Automatic extraction of corpus callosum from midsagittal head MR image and examination of Alzheimer-type dementia objective diagnostic system in feature analysis

We studied the objective diagnosis of Alzheimer-type dementia based on changes in the corpus callosum. We examined midsagittal head MR images of 40 Alzheimer-type dementia patients (15 men and 25 women; mean age, 75.4+/-5.5 years) and 31 healthy elderly persons (10 men and 21 women; mean age, 73.4+/-7.5 years), 71 subjects altogether. First, the corpus callosum was automatically extracted from midsagittal head MR images. Next, Alzheimer-type dementia was compared with the healthy elderly individuals using the features of shape factor and six features of Co-occurrence Matrix from the corpus callosum. Automatic extraction of the corpus callosum succeeded in 64 of 71 individuals, for an extraction rate of 90.1%. A statistically significant difference was found in 7 of the 9 features between Alzheimer-type dementia patients and the healthy elderly adults. Discriminant analysis using the 7 features demonstrated a sensitivity rate of 82.4%, specificity of 89.3%, and overall accuracy of 85.5%. These results indicated the possibility of an objective diagnostic system for Alzheimer-type dementia using feature analysis based on change in the corpus callosum.     

Development of automatic extraction of the corpus callosum from magnetic resonance imaging of the head and examination of the early dementia objective diagnostic technique in feature analysis

We examined the objective diagnosis of dementia based on changes in the corpus callosum. We examined midsagittal head MR images of 17 early dementia patients (2 men and 15 women; mean age, 77.2+/-3.3 years) and 18 healthy elderly controls (2 men and 16 women; mean age, 73.8+/-6.5 years), 35 subjects altogether. First, the corpus callosum was automatically extracted from the MR images. Next, early dementia was compared with the healthy elderly individuals using 5 features of the straight-line methods, 5 features of the Run-Length Matrix, and 6 features of the Co-occurrence Matrix from the corpus callosum. Automatic extraction of the corpus callosum showed an accuracy rate of 84.1+/-3.7%. A statistically significant difference was found in 6 of the 16 features between early dementia patients and healthy elderly controls. Discriminant analysis using the 6 features demonstrated a sensitivity of 88.2% and specificity of 77.8%, with an overall accuracy of 82.9%. These results indicate that feature analysis based on changes in the corpus callosum can be used as an objective diagnostic technique for early dementia.     

Texture‐based classification of focal liver lesions on MRI at 3.0 Tesla: A feasibility study in cysts and hemangiomas

Purpose:

To determine the feasibility of texture analysis for the classification of liver cysts and hemangiomas, on nonenhanced, zero‐fill interpolated T1‐ and T2‐weighted MR images.

Materials and Methods:

Forty‐five patients (26 women and 19 men; mean age, 58.1 ± 16.9 years) with liver cysts or hemangiomas were enrolled in the study. After exclusion of images with artifacts, T1‐weighted images of 42 patients, and T2‐weighted images of 39 patients, obtained at 3.0 Tesla (T), were available for further analysis. Texture features derived from the gray‐level histogram, co‐occurrence and run‐length matrix, gradient, autoregressive model, and wavelet transform were calculated. Fisher, probability of classification error and average correlation (POE+ACC), and mutual information coefficients were used to extract subsets of optimized texture features. Linear discriminant analysis (LDA) in combination with k nearest neighbor (k‐NN) classification, and k‐means clustering, were used for lesion classification.

Results:

LDA/k‐NN produced misclassification rates of 16–18% on T1‐weighted, and 12–18% on T2‐weighted images. K‐means clustering yielded misclassification rates of 15–23% on T1‐weighted, and 15–25% on T2‐weighted images.

Conclusion:

Texture‐based classification of liver cysts and hemangiomas is feasible on zero‐fill interpolated MR images obtained at 3.0T. Further studies are warranted to investigate the value of texture‐based classification of other liver lesions, such as hepatocellular and cholangiocellular carcinoma, on MRI. J. Magn. Reson. Imaging 2010;32:352–359. © 2010 Wiley‐Liss, Inc.     

Quantification of intact quadriceps tendon, quadriceps tendon insertion, and suprapatellar fat pad: MR arthrography, anatomy, and cryosections in the sagittal plane.

