One-dimensional-ratio measures of atrophy progression in multiple sclerosis as evaluated by longitudinal magnetic resonance imaging.

BACKGROUND: For decades, normalized one-dimensional (1D) measures have been used in the evaluation of brain atrophy. In multiple sclerosis (MS), the use of normalized linear measures over longitudinal follow-up remains insufficiently documented. PURPOSE: To evaluate the association between different regional atrophy measures and disability in MS patients over four decades in a longitudinal cross-sectional study. MATERIAL AND METHODS: 37 consecutively selected MS patients were included. At baseline, patients had a range of disease duration (1-33 years) and age (24-65 years). Each patient was followed by magnetic resonance imaging (MRI) for a mean of 9.25 years (range 7.3-10 years). Four 1D measures were applied at three time points on axial 5-mm T1-weighted images. Three clinical MS subgroups were represented: relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and primary progressive MS (PPMS). RESULTS: There were significant changes in all 1D ratios during follow-up. The Evans ratio (ER) and the bifrontal ratio (BFR) were associated with the development of disability. Changes of ER and BFR reflected more aggressive disease progression, as expressed by MS severity score (MSSS). CONCLUSION: All four normalized ratios showed uniform atrophy progression, suggesting a consistent rate of atrophy over long-term disease duration independent of MS course. Disability status correlated with 1D measures, suggesting that serial evaluation of Evans and bifrontal ratios might contribute to the radiological evaluation of MS patients.

Voxel-based correlation between coregistered single-photon emission computed tomography and dynamic susceptibility contrast magnetic resonance imaging in subjects with suspected Alzheimer disease.

BACKGROUND: Current diagnosis of Alzheimer disease is made by clinical, neuropsychologic, and neuroimaging assessments. Neuroimaging techniques such as magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) could be valuable in the differential diagnosis of Alzheimer disease, as well as in assessing prognosis. PURPOSE: To compare SPECT and MRI in a cohort of patients examined for suspected dementia, including patients with no objective cognitive impairment (control group), mild cognitive impairment (MCI), and Alzheimer disease (AD). MATERIAL AND METHODS: 24 patients, eight with AD, 10 with MCI, and six controls, were investigated with SPECT using (99m)Tc-hexamethylpropyleneamine oxime (HMPAO, Ceretec; GE Healthcare Ltd., Little Chalsont UK) and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with a contrast-enhancing gadobutrol formula (Gadovist; Bayer Schering Pharma, Berlin, Germany). Voxel-based correlation between coregistered SPECT and DSC-MR images was calculated. Region-of-interest (ROI) analyses were then performed in 24 different brain areas using brain registration and analysis of SPECT studies (BRASS; Nuclear Diagnostics AB, Stockholm, Sweden) on both SPECT and DSC-MRI. RESULTS: Voxel-based correlation between coregistered SPECT and DSC-MR showed a high correlation, with a mean correlation coefficient of 0.94. ROI analyses of 24 regions showed significant differences between the control group and AD patients in 10 regions using SPECT and five regions in DSC-MR. CONCLUSION: SPECT remains superior to DSC-MRI in differentiating normal from pathological perfusion, and DSC-MRI could not replace SPECT in the diagnosis of patients with Alzheimer disease.

Magnetic resonance imaging to evaluate NASHA/Dx gel (Zuidex) for stress urinary incontinence.

The Zuidex system for the treatment of stress urinary incontinence consists of non-animal stabilised hyaluronic acid/dextranomer (NASHA/Dx) gel and a precision guide, the Implacer. Whether the Implacer accurately deposits NASHA/Dx gel in the desired location within the urethral wall was investigated by magnetic resonance imaging (MRI), performed at a mean of 35 days post-treatment. Three or more deposits were observed in 11 of 16 patients (68.8%), with 39 of the 50 deposits clearly located within the urethral wall, as intended. Fourteen of 16 patients (87.5%) demonstrated improvement in their incontinence at 3 months, sustained at 12 months in 13 patients. No significant correlations between total implant volume and improvements in incontinence were observed at 3 months (p > or = 0.16) and 12 months (p > or = 0.30). In conclusion, accurate placement of NASHA/Dx gel into the desired location within the urethral wall was achieved in the majority of cases using the Implacer device, without endoscopic guidance.

Dynamic MR imaging of the breast. Analysis of kinetic and morphologic diagnostic criteria.

PURPOSE: To assess the value of kinetic and architectural diagnostic criteria on dynamic MR breast imaging, and to construct a scoring system for lesion characterization. MATERIAL AND METHODS: A total of 92 women with 109 histopathologically verified breast lesions were included in this retrospective study. The patients were examined by a 1.5 T system using a dedicated double breast coil. A dynamic examination with one precontrast and seven postcontrast series was performed, using a T1-weighted 3D FLASH sequence. Thirty lesions (15 malignant and 15 benign) were randomly chosen for the validation set, and the remaining 79 lesions (62 malignant and 17 benign) formed the estimation set, in which multivariate analysis was performed in order to select the most important features. These parameters were then used for constructing the scoring system, which was tested on the validation set. The scoring system was compared with the routine standard evaluation that used all established diagnostic criteria. ROC curves were generated to assess the diagnostic accuracy of different approaches. RESULTS: In the multivariate analysis of the 79 lesions, time-to-peak enhancement and the descriptor of margins were found to be the most important independent factors for distinguishing benign from malignant lesions, and formed the basis of the scoring system. The areas under the ROC curves for the standard evaluation, and the scoring system were 0.813 and 0.880 in the 30 lesions. CONCLUSION: Time-to-peak enhancement and the descriptor of margins appear to be the most important diagnostic criteria for mass lesions in dynamic breast MR imaging.

Comparison of 99mTc-sestamibi scintimammography and dynamic MR imaging as adjuncts to mammography in the diagnosis of breast cancer.

PURPOSE: To compare the diagnostic accuracy of planar 99mTc-sestamibi scintimammography with dynamic contrast-enhanced MRI (CE-MRI) on the basis of histopathologic results, and to determine the clinical value of these methods as adjuncts to mammography. MATERIAL AND METHODS: A total of 90 consecutive women with 111 histopathologically verified breast lesions were enrolled in the study. Patients underwent scintimammography and CE-MRI in addition to mammography. Each finding was classified on a BI-RADS-like five-point rating scale describing the degree of suspicion for malignancy, and all findings were correlated with the histopathological results. RESULTS: The overall sensitivity/specificity/accuracy was 85%/59%/78% for mammography, 94%/47%/80% for CE-MRI, and 82%/75%/80% for scintimammography, respectively. CE-MRI showed higher sensitivity (p = 0.008), but its specificity was lower than scintimammography (p = 0.049). Using ROC analysis, significant improvement ( p = 0.034) was found between mammography and the combination of mammography + CE-MRI, while mammography + scintigraphy showed no higher diagnostic accuracy than mammography alone. CONCLUSION: If high sensitivity and spatial resolution are needed, CE-MRI is to be preferred in clinical practice as an adjunct to mammography, rather than scintigraphy.