Radiation Dose Reduction in 4D Cerebral CT Angiography by Individualized Estimation of Cerebral Circulation Time.

BACKGROUND AND PURPOSE: The novel technique of 4D CTA for dynamic assessment of the intracranial vessels has a greater radiation burden than conventional CTA. Previous descriptions of the technique used a fixed-duration exposure protocol. This study examines the potential for dose reduction by individualizing exposure time to patient physiology by the use of time-enhancement curve techniques as previously applied in CT angiography and venography. MATERIALS AND METHODS: 4D-CTA examinations performed at our institution were retrospectively reviewed. Scan protocols used a test-bolus scan with either a subjective estimate of the main acquisition timing (estimated-duration method) or a quantitative measure (measured-duration method). The estimated-duration method used peak arterial enhancement to determine the start of exposure, with the duration chosen at the radiologist's discretion. The measured-duration method used arterial and venous time-enhancement curves to determine exposure start and duration. Exposure duration, study adequacy, quality score, and maximum venous enhancement were compared among groups. RESULTS: One hundred fifty-one examinations used the estimated-duration method, and 53 used measured-duration. The measured-duration method used a shorter exposure time (10 versus 15.8 seconds; P < .001). There was no statistically significant difference in the study adequacy rate, subjective quality score, or maximum venous enhancement. The radiation dose was reduced by 51% in the measured-duration method (3021 mGy × cm, 6.9 mSv, versus 1473 mGy × cm, 3.4 mSv). Both methods showed good agreement with DSA (κ = 0.88 for estimated-duration, κ = 1.0 for measured duration). CONCLUSIONS: Exposure time in 4D-CTA can be reduced with dual time-enhancement curves to match exposure to physiology without degrading study adequacy or quality.

The reliability of routine clinical post-processing software in assessing potential diffusion-weighted MRI "biomarkers" in brain metastases.

BACKGROUND AND PURPOSE: Diffusion MRI characteristics have been used as biomarkers to guide prognosis in cerebral pathologies including brain metastases. The measurement of ADC is often described poorly in clinical and research studies with little detail given to the practical considerations of where to place ROIs, which post processing software package to use and how reproducible the resulting metrics will be. METHOD: We investigated a series of 12 patients with brain metastases and preoperative DWI. Three post processing platforms were used. ROI were placed over the tumour, peritumoural region and across the brain-tumour interface. These recordings were made by a neurosurgeon and a neuroradiologist. Inter-intra-observer variability was assessed using Bland-Altman analysis. An exploratory analysis of DWI with overall survival and tumour type was made. RESULTS: There was excellent correlation between the software packages used for all measures including assessing the whole tumour, selective regions with lowest ADC, the change of ADC across the brain-tumour interface and the relation of the tumour ADC to peritumoural regions and the normal white matter. There was no significant inter- or intra-observer variability for repeated readings. There were significant differences in the mean values obtained using different methodologies and different metrics had differing relationships to overall survival and primary tumour of origin. CONCLUSION: Diffusion weighted MRI metrics offer promise as potential non-invasive biomarkers in brain metastases and a variety of metrics have been shown to be reliably measured using differing platforms and observers.

3D CT cerebral angiography technique using a 320-detector machine with a time-density curve and low contrast medium volume: comparison with fixed time delay technique.

AIM: To describe a cerebral computed tomography angiography (CTA) technique using a 320-detector CT machine and a small contrast medium volume (35 ml, 15 ml for test bolus). Also, to compare the quality of these images with that of the images acquired using a larger contrast medium volume (90 or 120 ml) and a fixed time delay (FTD) of 18 s using a 16-detector CT machine. MATERIALS AND METHODS: Cerebral CTA images were acquired using a 320-detector machine by synchronizing the scanning time with the time of peak enhancement as determined from the time-density curve (TDC) using a test bolus dose. The quality of CTA images acquired using this technique was compared with that obtained using a FTD of 18 s (by 16-detector CT), retrospectively. Average densities in four different intracranial arteries, overall opacification of arteries, and the degree of venous contamination were graded and compared. RESULTS: Thirty-eight patients were scanned using the TDC technique and 40 patients using the FTD technique. The arterial densities achieved by the TDC technique were higher (significant for supraclinoid and basilar arteries, p < 0.05). The proportion of images deemed as having "good" arterial opacification was 95% for TDC and 90% for FTD. The degree of venous contamination was significantly higher in images produced by the FTD technique (p < 0.001%). CONCLUSION: Good diagnostic quality CTA images with significant reduction of venous contamination can be achieved with a low contrast medium dose using a 320-detector machine by coupling the time of data acquisition with the time of peak enhancement.

"Gilahari (lizard) syndrome" is it a new culture bound syndrome? - a case report.

Culture bound syndromes are generally limited to specific societies or cultural areas and are localized. Authors report a case which seems to be a new culture bound syndrome, has atypical presentation and difficult to categories but could be diagnosed as somatoform NOS (F-45.9). This syndrome is commonly called Gilahari (Lizard) among local public and considered to be very serious and fatal illness prevalent in areas of west Rajasthan. According to public a small swelling climbs from the back reaches to neck leading to obstruction of airways and followed by death, though after examination and investigation patient did not revealed any physical illness so is seems to be a new culture bound syndrome.

Psychiatric morbidity among patients attending cardiac opd.

One hundred patients were selected from the cardiology outpatient department by non-probability purposive method. Each patient was evaluated by a psychiatrist and a consultant cardiologist The informations were recorded in a self designed proforma. The Hindi version of Goldberg's General Health Questionnaire and modified adjective check list for type A and type B personality characteristics were administered. Seventy five percent of the patients were having psychiatric problems. The cardiac patients were having psychiatric problems. The cardiac patients were having predominantly type A personality characteristics. Panic disorder was the predominant diagnosis in the psychiatric patients and depression was the main diagnosis in cardiac patients. These patients presented with complaints of chest pain, palpitation, ghabarahat, weakness, increased sweating, hot and cold flushes, choking, breathlessness, decreased appetite.etc.in cardiac OPD.

A study of attributional style in depression compared with schizophrenic and normal patients.

Seligman and his associates have advocated a particular attributional style in depressive patients. The present study aimsat investigating attributional styles in depressive patients, in comparison to schiziphrcnic and non psychiatric medical patients. A matched sample of 30 depressive, 30 schizophrenic and 30 medical patients was selected from out-door and indoor facilities of psychiatric centre and S. M. S. Hospital, Jaipur. All the patients were administered Seligman's (1981) attributional sytle questionnaire.

Body image, hopelessness and personality dimensions in lower limb amputees.

A sample of lower limb amputees and equal number of matched surgical controls was studied on body image, hopelessness and personality dimensions using Fisher's Body Distortion Questionnaire (BDQ). Beck's Hopelessness Scale and Hindi PEN Inventory. Amputees had significantly higher mean scores on body distortion (x 27.86), hopelessness (x 14.08) and neuroticism (x 9.30) as compared to surgical controls. Furthermore they had significantly lesser scores on extraversion (x 11.26) in comparison to their surgical counterparts. No significant differences were found on psychoticism in the two groups. Psychological aspects of amputation have not received much attention. By and large, amputees are believed to have more difficulty in dealing with people than things. It is the loss of ability to relate psychologically, socially, sexually and vocationally that inhibits the amputees most.