Gadopentetate Dimeglumine-enhanced Magnetic Resonance Imaging Research Articles

A Nomogram Based on Contrast-Enhanced Ultrasound to Predict the Microvascular Invasion in Hepatocellular Carcinoma

The aim of this study was to establish and validate a contrast-enhanced ultrasound (CEUS) nomogram for pre-operative microvascular invasion (MVI) prediction in hepatocellular carcinoma (HCC), and compare it with the nomogram based on gadopentetate dimeglumine-enhanced magnetic resonance imaging (Gd-MRI). A total of 251 patients with a single HCC were enrolled in this prospective study, including 176 patients in the training cohort and 75 patients in the validation cohort. Contrast-enhanced ultrasound (CEUS) with Sonazoid and Gd-MRI was performed pre-operatively. Post-operative histopathology was the gold standard for MVI. Univariate and multivariate logistic regression was performed to determine independent risk factors for MVI. Nomograms based on CEUS and Gd-MRI were established, and their discrimination, calibration and decision curve analysis were evaluated and compared. Multivariate logistic regression revealed that arterial circular enhancement, non-enhancing area and thick ring-like enhancement in the post-vascular phase were independent risk factors for MVI. The areas under the receiver operating characteristic curve of the nomogram were 0.841 (0.779-0.892) and 0.914 (0.827-0.966) in the training and validation cohorts, with no significant difference compared with the Gd-MRI nomogram (p=0.294, 0.321). The C-indexes were 0.821 and 0.870 in the training and validation cohorts. Decision curve analysis revealed that the CEUS nomogram had better clinical applicability than the Gd-MRI nomogram when the threshold probability was between 0.35 and 0.95. The CEUS-based nomogram was available for predicting MVI in HCC, and its predictive performance was not inferior to that of Gd-MRI.

Value of CT and three-dimensional reconstruction revealing specific radiological signs for screening causative high jugular bulb in patients with Meniere\u2019s disease

BackgroundThe aim of the present study was to investigate the pathological features of vestibular aqueduct (VA) related high jugular bulb (HJB) and explore the possible cause-consequence relation between HJB and endolymphatic hydrops (EH), and the potential specific radiological signs for screening causative HJB in Meniere’s disease (MD).MethodsHigh-resolution computed tomography (HRCT) and three-dimensional reconstruction (3DRC) were used to detect the anatomical variables associated with VA and jugular bulb (JB) in hydropic and non-hydropic ears. The presence or absence of EH in the inner ear was determined by gadopentetate dimeglumine-enhanced magnetic resonance imaging. The presence of different types of HJB, the anatomical variables of the VA and JB and the three types of anatomical relationship between the VA and HJB were compared between the hydropic and non-hydropic ears using the χ2 or Fisher’s exact tests. P < 0.05 was considered to indicate a statistically significant difference.ResultsJB was classified as: Type 1, no bulb; type 2, below the inferior margin of the posterior semicircular canal (PSCC); type 3, between the inferior margin of the PSCC and the inferior margin of the internal auditory canal (IAC); type 4, above the inferior margin of the IAC. There were no significant differences in the presence of types 1, 2 and 3 JB between two groups. The presence of type 4 JB, average height of the JB and prevalence of the non-visualization of the VA in CT scans showed significant differences between two groups. The morphological pattern between the JB and VA revealing by 3DRC was classified as: Type I, the JB was not in contact with the VA; type II, the JB was in contact with the VA, but the latter was intact without obstruction; type III, the VA was obliterated by HJB encroachment. There were no significant differences in the presence of type I and II between two groups. Type III was identified in 5 hydropic ears but no non-hydropic ears, with a significant difference observed between the two groups.ConclusionThe present results showed that JB height and non-visualization of the VA on Pöschl’s plane could render patients susceptible to the development of EH. A jugular bulb reaching above the inferior margin of the IAC (type 4 JB) could obstruct VA, resulting in EH in a few isolated patients with MD. VA obliteration revealed by 3DRC, as a specific radiological sign, may have the potential for screening causative HJB in MD.

