Janet R. Reid

Optimization of Kilovoltage and Tube Current–Exposure Time Product Based on Abdominal Circumference: An Oval Phantom Study for Pediatric Abdominal CT

OBJECTIVE This CT study evaluates image noise and radiation dose using a modified CT dose index phantom to approximate pediatric abdominal shape. Contrast-to-noise ratio (CNR) and radiation dose were measured. MATERIALS AND METHODS The oval shape was simulated by fixing 1000-mL saline bags aside cylindric phantoms with variable circumferences. The doses at the center and peripheral holes in the phantom were recorded. Measurements were obtained at 50-400 mAs and 80-140 kVp. Diluted iodine contrast agent filled the center hole, and distilled water filled the peripheral holes. CNR was defined as the difference in CT number between diluted iodine and water divided by the standard deviation (SD) of CT number of water. RESULTS Dose increased linearly with increases in tube current-exposure time product and by a power function (proportional to kVp(n), where n = 2.64-3.09) for increases in kilovoltage. A range of scanning parameters was established for each circumference from which technique optimization curves were created to determine the best tube current-time product and kilovoltage pairs when noise was less than 20 HU and dose was less than 2.5 cGy. CNR increased by 40% as kilovoltage was reduced from 140 to 80 kVp. A dose reduction of 70% was observed for 140 versus 80 kVp for the same CNR. CONCLUSION Because pediatric patients of the same age and weight come in all shapes and sizes, abdominal circumference is a useful clinical parameter on which to base CT scan techniques controlling radiation output--namely kilovoltage and tube current-time product. Low-kilovoltage techniques for patients with small circumference show better iodine CNR.

Thoracic outlet syndrome with subclavian aneurysm in a very young child: the complementary value of MRA and 3D-CT in diagnosis

Thoracic outlet syndrome (TOS) is rare in childhood. In adults, TOS results in compression of the neurovascular bundle (branches of the brachial plexus and the subclavian artery), but more than 95% of cases present solely with neurologic compression. We present a case of TOS in a very young child and describe the rare finding of subclavian artery compression and post-stenotic aneurysm. The clinical features, imaging workup, and surgical findings are discussed. The combination of three-dimensional MR angiography and CT was of great value in diagnosis and surgical planning.

Worldwide Utilization of a Web-Based Learning Tool for Pediatric Radiology

OBJECTIVE The purpose of this study was to determine the reach, appeal, and learning effectiveness of a Web-based pediatric radiology curriculum with attention to level of training, test format, program size, subspecialty, and country of study. MATERIALS AND METHODS Registration demographics, the 10-point evaluation form, and pre- and posttest scores from approximately 17,000 modules completed from October 2011 to July 2012 were analyzed. RESULTS There were 20,583 registered users from 298 institutions, 43 states and Puerto Rico, and 53 countries, with on average 256 new registrants each year. Evaluation scores were 3.30-4.16 of 5 points. Small programs benefited most with an average improvement of 16.78%, with an average improvement of 16.31% for medium and large programs (p < 0.001). First-year residents showed greatest improvement (18.15%), followed by second-year (16.74%), third-year (16.16%), and fourth-year (12.94%) residents. Radiology residents showed greater improvement (16.63%) over others collectively (16.21%), dependent on job training (p < 0.0001). Average improvement for true/false versus multiple-choice tests was 15.53% and 26.00%, respectively (p < 0.0001). Improvement was higher for international (16.91%) than North American (16.43%) users, with all modules showing improvement with similar trends for all modules; however, the pretest average was higher for United States and Canada than for the rest of the world (63.67% vs 61.92%). Mean improvement over all modules was 16.45% (SD, 18.36%) with 95% confidence interval of 16.18%-16.73% (p < 0.001). CONCLUSION The pediatric radiology curriculum is universally popular both within North America and internationally, easy to use and enjoyable, and effective for learners at all levels within radiology and allied fields. In addition, it serves as an excellent springboard for future development of more sophisticated learning tools.

Ultrasound Tutorials in Under 10 Minutes: Experience and Results.

