Yann Fargeaudou

Preoperative detection of hepatic metastases: Comparison of diffusion-weighted, T2-weighted fast spin echo and gadolinium-enhanced MR imaging using surgical and histopathologic findings as standard of reference

PURPOSE The purpose of this study was to retrospectively compare the respective sensitivities of diffusion-weighted (DW), T2-weighted fast spin-echo (T2WFSE) and gadolinium chelate-enhanced MR imaging in the preoperative detection of hepatic metastases using intraoperative ultrasonographic and histopathologic findings as the standard of reference. MATERIALS AND METHODS Twenty-seven patients with 64 surgically and histopathologically proven hepatic metastases had MR imaging of the liver, including DW, T2WFSE and dynamic gadolinium chelate-enhanced MR imaging. Images from each MR sequence were separately analyzed by two readers with disagreements resolved by consensus readings. The findings on MR images were compared with intraoperative ultrasonographic and histopathologic findings on a lesion-by-lesion basis to determine the sensitivity of each MR sequence. Statistical review of the lesion-by-lesion analysis was performed with the McNemar test. RESULTS DW, T2WFSE and gadolinium chelate-enhanced MR imaging allowed the depiction of 54/64 (84.4%; 95% CI: 73.1-92.2%), 44/64 (68.8%; 95% CI: 55.9-79.8%), and 51/64 (79.7%; 95% CI: 67.8-88.7%) hepatic metastases respectively. DW MR images allowed depiction of significantly more hepatic metastases than did T2WFSE and was equivalent to gadolinium chelate-enhanced MR imaging (P=.002 and P=.375, respectively). CONCLUSION DW MR imaging is superior to T2WFSE imaging and equivalent to gadolinium chelate-enhanced MR imaging for the preoperative detection of hepatic metastases. Further studies however are needed to determine at what extent DW MR imaging can be used as an alternative to gadolinium chelate-enhanced MR imaging for the preoperative depiction of hepatic metastases.

Suspected Anastomotic Recurrence of Crohn Disease after Ileocolic Resection: Evaluation with CT Enteroclysis

PURPOSE To determine the utility of computed tomographic (CT) enteroclysis for characterization of the status of the anastomotic site in patients with Crohn disease who had previously undergone ileocolic resection. MATERIALS AND METHODS Written informed consent was prospectively obtained from all patients, and the institutional review board approved the study protocol. CT enteroclysis findings in 40 patients with Crohn disease who had previously undergone ileocolic resection were evaluated independently by two readers. Endoscopic findings, histopathologic findings, and/or the Crohn disease activity index was the reference standard. Interobserver agreement between the two readers was calculated with kappa statistics. Associations between CT enteroclysis findings and anastomotic site status were assessed at univariate analysis. The sensitivity, specificity, and accuracy of CT enteroclysis, with corresponding 95% confidence intervals (CIs), for the diagnosis of normal versus abnormal anastomosis and the diagnosis of anastomotic recurrence versus fibrostenosis were estimated. RESULTS Interobserver agreement regarding CT enteroclysis criteria was good to perfect (kappa = 0.72-1.00). At univariate analysis, stratification and anastomotic wall thickening were the two most discriminating variables in the differentiation between normal and abnormal anastomoses (P < .001). Stratification (P < .001) and the comb sign (P = .026) were the two most discriminating variables in the differentiation between anastomotic recurrence and fibrostenosis. In the diagnosis of anastomotic recurrence, severe anastomotic stenosis was the most sensitive finding (95% [20 of 21 patients]; 95% CI: 76.18%, 99.88%), both comb sign and stratification had 95% specificity (18 of 19 patients; 95% CI: 73.97%, 99.87%), and stratification was the most accurate finding (92% [37 of 40 patients]; 95% CI: 79.61%, 98.43%). In the diagnosis of fibrostenosis, both severe anastomotic stenosis and anastomotic wall thickening were 100% sensitive (eight of eight patients; 95% CI: 63.06%, 100.00%), and using an association among five categorical variables, including severe anastomotic stenosis, anastomotic wall thickening with normal or mild mucosal enhancement, absence of comb sign, and absence of fistula, yielded 88% sensitivity (seven of eight patients; 95% CI: 47.35%, 99.68%), 97% specificity (31 of 32 patients; 95% CI: 83.78%, 99.92%), and 95% accuracy (38 of 40 patients; 95% CI: 83.08%, 99.39%). CONCLUSION CT enteroclysis yields objective and relatively specific morphologic criteria that help differentiate between recurrent disease and fibrostenosis at the anastomotic site after ileocolic resection for Crohn disease. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.09091165/-/DC1.

