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F Q Gao

Publications and source records attributed to F Q Gao.

8 recordsLinked to original sources
PubMed2004

Semiautomatic brain region extraction: a method of parcellating brain regions from structural magnetic resonance images.

Structural MR imaging has become essential to the evaluation of regional brain changes in both healthy aging and disease-related processes. Several methods have been developed to measure structure size and regional brain volumes, but many of these methods involve substantial manual tracing and/or landmark identification. We present a new technique, semiautomatic brain region extraction (SABRE), for the rapid and reliable parcellation of cortical and subcortical brain regions. We combine the SABRE parcellation with tissue compartment segmentation [NeuroImage 17 (2002) 1087] to produce measures of gray matter (GM), white matter (WM), ventricular CSF, and sulcal CSF for 26 brain regions. Because SABRE restricts user input to a few easily identified landmarks, inter-rater reliability is high for all volumes, with all coefficients between 0.91 and 0.99. To assess construct validity, we contrasted SABRE-derived volumetric data from healthy young and older adults. Results from the SABRE parcellation and tissue segmentation showed significant differences in multiple brain regions in keeping with regional atrophy described in the literature by researchers using lengthy manual tracing methods. Our findings show that SABRE is a reliable semiautomatic method for assessing regional tissue volumes that provides significant timesavings over purely manual methods, yet maintains information about individual cortical landmarks.

Adult↗
PubMed2004

Linear width of the medial temporal lobe can discriminate Alzheimer's disease from normal aging: the Sunnybrook dementia study.

To discriminate Alzheimer's disease (AD) from healthy controls, the thinnest medial temporal lobe (tMTL) width on 3D-MRI was measured according to a newly developed method at the inter-collicular sulcus (ICS) level with scans aligned to the long axis of the hippocampus in 22 mild, 27 moderate probable AD patients and 41 healthy controls. For comparison, MTL width replicating the technique of Jobst et al. (jMTL) as well as hippocampal and parahippocampal volumes, were also measured. Using logistic regression taking into account age, sex, and education, tMTL width classified mild AD from controls with a sensitivity of 86%, specificity of 95% and accuracy of 92%. Similar values were obtained for moderate or total AD group versus controls. By comparison, jMTL width was only useful in distinguishing moderate AD from controls, and volumetric measures were equally sensitive in classifying mild and moderate AD in our sample. This quick, reliable, and standardized measurement of tMTL can be helpful in differentiating even mild AD from controls with reasonable accuracy.

Aged↗
PubMed1998

MR in temporal lobe epilepsy: analysis with pathologic confirmation.

PURPOSE: We evaluated the MR findings in patients with temporal lobe epilepsy to determine the predictive value of MR imaging in assessing patient outcome. METHODS: MR studies from 186 of 274 consecutive patients who underwent temporal lobectomy for intractable epilepsy were reviewed retrospectively. Images were interpreted by an experienced neuroradiologist, who was blinded to the side of seizure activity and to pathologic findings. RESULTS: MR imaging exhibited 93% sensitivity and 83% specificity in detecting hippocampal/amygdalar abnormalities (n = 121), and 97% sensitivity and 97% specificity in detecting abnormalities in the rest of the temporal lobe (n = 60). Abnormal high signal of the hippocampus on T2-weighted images had a sensitivity of 93% and specificity of 74% in predicting mesial temporal sclerosis (n = 115). The presence of hippocampal atrophy on MR correlated with the duration of seizures. Sensitivity and specificity of MR imaging in detecting temporal lobe tumors (n = 42) were 83% and 97%, respectively, based on abnormal signal and mass effect. After surgery, 63% of patients were seizure free and 28% had a significant reduction of seizure frequency at an average of 24 months (range, 12 to 78 months) after surgery. Patients with a single lesion in the anterior temporal lobe or hippocampus/amygdala had a better outcome than patients with multiple lesions (n = 22). Interrater agreement varied from 0.4 to 0.93, with best agreement for tumors or abnormal hippocampal signal on T2-weighted images. CONCLUSION: MR imaging is highly sensitive in detecting and locating abnormalities in the temporal lobe and the hippocampus/amygdala in patients with temporal lobe epilepsy. Hippocampal atrophy appears to correspond to the duration of seizure disorder.

