The purpose of this study was to assess the predictors of functional outcome after right hemisphere stroke at 6-month follow up in patients with or without thrombolytic treatment. Thrombolysis did not predict functional outcome in instrumental activities of daily living (IADL). Lower acute phase basic activities of daily living (ADL) measured by the Barthel Index was a statistically significant predictor of IADL when adjusted for age and education (p = .015) and had borderline significance (p = .076) as a predictor of functional outcome when adjusted for severity of stroke at admission. When stroke severity was taken into account also higher age became a statistically significant (p = .039) predictor of functional outcome. The acute phase neuropsychological symptoms predicted the functional outcome in unadjusted analyses but when adjusted for age, education, and severity of stroke no independent association was found.
Background: Dynamic infrared (IR) imaging is an emerging functional imaging modality for the detection of breast cancer without evidence of optimal imaging and diagnostic application. Purpose: To evaluate dynamic IR imaging in breast cancer diagnostics by comparing a stepwise diagnostic scheme to digital mammography and postoperative histopathology. Material and Methods: Dynamic IR imaging of breasts was undertaken preoperatively with a long-wave quantum well (QWIP) and two mid-wave photovoltaic (PV) IR cameras in 10 cases (age 34–80 years) with breast cancer size 6–45 mm on mammography. Image stabilization, two-phase frequency analysis, and two image-processing algorithms were applied. Results: Combining image processing with frequency analysis proved advantageous in detecting breast cancer. The IR imaging process recognized the cancer area independently of tissue density, cancer size, and cancer appearance on mammography. Compared to histopathology, all cancers yielded abnormal analysis results, including one case of ductal carcinoma in situ. Evidence of lymphatic invasion in postoperative histopathology, imaging with PV camera, and image processing with the Wiener filtering combination correlated with highest confidence between normal and cancer tissue measured by the calculated superiority value. Conclusion: Dynamic IR imaging with image-processing-guided frequency analysis is a promising modality for breast cancer detection and may not have the tissue-dependent limitations of mammography. Our results encourage further work on medical IR imaging and comparison to established breast-imaging modalities.
To examine neurological and magnetic resonance imaging (MRI) changes following discontinuation of interferon (IFN)-beta-1a treatment in secondary progressive multiple sclerosis (SPMS).The study involved 21 SPMS patients who received subcutaneous (s.c.) IFN-beta-1a 44 microg three times weekly (t.i.w.) for 12 months and were thereafter followed up without treatment for a further 12 months. The number of relapses, disability on the Expanded Disability Status Scale (EDSS) and MRI were recorded at baseline, at 12 months of IFN-beta-1a 44 microg t.i.w. and 1 year after discontinuation of treatment.During the 12-month treatment EDSS score and volumes of brain T2- and T1-weighted lesions remained without significant progression, but at 12 months after treatment discontinuation both EDSS score and the volumes of cerebral lesions increased significantly. Cerebrospinal fluid fraction increased significantly both during the treatment and during follow-up.Discontinuation of IFN-beta-1a 44 microg t.i.w. in SPMS may be associated with an increase in neurological disability and brain lesions on MRI.
We studied the impact of the location of the thrombus (internal carotid artery, proximal M1 segment, distal M1 segment, M2 segment, and M3 segment of the middle cerebral artery) in predicting the clinical outcome of patients treated with intravenous thrombolytic therapy (<3 h) in a retrospective cohort.Anterior circulation thrombus was detected with computed tomography angiography in 105 patients. Baseline clinical and radiological information was collected and entered into logistic regression analysis to predict favorable clinical outcome (3-month modified Rankin Scale from 0 to 2 was a primary outcome measure).Three months after stroke, there was a significant increase in mortality (32% vs. 3%, P < 0.001) and functional dependency (82% vs. 29%, P < 0.001) in patients with internal carotid artery or proximal M1 segment of the middle cerebral artery thrombus compared to a more distal occlusion. In the regression analysis, after adjusting for National Institutes of Health Stroke Scale, age, sex, and onset-to-treatment time, the clot location was an independent predictor of good clinical outcome (P = 0.001) and exhibited dose-response type behavior when moving from a proximal vessel position to a more distal one. When the location was dichotomized, a cutoff between the proximal and the distal M1 segments best differentiated between good and poor clinical outcome (OR = 16.0, 95% CI 3.9-66.2).The outcome of acute internal carotid artery or proximal M1 segment of the middle cerebral artery occlusion is generally poor even if treated with intravenous thrombolysis. Alternative revascularization strategies should be considered. Vascular imaging at the admission is required to guide this decision.
