How to differentiate benign from malignant myometrial tumours using MR imaging.

PURPOSE: To retrospectively evaluate the ability of magnetic resonance imaging (MRI) to differentiate malignant from benign myometrial tumours. METHODS: Fifty-one women underwent MRI before surgery for evaluation of a solitary myometrial tumour. At histopathology, there were 25 uncertain or malignant mesenchymal tumours and 26 benign leiomyomas. Conventional morphological MRI criteria were recorded in addition to b 1,000 signal intensity and apparent diffusion coefficient (ADC). Odds ratios (OR) were calculated for each criterion. A multivariate analysis was performed to construct an interpretation model. RESULTS: The significant criteria for prediction of malignancy were high b 1,000 signal intensity (OR = +∞), intermediate T2-weighted signal intensity (OR = +∞), mean ADC (OR = 25.1), patient age (OR = 20.1), intra-tumoral haemorrhage (OR = 21.35), endometrial thickening (OR = 11), T2-weighted signal heterogeneity (OR = 10.2), menopausal status (OR = 9.7), heterogeneous enhancement (OR = 8) and non-myometrial origin on MRI (OR = 4.9). In the recursive partitioning model, using b 1,000 signal intensity, T2 signal intensity, mean ADC, and patient age, the model correctly classified benign and malignant tumours in 47 of the 51 cases (92.4 %). CONCLUSION: We have developed an interpretation model usable in routine practice for myometrial tumours discovered at MRI including T2 signal, b 1,000 signal and ADC measurement. KEY POINTS: • MRI is widely used to differentiate benign from malignant myometrial tumours. • By combining T2-weighted, b 1,000 and ADC features, MRI is 92.4 % accurate. • DWI may limit misdiagnoses of uterine sarcoma as benign leiomyoma. • Patient age is important when considering a solitary myometrial tumour.

Stroke occurrence and patterns are not influenced by the degree of stenosis in cervical artery dissection.

BACKGROUND AND PURPOSE: In stroke attributable to spontaneous dissection of the cervical artery, it is unclear whether the occurrence and pattern of stroke depend on the degree of stenosis. METHODS: In 147 consecutive dissection of the cervical artery patients with (n=88) and without stroke (n=59), we compared the number, volume, and patterns of cerebral diffusion-weighted imaging stroke lesions among patients with <70% stenosis (Group 1), ≥70% stenosis (Group 2), and occlusion (Group 3). RESULTS: The presence (26 of 45 in Group 1, 32 of 59 in Group 2, 30 of 43 in Group 3; P=0.27) and the number of diffusion-weighted imaging lesions (mean±SD [interquartile range], 3.5±3.9 [1-4] in Group 1; 4.2±4.1 [1-5] in Group 2; 3.3±4.0 [1-3] in Group 3; P=0.85) were independent of lumen patency, whereas volume of diffusion-weighted imaging lesions was larger in occlusive dissection of the cervical artery (82±90 mm [17-91] versus 34±54 [2-48]; P=0.03). There were no differences in the breakdown of diffusion-weighted imaging lesion patterns according to degree of stenosis. CONCLUSIONS: The occurrence and diffusion-weighted imaging lesion patterns in dissection of the cervical artery patients may not be influenced by the degree of stenosis of the dissected artery. Occlusive dissection of the cervical artery was associated with larger infarcts.

Mechanism of ischemic infarct in spontaneous cervical artery dissection.

BACKGROUND AND PURPOSE: It is unclear whether strokes in patients with spontaneous cervical artery dissection (CAD) are due to secondary thromboembolism or to a reduction in cerebral blood flow from the primary cervical lesion. The aim of this study was to identify the most likely mechanism of stroke using cervical and cerebral imaging parameters in patients with CAD. METHODS: The study was approved by the local Ethics Committee. Informed consent was waived. We retrospectively evaluated the cerebrovascular ultrasound, cervical MR angiography, and stroke brain MRI in consecutive patients with CAD. An embolic mechanism was considered in the case of direct visualization of an intracranial embolism as a susceptibility vessel sign on T2* or in the case of pial artery territory infarction on diffusion-weighted imaging. A hemodynamic mechanism was considered in the case of watershed infarction and in the case of an association of watershed infarction and pial artery territory infarction when ≥ 2 of the following were present: severe stenotic or occlusive CAD, reduced intracranial velocity on cerebrovascular ultrasound or signal on MR angiography, or hyperintense vessel sign on fluid-attenuated inversion recovery. The remaining patients were considered to have a mixed mechanism. RESULTS: Of 172 consecutive patients with CAD, 100 (58%) had acute stroke on diffusion-weighted imaging. Stroke was attributed to a thromboembolic mechanism in 85 of 100 patients, a hemodynamic mechanism in 12 of 100 patients, and a mixed mechanism in 3 of 100 patients. CONCLUSIONS: Stroke in patients with CAD is most frequently associated with both direct and indirect signs of artery-to-artery embolization on imaging, a finding that should help design future therapeutic trials.