Evaluation of Angioarchitectural Features of Unruptured Brain Arteriovenous Malformation by Susceptibility Weighted Imaging.

OBJECTIVES: A precise assessment of angioarchitectural characteristics using noninvasive imaging is helpful for serial follow-up and weighting risk of natural history in unruptured brain arteriovenous malformation (bAVM). This study aimed to test the hypothesis that susceptibility weighted imaging (SWI) would provide an accurate evaluation of angioarchitectural features of unruptured bAVM. METHODS: A total of 81 consecutive patients with unruptured bAVM were examined. Image quality of SWI for the assessment of bAVM angioarchitectural features was determined by a 5-point scale. The accuracy of SWI for detection of angioarchitectural features was evaluated using digital subtraction angiography as a standard reference and further compared among unruptured bAVMs with or without silent intralesional microhemorrhage on SWI to examine the potential confounding effect of microhemorrhage on image analysis. RESULTS: All lesions were identified on SWI. Image quality of SWI was judged to be at least adequate for diagnosis (range, 3-5) in all patients by both readers. Using digital subtraction angiography as a reference standard, the area under the receiver operating curve of detection of deep or posterior fossa location, exclusively deep venous drainage, venous ectasia, venous varices, and the presence of associated aneurysm on SWI was 1, 0.93, 0.94, 0.95, and 0.83, respectively. Silent intralesional microhemorrhage were detected in 39 patients (48.15%) on SWI and no significant difference (P > 0.05) was found in angioarchitectural features between patients with and without silent microhemorrhage. CONCLUSIONS: SWI might be a noninvasive alternative technique for angiography in the angioarchitectural assessment of unruptured bAVM.

Dynamic radiological change of gliomas located in the paralimbic system and its clinical significance.

BACKGROUND: The paralimbic system, which is composed of three parts, is an important functional unit. Gliomas located in the region remain a challenge for clinical treatment. However, the dynamic change of gliomas in the area has not been well documented. The purpose of this study was to identify the growth tendency of gliomas located in the paralimbic system and to obtain some suggestions for clinical treatment. METHODS: Eleven cases of gliomas located in the paralimbic system were recruited in the study. All of them were proven by pathology. Analysis of the serial radiological examinations in each patient was performed from the initial to the final examination, taking into consideration the following items: initial tumor location, final location and the growth tendency. RESULTS: In the initial and final examinations the ratios of insula involvement were 64% and 100%, respectively. On the other hand, the ratios of gliomas located in two or more parts of paralimbic system increased from 64% to 100% during the dynamic examination. CONCLUSIONS: Even though the paralimbic system is composed of three independent anatomical parts, gliomas tend to involve all three parts, especially the insula. Therapeutic plans should aim at the whole region of the system, even during the early stages of gliomas.

Preoperative blood oxygen level-dependent functional magnetic resonance imaging in patients with gliomas involving the motor cortical areas.

BACKGROUND: Blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) plays an important role in identifying functional cortical areas of the brain, especially in patients with gliomas. This study aimed to assess the value of fMRI in presurgical planning and functional outcome of patients with gliomas in the motor cortical areas. METHODS: Twenty-six patients with gliomas in the motor cortex were recruited in the study. Before operation, fMRI was performed in each patient to obtain the mapping of bilateral hands area on the primary sensorimotor cortex. This examination was performed on a 3.0T scanner with a bilateral hands movement paradigm. During microsurgery under awake anesthesia, the motor area was identified using direct electrical stimulation and compared with preoperative mapping. Finally the tumor was resected as much as possible with the motor cortex preserved in each patient. Karnofsky performance status (KPS) was evaluated in all patients before and after operation. RESULTS: Twenty-three patients showed a successful fMRI mapping. Among them, 19 were classified to be grade III; 4, grade II; 3, grade I. The operation time was about 7 hours in the 23 patients, 8.5 hours in the other 3. The pre- and postoperative KPS score was 82.3 +/- 8.6 and 94.2 +/- 8.1, respectively. CONCLUSIONS: Preoperative fMRI of the hand motor area shows a high consistency with intraoperative cortical electronic stimulation. Combined use of the two methods shows a maximum benefit in surgical treatment.