The shape-from-focus (SFF) method uses a sequence of frames to estimate the structure of a 3-D object. Its accuracy depends on the step size by which the translational table is moved while capturing the images. Existing SFF algorithms use an ad hoc interpolation strategy to account for the error due to the finite step size. We propose an improved SFF method that uses relative defocus blur derived from actual image data to arrive at the final estimates of the structure of the object. A space-variant image restoration scheme is also proposed to obtain a focused image of the 3-D object. The reconstructed 3-D structure as well as the quality of the restored image are superior for the proposed method in comparison to traditional SFF.

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Background Thermal injuries in a patient undergoing magnetic resonance imaging (MRI) are rare; more so, when the patient in question is being operated upon. We attempt to elucidate the various factors that may predispose to such an unfortunate circumstance, through a series of four cases. Materials and Methods We conducted a retrospective review of our experience with intraoperative MRI and found four cases of burns attributed to MRI. Factors leading to possible injury were examined after other causes were ruled out. Results Collection of moisture between the leads and the patient's skin was the most common factor for the burns. There were no instances of closed loop formation or injury due to direct contact of cables to the skin. Conclusion Awareness of the causative factor can lead to prevention. Proper education of all concerned personnel involved in the conduction of the intraoperative MRI is paramount to prevention of the same.

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BACKGROUND Advances in MRI techniques have provided new tools for the diagnosis of PD in its early stages and have discriminated it from other atypical PD syndromes. Aims and Objectives-To study the clinical profile and neuroimaging aspects of patients presenting with parkinsonian symptoms and aiding in their diagnosis and management. To explore the role of DTI in early diagnosis and its utility as a potential screening tool for parkinsonian syndromes. MATERIALS AND METHODS 50 patients aged above 18 yrs. presenting with primary parkinsonism, parkinsonism plus syndromes, predominant parkinsonism features in heredodegenerative parkinsonism groups were included. Patients were subjected to detailed case proforma questionnaires and categorized under two groups typical and atypical parkinsonism. Clinical assessment was done by Unified Parkinson's Disease Rating Scale (UPDRS), Modified Hoehn and Yahr staging and a 750 wide bore 3 Tesla GE-made MRI with Echo planar and diffusion weighted imaging in 25 directions was used for imaging of the brain. In the present study, 25 patients and 10 controls in whom DTI was performed, fractional anisotropy (FA) values were obtained from regions of interest (ROI)cingulate cortex, basal ganglia, corticospinal tracts, superior longitudinal fasciculus, substantia nigra, thalamus regions of brain. RESULTS In our study, male population represented higher cases than females and mean age of presentation was 49.94 yrs. Typical PD patients constituted 84% and atypical PD 16%. Median UPDRS-III motor scale for typical PD patients was 36 and atypical PD patients was 55. The mean FA values of substantia nigra regions of PD patients when compared to controls, was lower but statistically not significant (0.4256 vs 0.44801, p=0.076). None of the FA values in studied regions showed statistically significant difference between patients and controls. CONCLUSION Our study DTI findings using ROI analysis helped in differentiating typical vs atypical PD syndromes and also diagnosing PD patients at an early stage. Even though there was no statistical significance among core parameters obtained, this study reinforces the findings in terms of trends in FA values thereby establishing the role of DTI in diagnosing PD patients.