Sarangi S, San Pedro E C, Mountz J M
Department of Radiology, University of Alabama at Birmingham Medical Center, USA.
Clin Nucl Med. 2000 Mar;25(3):187-90. doi: 10.1097/00003072-200003000-00006.
The authors describe a patient in whom neuroimaging using Tc-99m HMPAO SPECT, F-18 fluorodeoxyglucose (F-18 FDG) coincidence imaging, and magnetic resonance imaging (MRI) identified an anterior choroidal artery infarction. Neuroimaging played a critical role in confirming this diagnosis, because the patient had symptoms of progressive cognitive decline and satisfied the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for Alzheimer's disease (AD).
Tc-99m HMPAO brain SPECT was performed using a triple-head gamma camera. F-18 FDG scanning was obtained 40 minutes after intravenous injection of 5 mCi F-18 FDG using a coincidence camera. A brain MRI scan was performed using a 1.5-Tesla scanner.
Tc-99m HMPAO SPECT showed focal hypoperfusion to the right parahippocampal cortex. F-18 FDG coincidence imaging showed a more extensive reduction in glucose metabolism compared with SPECT. The MRI scan confirmed the presence of a small segmental choroidal artery infarction. The Tc-99m HMPAO and F-18 FDG scans were not consistent with AD.
This case illustrates the value of the regional cerebral blood flow SPECT for evaluating memory impairment in the elderly. Decreased regional cerebral blood flow to the posterior temporoparietal region is consistent with AD, whereas regional cerebral blood flow diminution in a vascular territory is consistent with vascular dementia. In this case, the patient was clinically diagnosed with AD, and SPECT was performed to establish the baseline regional cerebral blood flow before the cholinesterase inhibitor donepezil was administered. An infarction was diagnosed on the regional cerebral blood flow brain SPECT scan, which was later confirmed by MRI. Infarctions of the parahippocampal cortex may resuft in memory impairment, which can appear clinically similar to AD.
作者描述了一名患者，通过使用锝-99m六甲基丙烯胺肟单光子发射计算机断层扫描（Tc-99m HMPAO SPECT）、氟-18氟脱氧葡萄糖（F-18 FDG）符合线路成像及磁共振成像（MRI）确定其为脉络膜前动脉梗死。神经影像学在确诊中发挥了关键作用，因为该患者有进行性认知功能减退症状，且符合美国国立神经疾病与中风研究所-阿尔茨海默病及相关疾病协会（National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association）的阿尔茨海默病（AD）诊断标准。
使用三头γ相机进行Tc-99m HMPAO脑SPECT检查。静脉注射5毫居里F-18 FDG 40分钟后，使用符合线路相机进行F-18 FDG扫描。使用1.5特斯拉扫描仪进行脑部MRI扫描。
Tc-99m HMPAO SPECT显示右侧海马旁皮质局部灌注减低。与SPECT相比，F-18 FDG符合线路成像显示葡萄糖代谢有更广泛的减低。MRI扫描证实存在一小段脉络膜动脉梗死。Tc-99m HMPAO和F-18 FDG扫描结果与AD不符。
该病例说明了区域脑血流SPECT在评估老年人记忆障碍中的价值。颞顶叶后部区域的区域脑血流减少与AD相符，而血管区域的区域脑血流减少与血管性痴呆相符。在该病例中，患者临床诊断为AD，并在给予胆碱酯酶抑制剂多奈哌齐之前进行SPECT检查以建立区域脑血流基线。区域脑血流脑SPECT扫描诊断为梗死，随后经MRI证实。海马旁皮质梗死可能导致记忆障碍，其临床表现可能与AD相似。
