Diagnosis of regional cerebral blood flow abnormalities using spect: agreement between individualized statistical parametric maps and visual inspection by nuclear medicine physicians with different levels of expertise in nuclear neurology.

INTRODUCTION: Visual analysis is widely used to interpret regional cerebral blood flow (rCBF) SPECT images in clinical practice despite its limitations. Automated methods are employed to investigate between-group rCBF differences in research studies but have rarely been explored in individual analyses. OBJECTIVES: To compare visual inspection by nuclear physicians with the automated statistical parametric mapping program using a SPECT dataset of patients with neurological disorders and normal control images. METHODS: Using statistical parametric mapping, 14 SPECT images from patients with various neurological disorders were compared individually with a databank of 32 normal images using a statistical threshold of p<0.05 (corrected for multiple comparisons at the level of individual voxels or clusters). Statistical parametric mapping results were compared with visual analyses by a nuclear physician highly experienced in neurology (A) as well as a nuclear physician with a general background of experience (B) who independently classified images as normal or altered, and determined the location of changes and the severity. RESULTS: Of the 32 images of the normal databank, 4 generated maps showing rCBF abnormalities (p<0.05, corrected). Among the 14 images from patients with neurological disorders, 13 showed rCBF alterations. Statistical parametric mapping and physician A completely agreed on 84.37% and 64.28% of cases from the normal databank and neurological disorders, respectively. The agreement between statistical parametric mapping and ratings of physician B were lower (71.18% and 35.71%, respectively). CONCLUSION: Statistical parametric mapping replicated the findings described by the more experienced nuclear physician. This finding suggests that automated methods for individually analyzing rCBF SPECT images may be a valuable resource to complement visual inspection in clinical practice.

Hyperventilation revisited: physiological effects and efficacy on focal seizure activation in the era of video-EEG monitoring.

PURPOSE: Hyperventilation is an activation method that provokes physiological slowing of brain rhythms, interictal discharges, and seizures, especially in generalized idiopathic epilepsies. In this study we assessed its effectiveness in inducing focal seizures during video-EEG monitoring. METHODS: We analyzed the effects of hyperventilation (HV) during video-EEG monitoring (video-EEG) of patients with medically intractable focal epilepsies. We excluded children younger than 10 years, mentally retarded patients, and individuals with frequent seizures. RESULTS: We analyzed 97 patients; 24 had positive seizure activation (PSA), and 73 had negative seizure activation (NSA). No differences were found between groups regarding sex, age, age at epilepsy onset, duration of epilepsy, frequency of seizures, and etiology. Temporal lobe epilepsies were significantly more activated than frontal lobe epilepsies. Spontaneous and activated seizures did not differ in terms of their clinical characteristics, and the activation did not affect the performance of ictal single-photon emission computed tomography (SPECT). CONCLUSIONS: HV is a safe and effective method of seizure activation during monitoring. It does not modify any of the characteristics of the seizures and allows the obtaining of valuable ictal SPECTs. This observation is clinically relevant and suggests the effectiveness and the potential of HV in shortening the presurgical evaluation, especially of temporal lobe epilepsy patients, consequently reducing its costs and increasing the number of candidates for epilepsy surgery.

Diagnosis of regional cerebral blood flow abnormalities using SPECT: agreement between individualized statistical parametric maps and visual inspection by nuclear medicine physicians with different levels of expertise in nuclear neurology

INTRODUCTION: Visual analysis is widely used to interpret regional cerebral blood flow (rCBF) SPECT images in clinical practice despite its limitations. Automated methods are employed to investigate between-group rCBF differences in research studies but have rarely been explored in individual analyses. OBJECTIVES: To compare visual inspection by nuclear physicians with the automated statistical parametric mapping program using a SPECT dataset of patients with neurological disorders and normal control images. METHODS: Using statistical parametric mapping, 14 SPECT images from patients with various neurological disorders were compared individually with a databank of 32 normal images using a statistical threshold of p<0.05 (corrected for multiple comparisons at the level of individual voxels or clusters). Statistical parametric mapping results were compared with visual analyses by a nuclear physician highly experienced in neurology (A) as well as a nuclear physician with a general background of experience (B) who independently classified images as normal or altered, and determined the location of changes and the severity. RESULTS: Of the 32 images of the normal databank, 4 generated maps showing rCBF abnormalities (p<0.05, corrected). Among the 14 images from patients with neurological disorders, 13 showed rCBF alterations. Statistical parametric mapping and physician A completely agreed on 84.37 percent and 64.28 percent of cases from the normal databank and neurological disorders, respectively. The agreement between statistical parametric mapping and ratings of physician B were lower (71.18 percent and 35.71 percent, respectively). CONCLUSION: Statistical parametric mapping replicated the findings described by the more experienced nuclear physician. This finding suggests that automated methods for individually analyzing rCBF SPECT images may be a valuable resource to complement visual inspection in clinical practice.

Diagnóstico de lesão obstrutiva da artéria coronária descendente anterior em pacientes com bloqueio de ramo esquerdo através da medicina nuclear / Diagnosis of left anterior descending artery stenosis in patients with left bundle branch block through nuclear medicine

PURPOSE: To evaluate septal perfusion and contractility in patients with left bundle branch block (LBBB). METHODS: Twenty patients were submitted to myocardial scintigraphy with Tecnecium-99m isontrile after exercise and dipyridamole infusion. The septal contractility was observed during the radionuclide ventriculography. All patients were submitted to coronariography. RESULTS: Twenty patients were studied and 17 (85) had a normal left anterior descending (LAD) artery. Nine (53) patients had abnormalities in septal perfusion after the exercise and 2 (12) after dipyridamole infusion. All patients had abnormalities in septal contractility during the radionuclide ventriculography. CONCLUSION: The myocardial scintigraphy after dipyridamole infusion showed better specificity in the diagnosis of a LAD lesion. The radionuclide ventriculography was an efficient method to evaluate the septal contraction abnormalities in patients with LBBB

Objetivo - Avaliar a perfusão e a contratilidade do septo-interventricular nos pacientes com bloqueio de ramo esquerdo (BRE). Métodos - Foram estudados, prospectivamente, 20 pacientes que realizaram o estudo da perfusão do miocárdio através da cintilografia com isonitrila ligada ao Tecnécio-99m, após o esforço e à infusão de dipiridamol. A contratilidade do septo-interventricular foi analisada pelo estudo da função ventricular com radionuclideos. Todos os pacientes realizaram cinecoronariografia. Resultados - Dos 20 pacientes, 17 (85%) apresentavam a artéria coronária descendente anterior (DA) normal. Destes, 9 (53%) mostravam alterações na perfusão septal após o esforço e 2 (12%) após a infusão de dipiridamol. Todos apresentaram assincronismo da contração septal à ventriculografia com radionuclídeos (VR). Conclusão - A cintilografia do miocárdio após a infusão de dipiridamol apresentou maior especificidade no diagnóstico de lesão obstrutiva na DA. A VR mostrouse método eficaz para comprovar o assincronismo de contração septal nos pacientes com BRE