Sze G, Milano E, Johnson C, Heier L
Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021.
AJNR Am J Neuroradiol. 1990 Jul-Aug;11(4):785-91.
Contrast-enhanced MR studies were compared with noncontrast MR and contrast-enhanced CT scans in the evaluation of intraparenchymal brain metastases. Fifty consecutive inpatients were studied with short and long repetition time (TR) sequences before and after the administration of gadopentetate dimeglumine. In addition, a delayed short TR sequence was performed. The contrast CT, noncontrast MR, immediate postcontrast short TR sequence, postcontrast long TR sequence, and delayed postcontrast short TR sequence were each read blindly and independently by two neuroradiologists. These results were then compared with a final interpretation, reached by all the neuroradiologists in the study, using all the clinical information and imaging findings. Postcontrast short TR scans proved to be superior to other sequences. They were particularly useful in the detection of metastases in the posterior fossa and cortex. The delayed postcontrast short TR scan held no definite advantage over the immediate postcontrast short TR scan, although metastases were sometimes seen slightly better after the delay. While long TR sequences were not always sensitive or specific, they often did provide ancillary information and were particularly useful in cases of hemorrhagic metastases. Because of these findings, we recommend that the evaluation of intraparenchymal metastases consist of a single postcontrast long TR scan followed by a single postcontrast short TR scan. While these sequences should be very accurate in the detection of metastases, we also generally perform a single precontrast short TR scan as well, since the question of hemorrhage or bone lesion may be clinically relevant.
在评估脑实质内脑转移瘤时，对增强磁共振成像（MR）研究与非增强MR及增强CT扫描进行了比较。连续50例住院患者在静脉注射钆喷酸葡胺前后分别采用短重复时间（TR）和长TR序列进行检查。此外，还进行了延迟短TR序列检查。增强CT、非增强MR、增强后即刻短TR序列、增强后长TR序列以及增强后延迟短TR序列均由两位神经放射科医生独立进行盲法阅片。然后将这些结果与该研究中所有神经放射科医生综合所有临床信息和影像学表现得出的最终诊断结果进行比较。结果显示，增强后短TR扫描优于其他序列。它们在检测后颅窝和皮质的转移瘤方面特别有用。增强后延迟短TR扫描与增强后即刻短TR扫描相比并无明显优势，不过延迟后有时能更清晰地显示转移瘤。虽然长TR序列并非总是敏感或特异，但它们常常能提供辅助信息，在出血性转移瘤病例中尤其有用。基于这些发现，我们建议脑实质内转移瘤的评估应包括一次增强后长TR扫描，随后进行一次增强后短TR扫描。虽然这些序列在检测转移瘤方面应该非常准确，但我们通常也会进行一次平扫短TR扫描，因为出血或骨病变问题在临床上可能具有相关性。
