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.
brain tumor imaging; gadobenate dimeglumine; comparative studies; high field MRI
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.
Manual removal of placenta; Placenta accreta & increta; MRI; Methotrexate
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.
Placenta Increta; Hypogastric Artery; Balloon Occlusion
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.
Placenta Increta; First Trimester; Intraperitoneal Bleeding
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.
MRI; gadopentetate dimeglumine; contrast nephropathy; acute kidney injury; NAG; NGAL
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.
susceptibility weighted imaging; phase imaging; susceptibility; gadolinium contrast agent
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.
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.
Tuberculoma; Spinal cord; Tuberculosis, central nervous system; Magnetic resonance imaging
Cardiac magnetic resonance (CMR) T1 mapping has been used to characterize myocardial diffuse fibrosis. The aim of this study is to determine the reproducibility and sample size of CMR fibrosis measurements that would be applicable in clinical trials.
A modified Look-Locker with inversion recovery (MOLLI) sequence was used to determine myocardial T1 values pre-, and 12 and 25min post-administration of a gadolinium-based contrast agent at 3 Tesla. For 24 healthy subjects (8 men; 29 ± 6 years), two separate scans were obtained a) with a bolus of 0.15mmol/kg of gadopentate dimeglumine and b) 0.1mmol/kg of gadobenate dimeglumine, respectively, with averaged of 51 ± 34 days between two scans. Separately, 25 heart failure subjects (12 men; 63 ± 14 years), were evaluated after a bolus of 0.15mmol/kg of gadopentate dimeglumine. Myocardial partition coefficient (λ) was calculated according to (ΔR1myocardium/ΔR1blood), and ECV was derived from λ by adjusting (1-hematocrit).
Mean ECV and λ were both significantly higher in HF subjects than healthy (ECV: 0.287 ± 0.034 vs. 0.267 ± 0.028, p=0.002; λ: 0.481 ± 0.052 vs. 442 ± 0.037, p < 0.001, respectively). The inter-study ECV and λ variation were about 2.8 times greater than the intra-study ECV and λ variation in healthy subjects (ECV:0.017 vs. 0.006, λ:0.025 vs. 0.009, respectively). The estimated sample size to detect ECV change of 0.038 or λ change of 0.063 (corresponding to ~3% increase of histological myocardial fibrosis) with a power of 80% and an alpha error of 0.05 for heart failure subjects using a two group design was 27 in each group, respectively.
ECV and λ quantification have a low variability across scans, and could be a viable tool for evaluating clinical trial outcome.
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.
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.
myocardial infarction; contrast; ischemic heart disease
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.
A 13-year-old girl with a remote history of juvenile pilocytic astrocytoma developed acute onset flushing, tachycardia and shortness of breath immediately following administration of gadopentetate dimeglumine during routine brain MRI that subsided following intravenous diphenhydramine. A retrospective review of the MRI results revealed multiple areas of contrast enhancement of the face, consistent with observed urticaria. The patient received pretreatment medications prior to subsequent gadolinium injections without incident. Gadolinium allergy is extremely rare and has been reported in less than 0.1% of injections. However, in patients who undergo anesthesia for MRI studies, similar subtle extracranial MRI findings should alert the neuroradiologist to possible gadolinium allergy that may warrant premedication prior to future injections.
MRI; Gadolinium; Allergy
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.
Angiography; Doppler; Post partum; Haemorrhage; Uterine; Pseudoanerysm; Embolization; Arteriovenous; Malformation
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.
T1 mapping; Modified Look-Locker Inversion Recovery; partition coefficient; Gadopentetate dimeglumine; Gadobenate dimeglumine
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.
Myocardial Infarct; Gadolinium-based Contrast Medium; Multi-detector Computed Tomography; Magnetic Resonance Imaging
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.
Hepatocellular carcinoma (HCC); Gadoxetic acid-enhanced MRI; Gadobenate dimeglumine-enhanced MRI
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.
Contraception; expulsion; intrauterine device; post-placental insertion
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.
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.
Liver cirrhosis; Magnetic resonance imaging; Gadolinium; Iron; Chronic hepatitis B; Chronic hepatitis C
Background and Objectives:
The aim of this study was to compare in a prospective nonrandomized study, the efficacy of 2 methods of administering methotrexate (MTX) in the treatment of ectopic pregnancy (EP): transvaginal injection under sonographic control or intramuscular injection (IM).
