Relation of the Ankle Brachial Index to Left Ventricular Ejection Fraction in Patients Without Coronary Artery Disease.

BACKGROUND: The low ankle brachial index (ABI) values are indicative of peripheral arterial disease, but have recently been found to be associated with reduced left ventricular ejection fraction (LVEF). This may relate to coexisting coronary artery disease (CAD). AIM: This study prospectively assessed a potential ABI-LVEF association in patients without CAD. METHODS AND RESULTS: We studied 55 patients (age 57 ± 13 years, 49% male) with normal coronary arteries with LVEF determination. ABI, pulse wave velocity (PWV), and augmentation index (AI) were performed after coronary angiography. ABI correlated with LVEF (r = 0.40, p = 0.002), but not with PWV or AI. On linear regression analysis, ABI was independently associated with LVEF (B = 0.42, p = 0.004). The median LVEF was lower in subjects with low ABI values compared to those with normal ABI values (33 vs. 61%; p = 0.001). CONCLUSION: ABI may be influenced by LVEF independently of CAD, arterial stiffness or pressure wave reflection.

Radiation absorbed dose for cobalt-60 gamma source in phantoms for different materials.

Current practices in radiation therapy required high doses of radiation to be delivered with increased accuracy. Treatment planning task is exercised till an optimum dose distribution is achieved. The present reported work was performed to compare the various aspects of the cobalt-60 radiation beam therapy with fixed source-surface distance 70cm incident normally. This study was conducted in May 2012 at the Department of Radiation Physics of MD Anderson Cancer Centre, University of Texas, Houston, United States. Radiation doses were calculated in a solid phantom as well as in water phantom at different square field sizes and depths. It was noted that the rate of absorbed dose increased with the increase in the field size and decreased with the increase in depths. The rate of absorbed dose was found to be directly proportional to the increase in the square field size and inversely proportional to the increase in depth. Moreover, the solid phantom demonstrated more absorbed doses as compared to the water phantom.

Impact of brachytherapy applicators geometry on dose distribution in gynaecological cancer.

OBJECTIVE: To evaluate the efficacy of suitable applicators for intracavitary brachytherapy to treat cervical cancer. METHODS: This study was conducted at the Bahawalpur Institute of Nuclear Medicine and Oncology, Bahawalpur, Pakistan, in February 2014. Dose distributions for Fletcher and ring applicators were analysed at target points according to recommended protocols using Abacus software. The doses to the organs at risk, i.e. bladder and rectum, were also focused. SPSS 16 was used for data analysis. RESULTS: A total of 40 patients' plans were considered. The mean absorbed dose at target point A was 6.87±0.201Gy in case of Fletcher applicator (p=0.082) and 6.79±0.107Gy in case of ring applicator (p=0.001). Absorbed dose at the target point was significantly higher for the Fletcher type applicators as compared to the ring applicators. However, the amount of doses at bladder and rectum were smaller for the Fletcher applicators. CONCLUSIONS: Fletcher applicator was more effective in achieving a better dose distribution in gynaecological malignancies, resulting in better treatment outcome.

Diagnostic value of apparent diffusion coefficient for the accurate assessment and differentiation of intracranial meningiomas.

BACKGROUND: Diffusion-weighted imaging (DWI) along with the calculation of apparent diffusion coefficient (ADC), is a novel, non-invasive, and reliable technique of choice for accurate assessment and for the treatment planning of different types of brain tumors. It is more advantageous in the distinction and differentiation of benign from malignant meningiomas on the basis of ADC values. PURPOSE: To investigate the utility of DW magnetic resonance imaging (MRI), and to compare the apparent diffusion coefficient (ADC) obtained at two b-values for an authentic and preoperative characterization of meningiomas. MATERIAL AND METHODS: Twenty-six patients with clinically diagnosed or histologically verified meningioma (18 benign and 8 malignant) underwent imaging including DWI at 1.5 T. DW images were obtained at b = 1000 s/mm(2) and b = 2000 s/mm(2), ADC maps were generated at both the b-values. Signal intensities (SIs) and ADCs for solid tumorous tissues, contralateral normal tissues, and peritumoral edema were calculated and normalized ADC (NADC) ratio were determined for tumorous tissues. SI scores, ADC maps, and ADC values were analyzed visually and quantitatively, and were compared at both the b-values. RESULTS: DW images at b = 2000 s/mm(2) were more conspicuity (either hyperintense or hypointense) with improved contrast. The mean ADC of malignant meningiomas (0.64 ± 0.05 and 0.42 ± 0.03) was significantly lower (P < 0.05) as compared with benign meningiomas (1.04 ± 0.12 and 0.80 ± 0.07) at both the b-values. Mean NADC ratio in the malignant type was also significantly lower (P < 0.05) than the benign type at both the b-values. Mean ADC values for peritumoral edema do not differ between benign and malignant meningiomas. CONCLUSION: 1.5-T DWI using high b-values improved our ability to differentiate benign from malignant meningiomas. DWI may play an important role in the preoperative radiological evaluation and the recognition of these types for proper surgical treatment.