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Purpose: To study the enhancement pattern of differentiated and undifferentiated gastric carcinoma on multiphasic contrast-enhanced computed tomography (CT). Material and methods: Seventy patients with biopsy-proven gastric cancer underwent multiphasic contrast-enhanced CT. The CT protocol include plain, arterial, portal venous, and hepatic venous phase. Tumour size, location, peak-enhancement characteristics, and staging were evaluated. Results: The peak-enhancement type was ‘arterial’ in 20 out of 28 within the differentiated-type GCAs and ‘portalvenous’ in 37 out of 42 within the undifferentiated-type GCAs (χ² statistic with Yates correction = 23.3981, p < 0.00001). The maximum attenuation value was statistically significant for the arterial phase between differentiated and undifferentiated GCAs (p < 0.05). Conclusions: Assessing peak-enhancement in a multiphasic CT can help identify the histological subcategory of gastric carcinomas that has prognostic significance. Arterial phase peak-enhancement is frequently seen in differentiated carcinomas whereas venous phase peak-enhancement is seen in undifferentiated carcinomas. [ABSTRACT FROM AUTHOR]

The purpose of this report is to review the CT findings of cardiac hydatid disease and to emphasize the role of multidetector CT scan in diagnosing cardiac hydatidosis. The most common locations of cardiac hydatid cysts are left ventricle (LV), interventricular septum and right ventricle respectively. We reported three cases of cardiac hydatid disease, in which one patient had extensive lesions in pericardium and cardiac walls. Second patient had single lesion in the interventricular septum while third patient had lesion in wall of LV. The diagnosis was not definite on echocardiography, but MDCT was utilized to assess cysts and extent of disease. We present the CT imaging details and review of literature in cardiac hydatidosis. [ABSTRACT FROM AUTHOR]

PURPOSE: To reduce radiation dose from Multidetector computed tomography (MDCT) using techniques with low tube voltage and modified image parameters without significant degradation of image quality. AUDIT TARGET: Radiation dose reduction using 80 kV and 100 kV protocols for MDCT. MATERIALS AND METHODS: This is a prospective analysis with single blind selection of cardiac anomaly patients referred to radiology department of Rehman medical institute Peshawar for cardiac CT scan during Jan 2013 to Dec 2015. Total of 100 patients with age range of 1 week to 16 years were selected with echocardiography suspicion of cardiovascular anomalies. It was probability sampling. Scan was performed on 128 multislice Toshiba scanner. ECG gated retrospective and prospective scanning was performed using modified tube voltage (80 kVp, 100 kVp and 120 kVp) and with adjustment of low tube current. Radiation dose measurement was done by multiplying conversion factor with dose length product (DLP), which was provided by the CT scanner. Data was processed using Microsoft Excel 2010. Images were reviewed on 5.1 Vitrea workstation using multiplanar and 3D reconstruction. Two radiologists independently assessed subjective quality of the CT images to assess cardiac anomalies and normal anatomical structures. RESULTS: Prospective ECG gating significantly reduced the radiation dose 22 mSv (retrospective) to 13.96 mSv (prospective) with standard inbuilt 120 kVp setting. Reducing the kVp to 100 further reduced dose to 10.3 mSv and dropped down to 5.46 mSv with 80 kVp and no significant image distortion. Manually adjusting and reducing the mAs with added filtration reduced the radiation dose to 3.64 mSv. CONCLUSION: We conclude from our results that prospective ECG gated cardiac CT, low kVp and mAs values show great potential for substantially reducing radiation dose of cardiac CT angiography. By using different radiation lowering dose techniques i.e. prospective ECG gating technique, low kVp and mAs, we were able to reduce radiation dose by 83.45% (22 to 3.46 mSv). [ABSTRACT FROM AUTHOR]

Purpose: Lipoma arborescens (LA) is a benign intra-articular lipomatous proliferation of the synovial membrane. This extremely rare condition has previously been treated by intra-articular 90Y radiosynoviorthesis but dosimetry literature on this form of radionuclide therapy is nonexistent. The authors detail methodology for successful treatment of LA and provide for the first time estimates of radiation dosimetry. The authors also analyze the biodistribution of the radiopharmaceutical over the course of the patient's treatment through sequential imaging. Methods: A patient with bilateral LA underwent intracavity injection of 90Y citrate colloid to the right and left knee joint spaces (181 and 198 MBq, respectively). SPECT/CT datasets were acquired over 9 days to quantify the biodistribution and kinetics of the radiopharmaceutical. Radiation dosimetry was performed using the MIRD schema (through OLINDA software), a custom voxel-based method, and a direct Monte Carlo calculation (OEDIPE). Results: Follow-up MRI showed marked reduction in LA size in both knees. Mean absorbed doses to the LA were 21.2 ± 0.8 and 42.9 ± 2.3 Gy using OLINDA, 8.1 ± 0.3 and 16.7 ± 0.5 Gy using voxel based methodology, and 8.2 ± 0.3 and 15.7 ± 0.5 Gy for OEDIPE in the right and left LA, respectively. Distribution of the radiopharmaceutical within the joint space alters over the imaging period, with less than 1% of the remaining activity having moved posteriorly in the knee cavity. No uptake was detected outside of the joint space after assessment with whole-body scintigraphy. Conclusions: An activity of approximately 185 MBq successfully relieved clinical symptoms of LA. There was good correlation between direct Monte Carlo and voxel based techniques, but OLINDA was shown to overestimate the absorbed dose to the tumor. Accurate dosimetry may help select an activity more tailored to the specific size and location of the LA. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the role of multiplanar reformations (MPR) in the diagnosis of peripheral pulmonary embolism on multidetector computed tomography (MDCT) pulmonary angiography. Methodology: This was a retrospective cross sectional study carried out in Department of Radiology, Rehman Medical Institute, Peshawar from December 2012 to October 2017 on 437 patients with clinically suspected pulmonary embolism (PE). Age range was 20 to 90 years and patients presented with shortness of breath, nonspecific chest pain or pleuritic chest pain. CT pulmonary angiography (CTPA) was performed on 128 slice MDCT Toshiba scanner. Two sets of images were analyzed: overlapped axial sections and 2DMPR of obliquely oriented peripheral arteries. Results: Peripheral PE was diagnosed in small segmental branches in 184 (42%) cases on MDCT pulmonary angiography. MPR detected peripheral PE in oblique oriented vessels. Associated central right main pulmonary artery thrombus was seen in 94 patients and in left pulmonary artery in 93 patients. The presence of central embolism was easily detected on axial overlapped images. The peripheral segmental emboli were further confirmed or excluded with MPR. Conclusion: Multiplanar reformations enabled confident diagnosis of peripheral PE in 42% of cases. MDCT with MPR improves analysis of extent of thromboembolic disease and enables confident exclusion in inconclusive CT scans. [ABSTRACT FROM AUTHOR]