This paper describes the creation of an anatomically detailed high resolution model of the human head based on the Visible Human Female data from the National Library of Medicine archives. Automatic and semi-automatic segmentation algorithms were applied over the 3 image volumes - CT, MRI and anatomical cryo-sections of the cadaver - to label a total of 23 tissues. The results were combined to create a labeled volume of the head with voxel dimensions of 0.33×0.33×0.33 mm. The individual label matrices and their corresponding surface meshes are made available to be used freely. The detailed blood vessel network and ocular tissues will be of interest in computational modelling and simulation studies.
Diffusion tensor imaging (DTI) is increasingly used in various diseases as a clinical tool for assessing the integrity of the brain's white matter. Reduced fractional anisotropy (FA) and an increased apparent diffusion coefficient (ADC) are nonspecific findings in most pathological processes affecting the brain's parenchyma. At present, there is no gold standard for validating diffusion measures, which are dependent on the scanning protocols, methods of the softwares and observers. Therefore, the normal variation and repeatability effects on commonly-derived measures should be carefully examined. Thirty healthy volunteers (mean age 37.8 years, SD 11.4) underwent DTI of the brain with 3T MRI. Region-of-interest (ROI) -based measurements were calculated at eleven anatomical locations in the pyramidal tracts, corpus callosum and frontobasal area. Two ROI-based methods, the circular method (CM) and the freehand method (FM), were compared. Both methods were also compared by performing measurements on a DTI phantom. The intra- and inter-observer variability (coefficient of variation, or CV%) and repeatability (intra-class correlation coefficient, or ICC) were assessed for FA and ADC values obtained using both ROI methods. The mean FA values for all of the regions were 0.663 with the CM and 0.621 with the FM. For both methods, the FA was highest in the splenium of the corpus callosum. The mean ADC value was 0.727 ×10-3 mm2/s with the CM and 0.747 ×10-3 mm2/s with the FM, and both methods found the ADC to be lowest in the corona radiata. The CV percentages of the derived measures were < 13% with the CM and < 10% with the FM. In most of the regions, the ICCs were excellent or moderate for both methods. With the CM, the highest ICC for FA was in the posterior limb of the internal capsule (0.90), and with the FM, it was in the corona radiata (0.86). For ADC, the highest ICC was found in the genu of the corpus callosum (0.93) with the CM and in the uncinate fasciculus (0.92) with FM. With both ROI-based methods variability was low and repeatability was moderate. The circular method gave higher repeatability, but variation was slightly lower using the freehand method. The circular method can be recommended for the posterior limb of the internal capsule and splenium of the corpus callosum, and the freehand method for the corona radiata.
The popularity of digital imaging devices and PACS installations has increased during the last years. Still, images are analyzed and diagnosed using conventional techniques. Our research group begun to study the requirements for digital image diagnostic methods to be applied together with PACS systems. The research was focused on various image analysis procedures (e.g., segmentation, volumetry, 3D visualization, image fusion, anatomic atlas, etc.) that could be useful in medical diagnosis. We have developed Image Analysis software (www.medimag.net) to enable several image-processing applications in medical diagnosis, such as volumetry, multimodal visualization, and 3D visualizations. We have also developed a commercial scalable image archive system (ActaServer, supports DICOM) based on component technology (www.acta.fi), and several telemedicine applications. All the software and systems operate in NT environment and are in clinical use in several hospitals. The analysis software have been applied in clinical work and utilized in numerous patient cases (500 patients). This method has been used in the diagnosis, therapy and follow-up in various diseases of the central nervous system (CNS), respiratory system (RS) and human reproductive system (HRS). In many of these diseases e.g. Systemic Lupus Erythematosus (CNS), nasal airways diseases (RS) and ovarian tumors (HRS), these methods have been used for the first time in clinical work. According to our results, digital diagnosis improves diagnostic capabilities, and together with PACS installations it will become standard tool during the next decade by enabling more accurate diagnosis and patient follow-up.
