Imaging of the postoperative liver: review of normal appearances and common complications.

Several benign and malignant liver diseases may require surgical treatment for cure, including anatomical resections based on the segmental anatomy of the liver, non-anatomical (wedge) resections, and surgical management of biliary cysts. The type of surgery depends not only on the location and the nature of the disease, but also on the expertise of the surgeon. Whereas ultrasonography is often the first-line imaging examination in case of suspected postoperative complication, multidetector computed tomography (MDCT) is of greater value for identifying normal findings after surgery, early postoperative pathologic fluid collections and vascular thromboses, and tumor recurrence in patients who have undergone hepatic surgery. Magnetic resonance cholangiopancreatography (MRCP) is the imaging modality of choice for depicting early postoperative bile duct injuries and ischemic cholangitis that may occur in the late postoperative phase. Both MDCT and MRCP can accurately depict tumor recurrence. Radiologists should become familiar with these surgical procedures to better understand postoperative changes, and with the normal imaging appearances of various postoperative complications to better differentiate between complications and normal findings.

[Traumatic cord and nerve root injuries: imaging features at the acute and chronic phases]. / La moelle et les racines traumatiques: imagerie dans la prise en charge aiguë et chronique.

Cord injuries are frequent and severe lesions resulting in significant disability, most frequently in younger subjects. The area of cord injured results in clinical syndromes (Brown-Sequard, motor and/or sensory deficit...). Cord and rootlet injuries are best depicted on MRI. Diffusion tensor imaging with tractography enables depiction of the most severe cord lesions and some prediction of tissue viability which may provide an idea of the potential functional prognosis and patient recovery. MRI is optimal to demonstrate areas of cord hemorrhage or compression, partial or complete cord transsection, nerve root avulsion...

[Gastroduodenal perforation: the role of MDCT]. / Le scanner multi détecteurs améliore la détection des perforations d'ulcères gastro duodénaux.

OBJECTIVE: To determine whether multidetector computed tomography (MDCT) is helpful for early detection of gastroduodenal perforation. MATERIAL AND METHODS: Fifteen consecutive gastroduodenal perforations for ulcer were recorded in the HIS of a single institution. Reports were analyzed and classified according to the following signs: Was a pneumoperitoneum detected? Was there mention of a perforation site, and how was it depicted (axial or reformatted slices, thin or thick slices)? What were the other described features, including peritoneal fluid, abdominal fat blurring, and bowel wall thickening? RESULTS: All patients had a gastroduodenal perforation. MDCT identified pneumoperitoneum in 15 of 15 cases as compared with three of nine cases for plain films. The perforation site was seen in eight of 15: it was identified as a defect in the parietal wall (gastroduodenal). Six of eight cases were depicted in axial view. Two of them were only seen on MPR, coronal or sagittal view. CONCLUSION: MDCT improves the detection rate of pneumoperitoneum and provides critical data for locating the perforation using direct and indirect signs. Multiplanar images seem to improve radiologists' confidence.

MR imaging of pelvic extraperitoneal masses: A diagnostic approach.

Pelvic extraperitoneal pelvic masses are relatively uncommon conditions and generally raise diagnostic imaging challenges. Magnetic resonance (MR) imaging plays a central role in the diagnosis of these masses due to its unique tissue-specific multiplanar capabilities that allow optimal pelvic mass localization and internal characterization. This article reviews the MR imaging presentation of extraperitoneal pelvic masses, gives clues that allow identifying their extraperitoneal and/or specific origin as well as suggests different steps for narrowing the differential diagnosis. These steps include systematic analysis of the clinical context, tumor location, relationships with major pelvic structures and close study of the internal components of the lesions.

Preoperative portal vein embolization with a combination of trisacryl microspheres, gelfoam and coils.

PURPOSE: To evaluate the safety and efficiency of preoperative portal vein embolization (PVE) with a combination of trisacryl microspheres, gelfoam and coils for inducing lobar hypertrophy in hepatobiliary malignancy patients. MATERIALS AND METHODS: PVE was performed by a percutaneous left approach in 63 patients with hepatic malignancy (hepatocarcinoma=38, colorectal metastasis=14, cholangiocarcinoma=11). The indication of PVE and surgery was evaluated by hepatic tumor board take into consideration to the tumor extension and the hepatic volume on initial and post-embolization CT-scans. The total functional liver volume (TELV) and future liver remnant (FLR) volume were measured before and 24±5days after PVE to assess FLR, TELV and FLR/TELV ratios. Efficiency evaluation was based on FLR increase, the ability to perform the hepatectomy and the hepatic function after surgery. Safety evaluation was determined by clinical and biological follow-up after embolization and surgery. RESULTS: PVE was successful in all the patients. The mean FLR volume increases by 57±56% after embolization (449±180cm(3) to 663±254cm(3)) (P<0.0001). The FLR/TELV ratio increases by 11% after PVE (25±8% to 36±12%). Three minors' complications were registered without impact on surgery, and four patients developed portal hypertension. Forty-nine patients underwent hepatectomy; none of them developed liver failure. Surgery was not performed in 14 patients due to tumor progression (n=9), inadequate hypertrophy of FLR (n=1) and portal hypertension (n=4). CONCLUSION: Preoperative PVE with a combination of trisacryl microspheres, gelfoam and coils is a safe and effective method for inducing contralateral hypertrophy before right hepatectomy in patients with advanced hepatobiliary malignancy.