Severe postpartum haemorrhage from ruptured pseudoaneurysm: successful treatment with transcatheter arterial embolization

The purpose of this retrospective study was to evaluate the role of transcatheter arterial embolization in the management of severe postpartum haemorrhage due to a ruptured pseudoaneurysm and to analyse the clinical symptoms that may suggest a pseudoaneurysm as a cause of postpartum haemorrhage. A retrospective search of our database disclosed seven women with severe postpartum haemorrhage in whom angiography revealed the presence of a uterine or vaginal artery pseudoaneurysm and who were treated using transcatheter arterial embolization. Clinical files were reviewed for possible clinical findings that could suggest pseudoaneurysm as a cause of bleeding. Angiography revealed extravasation of contrast material in five out of seven patients. Transcatheter arterial embolization allowed to control the bleeding in all patients and subsequently achieve vaginal suture in four patients with vaginal laceration. No complications related to transcatheter arterial embolization were noted. Only two patients had uterine atony, and inefficiency of sulprostone was observed in all patients. Transcatheter arterial embolization is an effective and secure technique for the treatment of severe postpartum haemorrhage due to uterine or vaginal artery pseudoaneurysm. Ineffectiveness of suprostone and absence of uterine atony should raise the possibility of a ruptured pseudoaneurysm.

Value of pelvic embolization in the management of severe postpartum hemorrhage due to placenta accreta, increta or percreta.

OBJECTIVES To evaluate the role, efficacy and safety of pelvic embolization in the management of severe postpartum hemorrhage in women with placenta accreta, increta or percreta. METHODS The clinical files and angiographic examinations of 12 consecutive women with placenta accreta (n=4), increta (n=2) or percreta (n=6) who were treated with pelvic embolization because of severe primary (n=10) or secondary (n=2) postpartum hemorrhage were reviewed. Before embolization, four women had complete placental conservation, four had partial placental conservation, three had an extirpative approach and one had hysterectomy after failed partial conservative approach. RESULTS In 10 women, pelvic embolization was successful and stopped the bleeding, after one (n=7) or two sessions (n=3). Emergency hysterectomy was needed in two women with persistent bleeding after embolization, both with placenta percreta and bladder involvement first treated by extirpation. One case of regressive hematoma at the puncture site was the single complication of embolization. CONCLUSIONS In women with severe postpartum hemorrhage due to placenta accreta, increta or percreta, pelvic embolization is effective for stopping the bleeding in most cases, thus allowing uterine conservation and future fertility. Further studies, however, should be done to evaluate the potential of pelvic embolization in women with placenta percreta with bladder involvement.

CT enteroclysis features of uncomplicated celiac disease: retrospective analysis of 44 patients.

PURPOSE To describe the computed tomographic (CT) enteroclysis features of uncomplicated celiac disease (CD) and to determine the most indicative appearance of this condition by using a retrospective case-control study. MATERIALS AND METHODS This study had institutional review board approval. The CT enteroclysis examinations of 44 consecutive patients with proved uncomplicated CD (21 men, 23 women; mean age, 44.45 years) were reviewed by two blinded readers and compared with those obtained in 44 control subjects (21 men, 23 women; mean age, 44.48 years), who were matched for sex and age. Comparisons were calculated by using univariate analysis. RESULTS Reversed jejunoileal fold pattern had the highest specificity (100%; 44 of 44; 95% confidence interval [CI]: 91.96%, 100%) and was the most discriminating independent variable for the diagnosis of uncomplicated CD (odds ratio, 39.9; P < .0001) but had a sensitivity of 63.64% (28 of 44; 95% CI: 47.77%, 77.59%). Ileal fold thickening, vascular engorgement, and splenic atrophy were other variables that strongly correlated with the presence of uncomplicated CD. CONCLUSION CT enteroclysis may help establish a diagnosis of uncomplicated CD and may clarify the cause of nonspecific gastrointestinal symptoms in patients with unknown CD. However, future prospective trials are needed to determine the actual value of CT enteroclysis in patients with CD and validate the clinical usefulness of CT enteroclysis in the detection of unknown uncomplicated CD.

Differentiation between cavernous hemangiomas and untreated malignant neoplasms of the liver with free-breathing diffusion-weighted MR imaging: Comparison with T2-weighted fast spin-echo MR imaging