OBJECTIVE: The purpose of this study was to quantify quadriceps tendon length, thickness, and insertion in relation to the suprapatellar fat pad. SUBJECTS AND METHODS: We used three methods to analyze the anatomy of intact quadriceps tendons and insertions into the patellar base: MR arthrography (53 knees with intact extensor mechanisms), gross anatomy (16 cadaveric knees), and cryosections (four cadaveric knees). With an electronic cursor, two observers independently quantified the extensor mechanism on midline sagittal T1-weighted spin-echo sequences acquired on a low-field-strength (0.23 T) scanner. RESULTS: On MR arthrograms, quadriceps tendon length, determined from the superior patellar pole to the most superior part of the suprapatellar recess, measured 49 +/- 7 mm in women and 50 +/- 9 mm in men. Thickness of quadriceps tendon at three sites (suprapatellar recess, center, and superior patellar pole) measured 7 +/- 1 mm in women and 8 +/- 1 mm in men. Thickness was significantly larger in men at all measurement locations. Quadriceps tendon insertion and the suprapatellar fat pad along the patellar base measured 16 +/- 2 and 6 +/- 2 mm, respectively, in women, and 18 +/- 3 and 7 +/- 2 mm, respectively, in men. CONCLUSION: On midline MR images, sagittal thickness of the quadriceps tendon and its insertion was significantly larger in men than in women. The prevalence of the suprapatellar fat pad was 100%.     

Assessment of coronary arteries with total study time of less than 30 minutes by using whole-heart coronary MR angiography

This study had institutional review board approval, and all patients gave informed consent. The purpose of this study was to prospectively evaluate the use of whole-heart three-dimensional (3D) coronary magnetic resonance (MR) angiography in patients suspected of having coronary artery disease. Whole-heart coronary MR angiography was performed in 39 patients (30 men and nine women; mean age, 63.9 years +/- 15.6 [standard deviation]) by using a steady-state free precession sequence with free breathing. Twenty patients (16 men and four women; mean age, 64.9 years +/- 11.7) also underwent conventional coronary angiography. MR angiography was successfully completed in 34 of 39 patients (87%); the average imaging time was 13.8 minutes +/- 3.8. Sensitivity and specificity of MR angiography for detecting significant stenosis were 82% (14 of 17 arteries) and 91% (39 of 43 arteries), respectively. Whole-heart coronary MR angiography with a navigator-gated steady-state sequence can enable reliable 3D visualization of the coronary arteries in patients suspected of having coronary artery disease.     

基于CT双期增强影像组学预测甲状腺乳头状癌淋巴结转移

目的:探讨基于CT双期增强影像组学模型对甲状腺乳头状癌(PTC)淋巴结转移的预测价值.方法:回顾性分析经手术病理证实的80例PTC患者的病例资料,共搜集173个淋巴结,其中转移性淋巴结89个、未转移性淋巴结84个.患者术前均行CT平扫和双期增强扫描.采用达尔文科研平台,分别在动脉期和静脉期CT图像上于淋巴结内勾画ROI...     

Myocardial viability: assessment with three-dimensional MR imaging in pigs and patients

PURPOSE: To prospectively evaluate the correlation between a three-dimensional (3D) delayed enhancement magnetic resonance (MR) imaging sequence and a two-dimensional (2D) delayed enhancement MR imaging sequence for noninvasive assessment of myocardial viability in pigs and patients. MATERIALS AND METHODS: The pig and patient studies were approved by the responsible authorities, and patients gave written informed consent. MR imaging was performed by using a rapid 3D inversion-recovery balanced steady-state free precession sequence and a 2D segmented inversion-recovery fast low-angle shot sequence as the reference standard. Fourteen pigs with reperfused (n=7) or nonreperfused (n=7) myocardial infarction and 17 patients (13 men, four women; mean age, 64.9 years+/-8.6 [standard deviation]) suspected of having myocardial infarction were included. Linear regression analysis and Bland-Altman analysis were used to compare the infarction volumes. RESULTS: In 10 of the 14 pigs the induction of myocardial infarction was successful. In these pigs, altogether 81 segments with myocardial infarction were demonstrated by both MR sequences, and agreement between the two sequences for classification of transmural extent of myocardial infarction was 99.7%. The infarction volume determined by using 3D MR imaging (4.64 cm3+/-2.48) in the pigs highly correlated with that of 2D MR imaging (4.65 cm3+/-2.39, r=0.989, P<.001) and that of staining by using triphenyltetrazolium chloride (4.67 cm3+/-2.44, r=0.996, P<.001). Thirteen of the 17 patients examined showed myocardial infarction in 34 myocardial segments with both sequences, and agreement between the two sequences for classification of transmural extent of myocardial infarction was 98.6%. In the patients, the infarction volume determined with both sequences highly correlated (9.71 cm3+/-7.47 for the 3D sequence vs 10.01 cm3+/-8.04 for the 2D sequence, r=0.982, P<.001). The breath-hold time necessary for the 3D MR imaging (21.0+/-2.3 seconds) was significantly shorter than that for 2D MR imaging (188.3+/-20.2 seconds, P<.001). CONCLUSION: Myocardial infarction volumes obtained with the 3D MR imaging sequence are highly correlated and in good agreement with volumes obtained with the 2D MR imaging standard approach and reduced the acquisition time by a factor of nine.     

