining LV myocardial infarct size.
PMCID: PMC2705952  PMID: 19478622
myocardial infarction; contrast; ischemic heart disease
9.  High resolution magnetic resonance imaging of the anal sphincter using an internal coil. 
Gut  1995;37(2):284-287.
An internal receiver coil was used to obtain high resolution transverse and oblique coronal magnetic resonance images of the anal sphincter in five normal volunteers and five patients. The internal sphincter had a high signal intensity on T1 weighted, T2 weighted, and STIR sequences whereas the conjoined longitudinal muscle and external sphincter had a low signal intensity. The internal sphincter (but not the external sphincter) showed contrast enhancement after administration of intravenous gadopentetate dimeglumine. The oblique coronal plane was particularly useful for showing the thickness and the relations of the external sphincter. Sphincteric abscesses as well as muscle defects, hypertrophy, and atrophy were clearly shown. The coil was well tolerated by most subjects. It has considerable potential for improving the diagnosis of anorectal disease.
PMCID: PMC1382733  PMID: 7557583
10.  Gadoxetic Acid (Gd-EOB-DTPA)-Enhanced MRI versus Gadobenate Dimeglumine (Gd-BOPTA)-Enhanced MRI for Preoperatively Detecting Hepatocellular Carcinoma: an Initial Experience 
Korean Journal of Radiology  2010;11(4):433-440.
This study was designed to compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance imaging (MRI) with gadobenate dimeglumine-enhanced MRI for preoperatively detecting hepatocellular carcinoma (HCC).
Materials and Methods
Eighteen consecutive patients (17 men and one woman, age range: 31-73 years) with 22 HCCs underwent examinations with gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI on a 3.0-Tesla unit. The diagnosis of HCC was established after surgical resection and pathological conformation. Three observers independently reviewed each MR image in a random order on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for the detection of HCC was assessed by performing an alternative free-response receiver operating characteristic (ROC) analysis. The sensitivity and positive predictive values were evaluated.
The average value of the area under the ROC curve (Az) for gadoxetic acid enhanced MRI (0.887) was not significantly different from the Az (0.899) for gadobenate dimeglumine-enhanced MRI (p > 0.05). The overall sensitivities of gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI were 80% and 83%, respectively, with no significant difference (p > 0.05). The differences of the positive predictive values for the two contrast agents for each observer were not statistically significant (p > 0.05).
The diagnostic performance of gadoxetic acid-enhanced MRI and gadobenate dimeglumine-enhanced MRI for preoperatively detecting HCC is quite similar.
PMCID: PMC2893314  PMID: 20592927
Hepatocellular carcinoma (HCC); Gadoxetic acid-enhanced MRI; Gadobenate dimeglumine-enhanced MRI
11.  Segmental Difference of the Hepatic Fibrosis from Chronic Viral Hepatitis due to Hepatitis B versus C Virus Infection: Comparison Using Dual Contrast Material-Enhanced MRI 
Korean Journal of Radiology  2011;12(4):431-438.
We wanted to identify the geographic differences in hepatic fibrosis and their associations with the atrophy-hypertrophy complex in patients with chronic viral hepatitis using the dual-contrast material-enhanced MRI (DC-MRI) with gadopentetate dimeglumine and ferucarbotran.
Materials and Methods
Patients with chronic C (n = 22) and B-viral hepatitis (n = 35) were enrolled for determining the subjective grade of fibrosis (the extent and thickness of fibrotic reticulations) in the right lobe (RL), the caudate lobe (CL), the medial segment (MS) and the lateral segment (LS) of the liver, with using a 5-grade scale, on the gradient echo T2*-weighted images of DC-MRI. The fibrosis grades of different segments were compared using the Kruskal-Wallis test followed by post-hoc analysis to establish the segment-by-segment differences. The incidences of two pre-established morphologic signs of cirrhosis were also compared with each other between the two groups of patients.
