Improved Characterization of Epidermoid Tumor and Arachnoid Cyst with Variable Bandwidth Steady-State Free-Precession (VBSSFP) MR Imaging

利用VBSSFP磁振造影影像鑑別診斷類上皮瘤及蛛網膜囊腫

田德敭(Robert D. Tien) ； Gary J. Felsbery

《中華放射線醫學雜誌》 20卷1期 (1995/03) Pp. 1-12

摘要

我們收集了十二例顱內類上皮瘤及二十三例蛛網膜囊腫共三十五例病人接受傳統spin echo磁振造影及VBSSFP(variable-band width steady-state free-precessicn)磁振造影，來評估VBSSFP對鑑別診斷這兩種腫瘤及腫瘤邊綠的定位所扮演的角色。
結果發現在某些較不典型的病型（如蛛網膜囊腫合併出血或類上皮瘤有較平滑的邊綠等），在SE磁振造影上有時很難作鑑別診斷，但利用VBSSFP可改善此情形，VBSSFP不僅可顯示出兩種腫瘤不同的內含物及其邊綠，並可與周圍的腦脊髓液腔區別。在二十五例接受手術的病人，全部證實了手術前的診斷。
所以VBSSFP磁振造影技術是傳統SE磁振造影的一項輔助脈波程序，可用以幫助鑑別診斷類上皮瘤及蛛網膜囊腫，增加放射線科醫師之信心，並使外科醫師在手術前即可擬定適當的開刀計劃。

關鍵字

蜘蛛膜，囊腫 ； 蜘蛛膜，核磁共振 ； 腦腫瘤，核磁共振 ； 類上皮瘤 ； 核磁共振，脈衝序列 ； 核磁共振，技術學 ； 核磁共振，組織特性

並列摘要

Objective. To evaluate variable bandwidth steady-state free-precession (VBSSFP) MR in characterization of epidermoid tumor and arachnoid cyst.
Subjects and Methods. Axial conventional spin echo and VBSSFP MR images were obtained in 12 patients with epidermoid tumors and in 23 patients with arachnoid cysts, and examined for ability to characterize these two lesions and to delineate lesion margins.
Results. On conventional spin echo MR, characterization of epidermoid tumor and arachnoid cyst was occasionally difficult secondary to atypical cases. On VBSSFP MR, lesion characterization was improved by recognition of two distinct patterns of internal texture (Types 1 & 2) and margins of the lesions could be separated from the surrounding CSF. Type 1 was characterized by lesion homogeneity; lesion signal was slightly hypointense to CSF centrally, with a thin peripheral margin of hyperintensity (isointensity to CSF). This pattern was seen exclusively in all cases of arachnoid cysts. Type 2 was characterized by lesion inhomogeneity; the lesion signal was more markedly hypointense to CSF. No peripheral margin of hyperintensity was seen and this pattern was seen exclusively in epidermoid tumors. In the 25 cases (13 cases of arachnoid cysts, 10 cases of epidermoid tumors and 2 cases of recurrent or residual epidermoid tumors) that were operated, the imaging impression was confirmed by pathological diagnosis.
Conclusions. Epidermoid tumor was more easily differentiated from arachnoid cyst, and both were better defined, using VBSSFP MR. VBSSFP MR is a technique supportive to conventional spin echo imaging to help characterize epidermoid tumors and arachnoid cysts. The improved characterization of these cystic masses with VBSSFP MR imaging can help radiologists and surgeons establish more accurate preoperative diagnoses and more appropriate treatment plans.

並列關鍵字

Arachnoid, cysts ； arachnoid, MR ； brain neoplasms, MR ； epidermoid ； magnetic resonance MR, pulse sequences ； magnetic resonance MR, technology ； magnetic resonance MR, tissue characterization