Comparison of gadoxetic acid versus gadopentetate dimeglumine for the detection of hepatocellular carcinoma at 1.5\u2009T using the liver imaging reporting and data system (LI-RADS v.2017)

PurposeThe goal of this study was to investigate the Liver Imaging Reporting and Data System (LI-RADS) v.2017 for the categorization of hepatocellular carcinomas (HCCs) with gadoxetic acid compared with gadopentetate dimeglumine-enhanced 1.5-T magnetic resonance imaging (MRI).Material and methodsWe included 141 high-risk patients with 145 pathologically-confirmed HCCs who first underwent gadopentetate dimeglumine-enhanced 1.5-T followed by gadoxetic acid-enhanced 1.5-T MRI. Two independent radiologists evaluated the presence or absence of major HCC features and assigned LI-RADS categories after considering ancillary features on both MRIs. Finally, the sensitivity of LI-RADS category 5 (LR-5) and the frequencies of major HCC features were compared between gadoxetic acid- and gadopentetate dimeglumine-enhanced 1.5-T MRI using the Wilcoxon test.ResultsThe sensitivity of LR-5 for diagnosing HCCs was significantly different between gadoxetic acid- and gadopentetate dimeglumine-enhanced MRI (73.8% [107/145] vs 26.2% [38/145], P < 0.001; 71% [103/145] vs 29% [42/145], P < 0.001 for reviewers 1 and 2, respectively). Among the major HCC LI-RADS features, capsule appearance was less frequently demonstrated on gadoxetic acid-enhanced MRI than on gadopentetate dimeglumine-enhanced MRI (3.4% [5/145] vs 5.5% [8/145], P = 0.793; 4.1% [6/145] vs 5.5% [8/145], P = 0.87 for reviewers 1 and 2, respectively), and the frequency of arterial hyperenhancement was not significantly different between gadoxetic acid and gadopentetate dimeglumine (89% [129/145] vs 89% [129/145], P = 1.000). In addition, the frequency of a washout appearance was less in the transitional phase (TP) than in the portal venous phase (PVP) on gadoxetic acid-enhanced MRI (43% [46/107] vs 57% [61/107], P = 0.367).ConclusionGadoxetic acid-enhanced MRI showed a comparable sensitivity to gadopentetate dimeglumine-enhanced MRI for the diagnosis of HCCs, and LI-RADS category 4 (LR-4) hepatic nodules were upgraded to LR-5 when taking into account the major features according to LI-RADS v.2017.

Contrast-Enhanced MRI Evaluation of Bone-Patellar Tendon-Bone and Hamstring ACL Autograft Healing in Humans: A Prospective Randomized Study.

Background:Gadopentetate dimeglumine–enhanced magnetic resonance imaging (MRI), or gadolinium-enhanced MRI, was used to prospectively study the postoperative course of bone–patellar tendon–bone (BPTB) and combined semitendinosus and gracilis (STG) tendon autografts following arthroscopically assisted reconstruction of the anterior cruciate ligament (ACL) in humans. Gadopentetate dimeglumine is a contrast agent that has been shown to enhance the signal of vascularized tissue when examined by MRI.Purpose:To prospectively determine and compare the pattern and timing of autograft revascularization following arthroscopically assisted ACL reconstruction by BPTB or STG autografts.Study Design:Randomized controlled trial; Level of evidence, 1.Methods:A total of 73 patients (63 males, 10 females) with ACL tears who were scheduled to undergo reconstruction consented to participate in this study. The patients were randomized to receive arthroscopically assisted reconstruction of the ACL employing either BPTB or STG autografts. Gadolinium-enhanced MRI scans were scheduled at 3-month intervals during the first postoperative year to assess the integrity, timing, and pattern of enhancement of the ACL graft. The temporal sequence and morphologic characteristics of imaged signals were compared for both types of ACL reconstructions.Results:Based on all knees with 1 exception, there were no statistically significant differences in gadopentetate dimeglumine–mediated graft enhancement grade observed between BPTB and STG autografts.Conclusion:The results suggest that autograft revascularization probably varies in intensity and location during the time course of graft healing. The interval signal changes observed 3 to 9 months, but especially 6 to 9 months, postoperatively are due to increased contrast uptake as a reflection of ongoing neovascularization during the process of ligamentization.