There were significant intersegmental differences in fibrosis grades of the C-viral group (p = 0.005), and the CL showed lower fibrosis grades as compared with the grades of the RL and MS, whereas all lobes were similarly affected in the B-viral group (p = 0.221). The presence of a right posterior hepatic notch was significantly higher in the patients with intersegmental differences of fibrosis between the RL and the CL (19 out of 25, 76%) than those without such differences (6 out of 32, 19%) (p < 0.001). An expanded gallbladder fossa showed no significant relationship (p = 0.327) with the segmental difference of the fibrosis grades between the LS and the MS.
The relative lack of fibrosis in the CL with more advanced fibrosis in the RL can be a distinguishing feature to differentiate chronic C-viral hepatitis from chronic B-viral hepatitis and this is closely related to the presence of a right posterior hepatic notch.
PMCID: PMC3150670  PMID: 21852903
Liver cirrhosis; Magnetic resonance imaging; Gadolinium; Iron; Chronic hepatitis B; Chronic hepatitis C
12.  Peripheral Artery Wall Imaging Using Contrast-Enhanced, Susceptibility Weighted Phase Imaging 
To demonstrate improved delineation of peripheral artery wall in susceptibility weighted imaging (SWI) phase images by utilizing gadolinium contrast agent.
Materials and methods
Superficial femoral arteries were imaged using high resolution SWI in 11 healthy volunteers before, and after injection of gadopentetate dimeglumine. Two post-contrast scans started 1 min and 11 mins after injection respectively. Eight out of the 11 volunteers also underwent double-inversion-recovery (DIR) turbo-spin-echo (TSE) scans. The same resolution and matrix size were used between SWI and TSE studies, and TSE locations were matched to SWI images. Arterial lumen-wall phase difference and phase contrast-to-noise ratio (CNR) were measured and compared between pre- and post-contrast SWI measurements. The lumen and wall areas measured on both TSE and matching SWI images were respectively analyzed for agreement. Another 2 volunteers participated in a double-echo gradient-echo study. Results were compared to SWI.
By injecting gadolinium contrast agent, phase difference changed by 54.5% and −1.6%, and phase CNR changed by 85.7% and 27.0%, for the 1st and 2nd post-contrast scans respectively. Morphological measurements showed insignificant difference between TSE and SWIs based on paired t-tests; good agreements in Bland-Altman plots were achieved. The double-echo gradient-echo study had similar phase measurements as SWI.
Contrast-enhanced phase imaging improves artery wall delineation in SWI of peripheral artery wall. Contrast-enhanced SWI is a promising vessel wall imaging technique.
PMCID: PMC3516194  PMID: 22261774
susceptibility weighted imaging; phase imaging; susceptibility; gadolinium contrast agent
13.  Beyond blood brain barrier breakdown – in vivo detection of occult neuroinflammatory foci by magnetic nanoparticles in high field MRI 
Gadopentate dimeglumine (Gd-DTPA) enhanced magnetic resonance imaging (MRI) is widely applied for the visualization of blood brain barrier (BBB) breakdown in multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). Recently, the potential of magnetic nanoparticles to detect macrophage infiltration by MRI was demonstrated. We here investigated a new class of very small superparamagnetic iron oxide particles (VSOP) as novel contrast medium in murine adoptive-transfer EAE.
EAE was induced in 17 mice via transfer of proteolipid protein specific T cells. MR images were obtained before and after application of Gd-DTPA and VSOP on a 7 Tesla rodent MR scanner. The enhancement pattern of the two contrast agents was compared, and correlated to histology, including Prussian Blue staining for VSOP detection and immunofluorescent staining against IBA-1 to identify macrophages/microglia.
Both contrast media depicted BBB breakdown in 42 lesions, although differing in plaques appearances and shapes. Furthermore, 13 lesions could be exclusively visualized by VSOP. In the subsequent histological analysis, VSOP was localized to microglia/macrophages, and also diffusely dispersed within the extracellular matrix.
VSOP showed a higher sensitivity in detecting BBB alterations compared to Gd-DTPA enhanced MRI, providing complementary information of macrophage/microglia activity in inflammatory plaques that has not been visualized by conventional means.