Adult↗
PubMed1996

Duplex and color Doppler flow sonography of occlusion and near occlusion of the carotid artery.

PURPOSE: To determine whether color Doppler flow imaging with the use of slow-flow sensitivity improves sensitivity and specificity in the differentiation of occlusion and near occlusion of the internal carotid artery. METHODS: Color Doppler and duplex sonography were performed in symptomatic patients who had angiographically confirmed occlusion and/or near occlusion of the internal carotid artery. The study consisted of two phases: in the first, we assessed the usefulness of color Doppler flow imaging by retrospectively reviewing the records of 35 patients with 36 angiographically confirmed occlusions or near occlusions of the internal carotid artery who were examined with color Doppler flow imaging at our institution during a period of 4 years; in the second phase, we incorporated color Doppler sonography into the routine scanning protocols of 39 patients with 41 occluded or nearly occluded internal carotid arteries seen over a period of 2 1/2 years. RESULTS: Overall, color Doppler imaging correctly showed all 34 of the near occlusions (sensitivity, 100%) and 36 of the 43 occlusions (specificity, 84%). Seven patients with angiographically confirmed occlusion had sonographic findings that suggested near occlusion. In the first phase, eight near occlusions were misinterpreted as occlusions with conventional duplex sonography, but were correctly shown with color Doppler flow imaging. In the second phase, sensitivity increased from 50% to 100% (18 or 18) because of better detection of the nearly occluded lumen. This was at the expense of a decrease in specificity (from 100% to 78%). owing to identification of apparent flow in the internal carotid artery on color Doppler flow images in five of 23 occlusions. CONCLUSION: Because of its ability to depict slow flow, color Doppler imaging with slow-flow sensitivity is superior to conventional duplex sonography for the noninvasive discrimination of occlusion from near occlusion of the internal carotid artery.

Arterial Occlusive Diseases↗
PubMed1992

[A study of muscle fibers typing on Duchenne muscular dystrophy].

Quantitative analysis of muscle fibers typing in 15 cases of Duchenne muscular dystrophy has been done. Mean diameter, area, variability coefficient were estimated by computer. The results show that type IIC fibers were remarkably increased and type IIB fibers was deficiency in DMD. Atrophy and hypertrophy occurred in different typing fibers. The results indicated that DMD has a prominent atrophy and hypertrophy and active regenerating process.

Child↗
PubMedDate not supplied

A reliable MR measurement of medial temporal lobe width from the Sunnybrook Dementia Study.

We studied the hippocampal angle and spatial relationships of medial temporal lobe (MTL) structures, using midbrain colliculi and inter-collicular sulcus (ICS) as landmarks, and measured MTL width on axial 3D-T1-weighted MRI at ICS level in 41 normal, aged participants. Mean hippocampal angle was 29 degrees (range 17-42 degrees ) caudal to the anterior-posterior commissure (AC-PC) line. The slice at the ICS, parallel to the long axis of the hippocampus, best revealed a longitudinal view of hippocampus and parahippocampal gyrus in 76% of participants, compared to only 7% when slices were 20 degrees caudal to orbitomeatal line (OML), an accepted technique used to examine MTL width in previous CT studies. The MTL width measured midway and at its thinnest between the anterior-posterior borders of the midbrain was highly reproducible (intraclass correlation coefficients >0.98) using these new methods. These simple decision rules, individualized orientation along the hippocampus and using a standardized landmark like the ICS, make these measures more comparable across subjects, and hence more useful in detecting and monitoring MTL atrophy in dementia.

Aged↗