LI-RADS v2014 categorization of hepatocellular carcinoma: Intraindividual comparison between gadopentetate dimeglumine-enhanced MRI and gadoxetic acid-enhanced MRI.

To use Liver Imaging Reporting and Data System (LI-RADS) categorization and features of hepatocellular carcinomas (HCCs) to intraindividually compare gadopentetate dimeglumine-enhanced magnetic resonance imaging (Gd-DTPA-MRI) and gadoxetic acid-enhanced MRI (Gd-EOB-MRI), before and after applying modified major features. Of 77 HCCs in 64 patients analysed, 17 HCCs were confirmed histopathologically and 46 patients had cirrhosis. Gd-EOB-MRI and Gd-DTPA-MRI were evaluated for the presence of major and ancillary features by two radiologists. LI-RADS categorization was done for Gd-DTPA-MRI (LI-RADS-DTPA) and for Gd-EOB-MRI before and after applying modified major features (hepatobiliary phase [HBP] hypointensity as an additional major feature, LI-RADS-EOBm1; HBP hypointense rim as capsule appearance, LI-RADS-EOBm2; and transitional phase [TP] hypointensity as washout appearance, LI-RADS-EOBm3). Sensitivities of LR-5 categorization for the diagnosis of HCC were compared. Washout (p=0.012) and capsule appearance (p<0.001) were less frequently observed on Gd-EOB-MRI. Sensitivity for LR-5 categorization was significantly higher with LI-RADS-DTPA compared with LI-RADS-EOB (p=0.001) and LI-RADS-EOBm2 (p=0.004), while sensitivity for LR-5 categorization with LI-RADS-EOBm1 (p=0.210) and LI-RADS-EOBm3 (p=0.727) was comparable. Modifying LI-RADS for use with Gd-EOB-MRI, such as applying HBP hypointensity as an additional major feature or using TP hypointensity as washout appearance, can improve the sensitivity for the detection of HCC. • Adding HBP hypointensity as additional major feature improved sensitivity of LR-5 categorization. • Adding TP hypointensity as modified washout appearance improved sensitivity of LR-5 categorization. • Sensitivities for LR-5 classification were comparable between LI-RADS-DTPA, LI-RADS-EOBm1, and LI-RADS-EOBm3.

Gadolinium deposition within the paediatric brain: no increased intrinsic T1-weighted signal intensity within the dentate nucleus following the administration of a minimum of four doses of the macrocyclic agent gadobutrol.

To determine whether repeated administration of the macrocyclic gadolinium-based contrast agent (GBCA) gadobutrol in children is associated with T1-weighted hyperintensity within the dentate nucleus, an imaging surrogate for gadolinium deposition. With institutional review board approval, we identified a cohort of eight patients aged 18 years or younger who underwent at least four gadobutrol-enhanced magnetic resonance imaging (MRI) examinations of the brain from 2013 to 2017. For comparison, we identified a cohort of 19 patients who underwent at least four gadopentetate dimeglumine-enhanced MRI examinations. For each examination, both dentate nuclei were contoured on unenhanced images; the mean dentate-to-pons signal intensity (DN-P SI) ratio was calculated. DN-P SI ratios from the first and last MRI exams were compared using Wilcoxon signed ranks tests and linear regression analyses. In the gadobutrol cohort, there was no significant change in the mean DN-P SI ratio from the first to the last scan (1.02 vs 1.02, p = 1.00). In the gadopentetate dimeglumine cohort, there was a significant increase in the mean DN-P SI ratio from the first to the last scan (1.05 vs 1.13, p = 0.003). After controlling for potentially confounding variables, the change in DN-P SI ratio from the first to the last scan was significantly lower for patients in the gadobutrol group than in the gadopentetate dimeglumine group (β = -0.08, p = 0.04). Repeated administration of the macrocyclic GBCA gadobutrol in children was not associated with T1-weighted dentate hyperintensity, while the repeated administration of the linear GBCA gadopentetate dimeglumine was associated with T1-weighted dentate hyperintensity, presumably due to gadolinium deposition. • Gadolinium-based contrast agents are routinely used in magnetic resonance imaging. • Repeated administration of the macrocyclic agent gadobutrol in children was not associated with T1-weighted dentate hyperintensity.