Contributions of strength and body composition to the gender difference in anaerobic power

BACKGROUND: The purpose of this study was to determine the significant factors contributing to the difference between men and women in anaerobic power (AP) generation. METHODS. PARTICIPANTS: College men (n = 113) and women (n = 175) were randomly selected for evaluation from a fitness class prior to training. Measures: AP was determined from the Margaria-Kalamen stair run. Dynamic strength was evaluated from the 1-RM single-leg extension. Body composition was estimated from gender-specific skinfold prediction equations. RESULTS: Discriminant analysis identified %fat, fat-free mass (FFM), and leg extension strength as significant components differentiating between men and women and allowed proper gender classification in 99% of the cases. When both strength and body composition variables were held constant by covariance, there was no significant difference between men and women in AP (F = 1.25). A multiple regression equation using %fat, FFM, and leg extension strength predicted AP (R = 0.91) with an error of 150 W. When the multiple regression equations was applied to a cross-validation sample, AP could be accurately predicted (r = 0.91, t = 0.17) with an average error of 3% +/- 21%. CONCLUSIONS: Body size and dynamic strength are the major factors explaining the explosive leg power difference between men and women without a specific or unique gender quality.     

Diagnostic agreement of quantitative sonography of the calcaneus with dual X-ray absorptiometry of the spine and femur.

OBJECTIVE: The aim of our study was to evaluate the diagnostic agreement between quantitative sonography of the calcaneus and dual X-ray absorptiometry (DXA) of the spine and femur for revealing osteoporosis. SUBJECTS AND METHODS: In 1252 patients (795 women, 54.9+/-15 years old; 457 men, 50.5+/-15 years old [mean+/-SD]), bone mineral density measurements of the lumbar spine (posteroanterior, L1-L4) and the proximal femur (neck, trochanter, intertrochanteric region, total proximal femur, and Ward's triangle) and quantitative sonographic measurements of the stiffness of the calcaneus were performed. The presence of osteoporosis is defined, according to the World Health Organization criteria, as a T-score lower than -2.5. The percentage of patients below the threshold (prevalence of osteoporosis) was calculated for each imaging technique. The diagnostic agreement in identifying individuals as osteoporotic was assessed using kappa scores. RESULTS: Forty-nine percent of the women and 42% of the men were classified as osteoporotic by quantitative sonography, 32% of women and 30% of men by DXA of the spine, and 23-54% of women and 16-54% of men by the different regions of interest revealed on femoral DXA. Kappa analysis showed the diagnostic agreement among these measures to be generally poor (kappa = .28-.41 [women] and .25-.45 [men]). CONCLUSION: The considerable diagnostic disagreement between quantitative sonography and DXA could cause confusion in the daily practice of radiology and make establishing the correct diagnosis a difficult task. The choice of imaging technique influences which patients are diagnosed as osteoporotic.     

