MR-enterography with diffusion weighted imaging: ADC values in normal and pathological bowel loops, a possible threshold ADC value to differentiate active from inactive Crohn's disease.

OBJECTIVE: The aim of our study was to compare the apparent diffusion coefficient (ADC) values of pathological bowel loops wall (pADC) with the ADC values of normal appearing ones (naADC) and to determine a discriminating threshold. PATIENTS AND METHODS: 60 patients were studied at our Institution through a MR-enterography that included free-breathing axial Diffusion Weighted Imaging (DWI) with two b (0 and 800 s/mm2) after histological diagnosis of active Crohn's disease (CD). The one (when unique) or the best analyzable (when multiple) pathological bowel loop was identified in each patient, on the basis of the MRI features: wall thickness, presence of mural oedema and wall contrast enhancement after contrast medium administration. A normal appearing bowel loop was used for comparison. ADC values were measured in consensus by two radiologists, and they were compared with t-test. The ADC threshold value for the differentiation between pathological and normal appearing bowel loops was determined. RESULTS: The pADC values were significantly lower than the naADC values (1.48 ± 0.058 x 10-3 mm2/s versus 3.525 ± 0.07 x 10-3 mm2/s; p < 0.05). A threshold of 2.416 x 10-3 mm2/s showed 100% sensitivity and 100% specificity for the discrimination between normal and pathological bowel loops. CONCLUSIONS: In patients with active CD the ADC values of the pathological bowel wall are significantly lower than those of normal appearing bowel loops. A threshold of ADC value of 2.416 10-3 mm2/s could discriminate normal from pathological bowel loops.

Uterine inversion in association with uterine sarcoma: a case report with MRI findings and review of the literature.

Non-puerperal uterine inversion due to uterine sarcomas represents a very rare event with no reliable estimate of frequency in the literature. Clinically, the diagnosis of inversion may be difficult, as far as imaging procedures are concerned, although ultrasonography may prove to be useful. However, some characteristics such as the indentation of the fundic area and a depressed longitudinal groove extending from the uterus to the center of the inverted portion are difficult to recognize. Moreover, there is no specific computed tomography feature accurate enough to aid in the differential diagnosis. Here, we report a case of uterine inversion due to Müllerian uterine adenosarcoma whose preoperative workup and diagnosis took advantage of the application of magnetic resonance imaging.

Lymph node imaging: from conventional radiology to diagnostic imaging.

From Herophilus, Aristotle in the 3rd century BC, Aselli, Pecquet, Mascagni to Jossifow and Rouviere the lymphatic system was investigated. Kinmonth and Wallace were the first to study it with lymphangiography. Mediastinal lymph nodes were poorly visualized in high contrast radiography before the seventies; subsequently with the high voltage technique, xerography and signs from mediastinal lines they were better identified. However these procedures were replaced by CT, with which even lymph nodes less than 0.5 cm in size, are recognized. The differentiation between normal and pathologic lymph nodes is based on dimensional, morphologic and densitometric criteria. CT is able to identify typical patterns of inflammatory, systemic and metastatic lymph nodes. On lymphography a great number of signs as gross and dense dotting, foaming, chipping and lacunae are identified, which allow the differentiation of inflammatory, systemic and metastatic patterns. On sonography some nodal characteristics are evidenced as the round shape, hypoechogenicity, absence of hyperechoic medullary line. CT has replaced lymphangiography in the study of abdominal lymph nodes.