Does Performing Image Registration and Subtraction in Ictal Brain SPECT Help Localize Neocortical Seizures?

Journal of Nuclear Medicine

Jitka Sojkova¹  Colin Studholme¹  Petra J. Lewis¹  Terrance M. Darcey¹  Adrian M. Siegel¹  Alan Siegel¹  Karen L. Gilbert¹  David W. Roberts¹  Vijay M. Thadani¹  Peter D. Williamson¹ 

[1] Departments of Radiology, Neurology, and Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; and Department of Radiology, Yale Medical School, New Haven, Connecticut Departments of Radiology, Neurology, and Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; and Department of Radiology, Yale Medical School, New Haven, Connecticut Departments of Radiology, Neurology, and Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; and Department of Radiology, Yale Medical School, New Haven, Connecticut

关键词: SPECT;    epilepsy;    image registration;    ^99mTc–ethyl cysteinate dimer;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

Ictal brain SPECT (IS) findings in neocortical epilepsy (patients without mesiotemporal sclerosis) can be subtle. This study is aimed at assessing how the seizure focus identification was improved by the inclusion of individual IS and interictal brain SPECT (ITS)–MRI image registration as well as performing IS − ITS image subtraction. Methods: The study involved the posthoc analysis of 64 IS scans using 99mTc–ethyl cysteinate dimer that were obtained in 38 patients without mesiotemporal sclerosis but with or without other abnormalities on MRI. Radiotracer injection occurred during video-electroencephalographic (EEG) monitoring. Patients were injected 2–80 s (median time, 13 s) after clinical or EEG seizure onset. All patients had sufficient follow-up to correlate findings with the SPECT results. All patients had ITS and MRI, including a coronal volume sequence used for registration. Image registration (IS and ITS to MRI) was performed using automated software. After normalization, IS − ITS subtraction was performed. The IS, ITS, and subtraction studies were read by 2 experienced observers who were unaware of the clinical data and who assessed the presence and localization of an identifiable seizure focus before and after image registration and subtraction. Correlation was made with video-EEG (surface and invasive) and clinical and surgical follow-up. Results: Probable or definite foci were identified in 38 (59%) studies in 33 (87%) patients. In 52% of the studies, the image registration aided localization, and in 58% the subtraction images contributed additional information. In 9%, the subtraction images confused the interpretation. In follow-up after surgery, intracranial EEG or video-EEG monitoring (or both) has confirmed close or reasonable localization in 28 (74%) patients. In 6 (16%) patients, SPECT indicated false seizure localization. Conclusion: Image registration and image subtraction improve the localization of neocortical seizure foci using IS, but close correlation with the original images is required. False localizations occur in a minority of patients.

【 授权许可】

Unknown