Pulmonary arterial hypertension: diagnosis with fast perfusion MR imaging and high-spatial-resolution MR angiography--preliminary experience

PURPOSE: To determine prospectively the accuracy of a magnetic resonance (MR) perfusion imaging and MR angiography protocol for differentiation of chronic thromboembolic pulmonary arterial hypertension (CTEPH) and primary pulmonary hypertension (PPH) by using parallel acquisition techniques. MATERIALS AND METHODS: The study was approved by the institution's internal review board, and all patients gave written consent prior to participation. A total of 29 patients (16 women; mean age, 54 years +/- 17 [+/- standard deviation]; 13 men; mean age, 57 years +/- 15) with known pulmonary hypertension were examined with a 1.5-T MR imager. MR perfusion imaging (temporal resolution, 1.1 seconds per phase) and MR angiography (matrix, 512; voxel size, 1.0 x 0.7 x 1.6 mm) were performed with parallel acquisition techniques. Dynamic perfusion images and reformatted three-dimensional MR angiograms were analyzed for occlusive and nonocclusive changes of the pulmonary arteries, including perfusion defects, caliber irregularities, and intravascular thrombi. MR perfusion imaging results were compared with those of radionuclide perfusion scintigraphy, and MR angiography results were compared with those of digital subtraction angiography (DSA) and/or contrast material-enhanced multi-detector row computed tomography (CT). Sensitivity, specificity, and diagnostic accuracy of MR perfusion imaging and MR angiography were calculated. Receiver operator characteristic analyses were performed to compare the diagnostic value of MR angiography, MR perfusion imaging, and both modalities combined. For MR angiography and MR perfusion imaging, kappa values were used to assess interobserver agreement. RESULTS: A correct diagnosis was made in 26 (90%) of 29 patients by using this comprehensive MR imaging protocol. Results of MR perfusion imaging demonstrated 79% agreement (ie, identical diagnosis on a per-patient basis) with those of perfusion scintigraphy, and results of MR angiography demonstrated 86% agreement with those of DSA and/or CT angiography. Interobserver agreement was good for both MR perfusion imaging and MR angiography (kappa = 0.63 and 0.70, respectively). CONCLUSION: The combination of fast MR perfusion imaging and high-spatial-resolution MR angiography with parallel acquisition techniques enables the differentiation of PPH from CTEPH with high accuracy.     

Subarachnoid hemorrhage in the subacute stage: elevated apparent diffusion coefficient in normal-appearing brain tissue after treatment

PURPOSE: To prospectively evaluate whether subarachnoid hemorrhage (SAH) is associated with a change in the apparent diffusion coefficient (ADC) in normal-appearing brain parenchyma. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for all patient and volunteer studies. One hundred patients (48 men, 52 women; mean age, 52 years +/- 12 [standard deviation]) with aneurysmal SAH underwent conventional and diffusion-weighted magnetic resonance (MR) imaging at a mean of 9 days +/- 3 after SAH to evaluate possible lesions caused by SAH, treatment of SAH, and vasospasm. Aneurysms were treated surgically (n = 70) or endovascularly (n = 30) before MR imaging. Diffusion-weighted MR imaging was performed at 1-year follow-up in 30 patients (10 men, 20 women; mean age, 51 years +/- 11). Thirty healthy age-matched volunteers (11 men, 19 women; mean age, 54 years +/- 16) underwent MR imaging with an identical protocol. ADC values were measured bilaterally in the gray and white matter (parietal, frontal, temporal, occipital lobes; cerebellum; caudate nucleus; lentiform nucleus; thalamus; and pons) that appeared normal on T2-weighted and diffusion-weighted MR images. Linear mixed model was used for comparison of ADC values of supratentorial gray matter and white matter; general linear regression analysis was used for comparison of ADC values of cerebellum and pons. RESULTS: In patients with SAH, the ADC values in normal-appearing white matter, with a single exception in the frontal lobe (P = .091), were significantly higher than they were in healthy volunteers (P /= .121). CONCLUSION: SAH and its treatment may cause global mild vasogenic edema in white matter and deep gray matter that is undetectable on T2-weighted and diffusion-weighted MR images but is detectable by measuring the ADC value in the subacute stage of SAH.     

A progressive shuttle run test to estimate maximal oxygen uptake.