Meningeal carcinomatosis: three case-reports

BackgroundMeningeal carcinomatosis (MC) is characterized by diffuse infiltration of tumor cells in meninges. There is no tumor mass in the brain and parenchyma of the spinal cord. MC is divided into primary and metastatic types. MC cases were previously diagnosed postoperatively or at autopsy. Recent advances in spinal abbreviation cytology and imaging have led to increase in number of reported cases. In this study, we discuss the manifestations of MC patients based on magnetic resonance imaging (MRI) findings, as well as the correlation between the manifestations and pathology.Case presentationMC was confirmed in all three cases by lumbar puncture and gadopentetate dimeglumine-enhanced magnetic resonance imaging. Due to different primary diseases, the patients had specific imaging manifestations.ConclusionEnhanced MRI examination is extremely sensitive for detecting abnormalities in meninges, which plays a very important role in the diagnosis of MC. Since meninges of some MC patients cannot be enhanced, the enhanced MRI examination cannot be replaced by conventional cerebrospinal abbreviation examination. Attribute to the diversity of MR contrast agents, which could provide higher lesion conspicuity and enhances lesion detection, there may be some more choices to improve the detection rate of MC patients and prolong their survival lifetime.

Gadobutrol-enhanced magnetic resonance imaging of meningeal carcinomatosis: case report with emphasis on early diagnosis

BackgroundTimely diagnosis of meningeal carcinomatosis is often difficult even with the assistant of magnetic resonance imaging examination, cerebrospinal fluid analysis, or both. To the best of our knowledge, gadobutrol-enhanced MRI has not been reported in the diagnosis of meningeal carcinomatosis. Here we present two cases where meningeal carcinomatosis was identified on gadobutrol-enhanced magnetic resonance imaging.Case presentationWe identified two cases of meningeal carcinomatosis who had been diagnosed with malignant tumors several years ago. Both patients presented with progressive headache and seizures. Gadopentetate dimeglumine-enhanced magnetic resonance imaging of the brain was performed and did not detect any abnormality of meninges. Lumbar puncture was performed repeatedly, but cerebrospinal fluid cytology showed no evidence of malignant cells. Finally the gadobutrol-enhanced magnetic resonance imaging detected the meningeal metastasis, and supported the diagnosis of meningeal carcinomatosis.ConclusionGadobutrol provides higher lesion conspicuity and enhances lesion detection in meningeal metastasis compared with gadopentetate dimeglumine. Our observation is a cue to analyze the accuracy in the diagnosis of meningeal carcinomatosis, and presents a choice that may facilitate early diagnosis.

Imaging features of glucagonoma syndrome: A case report and review of the literature.

Glucagonoma syndrome appears as an extremely rare neuroendocrine tumour, with few studies ever having detailed its imaging manifestations. In particular, the magnetic resonance imaging (MRI) features of the lesion have not yet been reported. The present study describes a 54-year-old male who presented with uncontrollable skin erythema and weight loss that had been apparent for two years, and diabetes mellitus that had been apparent for five years. The glucagon level was 180 pg/ml. The plain abdominal computed tomography (CT) scan revealed a solid tumour in the neck of the pancreas, which was slightly reinforced during the arterial phase of the enhanced CT scan. Upon MRI, the lesion exhibited a low signal on T1-weighted imaging, and a slightly high signal on T2-weighted and half-Fourier acquisition single-shot turbo spin echo sequence imaging, which measured ~4.5×3.0×3.0 cm in size. Upon diffusion-weighted imaging, the lesion demonstrated heterogeneous hyperintensity, which was mildly enhanced during the arterial phase and washed out during the portal venous phase of gadopentetate dimeglumine-enhanced MRI. 18F-fludeoxyglucose (18F-FDG) positron emission tomography (PET)-CT identified a mild uptake of 18F-FDG by the lesion. The patient was diagnosed with glucagonoma syndrome, and a distal pancreatectomy and splenectomy were subsequently performed. Microscopy revealed that the tumour cells exhibited nest- and belt-like arrangements. The immunohistochemical staining identified positive reactions for glucagon, synaptophysin and chromogranin A, which are consistent with a diagnosis of glucagonoma. Following surgery, the symptoms disappeared and the glucagon level returned to normal. In conclusion, imaging examinations are useful for determining the location and size of a glucagonoma. In particular, MRI is able to identify the distinctive morphological features of the lesion. Immunohistochemical staining provides diagnostic evidence based upon the neuroendocrine features.

