RESUMO
Objective：To explore MR examination scheme for common peroneal nerve and its branches in the popliteal fossa. Methods： Oblique coronal improved fast spin echo (FSE-XL) T1W, FSE-XL T2W, FSE-XL T2W+iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL), short time inversion recovery (STIR) and sagittal three-dimensional fast spoiled gradient-recall echo (3D FSPGR)+IDEAL scanning were performed on 30 popliteal fossa of 30 volunteers. CNR of the peroneal nerve/femoral muscles in oblique coronal images of different sequences were calculated and compared. The displaying scores of the common peroneal nerve and its branches in oblique coronal images, of sagittal 3D FSPGR+IDEAL on common peroneal nerve and its branches were all analyzed. Results ：The overall differences of CNR in the oblique coronal FSE-XL T1W, FSE-XL T2W, STIR, FSE-XL T2W+IDEAL had statistical significance (F=123.57, P<0.01), of CNR between FSE-XL T1W, FSE-XL T2W and STIR, FSE-XL T2W+IDEA were also statistical significance (all P<0.01). There was no significant difference in overall scores of common peroneal nerve (χ2=0.077, P=0.942) among FSE-XL T1W, FSE-XL T2W, STIR and FSE-XL T2W+IDEAL, while the overall differences of the scores of lateral peroneal cutaneous nerve, deep peroneal nerve and superficial peroneal nerve among the 4 sequence images were statistical significance (all P<0.05), FSE-XL T2W+IDEAL and STIR sequence images showed statistical significance differences of lateral peroneal cutaneous nerve, the deep peroneal nerve and superficial peroneal nerve (all P<0.05). The displaying rate of 3D FSPGR+IDEAL imaging for common peroneal nerve and its branch were all 100%. Conclusion： MRI can well display common peroneal nerve and its branches in the popliteal fossa with recommended FSE-XL T2W+IDEAL and sagittal 3D FSPGR+IDEAL sequences.
RESUMO
Objective: To explore the image characteristics of developmental venous anomaly (DVA) in different routine imaging sequence of magnetic resonance (MR) and the diagnostic value of these different sequence. Methods:The imaging data of 54 patients with DVA which were confirmed by using MR enhanced scan that was the contrasted standard were selected. The imaging features obtained from the T1WI, T2WI and FLAIR sequences were researched by using retrospective analysis, and the specificity and accuracy of diagnosis of each imaging sequence were calculated. Results: In the 54 patients, the accuracy of T1WI was 75.9% (41/54), and accuracy of T2WI was 68.5% (37/54), and that of FLAIR T2was 92.6% (50/54). The performance of MRI was that many of medullary vein drained into the central venous, and the shorter draining vein showed typical phenomenon of "jellyfish head"and many medullary vein of the longer draining vein showed the phenomenon of "centipede". The abnormal blood vessel on the T1WI showed strip low signal intensity, and many abnormal blood vessel on T2WI showed strip high signal intensity and minority of them showed strip low signal intensity. The larger central vein and peripherally scattered small medullary veins could be found on the sequence scan of T2FLAIR, and many of abnormal blood vessels showed strip high signal and a small part of abnormal blood vessels showed equisignal and low signal. Besides, the specificity of the diagnosis of sequence of T2FLAIR was 100% without false positive. And the accuracy of T2FLAIR was 92.6% that was higher than 75.9% of T1WI and 68.5% of T2WI. Conclusion: The sequence technique of T2FLAIR has higher accuracy for the detection of DVA and it can clearly display most abnormal blood vessel. Therefore, it has important reference value for diagnosing DVA of brain.