The purpose of the present study was to examine the validity of using a 20 m progressive shuttle run test to estimate maximal oxygen uptake. Running ability was described as the final level attained on the shuttle run test and as time on a 5 km run. Maximal oxygen uptake (VO2 max) was determined directly for seventy-four volunteers (36 men, 38 women) who also completed the shuttle run test. Maximal oxygen uptake values were 58.5 +/- 7.0 and 47.4 +/- 6.1 ml.kg-1.min-1 for the men and women respectively (mean +/- SD, P less than 0.01). The levels attained on the shuttle run test were 12.6 +/- 1.5 (men) and 9.6 +/- 1.8 (women; P less than 0.01). The correlation between VO2 max and shuttle level was 0.92. The correlation between VO2 max and the 5 km run was -0.94 and the correlation between both field tests was -0.96. The results of this study suggest that a progressive shuttle run test provides a valid estimate of VO2 max and indicates 5 km running potential in active men and women.     

Left-to-right cardiac shunts: comparison of measurements obtained with MR velocity mapping and with radionuclide angiography

PURPOSE: To investigate the agreement between two noninvasive methods, magnetic resonance (MR) velocity mapping and first-pass radionuclide angiography, to quantify the pulmonary-to-systemic blood flow ratio (QP/QS) in adults, adolescents, and children with left-to-right cardiac shunts. MATERIALS AND METHODS: The accuracy and precision of MR velocity mapping were studied in 12 control subjects (six men, six women) and in a phantom. MR velocity mapping and radionuclide angiography were performed on the same day in 24 patients (16 adults, two adolescents, six children; five male patients, 19 female patients). RESULTS: The mean error in QP/QS at MR velocity mapping in phantom experiments was -1% +/- 1 (mean +/- SD). In control subjects, QP/QS at MR velocity mapping was 1.03 +/- 0.03, and the cardiac index was 3.1 L/min/m2 +/- 0.2 and 3.2 L/min/m2 +/- 0.3 for women and men, respectively. In patients, QP/QS at radionuclide angiography was 14% +/- 13, higher than at MR velocity mapping. Interobserver variability was four times higher for radionuclide angiography compared with MR velocity mapping, 0% + 16 versus 0% +/- 4 (n = 12). The difference between repeated MR flow measurements in the same vessel was -1% +/- 5 (n = 36). CONCLUSION: The data suggest that MR velocity mapping is accurate and precise for measurements of shunt size over the whole range of possible QP/QS values.     

Prediction rule for diagnosis of arrhythmogenic right ventricular dysplasia based on wall thickness measured on MR imaging.

MRI is seeing an increasing role in the evaluation of suspected arrhythmogenic right ventricular dysplasia (ARVD). Our aims were to establish wall thickness criteria for diagnosis of ARVD based on MR imaging measurements. A cross-sectional case-control retrospective study of 21 cardiac MR exams over a 3 year period identified five patients (two men, three women) of average age 43 years (range 36-48) who were diagnosed with ARVD and 16 patients (nine men, seven women) of average age 52 years (range 25-78) who were diagnosed with normal right ventricular wall motion. Patient demographic characteristics (age, sex) and right ventricular free wall thickness (RVFWT) were evaluated for predictive ability. Calculated RVFWT was (mean+/-SD, in mm); (4.4+/-1.4) for ARVD, and (7.8+/-2.9), controls with P<0.001. Logistic regression analysis indicated that sex and age were not significant independent predictors (P>0.05). RVFWT allowed for a prediction rule with Area under the receiver operator curve of 0.94 to be generated. In our study, measurement of the thickness of the right ventricular free wall using cardiac-gated MRI proved to be a statistically significant predictor of ARVD.     

Acute myocardial infarction: evaluation with first-pass enhancement and delayed enhancement MR imaging compared with 201Tl SPECT imaging