PMCID: PMC2731086  PMID: 19660125
14.  Four-dimensional Transcatheter Intra-arterial Perfusion MRI Monitoring of Radiofrequency Ablation of Rabbit VX2 Liver Tumors 
To investigate the hypothesis that four-dimensional (4D) transcatheter intra-arterial perfusion (TRIP) MRI can quantify immediate perfusion changes after radiofrequency (RF) ablation in rabbit VX2 liver tumors.
Materials and Methods
Nine New Zealand White rabbits were used to surgically implant VX2 liver tumors. During ultrasound-guided RF ablation, tumors received either a true or sham ablation. After selective catheterization of the left hepatic artery under X-ray fluoroscopy, we acquired pre and post-RF ablation 4D TRIP MR images using 3 mL of 2.5% intra-arterial gadopentetate dimeglumine. Two regions-of-interest were drawn upon each tumor to generate signal-intensity time curves. Area under the curve (AUC) was calculated to provide semi-quantitative perfusion measurements that were compared using a paired t test (α = 0.05). Ablated tissue was visually confirmed on pathology using Evans blue dye.
Mean AUC perfusion of VX2 tumors for the true ablation group decreased by 92.0% (95% CI: 83.3%–100%), from 1913 (95% CI: 1557, 2269) before RF ablation to 76.6 (95% CI: 18.4, 134.8) after RF ablation (a.u., p < 0.001). Sham-ablated tumors demonstrated no significant perfusion changes.
4D TRIP MRI can quantify liver tumor perfusion reductions in VX2 rabbits after RF ablation. This MRI technique can potentially be used to improve tumor response assessment at the time of RF ablation.
PMCID: PMC3527903  PMID: 21761464
radiofrequency ablation; transcatheter intra-arterial perfusion MRI; VX2 rabbits; functional imaging biomarker; hepatocellular carcinoma
15.  System for MR Image–guided Prostate Interventions: Canine Study 
Radiology  2003;228(3):886-894.
The purpose of this study was to demonstrate the use of a transrectal system that enables precise magnetic resonance (MR) image guidance and monitoring of prostate interventions. The system used a closed-bore 1.5-T MR imaging unit and enables one to take advantage of the higher signal-to-noise ratio achieved with traditional magnet designs, which is crucial for accurate targeting and monitoring of prostate interventions. In the first of the four canine studies, reliable needle placement, with all needles placed within 2 mm of the desired target site, was achieved. In two other studies, MR imaging was used to monitor distribution of injected contrast agent solution (gadopentetate dimeglumine mixed with trypan blue dye) in and around the prostate, thereby confirming that solution had been delivered to the desired tissue and also detecting faulty injections. In the final study, accurate placement and MR imaging of brachytherapy seeds in the prostate were demonstrated. The described system provides a flexible platform for a variety of minimally invasive MR image–guided therapeutic and diagnostic prostate interventions.
PMCID: PMC3302165  PMID: 12954903
Magnetic resonance (MR), experimental studies; Magnetic resonance (MR), guidance; Prostate neoplasms, MR; Prostate neoplasms, therapeutic radiology
16.  Bimodal visualization of colorectal uptake of nanoparticles in dimethylhydrazine-treated mice 
AIM: To investigate colorectal uptake of solid lipid nanoparticles (SLNs) in mice receiving different doses of 1,2-dimethylhydrazine (DMH) using magnetic resonance (MR) and laser-scanning confocal fluorescence microscope (LSCFM) imaging.
METHODS: Eight mice were sacrificed in a pilot study to establish the experimental protocol and to visualize colorectal uptake of SLNs in normal mice. Gadopentetate dimeglumine and fluorescein isothiocyanate (FITC)-loaded SLN (Gd-FITC-SLN) enemas were performed on mice receiving DMH for 10 wk (group 1, n = 9) or 16 wk (group 2, n = 7) and FITC-SLN enema was performed on 4 DMH-treated mice (group 3). Pre- and post-enema MR examinations were made to visualize the air-inflated distal colorectum. Histological and LSCFM examinations were performed to verify colorectal malignancy and to track the distribution of SLNs.
