Radiation exposure during paediatric CT in Sudan: CT dose, organ and effective doses.

The purpose of this study was to assess the magnitude of radiation exposure during paediatric CT in Sudanese hospitals. Doses were determined from CT acquisition parameters using CT-Expo 2.1 dosimetry software. Doses were evaluated for three patient ages (0-1, 1-5 and 5-10 y) and two common procedures (head and abdomen). For children aged 0-1 y, volume CT air kerma index (Cvol), air Kerma-length product and effective dose (E) values were 19.1 mGy, 265 mGy.cm and 3.1 mSv, respectively, at head CT and those at abdominal CT were 8.8 mGy, 242 mGy.cm and 7.7 mSv, respectively. Those for children aged 1-5 y were 22.5 mGy, 305 mGy.cm and 1.1 mSv, respectively, at head CT and 12.6 mGy, 317 mGy.cm, and 5.1 mSv, respectively, at abdominal CT. Dose values and variations were comparable with those reported in the literature. Organ equivalent doses vary from 7.5 to 11.6 mSv for testes, from 9.0 to 10.0 mSv for ovaries and from 11.1 to 14.3 mSv for uterus in abdominal CT. The results are useful for dose optimisation and derivation of national diagnostic reference levels.

Underlying deep venous abnormalities in patients with unilateral chronic venous disease.

OBJECTIVES: To report our initial experience using direct multidetector computed tomography venography (MDCT-V) for imaging lower limb deep veins. CT findings in limbs with chronic venous disease (CVD) were compared with contralateral healthy limbs. METHODS: MDCT-V with bilateral direct pedal injection of contrast was used to image the deep veins in both lower limbs. Eight patients with unilateral lower limb CVD of varying severity (according to the Clinico-Etiological-Anatomical and Pathological classification [CEAP] class 2-6) were studied. Five patients had primary CVD, while three patients had CVD secondary to previous deep vein thrombosis. RESULTS: Deep venous obstruction (>50%) or occlusion was identified in all CVD limbs and was not seen in contralateral healthy limbs. These lesions were not only iliac, were not exclusively present in advanced CVD and were independent of the presence or absence of deep venous reflux. CONCLUSION: Morphologically significant lesions could be underlying in patients with clinically significant CVD. Direct MDCT-V provides clear reconstructable cross-sectional images of the whole deep venous tree, including infrainguinal areas, beyond the reach of intravascular ultrasound. Utilization of new venous imaging modalities may uncover previously undiagnosed and potentially treatable venous pathology in patients with CVD.