Lateral trochlear inclination (LTI) of the knee was compared on magnetic resonance (MR) images obtained in 30 patients with patellar instability (PI) and 30 patients with nonspecific internal knee derangement. Differences in LTI values between the two populations were significant (P <.001). Reproducibility of the measurement was judged excellent with an intraclass correlation superior to 0.98. Below a threshold value fixed at 11 degrees, LTI appears to be an excellent diagnostic test of PI with a sensitivity of 0.93 (28/30), a specificity of 0.87 (26/30), and an accuracy of 0.90 (54/60).

The authors present their US findings in 24 patients with proved complicated midgut malrotation: volvulus in 18 and occlusive Ladd's bands in 6. All the 24 patients have had US examination prior to surgery. Contrast examinations were performed in only 9 patients, always after US and before surgery. The sonographic "whirlpool" pattern of the superior mesenteric vein and mesentery around the superior mesenteric artery was detected in 15 of the 18 patients with midgut volvulus, and was best seen using Doppler color. Embryological signification of midgut malrotation is discussed.

Marchiafava-Bignami disease (MBD), an acute toxic demyelination of the corpus callosum in alcoholics, is associated with poor evolution in the majority of patients. We report here the early and late diffusion magnetic resonance imaging (MRI) and apparent diffusion coefficient (ADC) studies of two patients suffering from MBD with favourable outcome. Diffusion and anatomical MRI changes were parallel to the clinical evolution, suggesting that MRI studies can be helpful for diagnosis and follow-up. Unlike in stroke, restricted diffusion on ADC maps does not seem to be a sign of irreversibility.

Emphysematous pyelonephritis (EPN) is an uncommon and life-threatening necrotizing infection of the renal parenchyma occurring mostly in diabetic patients. It is usually unilateral. Nephrectomy is the current therapeutic procedure. We report the plain radiograph, US and CT findings in a 26-year-old diabetic woman who presented with bilateral EPN and was cured by medical treatment alone.

A case of neonatal manifestation of giant hypothalamic hamartoma is reported. It is suggested that hypothalamic hamartoma should be included in the list of neonatal intracerebral tumors. Magnetic resonance imaging appearance similar to that of normal gray matter on T1-weighted images and slightly hyperintense on T2-weighted images, without enhancement after gadolinium injection, is suggestive of the diagnosis. Hypothalamic hamartomas are congenital malformations, consisting of disorganized mature neuronal elements in proportions similar to that of normal tissue [1]. They are clinically evidenced in infants ranging from 1 to 7 years of age [1-5]. This report describes a histologically proved giant hypothalamic hamartoma diagnosed in the neonatal period. Magnetic resonance imaging (MRI) is helpful to distinguish this congenital non-evolutive malformation from more aggressive neonatal tumors.