Comparison of gadoxetic acid and gadopentetate dimeglumine-enhanced MRI for HCC detection: prospective crossover study at 3 T.

BackgroundGadoxetic acid and gadopentetate dimeglumine are gadolinium-based contrast agents (GBCAs) with an established role in HCC detection and characterization.PurposeTo compare gadopentetate dimeglumine and gadoxetic acid-enhanced magnetic resonance imaging (MRI) for image quality and hepatocellular carcinoma (HCC) detection/conspicuity.Material and MethodsIn this IRB approved cross-over pilot prospective study, 12 patients (all men; mean age, 56 years) with chronic liver disease at risk of HCC underwent two repeat MRI examinations using gadopentetate dimeglumine and gadoxetic acid (mean interval between studies, 5 days). Two independent observers analyzed images for image quality and HCC detection/conspicuity. Per-lesion sensitivity, positive predictive value, quantitative enhancement, and lesion-to-liver contrast ratio were calculated for both contrast agents.ResultsThere was no significant difference in image quality scores between both GBCAs (P = 0.3). A total of 20 HCCs were identified with reference standard in 12 patients (mean size 2.6 cm, range, 1.0–5.0 cm). Higher sensitivity was seen for observer 1 for gadoxetic acid-set in comparison with gadopentetate dimeglumine-set (sensitivity increased from 85.7% to 92.8%), while no difference was noted for observer 2 (sensitivity of 78.5%). Lesion conspicuity was significantly higher on hepatobiliary phase (HBP) images compared to arterial phase images with both GBCAs for both observers (P < 0.05). Lesion-to-liver contrast ratios were significantly higher for HBP compared to all dynamic phases for both agents (P < 0.05).ConclusionOur initial experience suggests that gadoxetic acid-set was superior to gadopentetate dimeglumine-set in terms of HCC detection for one observer, with improved lesion conspicuity and liver-to-lesion contrast on HBP images.

A multicenter, randomized, controlled, single‐blind comparison phase III study to determine the efficacy and safety of gadobutrol 1.0 M versus gadopentetate dimeglumine following single injection in patients referred for contrast‐enhanced MRI of the body regions or extremities

To demonstrate the noninferiority of gadobutrol-enhanced magnetic resonance imaging (MRI) compared with gadopentetate dimeglumine-enhanced MRI in Asian patients referred for contrast-enhanced imaging of the body or extremities. A multicenter, parallel-group comparison study of Asian adults referred for contrast-enhanced MRI were randomized (1:1) to either gadobutrol or gadopentetate dimeglumine. Lesions were assessed for three primary visualization variables: degree of contrast enhancement, border delineation, and internal morphology. Secondary efficacy variables included number of lesions detected, match of MRI diagnosis with final clinical diagnosis, and sensitivity and specificity for malignant lesion detection. Safety was monitored for 24 ± 4 hours after contrast agent administration. A total of 363 patients received either gadobutrol (n = 168) or gadopentetate dimeglumine (n = 178). Mean total scores for three primary visualization variables were 9.39 and 9.34 for gadobutrol and gadopentetate dimeglumine, respectively. The proportion of patients with matched MRI and final diagnosis and sensitivity for malignant lesion detection was greater for unenhanced versus combined images (gadobutrol: 72.2% vs. 81.7%; gadopentetate dimeglumine: 76.2% vs. 82.2%, respectively). Both contrast agents were well tolerated. Gadobutrol (0.1 mmol/kg BW) was well tolerated and effective in Asian patients referred for contrast-enhanced MRI of the body or extremities.