PURPOSE: To evaluate acute myocardial infarction by using first-pass enhancement (FPE) and delayed enhancement (DE) magnetic resonance (MR) imaging compared with thallium 201 ((201)Tl) single photon emission computed tomography (SPECT). MATERIALS AND METHODS: Contrast material-enhanced FPE MR, inversion-recovery DE MR, and rest-redistribution (201)Tl SPECT images were obtained in 60 consecutive patients (53 men, seven women; mean age [+/- SD], 56 years +/- 13; range, 30-78 years) at 6 days +/- 3 after reperfused first myocardial infarction. Presence of microvascular obstruction was determined on FPE MR images. Infarct size was defined on DE MR images as percentage of left ventricular (LV) area and compared with uptake defect on redistribution (201)Tl SPECT images. Differences in continuous data were analyzed with Student t test. Linear regression and Bland-Altman analysis were used to compare measurements of infarct size. RESULTS: Mean infarct size was not significantly different between DE MR imaging (20.7% +/- 11.5% of LV area) and (201)Tl SPECT (19.4% +/- 14.3% of LV area; P =.26); good correlation (r = 0.73; P <.001) and agreement were found, with a mean difference of +1.3% +/- 9.8% of LV area. (201)Tl SPECT failed to depict infarct in six (20%) of 30 patients with inferior myocardial infarction (mean size, 6.4% +/- 5.7% of LV area on DE MR images), whereas DE MR images showed the infarct in all patients (P <.01). FPE MR images depicted microvascular obstruction in 23 (38%) of 60 patients; these patients had larger infarctions at DE MR imaging than did patients without microvascular obstruction (30.4% +/- 9.0% vs 15.1% +/- 8.4% of LV area, P <.001). (201)Tl SPECT showed larger infarcts in patients with microvascular obstruction (26.7% +/- 16.2% vs 15.0% +/- 11.2% of LV area, P <.01). CONCLUSION: Good correlation and agreement with (201)Tl SPECT indicate DE MR imaging may be used to estimate infarct size 6 days after reperfused acute myocardial infarction. DE MR imaging is more sensitive for detection of inferior infarction than is (201)Tl SPECT. Patients with microvascular obstruction on FPE MR images have larger infarcts.     

Sonographic evaluation of spleen size in tall healthy athletes

OBJECTIVE: The purpose of this study was to establish the range of spleen sizes in tall healthy athletes. SUBJECTS AND METHODS: Sonographic measurements of spleen size and left renal length were performed on 129 college athletes (82 men, 47 women). Length, width, and thickness of the spleen and left renal length were obtained. In addition, the height, weight, and age of each athlete were recorded. Pearson's product moment correlation coefficients were calculated, and linear regression analysis was used to create a model for calculating normative values. RESULTS: The mean body height for men was 74.3 (189 cm) +/-(SD) 3.7 inches (9 cm) and for women was 69.3 (176 cm) +/- 3.7 inches (9 cm). Spleen length was greater than 12 cm in 31.7% of the men (mean spleen length, 11.4 +/- 1.7 cm) and in 12.8% of the women (mean spleen length, 10.3 +/- 1.3 cm). In women, height correlated with spleen length (r = 0.3, p = 0.05), width (r = 0.4, p = 0.01), and volume (r = 0.3, p = 0.02) but not with thickness (r = 0.08, p = 0.6). Spleen length did correlate with left renal length (r = 0.5, p = 0.0005). In men, height correlated with spleen length (r = 0.4, p = 0.0003), width (r = 0.5, p = 0.0001), and volume (r = 0.4, p = 0.0002) and less with thickness (r = 0.3, p = 0.01). Spleen length and left renal length were poorly correlated (r = 0.2, p = 0.04). Regression analysis showed that in women taller than 5 ft 6 inches (168 cm), the mean splenic length of 10 cm increased by 0.1 cm for each 1-inch incremental increase in height. In men taller than 6 ft (180 cm), the mean splenic length of 11 cm increased by 0.2 cm for each 1-inch incremental increase in height. CONCLUSION: Spleen size correlates with height in tall healthy athletes. Nomograms from this data can be used to gauge the risk of returning to play after episodes of acute splenomegaly, as with infectious mononucleosis.     

Symmetric temporal abnormalities on MR imaging in amyotrophic lateral sclerosis with dementia

BACKGROUND AND PURPOSE: Our aim was to clarify imaging findings of amyotrophic lateral sclerosis with dementia (ALSD). MATERIALS AND METHODS: T2-weighted MR images (T2WI) of 3 patients with ALSD (2 men, 1 woman; 58-71 years of age) and 21 patients with ALS without dementia (12 men, 9 women; 46-74 years of age) were examined for frontotemporal lobar atrophy and signal-intensity alterations in the white matter of the anterior temporal lobes, corticospinal tracts (CST), and precentral gyri and in precentral cortices. The brain of one of the patients with ALSD was examined at autopsy. RESULTS: All patients with ALSD showed bilateral frontotemporal atrophy mostly with temporal lobe dominance. In the ALSD group, T2WI demonstrated hyperintensity in the subcortical white matter on the medial side of the anterior temporal lobes, whereas in the group without dementia, none showed this imaging finding. MR images demonstrated no abnormal signal-intensity changes in CST in the internal capsule or the brain stem in the ALSD group. In the group without dementia, 6 patients (28.6%) showed this imaging finding. In neuropathologic examinations of the brain of 1 patient with ALSD, myelin-stained sections of the brain demonstrated loss of myelin in the subcortical white matter on the medial side of the anterior temporal white matter. CONCLUSIONS: A symmetric pattern of frontotemporal atrophy and anteromedial subcortical hyperintensities in the temporal lobes on T2WI could be characteristic of ALSD.     

