Transient cortical blindness after thoracic endovascular aneurysm repair

We report a patient who presented with transient cortical blindness 12 hours after completion of a thoracic endovascular aneurysm repair. Computed tomography of the brain demonstrated no acute findings. The patient's symptoms resolved spontaneously after 72 hours. To our knowledge, this is the first report of transient cortical blindness after endovascular aortic aneurysm repair. This is an uncommon diagnosis that is important to recognize in a modern vascular surgery practice.     

The role of single-photon emission computed tomography and SPECT/computed tomography in oncologic imaging

Single-photon emission computed tomography (SPECT) and hybrid SPECT/computed tomography (SPECT/CT) cameras have emerged as a dominant technology providing invaluable tools in the diagnosis, staging, therapy planning, and treatment monitoring of multiple cancers over the past decade. In the same way that positron emission tomography (PET) benefited from the addition of CT, functional SPECT and anatomic CT data obtained as a single study have shown improvements in diagnostic imaging sensitivity and specificity by improving lesion conspicuity, reducing false positives, and clarifying indeterminate lesions. Furthermore, the anatomic imaging better localizes the functional data, which can be critical in surgical and therapy planning. As more disease-specific imaging agents become available, the role of SPECT/CT in the new paradigms of molecular imaging for personalized medicine will expand. Established and emerging uses of SPECT/CT in a wide variety of oncologic diseases, as well as radiation exposure issues, are reviewed.     

静息/负荷82Rb PET门控心肌灌注显像定量分析的价值

目的 探讨门控和定量分析技术在82Rb PET心肌灌注显像中的应用价值.方法 对32例临床可疑冠心病患者进行静息/腺苷负荷82Rb PET门控心肌灌注显像.原始数据按常规处理成断层图像,再应用定量分析软件Emory Cardiac Toolbox(ECTb)进行定量分析.由3位有经验的核医学科医师分别对图像质量(优、良、一般、差、无法分析)、左心室射血分数(LVEF)的可信程度(同意、基本同意、不确定、基本不同意、不同意)、左心室功能的其他指标对诊断的价值(很有帮助、有帮助、不确定、基本无帮助、无帮助)进行评价.将观察指标分为肯定组和否定组,分别计算其百分率和90%可信区间.结果 192组分析结果中,图像质量优良者共计160组,占83.3%(160/192),其95%可信区间为78.1%～88.6%;图像质量为一般和差的共计32组,占16.7%(32/192),其95%可信区间为11.4%～21.9%.对LVEF的结果表示同意和基本同意者共计164组,占85.4%(164/192),其95%可信区间为80.4%～90.4%;认为不确定和基本不同意或不同意者共计28组,占14.6%(28/192),其95%可信区间为9.6%～19.6%.应用定量分析软件获得的除LVEF以外左心室功能的其他指标,认为很有帮助和有帮助者共计102组,占53.1%(102/192),其95%可信区间为46.1%～60.2%;不确定和基本无帮助或无帮助者90组,占46.9%(90/192),其95%可信区间为39.8%～53.9%.结论 门控和定量分析技术有助于PET图像阅片者作出更正确的诊断.     

Correct interpretation of a myocardial perfusion SPECT study in a patient with Ebstein’s anomaly through recognition of septal artifact

Conclusion  Quantitative assessment by use of polar maps and normal files increases the confidence of interpretation in most cases.^4,5 However, when altered anatomy not accounted for in the normal database is present, the results can be misleading. This case illustrates the necessity for complete review of the patient’s history, rotating planar images, oblique slices, and polar maps to properly interpret a study.     

Isoflurane Alters the Amount of Dopamine Transporter Expressed on the Plasma Membrane in Humans

Background: Isoflurane increases extracellular dopamine concentration and causes trafficking of the dopamine transporter (DAT) in transfected cells. Also, the binding potentials of highly specific positron-emitting DAT ligands are altered by isoflurane in rhesus monkeys. The purpose of this study was to determine the dose-response curve for isoflurane altering the binding potential of one of these ligands ([F-18]FECNT) in humans.

Methods: Twenty human volunteers underwent positron emission tomography using [F-18]FECNT. All subjects were scanned while awake and then again after assignment to one of four groups (n = 5 each): awake-control, propofol-control, or light or deep isoflurane anesthesia as defined by Bispectral Index monitoring. Bispectral Index values in the light anesthesia group were 40 +/- 7 (end-tidal isoflurane, 1.02 +/- 0.08) versus 27 +/- 10 (end-tidal isoflurane, 1.6 +/- 0.3) in the deep anesthesia group. The within-subject percent change in putamen binding potential between the awake and second scans was determined for each subject, averaged within groups, and compared across groups.

Results: The [F-18]FECNT binding potential exhibited a biphasic shape as a function of anesthetic dose. The binding potential for the second scan in the awake-control and propofol-control groups was significantly less than the initial scan; for the light anesthesia group, the binding potential was significantly increased during anesthesia, and no change was detected between the two scans in the deeper anesthesia group.