RESULTS: Homogeneous enhancement and dense fluorescence (FITC) deposition in colorectal wall were observed in normal mice and 1 DMH-treated mouse (group 1) on fluid attenuated inversion recovery (FLAIR) and LSCFM images, respectively. Heterogeneous mural enhancement was found in 6 mice (4 in group 1; 2 in group 2). No visible mural enhancement was observed in the other mice. LSCFM imaging revealed linear fluorescence deposition along the colorectal mucosa in all groups. Nine intraluminal masses and one prolapsed mass were detected by MR imaging with different enhancement modes and pathologies. Interstitial FITC deposition was identified where obvious enhancement was observed in FLAIR images. Bladder imaging agent accumulations were observed in 11 of 16 DMH-treated mice of groups 1 and 2.
CONCLUSION: There are significant differences in colorectal uptake and distribution of SLNs between normal and DMH-treated mice, which may provide a new mechanism of contrast for MR colonography.
PMCID: PMC3180018  PMID: 21987608
Solid lipid nanoparticles; Colorectal cancer; Magnetic resonance colonography
17.  Gadolinium in pediatric cardiovascular magnetic resonance: what we know and how we practice 
The association of gadolinium-based contrast agents (GBCAs) with nephrogenic systemic fibrosis (NSF) has led to a heightened awareness towards patients’ renal function. Whereas detailed guidelines exist for the use of GBCAs in adult patients, best practice is less well defined in children, especially in the very young. We aimed at identifying current practice with regards to the use of GBCAs in children who undergo Cardiovascular Magnetic Resonance.
We conducted a worldwide survey among cardiac imagers with pediatric expertise. The questionnaire contained 21 questions covering the imagers’ work environments, GBCAs used, monitoring of renal function, and a special emphasis was placed on the practice in neonates.
The survey yielded 70 replies. The single most commonly used GBCA was gadopentetate dimeglumine 34/70 (49%). Among the respondents, the choice of GBCA was more importantly based on availability 26/70 (37%) and approval by a pharmaceutical licensing body that most closely reflects the indication 16/70 (23%) than image quality 7/70 (10%) and side effect profile 8/70 (11%). 55/70 (79%) of respondents performed scans in neonates <1 week of age and 52/55 (95%) of them used GBCA in neonates. 65/70 (93%) respondents at least assess some of their patients’ renal functions. Formula-based estimate of glomerular filtration rate is the most popular assessment method 35/65 (54%). In patients with a glomerular filtration rate < 30 ml/min/1.73 m2 62/70 (89%) of respondents do not administer gadolinium at all. The single most common side effect of gadolinium was noted to be nausea/emesis 34/57 (60%) followed by discomfort at injection site 17/57 (30%).
Cardiac imagers are aware of the immature renal function and physiological differences of their pediatric patients that place them at risk for NSF. Epidemiological data is needed for pediatric cardiovascular licensure of gadolinium compounds and for the creation of practice guidelines which will replace current-day practice based on individual clinical judgment.
PMCID: PMC3492017  PMID: 22871150
18.  Transvenous Embolization of Dural Arteriovenous Fistula of the Cavernous Sinus 
Interventional Neuroradiology  2008;10(Suppl 1):85-92.
We reviewed magnetic resonance (MR) images and digital subtraction angiograms (DSA) from eight patients with dural arteriovenous fistula of the cavernous sinus (DAVFCS) to clarify the fistulous points and to evaluate the venous access routes into the cavernous sinus for transvenous embolization (TVE).
Multiplanar reconstruction of the MR images was achieved using three-dimensional fast spoiled gradient-recalled acquisition in the steady state (3-D fast SPGR) after the intravenous administration of gadopentetate dimeglumine (Gd-DTPA).
TVE was performed using microcoils via the inferior petrosal sinus (IPS) using the transfemoral approach in five patients, via the facial vein and superior ophthalmic vein (SOV) using the transfemoral approach in 1 patient, and by SOV puncture in two patients. Most fistulas were detected in the posterior portion of the cavernous sinus or in the posterior intercavernous sinus in all of the patients. Fistulas identified as hyperintense dots or lines on contrast-enhanced 3-D fast SPGR images and were replaced with the microcoils. Target embolization of the fistulas was feasible in three patients treated via the SOV and in one patient treated via the IPS. Contrast-enhanced 3-D fast SPGR can help to identify the fistulous points of DAVFCS. Precise identification of fistulous points and selection of the adequate access route are mandatory for efficient TVE of DAVFCS.
