Erly W K, Oh E S, Outwater E K
Department of Radiology, The University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ 85724-5067, USA.
AJNR Am J Neuroradiol. 2006 Jun-Jul;27(6):1183-8.
Benign and malignant fractures of the spine may have similar signal intensity characteristics on conventional MR imaging sequences. This study assesses whether in-phase/opposed-phase imaging of the spine can differentiate these 2 entities.
Twenty-five consecutive patients who were evaluated for suspected malignancy (lymphoma [4 patients], breast cancer [3], multiple myeloma [2], melanoma [2], prostate [2], and renal cell carcinoma [1]) or for trauma to the thoracic or lumbar spine were entered into this study. An 18-month clinical follow-up was performed. Patients underwent standard MR imaging with an additional sagittal in-phase (repetition time [TR], 90-185; echo time [TE], 2.4 or 6.5; flip angle, 90 degrees ) and opposed-phase gradient recalled-echo sequence (TR, 90-185, TE, 4.6-4.7, flip angle, 90 degrees ). Areas that were of abnormal signal intensity on the T1 and T2 sequences were identified on the in-phase/opposed-phase sequences. An elliptical region of interest measurement of the signal intensity was made on the abnormal region on the in-phase as well as on the opposed-phase images. A computation of the signal intensity ratio (SIR) in the abnormal marrow on the opposed-phase to signal intensity measured on the in-phase images was made.
Twenty-one patients had 49 vertebral lesions, consisting of 20 malignant and 29 benign fractures. There was a significant difference (P < .001, Student t test) in the mean SIR for the benign lesions (mean, 0.58; SD, 0.02) compared with the malignant lesions (mean, 0.98; SD, 0.095). If a SIR of 0.80 as a cutoff is chosen, with >0.8 defined as malignant and <0.8 defined as a benign result, in-phase/opposed-phase imaging correctly identified 19 of 20 malignant lesions and 26 of 29 benign lesions (sensitivity, 0.95; specificity, 0.89).
There is significant difference in signal intensity between benign compression fractures and malignancy on in-phase/opposed-phase MR imaging.
脊柱的良性和恶性骨折在传统磁共振成像序列上可能具有相似的信号强度特征。本研究评估脊柱的同相位/反相位成像能否区分这两种情况。
连续纳入25例因怀疑恶性肿瘤（淋巴瘤[4例]、乳腺癌[3例]、多发性骨髓瘤[2例]、黑色素瘤[2例]、前列腺癌[2例]和肾细胞癌[1例]）或胸腰椎创伤而接受评估的患者。进行了为期18个月的临床随访。患者接受标准磁共振成像检查，并额外进行矢状位同相位（重复时间[TR]，90 - 185；回波时间[TE]，2.4或6.5；翻转角，90度）和反相位梯度回波序列（TR，90 - 185，TE，4.6 - 4.7，翻转角，90度）检查。在同相位/反相位序列上识别出在T1和T2序列上信号强度异常的区域。在同相位和反相位图像上的异常区域进行信号强度的椭圆形感兴趣区测量，并计算反相位上异常骨髓的信号强度与同相位图像上测量的信号强度之比（SIR）。
21例患者有49个椎体病变，包括20个恶性病变和29个良性骨折。与恶性病变（平均值，0.98；标准差，0.095）相比，良性病变的平均SIR有显著差异（P <.001，学生t检验）（平均值，0.58；标准差，0.02）。如果选择SIR为0.80作为临界值，>0.8定义为恶性，<0.8定义为良性结果，同相位/反相位成像正确识别出20个恶性病变中的19个和29个良性病变中的26个（敏感性，0.95；特异性，0.89）。
在同相位/反相位磁共振成像上，良性压缩性骨折与恶性病变之间的信号强度存在显著差异。
