Emergency unenhanced multi-slice computed tomography in suspected urinary calculi—with dose reduction method (care dose 4D)

Objectives: To assess urinary calculi and the secondary signs of obstruction, in patients referred from the accident and emergency department, by unenhanced computed tomography examination and to review the radiation dose the patients received with the use of automatic dose modulation technique, care dose 4D. Material and methods: Medical records of unenhanced multi-slice computed tomography (MSCT) examinations for 114 patients referred to the emergency department for analysis of suspected urinary calculi were reviewed retrospectively. Their treatment involved automatic tube current modulation, a dose reduction method (care dose 4D), in Hamad General Hospital. The cases were analyzed for the presence of stones, size, site, density and the secondary signs of obstruction, namely hydronephrosis, hydroureter, perinephric fat stranding, peri-ureteric fat stranding and renal enlargement. A search for alternate diagnosis was made if no stone was found. The final diagnosis was noted from the discharge summary in medical records. The radiation dose, Computed Tomographic Dose Index volume (CTDI) and Dose Length Product (DLP) in each patient was recorded from patient protocol. Results: Of 114 patients referred to CT scan for suspected urinary calculi, between March and June 2008, urinary calculi were noted in 75.4 %. An alternate diagnosis was offered to 5.3 % and a diagnosis of normal was given to 19.3 %. The size of stones detected varied from 2mm-35mm. Density of stones varied from 110-1250 hounsfield units (HU). Solitary stones were seen in 54.4 % of cases observed and multiple stones in 22 %. Renal stones were observed in 6.1 % of cases, urteric stones in 26.3%, vesico-uretric junction stones in 18.4%, multiple sites in 23.7%. Hydronephrosis was seen in 68% of cases, hydroureter in 63%, perinephric fat stranding in 51%, periureteral fat stranding in 34%, ureteric rim sign in 28% and renomegaly in 24%. Time interval between onset of symptoms to imaging varied from 4 to 12 hours. The radiation dose, CTDI, ranged from 6.5-15.8 mGy and DLP from 257 to 918 mGy/cm with the use of automatic tube current modulation, care dose 4D. Final diagnosis and MSCT diagnosis were in concordance in 86 (75% of) patients of renal calculi and alternate diagnosis in 6 (5.3%) of patients and normal in rest of the patients. Conclusion: In clinically-suspected urinary calculi, unenhanced MSCT of abdomen with the use of care dose 4D, an automatic tube current modulation technique, is a fast and reliable investigation in an emergency setting to detect stones and secondary signs of obstruction. It offers alternate diagnosis with substantial reduction in radiation dose—both the computed tomography dose index (CTDI) and dose length product (DLP)

Diagnostic implications of computed tomography pulmonary angiography in patients with pulmonary embolism

Introduction: Pulmonary embolism (PE) is a serious cardiovascular and pulmonary complication worldwide. We aimed to assess the implications of different computed tomography pulmonary angiography (CTPA) parameters in patients with acute PE. Methods: A retrospective observational study to include patients presented with clinical suspicious of PE who underwent CTPA was conducted. Patients' demographics, clinical presentation, risk factors, laboratory investigations, management, and outcome were analyzed. Computed tomography findings included clot burden (Qanadli score [QS]) and right ventricular dysfunction (RVD) parameters. Results: A total of 45 patients with radiologically confirmed diagnosis of PE were included in the study; of these patients, 8 (17.8%) died during the hospital course. Patients who died were 13 years older than those who survived, and the mortality rate was significantly higher in patients with cancer. The two groups were comparable for cardiovascular parameters. The mean clot burden (QS) was 19.5 ± 11.3 points and 53% of patients had QS >18 points. Obesity (52.4% vs. 12.5%; P = 0.01), hypertension (54.4% vs. 23.8%; P= 0.03), and median D-dimer levels (7.8 vs. 3.4; P = 0.03) were significantly higher in patients with QS >18. Among right ventricular (RV) dysfunction parameters, only higher RV/left ventricular (LV) ratio (P = 0.001) and bowing of interventricular septum (P = 0.001) were associated with higher QS. A significant positive correlation was found between RV short axis (r = 0.499, P = 0.001), RV/LV ratio (r = 0.592, P = 0.001), and pulmonary artery (PA) diameter (r = 0.301, P = 0.04) with the PA clot burden. Receiver operating characteristic curve for clot burden showed a cutoff value of 17.5 points to accurately predict RV dysfunction. Conclusions: Clot burden >18 is associated with RV dysfunction in patients with acute PE. Echocardiography and RVD parameters showed no correlation with in-hospital deaths. CTPA has clinicoradiological implications for risk stratification in PE patients. As the sample size is small, our findings warrant further larger prospective studies

Renal artery injury secondary to blunt abdominal trauma : two case reports

BACKGROUND: Blunt abdominal trauma is routinely encountered in the Emergency Department. It is one of the main causes of morbidity and mortality amongst the population below the age of 35 years worldwide. Renal artery injury secondary to blunt abdominal trauma however, is a rare occurrence. Here, we present two such cases, encountered in the emergency department sustaining polytrauma following motor vehicle accidents. CASE REPORT: We hereby report two interesting cases of renal artery injury sustained in polytrauma patients. In these two cases we revealed almost the entire spectrum of findings that one would expect in renal arterial injuries. CONCLUSIONS: Traumatic renal artery occlusion is a rare occurrence with devastating consequences if missed on imaging. Emergency radiologists need to be aware of the CT findings so as to accurately identify renal artery injury. This case report stresses the need for immediate CT assessment of polytrauma patients with suspected renal injury, leading to timely diagnosis and urgent surgical or endovascular intervention