Akira Yogi MD, Presenter: Nothing to Disclose

Tomomi Koga, Abstract Co-Author: Nothing to Disclose

Satoko Yogi, Abstract Co-Author: Nothing to Disclose

Kazuhiko Ogawa, Abstract Co-Author: Nothing to Disclose

Sadayuki Murayama MD, PhD, Abstract Co-Author: Research grant, Toshiba Corporation

To retrospectively evaluate the potential of apparent diffusion coefficient (ADC) score with echo-planar diffusion-weighted images (EPDWI) for predicting the consistency of intracranial meningioma.

Nineteen patients with 20 meningiomas (1 man, 18 women; mean age, 58 years; range, 28-72 years) pathologically diagnosed at our institutions between October 2009 and August 2010 were enrolled. Cases with massive calcification, hemorrhage, or necrosis were excluded. All patients underwent MR examination with a 1.5-T clinical imager (Magnetom Avanto; Siemens, Munich, Germany). Conventional MR sequences with spin-echo T1-weighted image, turbo spin-echo T2-weighted image, and EPDWI with ADC map were performed; the following EPDWI parameters were used: matrix, 232×260; field of view, 220 mm; section thickness, 5 mm; intersection gap, 1 mm; and b value, 0 and 1000 sec/mm2. Two radiologists independently drew the regions of interest (ROI) manually around the meningioma in all slices with the lesion on the ADC map, and the minimal ADC value of all slices was calculated for each case. Meningioma consistency was evaluated at surgery and was classified as soft or hard, according to whether internal decompression could be completed by suction probe only. For these two groups, minimum ADC values were compared with tumor consistency by using the paired t test, and the best ADC cut-off values for differentiating between soft and hard were calculated with receiver operating characteristic curve analysis. Interobserver agreement was calculated by the κ statistics.

The minimum ADC values in the hard and soft groups were (0.56±0.11)×10-3mm2/sec and (0.72±0.12)×10-3mm2/sec, respectively, for observer 1 (P< .01) , and (0.57±0.16)×10-3mm2/sec and (0.74±0.18)×10-3mm2/sec, respectively, for observer 2 (P< .02). Minimum ADC values of the hard group were significantly lower than those for the soft group. The best ADC cut-off value for differentiating between soft and hard consistency was 0.65×10-3mm2/sec, which yielded a sensitivity of 91% and a specificity of 94%. Interobserver agreement was substantial (κ=0.72).

These findings suggest that ADC score with conventional MR examination can provide accurate information about the consistency of intracranial meningioma.

(dealing with DWI) “DWI and ADC score can predict the consistency of intracranial meningioma and is recommended as a part of preoperative study.”

Yogi, A, Koga, T, Yogi, S, Ogawa, K, Murayama, S, Echo-Planar Diffusion-weighted Images Can Predict Consistency of Intracranial Meningioma.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11004196.html