ABSTRACT
Objective To investigate the imaging findings and pathological characterislics of primitive neuroectodennal tumor (PNET). Meth-ods Imaging data of 22 cases of PN ET confirmed by pathology were retrospectively analyzed. Results There were 5 cases of central PNET, which were round or lobulated masses, 4 cases with cystic degeneration, 1 case with necrosis, and 4 cases with mild peritu moraledema. Magnetic resonance imaging (MRI) revealed isointensity or slightlyhy pointensity on Tl-and hyperin tensity on T2-weighted imag-es, and marked heterogeneous enhancement. There were 17 cases of peripheral PNET, which were mostly large lobulated soft tissue mass-es, 7cases with cystic degeneration, 3 cases with necrosis, and 8 cases with boned estructio n. Computed tomography (CT) scan showed iso-lowd ensity. MRI revealed isointensity or slightly hypointensity on Tl-and heterogeneous hypeiintensityon T2-weighted images, and marked heterogeneous enhancement. Hematoxylin-eosin staining showed Homer-Wright rosette arrangement of the tumor cells in 13 cases. Immunohistochemical staining revealed expression of CD99 (17/22), CD56 (16/18), Ki-67 (22/22), and vimentin (22/22) by the tumorcells. Conclusion MRI and CT findings of PNET are characteristic and helpful in differential diagnosis of the disease. CD99 is of signif-icant value as a diagnostic biomarker and in the classification of PNET.
ABSTRACT
This study evaluated the clinical value of three-dimensional computed tomography (3D-CT) images in the knees following arthroscopic anterior cruciate ligament (ACL) reconstruction. Sixty-five consecutive patients underwent arthroscopic ACL reconstruction with single-incision and single-tunnel techniques. Preoperative and postoperative (12 months in between) clinical evaluation were performed using the Lysholm knee score and a KT-1000 arthrometer (side to side). Computed tomography (CT) of the knees was performed in a week after operation in all cases and at mean follow-up of 12 months. All of the clinical evaluation scales performed showed an overall improvement. 3D-CT images can display not only the bone tunnels of the knees including femoral and tibia very distinctly, but also the contour of the reconstructed ACL including adjacent structures. The average femoral tunnel diameter increased significantly (3%) from (9.15 +/- 0.03) mm postoperatively to (9.48 +/- 0.5) mm after 12 months; tibial tunnel increased significantly (12%) from (9.11 +/- 0.09) mm to (10.2 +/- 0.3) mm. There was no statistical difference between tunnel enlargements. So multi-slices spiral CT can evaluate the contour and changes of contour and changes of the knee after ACL reconstruction, which will be helpful in the intraoperative location and postoperative assessment of the knees.