Subcortical damage and cortical functional changes in men and women with Fabry disease: a multifaceted MR study

PURPOSE: To prospectively compare brain magnetic resonance (MR) imaging and hydrogen 1 (1H) MR spectroscopy findings and to use functional MR imaging to explore the patterns of brain activation in men and women with Fabry disease (FD). MATERIALS AND METHODS: Eight men and eight women with FD (mean age, 38.8 years +/- 13.9 [standard deviation]) with absent or mild neurologic deficit and 16 healthy control subjects (eight men and eight women; mean age, 42.7 years +/- 15.3) gave informed consent to participate in the study, which was approved by the local ethical committee. Patients and control subjects underwent MR imaging, 1H MR spectroscopy of the frontal cortex and subcortical white matter, and functional MR imaging during repetitive flexion-extension of the last four fingers of the right hand. Extent of cerebral white matter damage was rated on fluid-attenuated inversion recovery MR images by using a visual score. Areas of activation were identified by using statistical parametric mapping software and the adoption of a height threshold of P < .001 (uncorrected) and an extent threshold of P < .05 (corrected). RESULTS: Men and women with FD showed a similar distribution of cerebral white matter changes, lacunar and cortical infarcts, small hemorrhages, and vertebrobasilar dolichoectasia. No significant (P > .05) difference was observed between patients with FD and control subjects for concentration of N-acetylaspartate, creatine, and choline. During the motor task, patients showed recruitment of additional cortical areas in comparison with control subjects. Increased activation of the contralateral sensorimotor area correlated (P = .002) with extent of white matter damage. CONCLUSION: Subcortical ischemic changes in men and women with FD are similar and are associated with increased recruitment of the sensorimotor network during a simple motor task, which might limit the functional effect of the white matter small-vessel disease.     

Assessment of human atherosclerotic carotid plaque components with multisequence MR imaging: initial experience

PURPOSE: To prospectively determine, by using a stepwise logistic regression model, the optimal magnetic resonance (MR) weighting (ie, pulse sequence) combinations for plaque assessment and corresponding cutoff values of relative signal intensities (rSIs). MATERIALS AND METHODS: Institutional review board approval and patient consent were obtained. Eleven patients (seven men, four women; mean age +/- standard deviation, 68 years +/- 4) with symptomatic carotid disease and stenosis of more than 70% were investigated at MR imaging before carotid endarterectomy. The MR images were matched with histologic features of the endarterectomy specimens (reference standard). The rSIs (compared with that of muscle tissue) from regions of interest were assessed qualitatively and semiquantitatively. For all major components (calcification, lipid core, intraplaque hemorrhage, and fibrous tissue), optimal cutoff points for the rSIs were determined for five MR weightings by means of receiver operating characteristic curves. The best predicting combinations of these five dichotomized MR weightings were selected by means of stepwise logistic regression analysis. The potential sensitivity and specificity of MR imaging for vulnerable plaque with hemorrhage and/or lipid core were determined. RESULTS: The same optimal MR weighting combinations for identifying the four plaque components were found with qualitative and semiquantitative analysis. Sensitivity and specificity for vulnerable plaque were 93% (95% confidence interval: 77%, 99%) and 96% (95% confidence interval: 86%, 100%), respectively, for the qualitative analysis and 76% (95% confidence interval: 56%, 90%) and 100% (95% confidence interval: 93%, 100%) for the semiquantitative analysis. CONCLUSION: This study demonstrates the potential of a systematic approach of atherosclerotic plaque assessment with multisequence MR imaging by using the information provided from five different MR weightings in a stepwise logistic regression model.