MR arthrography of the hip: normal intra-articular structures and common disorders.

This pictorial review illustrates the anatomical features of normal intra-articular components of the hip and their common disorders on MR arthrography. On T1-weighted MR arthrograms, the normal contrast-filled joint cavity shows a homogeneous high signal intensity. Normal acetabular labrum appears as a well-delineated triangle showing a low signal intensity, surrounded by contrast material in the perilabral recess. Intra-articular paramagnetic contrast outlines labral tears, loose bodies, communicating labral cysts and cartilage lesions (traumatic tears, focal defects, degenerative fissures and thinning), and improves their detection. Overall, MR arthrography enables accurate detection and staging of hip intra-articular structure abnormalities.

Focal nodular hyperplasia of the liver on ferumoxides-enhanced MR imaging: features on conventional spin-echo, fast spin-echo and gradient-echo pulse sequences.

The aim of this study was to assess the efficacy of a superparamagnetic iron oxide, ferumoxides, in the detection and characterization of focal nodular hyperplasia (FNH) on MR conventional spin-echo (SE), fast spin-echo (FSE) and gradient-echo (GRE) images. Fourteen adults with 27 FNHs were evaluated at 1.5 T before and after injection of ferumoxides. T1-weighted and T2-weighted SE, T2-weighted FSE and T2(*)-weighted GRE sequences were used and analysed qualitatively and quantitatively. One hundred percent of FNHs showed a significant postcontrast decrease in signal intensity on T2- and T2*-weighted images. Heavily T2-weighted SE images showed the maximum decrease in FNH signal-to-noise ratio (S/N). Postcontrast GRE T2(*)-weighted images improved the detection of the central scar and the delineation of FNHs and demonstrated the best lesion-to-liver contrast-to-noise ratio (C/N). Postcontrast T1-weighted SE images showed the least lesion-to-liver C/N. Ferumoxides-enhanced MR imaging can help detect and characterize FNH. Conventional pre- and postcontrast T2-weighted SE images and postcontrast GRE T2*-weighted images should be used preferentially.

[Subacute intestinal obstruction due to bladder distension]. / Occlusion intestinale subaiguë par globe vésical.

We report a case of subacute bowel obstruction due to a compression of the rectosigmoid junction by a chronically distended bladder, occurring in a 91-year-old male suffering from a long-standing diabetes mellitus and a prostatic adenoma. Radiographic, water-soluble contrast enema and pelvic CT features are reported.

[Imaging of small renal tumors]. / Imagerie des petites tumeurs rénales.

The increased incidence of detection of small renal tumours, less than or equal to 3 cm in diameter, is related to the generalization and improvement of radiological techniques. Many asymptomatic renal tumours are discovered by ultrasonography and computed tomography. Medical imaging is now able to identify simple cysts (morphological characters, absence of blood supply), angiomyolipomas (demonstration of the fatty contingent) and other solid renal tumours (tumour enhancement on computed tomography). Plain, followed by postcontrast CT looking for contrast enhancement of the lesions is the examination of choice in this context. MRI with Gadolinium injection looking for neoplastic enhancement can be useful in doubtful cases. Medical imaging is able to reliably demonstrate the vascular nature of solid lesions, but cannot distinguish between renal cancer, oncocytoma or another benign solid tumour. Medical imaging allows precise preoperative mapping when partial nephrectomy is envisaged.

[Cystic compression of the suprascapular nerve. Value of imaging. Apropos of 6 cases and review of the literature]. / Compression kystique du nerf sus-scapulaire. Intérêt de l'imagerie. A propos de 6 cas et revue de la littérature.

Six cases of suprascapular nerve entrapment by a ganglion cyst within the spinoglenoid notch or developed from the glenoid labrum are reported. Causes of injury or entrapment of the suprascapular nerve are described including traction or kinking of the nerve, trauma, repetitive exercise, or compression by ganglion cyst. The patients had non specific pain, weakness, and atrophy of the spinatus musculature. Electromyography showed evidence of denervation atrophy. Patients had plain radiographs, arthrography, CT-arthrography, magnetic resonance imaging (MRI) and MR-arthrography. Masses that caused suprascapular nerve entrapment were well localized and characterized wit magnetic resonance imaging, reflecting the superior soft-tissue contrast of this modality. In addition, MRI may demonstrate atrophy of the spinatus muscles. MR-arthrography allows to visualize lesions of the glenoid labrum and in some cases, demonstrates cysts filling.

Inflammatory aneurysms of the abdominal aorta: CT findings.

Inflammatory aneurysm of the abdominal aorta (IAAA) is a variant of atherosclerotic aneurysm that is characterized by inflammatory and/or fibrotic changes in the periaortic regions of the retroperitoneum [1, 2]. These inflammatory and/or fibrotic changes are probably the result of a local autoallergic reaction to certain components of atherosclerotic plaques [2]. This distinct entity has important implications, as the periaortic fibrotic tissue adherent to ureters, the duodenum, and the inferior vena cava may complicate surgical repair [1, 2]. The purpose of this essay is to illustrate the CT appearance of IAAA, with emphasis on the identification of IAAA and differentiation from conventional aortic aneurysms, evaluation of the involvement of adjacent structures by the periaortic fibrosis, and evaluation of the retroperitoneum after aneurysmal repair to analyze the resolution or the persistence of the periaortic fibrosis.