PMCID: PMC3490181  PMID: 20587279
dural arteriovenous fistula, cavernous sinus, transvenous embolization, MRI, fistulous point, 3-D fast SPGR, contrast-enhanced
19.  Partition coefficients for gadolinium chelates in the normal myocardium: Comparison of Gadopentetate dimeglumine and Gadobenate dimeglumine 
To evaluate the influence of contrast agents with different relaxivity on the partition coefficient (λ) and timing of equilibration by using a Modified Look-Locker Inversion Recovery (MOLLI) sequence in cardiac MRI.
Materials and Methods
MOLLI was acquired in 20 healthy subjects (1.5T) at mid-ventricular short axis pre contrast and 5, 10, 20, 25, and 30 min after administration of a bolus of 0.15mmol/kg Gadobenate dimeglumine (Gd-BOPTA) (n=10) or Gadopentetate dimeglumine (Gd-DTPA) (n=10). T1 times were measured in myocardium and blood pool. λ was approximated by ΔR1myocardium /ΔR1blood. Values for Gd-BOPTA and Gd-DTPA were compared. Inter-observer agreement was evaluated (intraclass correlation coefficient [ICC]).
T1 times of myocardium and blood pool (p<0.001) and λ (0.42±0.03 and 0.47±0.04, respectively, p<0.001; excluding 5 min for Gd-BOPTA) were significantly lower for Gd-BOPTA than Gd-DTPA. λ(Gd-DTPA) showed no significant variation between 5 and 30min. λ(Gd-BOPTA) values were significantly lower at 5min compared to other times (0.38 vs. 0.42; p<0.05). Inter-observer agreement for λ values was excellent with Gd-BOPTA (ICC=0.818) and good for Gd-DTPA (ICC=0.631).
λ(Gd-BOPTA) values are significantly lower compared to λ(Gd-DTPA) at the same administered dose. Using Gd-BOPTA, the equilibrium between myocardium and blood pool is not achieved at 5min post contrast.
PMCID: PMC3396792  PMID: 22488770
T1 mapping; Modified Look-Locker Inversion Recovery; partition coefficient; Gadopentetate dimeglumine; Gadobenate dimeglumine
20.  Prompt Diagnosis and Treatment of Uterine Arcuate Artery Pseudoaneurysm: A Case Report and Review of Literature 
Post–partum haemorrhage is a major determinant of maternal mortality. Traditionally, cases of post–partum haemorrhage caused by arterial injuries were managed by caesarean hysterectomies or bilateral internal iliac artery ligations. The diagnosis of aneurysms or arteriovenous malformations of uterine artery are often missed. Uterine curettage, caesarean section or vaginal delivery can result in uterine vascular anomalies like pseudo aneurysms, arteriovenous malformations, arteriovenous fistula and rupture of uterine vessels. Colour Doppler ultrasound pelvis allows detection of these vascular abnormalities. It helps in differentiating the vascular abnormalities that require embolization from non–vascular abnormalities which can be managed by uterine curretage. Vessel malformations can be treated safely with transcatheter uterine artery embolization, but they can develop disastrous consequences with inadvertent uterine curettage. Transcatheter uterine artery embolization after pelvic angiography is the treatment of choice for uterine artery malformations and it has the advantage of preserving the reproductive capacity. We recommend a routine use of colour Doppler ultrasound pelvis for evaluation of abnormal uterine bleeding.
PMCID: PMC3843416  PMID: 24298511
Angiography; Doppler; Post partum; Haemorrhage; Uterine; Pseudoanerysm; Embolization; Arteriovenous; Malformation
21.  Selective preservation of anterior pituitary functions in patients with Sheehan's syndrome  
Sheehan's syndrome manifests as hypopituitarism following a child birth usually preceded by postpartum hemorrhage. The symptoms range from vague feelings of ill health to symptoms of a full blown panhypopituitarism. A large series of such patients is not described in the literature.
