Faculty Bibliography

RATIONALE AND OBJECTIVES/OBJECTIVE:Simulation-based training has been shown to be a useful adjunct to standard didactic lecture in teaching residents appropriate management of adverse contrast reactions. In addition, it has been suggested that a biannual refresher is needed; however, the type of refresher education has not been assessed. MATERIALS AND METHODS/METHODS:This was a prospective study involving 31 radiology residents across all years in a university program. All residents underwent standard didactic lecture followed by high-fidelity simulation-based training. At approximately 6 months, residents were randomized into a didactic versus simulation group for a refresher. At approximately 9 months, all residents returned to the simulation center for performance testing. Knowledge and confidence assessments were obtained from all participants before and after each phase. Performance testing was obtained at each simulation session and scored based on predefined critical actions. RESULTS:There was significant improvement in knowledge (P < .002) and confidence (P < .001) after baseline education of combined didactic and simulation-based training. There was no statistical difference between the simulation and didactic groups in knowledge or confidence at any phase of the study. There was no significant difference in tested performance between the groups in either performance testing session. CONCLUSIONS:This study suggests that a curriculum consisting of an annual didactic lecture combined with simulation-based training followed by a didactic refresher at 6 months is an effective and efficient (both cost-effective and time-effective) method of educating radiology residents in the management of adverse contrast reactions.

OBJECTIVE:To compare the radiographic density of renal cysts on contrast-enhanced computed tomography (CT) scans performed at tube voltages of 100 versus 120 kVp. METHODS:Thirty-six renal cysts from contrast-enhanced CT performed on 21 subjects at both 120 kVp and 100 kVp were compared by Kolmogorov-Smirnov statistical testing. RESULTS:The radiographic density (mean+/-standard deviation in Hounsfield units) of cysts was greater on 100-kVp than on 120-kVp CT scans for both 5-mm and 2-mm reconstructed slice thicknesses: 16.6+/-5.6 versus 10.9+/-4.9 and 14.1+/-5.6 versus 8.5+/-3.9, respectively. CONCLUSIONS:Decrease in tube voltage significantly increases measured radiographic density of renal cysts on CT. Further studies are indicated to assess the clinical impact of lower-tube-voltage CT.

PURPOSE/OBJECTIVE:To compare image quality on contrast-enhanced dual-energy computed tomography (DECT) during the pancreatic parenchymal phase of pancreatic masses between linearly-blended simulated 120 kVp images (routine) and advanced image-based virtual monoenergetic reconstructions at 55 keV. METHODS:This was a retrospective evaluation of 24 nonconsecutive adults found to have a focal pancreatic mass on a multiphasic abdominal dual-source DECT (12 adenocarcinoma, 5 neuroendocrine, 7 cystic tumors). For pancreatic-parenchymal phase images, subjects had routine and 55 keV images reconstructed at the time of clinical evaluation. Quantitative evaluation by contrast-to-noise ratio and qualitative evaluations of image quality by (1) direct comparison of image pairs (preference) and (2) blinded assessment of image quality measures based on Likert scores were performed. RESULTS:Mean patient weight was 205.8 ± 26.6 lbs. Mean pancreatic lesion contrast-to-noise ratio was significantly higher at 55 keV (6.8 ± 4.1) compared to the routine image series (5.8 ± 3.8; P = 0.0002). All 3 readers preferred the 55-keV images over routine blended images in 70.1% to 95.8% of cases. No significant differences were observed for subjective sharpness of the mass, visualization of internal mass structures, or image noise. CONCLUSIONS:Use of a single advanced image-based virtual monoenergetic reconstruction at 55 keV in pancreatic DECT showed improved objective image quality and reader preference compared to routine images. As this image reconstruction can be incorporated into the scan protocol, this technique should be considered for routine clinical use.

A 44-year-old woman presented with a large pelvic mass. Pathology revealed a granulosa cell tumour of the left ovary. The patient was followed after surgery with inhibin B levels and interval imaging. Six years later, she began to experience severe back pain. A vertebral biopsy was positive for metastatic granulosa cell tumour. She underwent radiation to the spine. Inhibin B levels began to rise and, several months later, a CT scan showed a large heterogeneous mass essentially replacing the left kidney. She underwent an open left radical nephrectomy. Pathology revealed a 12 cm cystic nephroma with a 5 cm nodule of metastatic granulosa cell tumour. Immunohistochemistry demonstrated that the mass was inhibin and oestrogen receptor positive. This is a novel presentation of these coexisting pathologies. This unique case sheds light on the possibility of induction of cystic nephroma by the altered hormonal environment created by a granulosa cell tumour metastasis.