Lack of nephrotoxicity of gadopentetate dimeglumine-enhanced non-vascular MRI and MRI without contrast agent in patients at high-risk for acute kidney injury

BackgroundGadolinium 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).Material/MethodsWe 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.ResultsSerum 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).ConclusionsMRI 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.

Lymph Node Metastases from Gastric Cancer: Gadofluorine M and Gadopentetate Dimeglumine MR Imaging in a Rabbit Model

To compare the diagnostic performance of gadofluorine M with that of gadopentetate dimeglumine in the diagnosis of lymph node metastases with magnetic resonance (MR) imaging in a rabbit model of gastric cancer. The study protocol was approved by the institutional animal care committee. VX2 carcinomas were inoculated into the wall of the stomach in 20 rabbits. Gadopentetate dimeglumine-enhanced MR imaging was performed 4-6 weeks after inoculation, and gadofluorine M-enhanced MR imaging was performed approximately 24 hours later. Both MR imaging sets were analyzed separately and independently by four radiologists with respect to confidence level regarding the presence of metastases in lymph nodes and lymph node conspicuity. Statistical analysis was performed by using multiple-reader multiple-case (MRMC) receiver operating characteristic curve analysis and the Wilcoxon signed rank test. Metastases were confirmed at pathologic analysis in 32 of 104 lymph nodes from 16 rabbits. The area under the receiver operating characteristic curve (AUC) for confidence regarding the presence of metastases in lymph nodes was significantly greater for gadofluorine M than for gadopentetate dimeglumine (AUC, 0.947 vs 0.894; P = .009). However, most (81%, 25 of 32) metastatic nodes were necrotic, and no significant difference was obtained in nonnecrotic nodes. For lymph node conspicuity, the gadofluorine M MR imaging set was assigned a significantly higher score than was the gadopentetate dimeglumine MR imaging set by all readers (P < .001). Gadofluorine M showed significantly higher accuracy and better conspicuity than gadopentetate dimeglumine in the diagnosis of metastatic nodes, most of which were necrotic, in this animal model of gastric cancer.

Hypervascular hepatocellular carcinoma in the cirrhotic liver: diffusion-weighted imaging versus superparamagnetic iron oxide-enhanced MRI

Purpose The purpose of the study was to validate diffusion-weighted imaging (DWI) in the assessment of hypervascular hepatocellular carcinoma (HCC) compared with superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) in the cirrhotic liver. Material and Methods Forty-six consecutive patients with 106 hypervascular focal lesions in the cirrhotic liver who underwent DWI using three b factors and gadopentetate dimeglumine-enhanced dynamic MRI followed by SPIO-enhanced MRI were enrolled. Two independent radiologists evaluated two separated image sets (SPIO set, dynamic MRI and SPIO-enhanced T2*-weighted images; DWI set, DWI and dynamic MRI) and assigned confidence levels for diagnosis of HCC using a five-point scale for each lesion. Area under the receiver operating characteristic curve ( A z) was calculated for each image set. Results The A z value of the DWI set was larger than the SPIO set by both readers (reader 1, 0.936 vs. 0.900, P=.050; reader 2, 0.938 vs. 0.905, P=.110). For the sensitivity (reader 1, 93.1% vs. 86.2%, P=.146; reader 2, 95.4% vs. 88.5%, P=.070) and specificity (reader 1, 89.5% vs. 73.7%, P=.250; reader 2, 79.0% vs. 73.7%, P=1.000) of HCC diagnosis, DWI sets were superior to SPIO sets without statistically significant differences. Conclusion For assessment of hypervascular HCC, DWI in combination with dynamic MRI provides comparable or slightly better information compared with the combination of dynamic and SPIO-enhanced MRI.

