How low can we go? CT dose reduction in the assessment of the medial clavicular epiphysis in forensic age estimation: a prospective postmortem CT study.

BACKGROUND: Projection radiography and, more recently, computed tomography (CT) play an important role in forensic age estimation. Both in terms of general criminal responsibility and government regulations concerning refugee care, it is important to differentiate correctly between youths and adults. A disadvantage of age estimation in CT is the ionizing radiation exposure. PURPOSE: To investigate how far the CT dose can be reduced without losing diagnostic confidence in assessing the different stages of ossification of the medial clavicle. MATERIAL AND METHODS: We prospectively scanned 25 postmortem cases with a fixed parameters protocol (FPP) and a care dose modulation protocol (CDMP) for different scan parameters. Two radiologists assessed the diagnostic image quality using a 5-point Likert scale. Inter-reader agreement was evaluated with Cohen's kappa. Differences in doses between FPP and CDMP were assessed with the one-tailed t-test. RESULTS: The best combination of diagnostic image quality and lowest radiation dose was obtained using a CDMP with 100 kV and 40 mAs and an FPP with 100 kV and 30 mAs. Doses for 120 kV were significantly higher (one-tailed P < 0.001). The diagnostic image quality for 80 kV was insufficient overall. DISCUSSION: Our results confirm that CT imaging at 100 kV allows a sufficient image quality that is diagnostic for age estimation in the ossification of the medial clavicle.

Image quality and bile duct volumetry in MR cholangiopancreatography augmented with low-dose morphine.

OBJECTIVE: Opioids are applied to augment visualization of the biliary system in MR cholangiopancreatography (MRCP) to take advantage of a side effect, the constriction of the sphincter of Oddi. This prospective study was performed to determine the effect of IV low-dose morphine on image quality and bile duct delineation in MRCP. SUBJECTS AND METHODS: Fifteen healthy volunteers and 15 consecutive patients underwent MRCP on a 1.5-T MRI scanner. Strongly T2-weighted 3D single-shot fast spin-echo (SSFSE) sequences were acquired before and 10 minutes after IV administration of morphine (0.04 mg/kg of body weight; mean +/- SD, 2.9 +/- 0.5 mg). Maximum intensity projections were reconstructed from the SSFSE sequence data. Image quality was rated by two independent radiologists using a 4-point scale (1 = excellent, 4 = not diagnostic). Delineation of segmental and subsegmental intrahepatic bile duct orders before and after morphine administration was compared. Volumetry of the common bile duct (CBD) was performed using electronic measurements (AngioTux software, ECCET image processing system). RESULTS: IV morphine did not significantly improve subjective image quality of the extra- and intrahepatic bile ducts (mean image quality score before vs after morphine administration, 2.3 vs 2.0) or delineation of the intrahepatic bile duct orders. The volume of the CBD remained constant after morphine administration (mean CBD volume before vs after morphine administration, 14.1 vs 13.6 mL). Notable side effects of morphine were seen in two young healthy female volunteers. CONCLUSION: IV-administered low-dose morphine seems to have no essential influence on image quality or delineation of the bile duct system in MRCP. Therefore, the general advice to perform morphine-augmented MRCP should be discussed critically.