Materials and Methods:
We present the details of ten women with partial Sheehan's syndrome. They presented with post-partum hemorrhage and lactation failure.
After delivery, seven out of ten patients had regular menstrual cycles indicating preservation of gonadotroph function. Lactotroph, thyrotroph, and somatotroph failure were present in all and corticotrophs preservation was documented in four out of ten patients. The hypophysial magnetic resonance imaging (MRI) confirmed empty sella in all.
lactotroph, somatotroph and thyrotroph failure are common in patients with Sheehan's syndrome. In addition to known preservation of gonadotroph axis, corticotroph axis may be preserved in some of these patients arguing against the universal treatment of these patients with glucocorticoids.
PMCID: PMC3183521  PMID: 22029030
Corticotrophs; empty sella; postpartum hemorrhage; regular cycles; Sheehan's syndrome
22.  Post-placental intrauterine device insertion - A five year experience at a tertiary care centre in north India 
Background & objectives:
In view of high rate of unintended pregnancy in our country, particularly in post-partum women, there is a need for reliable, effective, long-term contraception such as intrauterine device (IUD) in post-partum women. The present study was planned to evaluate the safety and efficacy of immediate post-partum IUD insertion in women delivering vaginally or by caesarian section in a tertiary care centre facility in north India during a period of five years.
The women recruited had CuT 200B insertion immediately after delivery of placenta in vaginal or caesarean delivery. Women having post-partum haemorrhage (PPH), anaemia, pre-labour rupture of membranes >18 h, obstructed labour and distorted uterine cavity by fibroid or by congenital malformation were excluded from the study. The women were followed up at 6 wk and 6 months after delivery.
A total of 1317 women were included in the study. Of these, 1037 (78.7%) came for first follow up. The cumulative expulsion rate at the end of 6 months was 10.68 per cent. There was no case of misplaced IUD.
Interpretation & conclusions:
Although the expulsion rate for immediate post-partum insertion was higher than for interval insertion, the benefits of providing highly effective contraception immediately after delivery outweigh this disadvantage, particularly in country where women have limited access to medical care.
PMCID: PMC3510889  PMID: 23041736
Contraception; expulsion; intrauterine device; post-placental insertion
23.  The effects of tocilizumab on osteitis, synovitis and erosion progression in rheumatoid arthritis: results from the ACT-RAY MRI substudy 
Annals of the Rheumatic Diseases  2014;73(5):810-816.
To examine the imaging-detected mechanism of reduction of structural joint damage progression by tocilizumab (TCZ) in patients with rheumatoid arthritis (RA) using MRI.
In a substudy of a randomised, double-blind, phase 3b study (ACT-RAY) of biologic-naïve patients with RA who were methotrexate (MTX)-inadequate responders, 63 patients were randomised to continue MTX or receive placebo (PBO), both in combination with TCZ 8 mg/kg every 4 weeks, with optional additional disease-modifying antirheumatic drugs at week 24 if Disease Activity Score of 28 joints < 3.2. The most symptomatic hand was imaged with 0.2 Tesla extremity MRI at weeks 0, 2, 12 and 52. MR images were scored using Outcome Measures in Rheumatology–Rheumatoid Arthritis Magnetic Resonance Imaging Score. Predictors of week 52 erosion progression were determined by logistic regression analysis.
TCZ + PBO (n=32) demonstrated mean improvements in synovitis from baseline to weeks 2 (−0.92; p=0.0011), 12 (−1.86; p<0.0001) and 52 (−3.35; p<0.0001), while TCZ + MTX (n=31) had mean improvements in synovitis at week 12 (−0.88; p=0.0074), but not week 52 (−1.00; p=0.0711). TCZ+PBO demonstrated mean reductions in osteitis at weeks 12 (−5.10; p=0.0022) and 52 (−8.56; p=0.0006), while TCZ+MTX had mean reductions at weeks 2 (−0.21; p<0.05) and 12 (−3.63; p=0.0008), but not week 52 (−2.31; p=0.9749). Mean erosion scores did not worsen in either group. MRI erosion scores at weeks 12 and 52 correlated strongly with radiography erosion scores at week 52 (r>0.80). Baseline synovitis and worsening of osteitis predicted erosion progression.
