Nakamoto Yuji, Cohade Christian, Tatsumi Mitsuaki, Hammoud Dima, Wahl Richard L
Division of Nuclear Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21287-0817, USA.
Radiology. 2005 Nov;237(2):627-34. doi: 10.1148/radiol.2372031994.
To retrospectively evaluate lesion findings at computed tomography (CT) performed as part of a combined positron emission tomography (PET)/CT examination in patients suspected of having metastatic bone lesions-lesions that were detected with fluorine 18 fluorodeoxyglucose (FDG) PET as part of the same examination-and to correlate the CT and FDG PET findings.
This HIPAA-compliant study had institutional review board approval, and the need for patient informed consent was waived. Three hundred fifty-nine consecutive patients (191 male patients, 168 female patients; mean age, 56.9 years; age range, 8-92 years) underwent PET/CT. PET images were first reviewed by nuclear medicine physicians who had no clinical information regarding the presence or absence of bone metastasis by using a five-point grading system (0, a lesion was definitely negative for metastasis; 1, a lesion was probably negative; 2, a lesion was equivocal; 3, a lesion was probably positive; and 4, a lesion was definitely positive). For lesions assigned a grade of 3 or 4 at PET, CT characteristics such as the presence or absence of morphologic changes or accompanying findings (including bone destruction) were assessed by radiologists on the CT images obtained during the same imaging session.
One hundred seventy-nine lesions in 55 patients were considered to be probable or definite bone metastases at PET. One hundred thirty-three of these lesions in 33 patients were clinically confirmed to be bone metastases at follow-up and/or histopathologic examination. CT revealed osteolytic changes in 41 (31%) and osteoblastic changes in 21 (16%) of the 133 lesions, but no or nonspecific changes were seen at CT in 49 (37%) and 22 lesions (17%), respectively. Of the 179 lesions suspected at PET, 46 ultimately proved to be nonosseous or false-positive for bone metastasis. Of these 46 lesions, 38 were not located in the bone but in adjacent tissues such as the pleura.
CT images obtained as part of PET/CT scanning were useful in yielding the precise location of bone lesions and thus helping avoid misdiagnosis of bone metastasis; however, CT revealed morphologic changes in only half of the lesions assigned a grade of 3 or 4 at PET.
回顾性评估计算机断层扫描（CT）在疑似有骨转移瘤患者的正电子发射断层显像（PET）/CT联合检查中发现的病变情况，这些病变是在同一次检查中通过氟18氟脱氧葡萄糖（FDG）PET检测到的，并将CT和FDG PET的检查结果进行关联。
本研究符合健康保险流通与责任法案（HIPAA），并获得了机构审查委员会的批准，无需患者签署知情同意书。连续359例患者（191例男性，168例女性；平均年龄56.9岁；年龄范围8 - 92岁）接受了PET/CT检查。PET图像首先由不了解有无骨转移临床信息的核医学医师使用五分制分级系统进行评估（0分，病变肯定无转移；1分，病变可能无转移；2分，病变不明确；3分，病变可能有转移；4分，病变肯定有转移）。对于PET分级为3或4级的病变，放射科医师在同一次成像检查中获取的CT图像上评估其CT特征，如有无形态学改变或伴随表现（包括骨质破坏）。
55例患者的179个病变在PET检查中被认为可能或肯定为骨转移瘤。其中33例患者的133个病变在随访和/或组织病理学检查中被临床确认为骨转移瘤。CT显示133个病变中有41个（31%）为溶骨性改变，21个（16%）为成骨性改变，但分别有49个（37%）和22个病变（17%）在CT上未见改变或仅有非特异性改变。在PET检查中怀疑的179个病变中，最终有46个被证明不是骨病变或为骨转移假阳性。在这46个病变中，38个不在骨内，而是位于相邻组织如胸膜。
作为PET/CT扫描一部分获得的CT图像有助于明确骨病变的精确位置，从而有助于避免骨转移的误诊；然而，CT仅显示了PET分级为3或4级病变中的一半的形态学改变。
