Diagnostic Range Ionizing Radiation and Reactive Oxygen Species Production: an Initial Experience

Radiation is a common occurrence in our daily lives that comes from both natural and man-made sources. Ionizing Radiation (IR) causes damage either directly or indirectly through the generation of reactive oxygen species (ROS). Oxidative damage to DNA, lipids, proteins, and many metabolites occurs through a complex series of processes that are enhanced by endogenous signalling which is activated by free radicals. Though literature is abundant on ROS and antioxidants at high doses, no study to the best of our knowledge has assessed the ROS levels after Multi Detector Computed Tomography (MDCT) examination (i.e. in diagnostic range radiation). The aim of the present study was to assess the production of ROS after diagnostic level radiation by MDCT examination and at 24 hour follow up. The study involved fifty patients posted for clinically indicated MDCT which were recruited. The average radiation dose was 2-9 mGy. Three blood samples were drawn, one prior to CT (control sample), within half an hour of CT (post CT) and 24 hrs after CT. 3 ml venous blood was withdrawn in aseptic conditions and immediately serum was isolated for ROS assessment. The blood examination results were compared in immediate and post 24 hour after MDCT and both were compared with control values and correlated with radiation parameters. Our results have shown a significant increase in ROS level in immediate post CT samples compared to prior CT scan samples (control) (p value <0.0001). The ROS levels reduced at 24 hours compared to immediate post CT, however they were still higher than control values. Our findings reflect that there is a rapid increase in free radicals production in the mitochondria after diagnostic level radiation. Detection of higher ROS levels at 24 hours suggests incomplete repair with the presence of some residual oxidative species at 24 hours.

Imaging of Pancreatic Carcinoma on Multidetector Computed Tomography, A Tertiary Care Experience at Liaquat National Hospital, Karachi

Introduction: Pancreatic cancer is a lethal disease. The mortality rate for pancreatic tumor has changed over the last 20 years. Early diagnosis of pancreatic carcinoma is very important for therapeutic decisions and surgical planning. Contrast enhance CT facilitated the detection of primary tumor and staging. Objective: This study is to evaluate various presentations of pancreatic carcinomas on their initial MDCT (Multidetector Computed Tomography) and to evaluate its resectability and to compare CT features among resectable and non-resectable tumors. Methodology: All the patients underwent multi-phasic CT scan on a 16-slice MDCT. CT findings were analyzed included tumor location, size, enhancement pattern, nodal disease, duct dilatations, vascular involvement and evidence of metastatic disease. Results: Total 63 records of patients examined during 2017 and 2019 meeting the inclusion criteria were reviewed. The average age at time of MDCT examination was 62.51 ± 13.17 years. The disease was more common in males (n=36, 57.1%). Out of 63 pancreatic tumors, 14 (22.22%) tumors were identified as resectable tumors on MDCT examination. Tumor size (p<0.001), peripancreatic nodes (p=0.006), contrast enhancement (p=0.018), vessel involvement (p<0.001), ascites (p=0.006), hepatic metastases (p=0.001) and peripheral organ involvement (p<0.001) were significantly different among resectable and non-resectable tumors. Conclusion: MDCT is an excellent and most commonly used modality for diagnosis and staging of pancreatic carcinoma particularly with a high sensitivity for detection of vascular invasion and metastatic disease.

VIRTOPSY AFTER FATAL INJURY BY LANDING GEAR OF AN AIRCRAFT BOEING 737

The article presents a rare case of virtopsy of a mortally injured person on the runway by the landing gear of the overclocking Boeing 737 aircraft. A case from the expert practice of the Khimki forensic medical department with preliminary pre-sectional MDCT examination of the corpse (virtual autopsy) and subsequent MDCT anatomical comparison of the results.

Small Bowel Volvulus due to Mesenteric Lymphatic Malformation: MDCT Demonstration of Counterclockwise Barber Pole Sign

Counterclockwise barber pole sign (also known as reverse barber pole sign) is an angiographic sign described in patients with small bowel volvulus due to counterclockwise twisting of mesenteric vessels around the superior mesenteric artery (SMA). The sign was first described in a catheter angiographic examination; however, the concept can be translated to the display methods of computed tomography (CT). This sign can be depicted clearly on multiplanar and three-dimensionally rendered images of multidetector computed tomography (MDCT) examination. In the current report, the reverse barber pole sign is illustrated in a child with partial small bowel volvulus secondary to mesenteric lymphatic malformation. The clinical course, management, and imaging appearances are presented, highlighting the observation of counterclockwise barber pole sign on MDCT imaging. The importance of the sign in identification of volvulus and implications for patient management are emphasized.

Arterial Tortuosity Syndrome: An Approach through Imaging Perspective

This pictorial illustration demonstrates various aspects of arterial tortuosity syndrome (ATS) obtained predominantly from a multiple detector computed tomography (MDCT) examination of a patient. In addition, a comprehensive review of typical multi-modality imaging observations in patients with ATS is presented along with a description of a few imaging signs. Non-invasively obtained, conclusive information is required in patients with ATS in view of the fragile vascular structures involved. An amazing wealth of information can be obtained by reviewing the volumetric data sets of MDCT examination. In the context of incomplete clinical information or remote reading of radiographic examination with inadequate clinical details, ability to “image data mine” the hidden, unexplored information may be vastly useful. The role of MDCT as a single modality of evaluation in ATS is highlighted.

Blunt trauma of bone structures of the chest: Computed tomography vs multidetector computed tomography

Background/Aim. Computerized tomography (CT), especially multidetector CT (MDCT), has had a revolutionary impact in diagnostic in traumatized patients. The aim of the study was to identify and compare the frequency of injuries to bone structures of the thorax displayed with 5-mm-thick axial CT slices and thin-slice (MDCT) examination with the use of 3D reconstructions, primarily multiplanar reformations (MPR). Methods. This prospective study included 61 patients with blunt trauma submitted to CT scan of the thorax as initial assessment. The two experienced radiologists independently and separately described the findings for 5-mmthick axial CT slices (5 mm CT) as in monoslice CT examination; MPR and other 3D reconstructions along with thin-slice axial sections which were available in modern MDCT technologies. After describing thin-slice examination in case of disagreement in the findings, the examiners redescribed thinslice examination together which was ultimately considered as a real, true finding. Results. No statistically significant difference in interobserver evaluation of 5 mm CT examination was recorded (p > 0.05). Evaluation of fractures of sternum with 5 mm CT and MDCT showed a statistically significant difference (p < 0.05) in favor of better display of injury by MDCT examination. Conclusion. MDCT is a powerful diagnostic tool that can describe higher number of bone fractures of the chest in traumatized patients compared to 5 mm CT, especially in the region of sternum for which a statistical significance was obtained using MPR. Moreover, the importance of MDCT is also set by easier and more accurate determination of the level of bone injury.