OBJECTIVE To test interobserver variability of ADC measurements and compare the diagnostic performances of free-breathing diffusion-weighted (FBDW) with that of T2-weighted FSE (T2WFSE) MR imaging for differentiating between cavernous hemangiomas and untreated malignant hepatic neoplasms. MATERIALS AND METHODS Thirty-five patients with cavernous hemangiomas and 35 with untreated hepatic malignant neoplasms had FBDW and T2WFSE MR imaging. Hepatic lesions were characterized with ADC measurement and visual evaluation. Interobserver agreement for ADC measurement was calculated. Association between ADC value and lesion type was assessed using univariate analysis. Sensitivity, specificity and accuracy of ADC values and visual evaluation of MR images for the diagnosis of untreated malignant hepatic neoplasm were compared. RESULTS ADC measurements showed excellent interobserver correlation (intraclass correlation coefficient=0.980). Malignant neoplasms had lower ADC values than hemangiomas for the two observers (1.11×10(-3) mm2/s±.21×10(-3) vs. 1.77×10(-3) mm2/s±.29×10(-3) for observer 1 and 1.11×10(-3) mm2/s±.19×10(-3) vs. 1.79×10(-3) mm2/s±.32×10(-3) for observer 2) and univariate analysis found significant correlations between lesion type and ADC values. Depending on ADC threshold value, accuracy for the diagnosis of malignant neoplasm varied from 82.9% to 94.3%. Using visual evaluation, FBDW showed better specificity and accuracy than T2WFSE MR images for the diagnosis of malignant neoplasm (97.1% vs. 77.1% and 94.3% vs. 62.9%, respectively). CONCLUSION FBDW imaging provides reproducible quantitative information and surpasses the value of T2WFSE MR imaging for differentiating between cavernous hemangiomas and untreated malignant hepatic neoplasms.

Multi-detector row CT of patients with acute intestinal bleeding: a new perspective using multiplanar and MIP reformations from submillimeter isotropic voxels

Acute intestinal bleeding is a severe condition, with a mortality rate of up to 40% in case of associated hemodynamic instability. The diagnosis of acute intestinal bleeding is often challenging and to date, there is no definite consensus upon the most appropriate technique for this specific diagnosis. This pictorial essay illustrates our preliminary use of multiplanar (MPR) and maximum intensity projection (MIP) reformations using MDCT scanner with submillimeter and isotropic voxels as an adjunct to axial images in patients with acute intestinal bleeding. MDCT examinations were routinely performed with 64-slice helical CT scanner and images were reconstructed 0.6-mm thickness at 0.5-mm intervals. Multiplanar reconstructions and MIP views were created with a commercially available workstation. Reformatted images from submillimeter isotropic voxels enhanced the depiction of subtle vascular abnormalities and served as a useful adjunct to the axial plane images to improve diagnostic capabilities. Although we are aware that reformatted images should not replace careful analysis of the axial images in patients with acute gastrointestinal bleeding, reformatted images from submillimeter isotropic voxels may clarify the cause of the bleeding, add confidence to image analysis and help interventional radiologists or surgeons improving planning approach.

Three-dimensional MDCT angiography of splanchnic arteries: Pearls and pitfalls

Fast scanning along with high resolution of multidetector computed tomography (MDCT) have expanded the role of non-invasive imaging of splanchnic arteries. Advancements in both MDCT scanner technology and three-dimensional (3D) imaging software provide a unique opportunity for non-invasive investigation of splanchnic arteries. Although standard axial computed tomography (CT) images allow identification of splanchnic arteries, visualization of small or distal branches is often limited. Similarly, a comprehensive assessment of the complex anatomy of splanchnic arteries is often beyond the reach of axial images. However, the submillimeter collimation that can be achieved with MDCT scanners now allows the acquisition of true isotropic data so that a high spatial resolution is now maintained in any imaging plane and in 3D mode. This ability to visualize the complex network of splanchnic arteries using 3D rendering and multiplanar reconstruction is of major importance for an optimal analysis in many situations. The purpose of this review is to discuss and illustrate the role of 3D MDCT angiography in the detection and assessment of abnormalities of splanchnic arteries as well as the limitations of the different reconstruction techniques.

Celiac Disease in Adults: Evaluation with MDCT Enteroclysis

OBJECTIVE The purpose of this article is to present the MDCT enteroclysis features of the multiple complications of celiac disease and illustrate why this technique is helpful to adult patients with celiac disease. CONCLUSION MDCT enteroclysis findings can suggest the diagnosis in adult patients with unknown celiac disease, and many complications of celiac disease can be recognized because of their characteristic appearance. Familiarity with these signs can help in appropriate planning of further diagnostic procedures.

Imagerie des tumeurs stromales digestives

Imaging of gastrointestinal stromal tumors Gastrointestinal stromal tumors (GIST) arising from interstitial cells of Cajal, represent the first type of solid tumor, which is very sensitive to a specific molecularly targeted tyrosine kinase receptor blocker (i. e., imatinib). On CT, which is considered as the reference technique, GISTs typically present as large, well-delineated, heterogeneous and sometimes exophytic masses. In contrast with the absence of lymph node involvement, hepatic metastasis as well as mesenteric involvement can be observed. MR-enteroclysis is indicated to investigate the local extent of the disease in specific cases whereas MR imaging is used to detect hepatic metastasis. Because of a specific treatment, contrast-enhanced imaging is needed for the follow-up of treated tumors. Evaluation of tumor response to treatment is best assessed with CT which still remains the reference imaging technique whereas FDG-PET imaging is used in specific cases.