A new variant of Todani type I choledochal cyst. Imaging evaluation.

BACKGROUND AND AIM: Choledochal cysts are congenital segmental aneurysmal dilatations of any portion of bile ducts, most commonly of the main portion of the common bile duct. The classification system of choledochal cysts is based on the site of the cyst or dilatation and currently includes 5 major types. The purpose of our study is to describe the imaging findings of a new variant of choledochal cyst. MATERIALS AND METHODS: Six patients (4 children and 2 adults, 4 females and 2 males, 3-67 year old) were evaluated by US, CT, CT-cholangiography, MRI, magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP), because of jaundice, abdominal pain and a palpable mass. RESULTS: A new type of choledochal cyst was demonstrated in all cases. In this new variant apart from the dilatation of the common hepatic and the common bile duct, dilatation of the central portion of the cystic duct was also observed, giving a bicornal configuration to the cyst. CONCLUSION: The imaging findings of a new variant of choledochal cyst with participation of the cystic duct are described. We propose the classification of this type of choledochal cyst as a new subtype of Todani I cyst, namely Todani ID.

Magnetic resonance imaging and ultrasonographic evaluation of retinal detachment in orbital uveal melanomas.

We assess the role of ultrasonography (US) in the evaluation of retinal detachment in patients with uveal melanomas, in correlation with magnetic resonance imaging (MRI) findings. Twenty-six patients (13♂ and 13♀) with uveal melanomas underwent MRI and US examination. The signal intensity of the tumors and retinal detachments were depicted using MRI. The position of retinal detachment in correlation with the position of intraocular tumor was also evaluated performing ultrasound examination. MRI and US identified uveal melanoma in all 26 patients. In 11 of the 26 patients (42.3%) uveal melanoma was accompanied by retinal detachment. MRI demonstrated retinal detachment in nine patients. US disclosed retinal detachment in two more cases. US has an important role in the depiction of uveal melanomas and associated retinal detachment. It also appears to be more sensitive than MRI in detecting retinal detachment in patients with orbital uveal melanomas.

Evaluation of popliteal arteries with CT angiography in popliteal artery entrapment syndrome.

BACKGROUND: Popliteal artery entrapment is an uncommon clinical entity that occurs due to compression of the popliteal artery by adjacent muscle and tendinous structures. Early diagnosis should be established through a combined approach of careful physical examination and history-taking, duplex ultrasonography, and CT angiography. PATIENTS AND METHODS: We have studied retrospectively 16 patients of popliteal artery entrapment syndrome, 9 men and 7 women. All patients were scanned with a scanner Picker PQ 5000 after bolus injection of nonionic contrast medium and they all underwent a two-part examination first, with the knee in a neutral position, and, second, with the knee hyperextended. RESULTS: At the second phase of the examination 3 patients showed normal findings, 10 patients have shown mild stenosis of the popliteal artery or more severe stenosis due to compression, 2 patients have exhibited bilateral stenosis and 1 patient has also showed popliteal venous compression. CONCLUSION: CT angiography images and three-dimensional images are useful not only for depiction of the arterial changes but also identification of the abnormal anatomic structures responsible for the entrapment.

Enhancement of virchow-robin spaces. An MRI evaluation.

Virchow-Robin spaces are enclosed spaces filled with interstitial fluid and covered with pia that accompany arteries, arterioles, veins and venules as they perforate the brain. They are round, linear or punctuate areas depending on the image that parallel cerebrospinal fluid attenuation or signal intensity. They are classically described as isointense to cerebrospinal fluid on images obtained with all pulse sequences. They appear hypointense relative to brain on T1-weighted MR scans and present a high signal intensity on T2-weighted MR scans. They also show complete signal suppression on fluid-attenuated inversion recovery (FLAIR) scans and no enhancement after intravenous contrast administration. However, many pathologic states result in abnormal dilation with an increased number of Virchow-Robin spaces visible on MRI imaging and many pathological conditions cause the spaces to enhance. The purpose of this study is to present the major causes of Virchow-Robin enhancement.

CT guided percutaneous adrenal biopsy for lesions with equivocal findings in chemical shift MR imaging.

PURPOSE: The aim of this study was to evaluate the usefulness of CT guided adrenal biopsy in patients with equivocal MR chemical shift imaging findings. MATERIAL AND METHODS: Fifty seven patients, 32 with history of malignancy and 25 without history of malignancy, 30 men and 27 women (33-82 years, mean age:58.8 years), with equivocal findings in chemical shift MR imaging, were subjected to CT guided percutaneous adrenal biopsy. RESULTS: From the 57 lesions that were sent for histopathological evaluation, 31 proved to be metastases (54.4%), 20 adenomas (35.1%), 3 cortical carcinomas (5.3%), 1 benign pheochromocytoma (1.8%) and 2 samples were non diagnostic(3.5%). In oncology patients metastases were found in 28/32 of the patients (87.5%) and adenomas in 3/32 (9.4%), while in patients without history of malignancy, metastases were found in 3/25 of the patients (12%) and adenomas in 17/25 (68%). CONCLUSION: CT guided percutaneous adrenal biopsy is a safe and accurate method for a definite diagnosis of adrenal lesions. Since most adrenal lesions are benign, dedicated adrenal imaging is necessary for choosing which of them have to be further evaluated by biopsy. Chemical shift adrenal imaging alone seems to be a reliable method and can be used alternatively to CT enhancement washout technique for selecting which lesions are suspicious of malignancy and have to be investigated with biopsy, especially in cases where iodine contrast media is contraindicated.

Enhancement of robin-virchow spaces MRI evaluation.

The perivascular spaces are normally microscopic. Even in normal brain some Robin-Virchow spaces are usually seen in the area of substantia innominata at the level of anterior commissure. Many pathologic states result in abnormal dilatation with an increased number of spaces visible on MRI imaging. Dilatation is most commonly associated with anterior abnormalities that arise due to aging, diabetes, hypercholesterolemia, smoking, hypertension and other vascular risk factors. The precise etiology of dilatation is currently unknown.