Patients with EP who met specific inclusion criteria for medical treatment were treated with MTX: 63 patients (group 1) were treated by IM and 47 patients (group 2) by transvaginal local injection. In group 1, 50 mg/m2 of MTX was injected intramuscularly; in group 2, transvaginal injection of 1 mg/kg of MTX was injected into the ectopic sac under sonographic control. When an additional dose of MTX was required, it was administrated IM at the dosage of 50 mg/m2 in both groups.
The overall success rate, defined by a posttreatment normal hCG level (<10 mUI/mL) was 71.4% in group 1 versus 91.5% in group 2 (P<0.01); for patients with hCG levels <2000 mUI/mL, 83% and 96%, respectively (not significant); for patients with hCG ≥2000 mUI/mL, 37.5% and 86.4%, respectively (P<0.01).
In the medical treatment of EP, the efficacy of MTX is greater when administered by local transvaginal injection than by IM injection. We propose local treatment every time EP can be punctured, especially when hCG levels are ≥2000 mUI/mL.
Ectopic pregnancy; Local methotrexate; IM methotrexate
The objective of this study was to compare the blood pool agent Gadomer with a small contrast agent for the visualization of ultra-small, collateral arteries (diameter<1 mm) with high resolution steady-state MR angiography (SS-MRA) in a rabbit hind limb ischemia model. Ten rabbits underwent unilateral femoral artery ligation. On days 14 and 21, high resolution SS-MRA (voxel size 0.49×0.49×0.50 mm3) was performed on a 3 Tesla clinical system after administration of either Gadomer (dose: 0.10 mmol/kg) or a small contrast agent (gadopentetate dimeglumine (Gd-DTPA), dose: 0.20 mmol/kg). All animals received both contrast agents on separate days. Selective intra-arterial x-ray angiograms (XRAs) were obtained in the ligated limb as a reference. The number of collaterals was counted by two independent observers. Image quality was evaluated with the contrast-to-noise ratio (CNR) in the femoral artery and collateral arteries. CNR for Gadomer was higher in both the femoral artery (Gadomer: 73±5 (mean ± SE); Gd-DTPA: 40±3; p<0.01) and collateral arteries (Gadomer: 18±4; Gd-DTPA: 9±1; p = 0.04). Neither day of acquisition nor contrast agent used influenced the number of identified collateral arteries (p = 0.30 and p = 0.14, respectively). An average of 4.5±1.0 (day 14, mean ± SD) and 5.3±1.2 (day 21) collaterals was found, which was comparable to XRA (5.6±1.7, averaged over days 14 and 21; p>0.10). Inter-observer variation was 24% and 18% for Gadomer and Gd-DTPA, respectively. In conclusion, blood pool agent Gadomer improved vessel conspicuity compared to Gd-DTPA. Steady-state MRA can be considered as an excellent non-invasive alternative to intra-arterial XRA for the visualization of ultra-small collateral arteries.
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.
radiofrequency ablation; transcatheter intra-arterial perfusion MRI; VX2 rabbits; functional imaging biomarker; hepatocellular carcinoma
The aim of this article is to review the published cases of nephrogenic systemic fibrosis (NSF) in Japan. The Japanese medical literature database and MedLine were searched using the keywords NSF and nephrogenic fibrosing dermopathy (January 2000 to March 2009). Reports in peer-reviewed journals and meeting abstracts were included, and cases with biopsy confirmation were selected. 14 biopsy-verified NSF cases were found. In seven of eight patients reported after the association between gadolinium-based contrast agent (GBCA) and NSF was proposed, GBCA administration was documented: five received only gadodiamide; two received both gadodiamide and gadopentetate dimeglumine. In four cases, the amounts of contrast agent were registered: two received only a single dose (0.1 mmol kg−1 body weight) whereas the other two received 7–15 ml (the body weight was not disclosed) for each MR examination. Five patients had multiple injections of GBCA before NSF developed. Except for one patient in whom renal assessment was not reported, none of the patients had an estimated glomerular filtration rate >30 ml min−1 1.73 m−2 and all received dialysis. 5 of the 8 patients (63%) in whom GBCA exposure was confirmed were treated with peritoneal dialysis. Skin lesion of the lower extremity was the first symptom in 12 patients (86%), whereas 2 patients had primarily symptoms from the upper extremity. In three cases, GBCA was administered even after onset of the NSF symptoms because of the physicians' lack of knowledge about the possible association between GBCA and NSF. NSF is found among Japanese end-stage renal failure patients even after examinations using a single dose.
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.
Solid lipid nanoparticles; Colorectal cancer; Magnetic resonance colonography