Rapid suppression of synovitis and osteitis with reduction in structural joint damage progression occurred with TCZ, as monotherapy or in combination with MTX, through week 52.
PMCID: PMC3995246  PMID: 24525910
Rheumatoid Arthritis; DMARDs (biologic); Magnetic Resonance Imaging; Disease Activity; Synovitis
24.  Determination of Infarct Size in Ex Vivo Swine Hearts by Multi-detector Computed Tomography Using Gadolinium as Contrast Medium 
Investigative Radiology  2012;47(5):277-283.
To demonstrate the feasibility of using Multi-Detector Computed Tomography with gadolinium (Gd) contrast (Gd-MDCT) for the quantification of myocardial infarct (MI).
Materials and Methods
MI was induced in six male swine (n=6). One week later, the animals received 0.2mmol/kg gadopentetate dimeglumine (Gd-DTPA) and were sacrificed. On the excised hearts, Gd-MDCT with several tube voltages (80, 120 and 140kV), Late Gadolinium Enhancement MRI (LGE-MRI), and triphenyl-tetrazolium-chloride (TTC) staining were then conducted. We used a 2SD threshold for the CT images, and several threshold limits (2, 3, 4, 5, 6SD and FWHM) for the LGE-MRI images, to delineate the infarct area. Total infarct volume and infarct fraction (IF) of each heart were calculated.
MI size measured by MDCT at 140kV showed good correlation with the reference TTC value. Applying an 80kV tube voltage, however, significantly underestimated MI size. In our study, the LGE-MRI method, using the 6SD threshold provided the most accurate determination of MI size. LGE-MRI, using the 2 and 3SD threshold limits, significantly overestimated infarct size.
The Gd-MDCT technique has been found suitable for the evaluation of MI in an ex-vivo experimental setting. Gd-MDCT has the ability to detect MI even at low kV settings, but accuracy is limited by a high image noise due to reduced photon flux.
PMCID: PMC3325340  PMID: 22472796
Myocardial Infarct; Gadolinium-based Contrast Medium; Multi-detector Computed Tomography; Magnetic Resonance Imaging
25.  Small hypervascular hepatocellular carcinomas: value of diffusion-weighted imaging compared with “washout” appearance on dynamic MRI 
The British Journal of Radiology  2012;85(1018):e879-e886.
To compare the value of diffusion-weighted MRI (DWI) with the venous “washout” appearance during dynamic MRI for the assessment of small arterial hypervascular lesions in cirrhotic liver.
After exclusion of benign hypervascular lesions, including haemangiomas and subcapsular non-tumorous arterioportal shunts, indicated by typical imaging features, a total of 109 small arterial hypervascular lesions (0.5–3.0 cm in the longest diameter) in 65 patients with cirrhosis who underwent gadopentetate dimeglumine-enhanced dynamic MRI and DWI (b=50, 400, 800 s mm−2) at 1.5 T during a 16-month period were retrospectively analysed to determine the presence of venous washout during dynamic imaging or sustained hyperintensity upon increasing the b factor size on DWI.
Among the 99 hypervascular hepatocellular carcinomas (HCCs), sustained hyperintensity on DWI (92/99, 93%) was more prevalent than the washout appearance (72/99, 72%) on dynamic MRI (p<0.001). Depending on the lesion size, subcentimetre-sized HCCs had a significantly lower prevalence of venous washout (13/30, 43%) than the sustained hyperintensity on DWI (27/30, 90%) (p=0.001). In all 10 hypervascular benign conditions, there was no venous washout on dynamic MRI and no sustained hyperintensity on DWI. Sensitivity and specificity for diagnosis of hypervascular HCCs were 92.9% and 100% in DWI and 72% and 100% in dynamic MRI, respectively.
Compared with the venous washout during dynamic imaging, DWI provides more reliable information in the MRI assessment of small hypervascular HCCs, distinguishing them from atypical hypervascular benign or pseudolesions. DWI could complement the early diagnosis of small hypervascular HCCs that do not display venous washout during dynamic imaging.
PMCID: PMC3474029  PMID: 22573299

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