Imaging of a Marjolin's Ulcer: A Case Report

“Marjolin’s ulcer”refers to malignancies that developed in chronic venous ulcers, scars, or sinuses (1, 2). These malignancies also arise from various scars, including chronic ulcerations, inflammation, and fistulas after a long period of latency. Malignant transformation takes approximately 35 years. The incidence of malignant skin tumors that developed from scar tissue is 0.1-2.5%. Burn scars are the most common lesion causing this malignancy (3). The most common malignancy that arises from a Marjolin’s ulcer is squamous cell carcinoma, whereas basal cell carcinomas are rare. The malignancy is frequently multiple in the floor of an ulcer (3). The pathogenesis of a Marjolin’s ulcer is controversial (1, 3). Ulcer osteomas develop as a result of the heaping up of periosteum and associated subperiosteal sclerosis, and were seen as a knob-like mass protruding from the bone surface (1). These masses are rare in patients with chronic ulcers (1); however, they are frequently seen in patients with tropical ulcers, occurring in form of cutaneous leishmaniasis, which is a skin infection caused by a single-celled parasite that is transmitted by sandfly bites (4). A previous report described gadopentetate dimeglumine-enhanced magnetic resonance imaging (MRI) as a useful tool for evaluating a Marjolin’s ulcer (2). A multidisciplinary approach using three-dimensional computed tomography (CT) and positron emission tomography J Korean Soc Radiol 2011;64:593-598

Detection of Small Hepatocellular Carcinoma

To investigate whether gadoxetic acid-enhanced magnetic resonance imaging (MRI) has the diagnostic capability and sensitivity comparable to the combination of gadopentetate dimeglumine-enhanced MRI and superparamagnetic iron oxide-enhanced MRI (double-contrast MRI) in the detection of small hepatocellular carcinomas (HCCs). Forty-one patients with 56 HCCs (size range, 0.5-2.0 cm) who underwent gadoxetic acid-enhanced MRI and double-contrast MRI with a mean interval of 4 days (range, 3-9 days) were included in this study. HCCs were diagnosed by histology (n = 25) and imaging findings (n = 31). Two observers independently reviewed the gadoxetic acid set (unenhanced, early dynamic, and hepatocyte phase images) and the double-contrast MRI set, at an initial reading session, and then reached consensus. Diagnostic accuracy and sensitivity were evaluated using the alternative-free response receiver operator characteristic method. Diagnostic accuracy (AZ) and sensitivity were similar for both image sets (0.955, 83.9% for gadoxetic acid set; 0.952, 80.4% for double-contrast MRI set) (P > 0.05). There were 5 and 3 HCCs that were verified only on the gadoxetic acid set and double-contrast MRI set, respectively. All 9 HCCs that were not verified on the gadoxetic acid set were assigned a low confidence rating of 1 or 2. However, 3 of the 11 HCCs, which were not verified on double-contrast MRI, were not seen even upon retrospective review. Gadoxetic acid-enhanced MRI can replace double-contrast MRI for the detection of HCCs. Because all HCCs were delineated on gadoxetic acid-enhanced MRI, even with a low confidence rating, and 3 HCCs were not seen on double-contrast MRI, gadoxetic acid-enhanced MRI could be more advantageous than double-contrast MRI for HCC work-up.

Dynamic Contrast-Enhanced Magnetic Resonance Imaging Evaluation of VX2 Carcinoma in a Rabbit Model

