MR screening of candidates for thrombolysis: How to identify stroke mimics?

Stroke mimics account for up to a third of suspected strokes. The main causes are epileptic deficit, migraine aura, hypoglycemia, and functional disorders. Accurate recognition of stroke mimics is important for adequate identification of candidates for thrombolysis. This decreases the number of unnecessary treatments and invasive vascular investigations. Correctly identifying the cause of symptoms also avoids delaying proper care. Therefore, this pictorial review focuses on what the radiologist should know about the most common MRI patterns of stroke mimics in the first hours after onset of symptoms. The issues linked to the accurate diagnosis of stroke mimics in the management of candidates for thrombolysis will be discussed.

[Emergency computed tomography in a general hospital center]. / Scanner en urgence dans un centre hospitalier général.

This retrospective study was performed to precise indications of emergency CT in a general hospital over a 30 months period. We tried to determine, with help of prior studies, the indications for CT of the brain in the management of acute meningitis, acute headache, and in the management of head injury. In acute meningitis, there is no evidence to recommend CT of the brain before lumbar puncture, except to identify patients at increased risk of cerebral herniation. The imaging study of choice in subarachnoid hemorrhage is non enhanced CT scan. This exam has to be performed in case of acute headache. The CT evaluation of patients with minor head injury remains controversial.

[Tumor vascularization: contribution of Doppler ultrasonography]. / Etude de la vascularisation tumorale. Apport de l'échographie-Doppler.

PURPOSE: The purpose of this study was to evaluate the usefulness of Doppler sonography in quantifying tumor vascularization and in determining hemodynamic parameters by spectral analysis. MATERIALS AND METHODS: A total of 100 malignant tumors of different histologic types, were prospectively studied with spectral, color-coded and power Doppler sonography (Toshiba 140 A with 3.75 and 7.5 MHz probes). Internal or peripheral vascularization was scored from 0 (absence of color flow) to +3 (numerous vessels inside and/or beside the mass). Three parameters were calculated for each arterial waveform recorded: the peak systolic velocity (PSV, n = 84), the resistive index (RI, n = 130) and the pulsatility index (PI, n = 115). RESULTS: Tumoral vascularization was scored 0 in 13 cases, + in 39 cases, +2 in 29 cases and +3 in 19 cases. The mean value of the PSV was about 0.30 m/s. RI values ranged from 0.35 to 1 (mean = 0.63). PI values were < 1 in 28 cases and > 2 in 15 cases (mean = 1.68). CONCLUSION: Our results confirm the wide variability in tumor vascularization and in hemodynamic parameters values in malignant tumors.