Inter-observer agreement in the identification of the two bundles of the anterior cruciate ligament using magnetic resonance imaging.

BACKGROUND: Magnetic resonance imaging has become the method of choice to diagnose meniscal and ligament lesions of the knee. New approaches to the surgical treatment of partial anterior cruciate ligament tears led us to try to distinguish the two bundles of that ligament with MRI and to evaluate inter-observer agreement in different viewing planes. METHODS: Images of 50 right and 50 left ligament-intact knees were examined in the coronal and axial viewing planes. Each sequence was independently read by a radiologist and a medical student to note, in each viewing plane, the number of images in which the two-bundle structure of the ligament was clearly seen. Cohen's Kappa coefficients were used to determine inter-observer agreements. RESULTS: The percentage of sequences in which the two bundles were distinguished by the radiologist and the student on one image at least were 82 versus 73% in the coronal plane and 90 versus 93% in the axial plane, respectively. The average number of successive images with clear bundles was higher in the axial (2.7 vs. 1.7) than in the coronal plane (2.2 vs. 1). There was a poor inter-observer agreement in the coronal plane (k=0.176) but an intermediate agreement in the axial plane (k=0.385 or 0.522 depending on number pooling). CONCLUSIONS: The axial viewing plane seems more favourable to distinguish the two bundles of the anterior cruciate ligament with the best possible reproducibility. An oblique-axial plane is deemed to insure a clearer diagnosis of partial tears.

[Correlation between cranial vault size and brain size over time: preliminary MRI evaluation]. / Evolution comparative de la voûte crânienne et du parenchyme cérébral avec l'âge: étude préliminaire en IRM.

OBJECTIVES: To correlate changes of cranial vault measurements of an adult population during the aging process with brain size using the maximum width of the third ventricle in the axial AC-PC plane. MATERIALS AND METHODS: Prospective study of 126 adult subjects (range: 20 to 80 years) with normal brain MRI and without history of neuropsychiatric disorder. MEASUREMENTS INCLUDED: Cranial vault (Maximum length: Glabella-Opisthocranion, Maximum width: euryon-euryon, and maximum height: Basion-Vertex) measurements and maximum width of the third ventricle in the A C-PC plane. RESULTS: Vault measurements (length, width, high) were similar for every age group, irrespective of gender. The variability of cranial vault measurements between individuals was low (<1 cm). Cranial vault measurements were larger for men, but this was not significant when adjusted for body height Comparatively, a gradual widening of the third ventricle, with an exponential behavior, was observed with advancing age. CONCLUSION: Our results indicate that cranial vault measurements are stable over time (between 20-80 years) comparatively to brain atrophy with advancing age. The low variability of cranial vault measurements and their stability over time should be taken into account during segmentation and normalization of brain parenchymal structures.

[Factitious disorder revealed by polymicrobial septic arthritis of a lumbar facet joint diagnosed by percutaneous biopsy]. / Pathomimie révélée par une arthrite septique interapophysaire postérieure polymicrobienne: diagnostic par biopsie percutanée.

Septic arthritis of a lumbar facet joint is rare with few reports in the literature. Clinically, septic arthritis of a lumbar facet joint can mimic spondylodiscitis. Imaging is usually required for diagnosis. Bacteriological diagnosis is needed to optimize treatment with antibiotics. Most of the previously reported cases were due to staphylococcus aureus. We report one case due to rare bacteria which lead to a diagnosis of factitious disorder. Precise bacteriological diagnosis was obtained by CT-guided percutaneous biopsy.