To compare the enhancement characteristics and diagnostic performance of 1.0-M gadobutrol with those of 0.5-M gadopentetate dimeglumine in rabbit VX2 tumor models. Our study was approved by the Animal Care Committee of our hospital. VX2 carcinomas were implanted in both thighs of 14 rabbits 4 days before magnetic resonance (MR) imaging. The animals underwent 2 identical MR examinations with 2 different contrast media separated by 8 hours with the use of a 3.0 T magnet. T2-, T1- weighted fast spin echo images were obtained. Sequential MR imaging with the 3-dimensional-SPGR sequence were performed before and at 1, 2, 3, 4, 5, 10, 15, 20, and 30 minutes after injection of 0.05 mmol/kg of 1.0-M gadobutrol or 0.5-M gadopentetate dimeglumine. Four rabbits without tumor implantation underwent the same MR examinations. Percentage enhancement of the tumor was assessed by 2 radiologists in consensus. Three different readers without knowledge of the histopathologic results interpreted both MR images in terms of presence of tumor. Receiver operating characteristic analysis was conducted to compare the diagnostic value of both contrast agents. Sensitivities and specificities were also calculated. In addition, lesion-to-muscle contrast, degree of lesion delineation, and global preferences of the readers were determined using a scoring system. A total of 56 VX2 tumors were identified by histopathologic review. For the VX2 tumors, the percentage enhancement at each time point was consistently higher with injection of 1.0-M gadobutrol than with injection of 0.5-M gadopentetate dimeglumine (P < 0.01). The area under the receiver operating characteristic curve (Az) values for the use of 1.0-M gadobutrol-enhanced MR imaging were 0.937, 0.886, and 0.938 for readers 1, 2, and 3, respectively. The Az values for the use of 0.5-M gadopentetate dimeglumine-enhanced MR imaging were 0.908, 0.903, and 0.947. Sensitivities were 89.3%, 85.7%, and 89.3% for 1.0-M gadobutrol-enhanced MR imaging and 87.5%, 85.7%, and 89.3% for 0.5-M gadopentetate dimeglumine-enhanced MR imaging. Specificities were 87.5%, 75.0%, and 87.5% for 1.0-M gadobutrol-enhanced MR imaging and 100%, 81.3%, and 100% for 0.5-M gadopentetate dimeglumine-enhanced MR imaging. No significant differences were noted for the Az values, sensitivities, and specificities with the use of the 2 contrast agents. Lesion-to-muscle contrast, degree of lesion delineation, and global preferences of the readers were ranked significantly higher for 1.0-M gadobutrol-enhanced MR imaging in all readers (P < 0.001). Using a 3.0-T magnet, equivalent doses of 1.0-M gadobutrol-enhanced MR imaging showed a superior degree of enhancement for a VX2 tumor than 0.5-M gadopentetate dimeglumine-enhanced MR imaging, and a significant preference for readers was noted for 1.0-M gadobutrol-enhanced MR imaging.

Comparison of 1.0 M Gadobutrol and 0.5 M Gadopentetate Dimeglumine-Enhanced Magnetic Resonance Imaging in Five Hundred Seventy-Two Patients With Known or Suspected Liver Lesions

To evaluate the diagnostic efficacy (accuracy, sensitivity, specificity) of 1.0 M gadobutrol versus 0.5 M gadopentetate for the classification of lesions as either benign or malignant in patients with known or suspected liver lesions. A multicenter, phase-III, randomized, interindividually controlled comparison study with blinded reader evaluation was performed to investigate the diagnostic efficacy of a bolus injection of 1.0 M gadobutrol compared with 0.5 M gadopentetate at a dose of 0.1 mmol Gd/kg BW. The imaging protocol included a dynamic 3D-evaluation, static conventional, and fat saturated T1-weighted sequences. MR datasets were evaluated by 3 independent radiologists. The standard of reference was defined by an independent truth panel (radiologist or hepatologist). The safety evaluation included adverse events, vital signs, and physical examination. A total of 497 of 572 patients were eligible for the final efficacy analysis. Noninferiority of gadobutrol-enhanced magnetic resonance imaging (MRI) for the classification of liver lesions was demonstrated on the basis of diagnostic accuracy determined by the on-site investigators (-0.098, 0.021) as well as for the average reader of the blinded evaluation (-0.096, 0.014) (95% confidence interval), compared with the predefined standard of reference. Very similar increases in sensitivity (ranging from approximately 10% to approximately 55%) and specificity (ranging from approximately 1% to approximately 18%) compared with precontrast MRI were also observed for the 2 contrast agent groups, with maximum differences of 4%.Very similar, low rates of adverse events were recorded for each of the 2 groups. No clinically relevant changes in vital signs or the results of the physical examination were observed in any patient. This study documents evidence for the noninferiority of a single i.v. bolus injection of 1.0 M gadobutrol (0.1 mmol/kg body weight) to 0.5 M gadopentetate (0.1 mmol/kg body weight) in the diagnostic assessment of liver lesions with contrast-enhanced MRI. The known excellent safety profile of gadobutrol was confirmed in this clinical trial and is similar to that of gadopentetate.

Stability of linear and macrocyclic gadolinium based contrast agents

Stability of linear and macrocyclic gadolinium based contrast agents

Stability of linear and macrocyclic gadolinium based contrast agents

Stability of linear and macrocyclic gadolinium based contrast agents