Sanaâ El Mouhadi

Magnetic resonance cholangiography: Current and future perspectives.

Magnetic resonance cholangiography (MRC) has become the standard of reference for imaging of the biliary ducts. The use of three-dimensional (3D) sequences has resulted in improved spatial resolution with virtually isotropic voxel and improved signal/noise ratio. In addition to MRC images, 3D fat suppressed T1-weighted MR images should be systematically obtained to search for intrahepatic calculi. MRC plays a major role in the diagnosis of cholangiocarcinoma and assessment of its resectability. With modern MR systems the performance of MR is basically the same that of CT for evaluation of arterial and portal vein extent. MRC is a key imaging modality for the diagnosis of primary sclerosing cholangitis. Different imaging patterns may be observed including multifocal intra- and extrahepatic strictures alternating with slightly dilated ducts. Focal signal abnormality of the liver parenchyma and focal parenchymal atrophy represent the consequences of biliary duct obstruction on liver parenchyma. Diagnosis of biliary lithiasis is performed by combination of MRC and T1-weighted MR imaging. MRC can be performed for the diagnosis of secondary cholangitis including ascending cholangitis, ischemic cholangitis and IgG4-related sclerosing cholangitis. Hepatobiliary contrast agents could be used for demonstrating the site of biliary duct leakage after surgery and for functional imaging. MR imaging can also be used to determine the prognosis of PSC. The inherent limitations of MRC of bile ducts are still the suboptimal spatial resolution for evaluation of distal intrahepatic biliary ducts.

Non-contrast 3D MR lymphography of retroperitoneal lymphatic aneurysmal dilatation: a continuous spectrum of change from normal variants to cystic lymphangioma

ObjectiveOur objective was to demonstrate the characteristic features of retroperitoneal lymphatic aneurysmal dilatation with three-dimensional (3D) magnetic resonance (MR) lymphography.ConclusionThree-dimensional MR lymphography demonstrates that retroperitoneal lymphatic aneurysmal dilatation exhibits a continuous spectrum of change from normal variants to lymphatic aneurysmal dilatation and so-called cystic lymphangioma.Main MessageNon-contrast MR lymphography with very heavily T2-weighted fast spin echo sequences is a useful non-invasive technique without the need of contrast medium injection to obtain a unique evaluation of the lymphatic systemTo prove the lymphatic origin of a cystic formation, it is essential to demonstrate the communication with retroperitoneal lymphatic vessels3D MR lymphography demonstrates that retroperitoneal lymphatic aneurysmal dilatation exhibits a continuous spectrum of change from normal variants to lymphatic aneurysmal dilatation and so-called cystic lymphangioma

Magnetic resonance lymphography of chyluria

We report a case of chyluria with magnetic resonance (MR) imaging demonstrating communication of lymphatic vessels with the renal pelvis.

Noncontrast Magnetic Resonance Lymphography

BACKGROUND Different imaging techniques have been used for the investigation of the lymphatic channels and lymph glands. Noncontrast magnetic resonance (MR) lymphography has significant advantages in comparison with other imaging modalities. METHODS Noncontrast MR lymphography uses very heavily T2-weighted fast spin echo sequences which obtain a nearly complete signal loss in tissue background and specific display of lymphatic vessels with a long T2 relaxation time. The raw data can be processed with different algorithms such as maximum intensity projection algorithm to obtain an anatomic representation. RESULTS Standard T2-weighted MR images easily demonstrate the location of edema. It appears as subcutaneous infiltration of soft tissue with a classical honeycomb pattern. True collection around the muscular area may be demonstrated in case of severe lymphedema. Lymph nodes may be normal in size, number, and signal intensity; in other cases, lymph nodes may be smaller in size or number of lymph nodes may be restricted. MR lymphography allows a classification of lymphedema in aplasia (no collecting vessels demonstrated); hypoplasia (a small number of lymphatic vessels), and numerical hyperplasia or hyperplasia (with an increased number of lymphatic vessels of greater and abnormal diameter). CONCLUSION Noncontrast MR lymphography is a unique noninvasive imaging modality for the diagnosis of lymphedema. It can be used for positive diagnosis, differential diagnosis, and specific evaluation of lymphedema severity. It may also be used for follow-up evaluation after treatment.

MR Enterography versus MR Enteroclysis

688 radiology.rsna.org Radiology: Volume 266: Number 2—February 2013 est of a 12-pixel radius centered on the center of the fiducial seed was drawn on each image. This was performed with Matlab software (Mathworks, Natick, Mass) to ensure reproducibility and robustness. The vertical axis of the histogram in figure 7 by convention is the number of pixels at a given Hounsfield unit, as stated by Dr Wang and colleagues. The pixel values used in our study are Hounsfield units, per convention. The 21000 HU peak in the histogram shown in figure 7 was a result of streak artifact caused by fiducial seeds, which can be seen on multiple examples in the article. Finally, Dr Wang and colleagues urge caution with new software implementation. We agree that implementation of any new software should be done with caution. In our study, we evaluated very small gold fiducial seeds and not titanium. Furthermore, the field of view was identical on standard images and MARS reconstructions, so in our opinion the risk of image degradation is minimal. We agree that it will be useful to evaluate the usefulness of spectral imaging MARS in other types of metal artifacts in future research.

