Mäurer J, Tosi C, Hierholzer J, Bier J, Felix J, Lagalla R, Midiri M, Finazzo M
Istituto di Radiologia e Radioterapia, Virchow-Klinikum, Medizinische Fakultät, Humboldt-Universität, Berlin, Germania.
Radiol Med. 1998 Jun;95(6):563-6.
The technologic improvement of surface coils in MRI has allowed better visualization of the skin and thus permitted the clinical use of this technique in dermatology. MRI allows to assess the depth and extent of skin tumors and to detect any malignant transformation. The MR differentiation between benign and malignant skin lesions relies on morphological criteria which however do not have an absolute diagnostic value. We investigated the role of paramagnetic contrast agents in the differentiation between benign and malignant skin lesions.
Forty-one patients, 33 with benign and 8 with malignant skin tumors, were submitted to MRI. All the examinations were performed with a 1.5 T superconductive unit, with a 2.5 cm surface coil. Axial T1- and T2-weighted SE images were acquired with 2 mm slice thickness. Paramagnetic contrast material was administered to all patients. The signal intensity of the skin lesions was calculated before and after paramagnetic contrast agent administration positioning a region of interest. A percentage ratio of contrast enhancement was calculated to quantify contrast agent uptake and the relative values were compared between benign and malignant lesions. A qualitative analysis was also performed rating the contrast enhancement of each lesion as high, intermediate, or absent.
The quantitative analysis showed a statistically significant difference (p < .5) between the contrast enhancement values of benign and malignant lesions. In particular, malignancies had values ranging 117.3 (+/- 28.7) to 125 (+/- 32.4), while benign lesions had -20.6 to 99.8 (+/- 21.1). Conversely, no difference in contrast enhancement was found at qualitative analysis.
MRI is a promising tool for characterizing skin tumors. Our preliminary results should be confirmed on larger series of patients with the use of high temporal resolution imaging sequences.
磁共振成像（MRI）中表面线圈技术的改进使得皮肤的可视化效果更好，从而使该技术在皮肤科得以临床应用。MRI能够评估皮肤肿瘤的深度和范围，并检测任何恶性转变。良性和恶性皮肤病变之间的磁共振鉴别依赖于形态学标准，然而这些标准并没有绝对的诊断价值。我们研究了顺磁性造影剂在良性和恶性皮肤病变鉴别中的作用。
41例患者接受了MRI检查，其中33例患有良性皮肤肿瘤，8例患有恶性皮肤肿瘤。所有检查均使用1.5T超导设备及2.5cm表面线圈进行。轴向T1加权和T2加权SE图像以2mm层厚采集。所有患者均给予顺磁性造影剂。在给予顺磁性造影剂前后，通过设置感兴趣区来计算皮肤病变的信号强度。计算对比增强的百分比比值以量化造影剂摄取情况，并比较良性和恶性病变的相对值。还进行了定性分析，将每个病变的对比增强程度评定为高、中或无。
定量分析显示良性和恶性病变的对比增强值之间存在统计学显著差异（p < 0.5）。具体而言，恶性病变的值在117.3（±28.7）至125（±32.4）之间，而良性病变的值在-20.6至99.8（±21.1）之间。相反，定性分析未发现对比增强有差异。
MRI是一种用于表征皮肤肿瘤的有前景的工具。我们的初步结果应在更大系列的患者中使用高时间分辨率成像序列进行验证。