Hepatocellular carcinoma vascularization: from the most common to the lesser known arteries.

Hepatocellular carcinoma is the sixth most common cancer throughout the world. It is almost exclusively arterially vascularized, unlike the vascularization of the liver, which has a dual supply with a portal component of 75 to 80% and an arterial component of 20 to 25%. The reference treatment for intermediary stages of the Barcelona (B) classification is hepatic artery chemoembolization. The aim of chemoembolization is to inject the tumor chemotherapy into the artery and then to embolize the artery (or arteries), which supply the tumor. For this, knowledge of the anatomy of the hepatic artery is essential. Approximately 55% of the patients belong to the modal distribution, although numerous anatomical variants exist and must be recognized. In addition, primarily non-hepatic arteries may contribute to the vascularization of some hepatocellular carcinomas. Furthermore, new arterial supplies can be recruited by tumors after surgical or chemoembolization treatments. The aim of this article is to describe the different arteries, which may vascularize hepatocellular carcinomas. These arteries must be looked for, recognized, and reported by the radiologist on cross-section examinations in the pre-treatment assessment.

MR Imaging of sclerosing cholangitis.

MRCP is a non-invasive cholangiographic technique used in detection and characterization of bile ducts abnormalities. MRCP features of primary sclerosing cholangitis are randomly distributed annular strictures alternating with slightly dilated bile ducts. Secondary sclerosing processes including ascending, ischemic, caustic, AIDS-related, eosinophilic and autoimmune cholangitis can mimic PSC at MRCP.

Diagnosis and radiological treatment of digestive haemorrhage following supramesocolic surgery.

Digestive haemorrhage following supramesocolic abdominal surgery (cephalic duodenopancreatectomy, cholecystectomy, total oesogastrectomy) is a rare but serious complication, which can be life-threatening. Improvement in scanning techniques has made it possible to modify the diagnostic strategy and improve the therapeutic management of the patients. The aim of this iconographic review is to recall the causes of digestive haemorrhage following supramesocolic surgery and to illustrate the dominant role of tomodensitometry in diagnosing it and in planning and controlling the efficacy of endovascular treatment.

White matter abnormalities in mild traumatic brain injury: a diffusion tensor imaging study.

BACKGROUND AND PURPOSE: Traumatic axonal injury is a primary brain abnormality in head trauma and is characterized by reduction of fractional anisotropy (FA) on diffusion tensor imaging (DTI). Our hypothesis was that patients with mild traumatic brain injury (TBI) have widespread brain white matter regions of reduced FA involving a variety of fiber bundles and show fiber disruption on fiber tracking in a minority of these regions. MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. Twenty-one patients with mild TBI were investigated (men:women, 12:9; mean age +/- SD, 32 +/- 9 years). In a voxel-based comparison with 11 control subjects (men:women, 8:3; mean age, 37 +/- 9 years) using z score analysis, patient regions with abnormally reduced FA were defined in brain white matter. MR imaging, DTI, and fiber tracking characteristics of these regions were described and analyzed using Pearson correlation, linear regression analysis, or the chi(2) test when appropriate. RESULTS: Patients had on average 9.1 regions with reduced FA, with a mean region volume of 525 mm(3), predominantly found in cerebral lobar white matter, cingulum, and corpus callosum. These regions mainly involved supratentorial projection fiber bundles, callosal fibers, and fronto-temporo-occipital association fiber bundles. Internal capsules and infratentorial white matter were relatively infrequently affected. Of all of the involved fiber bundles, 19.3% showed discontinuity on fiber tracking. CONCLUSION: Patients with mild TBI have multiple regions with reduced FA in various white matter locations and involving various fiber bundles. A minority of these fiber bundles show discontinuity on fiber tracking.

Contribution of indirect computed tomographic venography to the diagnosis of postpartum venous thromboembolism.

BACKGROUND: The diagnostic value of indirect computed tomographic venography (CTV), following thoracic computed tomographic angiography (CTA), has not been specifically evaluated in postpartum patients with suspected pulmonary embolism. OBJECTIVES: To assess the diagnostic value of CTV in postpartum venous thromboembolism. METHODS: We reviewed all CTA and CTV procedures performed during the last 7 years in our institution for suspected pulmonary embolism during the postpartum period. We focused on the quality of CTA, the rates of positive CTA and isolated positive CTV findings, and alternative diagnoses provided by CTV. RESULTS: Fifty-five CTA and 33 CTV procedures were performed for suspected pulmonary embolism in 47 patients referred between 24 h and 2 months after Cesarean (34 patients) or vaginal (13 patients) delivery. Of the 33 patients who had both CTA and CTV, seven had positive CTA findings and four had isolated positive CTV findings. Thus, the absolute increase in the venous thromboembolism detection rate following CTV was 12.1% [95% confidence interval (CI) 4.0-29.1]. Subcapsular hematoma of the liver or spleen was found on CTV in another two patients without venous thromboembolism. Consequently, CTV had a direct impact on clinical management in six of 33 patients (18%). CONCLUSION: Our results suggest that postpartum patients with suspected pulmonary embolism have a significant rate of pelvic vein thrombosis and that the use of CTV leads to a 31% relative increase in the detection rate of venous thromboembolism as compared to CTA alone in these patients.