Fibrolamellar Hepatocellular Carcinoma

A 24-year-old man presented to hepatology department with a month history of right upper quadrant abdominal pain and weight loss. Ultrasonography revealed a large hepatic mass. There was no history of prior chronic liver disease. The results of laboratory test demonstrated normal levels of -fetoprotein 4 g/L and a mild elevation of transaminase levels, ASAT: 98 U/L, ALAT: 67 U/L. Magnetic resonance demonstrated a large lobulated, well-defined heterogeneous mass with a central scar in an otherwise normal liver (Fig. 1a). The tumor demonstrated dense heterogeneous enhancement in arterial and portal phase and progressively become homogeneous on delayed images (Fig. 1b). The central scar was of low signal intensity on all MR sequences. The diagnosis of fibrolamellar hepatocellular carcinoma was confirmed at surgery. Fibrolamellar hepatocellular carcinoma is a uncommon variant of hepatocellular carcinoma occurring in adolescents and young adults with no underlying cirrhosis or hepatitis [1]. It characteristically appears on MR images as heterogeneous mass, with low intensity central scar and is usually poorly enhanced and best demonstrated on delayed images, witch helps to distinguish it from focal nodular hyperplasia. Typical features of hepatocellular carcinoma such vascular invasion or multifocal disease and evidence of cirrhosis are uncommon. Patients with fibrolamellar carcinoma have a better prognosis than those with usual hepatocellular carcinoma, and

CT and MRI Features of Ileostomies

OBJECTIVE The purpose of this article is to describe CT and MRI features of normal anatomy, variants, and pathologic conditions of different ileostomies. CONCLUSION Multiplanar imaging techniques are useful to identify the complications related to stoma construction and preexisting disease. Understanding the indications for ileostomy construction, surgical techniques, and postoperative anatomy is important for differentiating normal and abnormal imaging features.

Intrahepatic cystic biliary dilatation constitutes a significant prognostic factor in patients with primary sclerosing cholangitis

AimsTo evaluate the prognostic value of cystic dilatation (CD) of the intrahepatic biliary ducts in patients with primary sclerosing cholangitis (PSC).MethodsA single-center cohort of 205 patients with PSC from 2003 to 2016 was analysed. CD was defined by quantitative and qualitative criteria. Radiological and clinical courses were assessed. A Kaplan-Meier analysis was used to estimate cumulative survival without liver transplantation (LT) from the date of PSC diagnosis. A log-rank test was performed to compare survival time of PSC patients with and without CD.ResultsA total of 15 (7.3%) PSC patients (12 males) with a median age of 23 years at diagnosis had CD. Five patients had one CD; seven patients had two or three CDs; and three patients had diffuse CD. CDs ranged in small diameter size from 12 to 32 mm. Radiological evolution of CD was markedly variable. However, a radiological worsening of PSC over time was observed in all patients. The clinical course was characterized by the occurrence of complications in most patients. Half of the patients with CD underwent LT at a median time of 40 months from diagnosis of CD and the median survival time from PSC diagnosis was significantly lower than in PSC without CD (10.7 vs. 23.4 years; HR 3.8, 95% confidence interval: 1.7–8.3, p = 0.001).ConclusionsCD in PSC is an unusual condition that mostly affects young patients. It is characterized by a rapid, unfavorable course and constitutes a significant prognostic factor.Key Points• Cystic dilatation of the intrahepatic biliary ducts affects young patients with primary sclerosing cholangitis and is characterized by a markedly variable radiological evolution.• Biliary wall inflammation, found in explanted livers, could be a key feature in the pathogenesis of cystic dilatation.• Cystic dilatation of the intrahepatic biliary ducts is characterized by an unfavorable course and constitutes a significant prognostic factor of primary sclerosing cholangitis.

Évaluation de la qualité des comptes rendus radiologiques des examens tomodensitométriques d’évaluation oncologiqueQuality assessment of radiologic reports of CT examinations for tumor response evaluation

PURPOSE Our purpose was to assess the quality of radiologic reports of CT scans performed for tumor response evaluation before and after corrective procedure. MATERIALS AND METHODS Our objective was to assess the presence of different items in radiologic reports of CT scans performed for tumor response evaluation. The present evaluation was formal, that is to say without checking the accuracy of the items identified. Ten simple items were evaluated before and after corrective procedure corresponding to an oral and written information concerning the tumor response evaluation technique with CT. RESULTS The results were variable depending on the items measured. Most of the criteria were improved after corrective procedure. But for some items the result remained poor or very poor as the appropriate choice of comparison review (baseline or nadir). CONCLUSION In the absence of use of the standard form, the feedback of the quality of radiologic reports of CT scans performed for tumor response evaluation shows that the quality remains largely suboptimal even after corrective procedure.

Évaluation de la qualité des comptes rendus radiologiques des examens tomodensitométriques d’évaluation oncologique

PURPOSE Our purpose was to assess the quality of radiologic reports of CT scans performed for tumor response evaluation before and after corrective procedure. MATERIALS AND METHODS Our objective was to assess the presence of different items in radiologic reports of CT scans performed for tumor response evaluation. The present evaluation was formal, that is to say without checking the accuracy of the items identified. Ten simple items were evaluated before and after corrective procedure corresponding to an oral and written information concerning the tumor response evaluation technique with CT. RESULTS The results were variable depending on the items measured. Most of the criteria were improved after corrective procedure. But for some items the result remained poor or very poor as the appropriate choice of comparison review (baseline or nadir). CONCLUSION In the absence of use of the standard form, the feedback of the quality of radiologic reports of CT scans performed for tumor response evaluation shows that the quality remains largely suboptimal even after corrective procedure.