OBJECTIVE The objective of the present study was to validate the use of web-based tutorials to teach technical skills in pediatric ultrasound. MATERIALS AND METHODS A series of 10 video tutorials, each of which was less than 10 minutes long, was created to improve the education of radiology trainees in terms of their ultrasound technique. Pediatric radiology fellow trainees from our institution in the United States and radiology resident trainees from our partner institution in Ethiopia were invited to participate in the study. Validation of the video tutorials was performed using two learning modules that focused on the renal bladder and the right upper quadrant (RUQ). Pretest and posttest skill and confidence assessments were also conducted. After watching the tutorials, the trainees completed questionnaires that assessed the reach, appeal, and learning effectiveness of the modules. RESULTS Ten fellow trainees and eight resident trainees participated in the study. The fellows were invited to evaluate both the RUQ and the renal bladder learning modules, whereas the residents evaluated the RUQ module only. Before reviewing the RUQ module, the fellows had performed a median of four RUQ ultrasound examinations, whereas the residents had performed a median of 400 RUQ ultrasound examinations. After the trainees viewed the learning module, the median skills test scores of the fellows increased from 20 to 37.5 (highest possible score, 45) (p < 0.01), and those of the residents increased from 38 to 40 (highest possible score, 40) (p = 0.04). With a total possible score of 15, the median confidence score improved from 8 to 11 for fellows (p < 0.01) and from 13.5 to 14.5 for residents (p = 0.04). After the fellows viewed the renal bladder learning module, their median skills test scores increased from 20 to 37.5 (highest possible score, 40) (p < 0.01), and their median confidence score increased from 8.5 to 11 (highest possible score, 15) (p = 0.01). Trainees gave the tutorials positive ratings overall. CONCLUSION Radiology fellow trainees and resident trainees with disparate backgrounds in ultrasound showed significant improvement in their technical skills in pediatric ultrasound and confidence after viewing the tutorials. The web-based design of the tutorials allows integration of international pediatric radiology training communities.

Comparison of Gonadal Radiation Doses From CT Enterography and Small-Bowel Follow-Through in Pediatric Patients

OBJECTIVE. CT enterography is superior to small-bowel follow-through (SBFT) for diagnosis of inflammatory bowel disease (IBD). It is widely assumed that the radiation dose from CT enterography is greater than that from SBFT in the pediatric patient. This study was designed to compare gonadal doses from CT enterography and SBFT to verify the best imaging choice for IBD evaluation in children. This study also challenges the assumption that CT enterography imparts a higher radiation dose through comparison of calculated radiation doses from CT enterography and SBFT. MATERIALS AND METHODS. Patients 0-18 years old who underwent either CT enterography or SBFT over a 2-year period were included. The CT enterography group consisted of 39 boys and 51 girls, whereas the SBFT group consisted of 89 boys and 113 girls. CT enterography was performed at 120 kVp and approximately 132 mAs (range, 54-330 mAs) using weight-based protocols. SBFT used automated control of kilovoltage and tube current-exposure time product. Patient demographics and technical parameters were collected for CT enterography and SBFT, data were cross-paired between CT enterography and SBFT, and gonadal dose was calculated. RESULTS. Mean (± SD) CT enterography testis and ovarian doses were 0.93 ± 0.3 cGy (n = 39) and 0.64 ± 0.2 cGy (n = 51), respectively. Mean SBFT testis and ovarian doses were 2.3 ± 1.6 cGy (n = 89) and 1.49 ± 0.3 cGy (n = 113), respectively. Mean fluoroscopy time for SBFT was 2.6 ± 2 minutes. Gonadal dose for CT enterography was significantly lower than that for SBFT in boys and girls (p < 0.001). SBFT dose was lower in girls than boys (p < 0.001), whereas CT enterography dose was higher in boys than girls (p < 0.001). CONCLUSION. Gonadal dose for CT enterography was lower than that for SBFT for boys and girls of all sizes and age. Controlled exposure time made CT enterography dose more consistent, whereas the range of dose for SBFT was highly operator dependent and related to extent of disease. Thus, for IBD, CT enterography is preferred over SBFT for all children.

How and how well do pediatric radiology fellows learn ultrasound skills? A national survey.

BackgroundUltrasound (US) comprises a significant portion of pediatric imaging. Technical as well as interpretive skills in US imaging are consequently fundamental in training pediatric radiologists. Unfortunately, formalized technical education regarding US imaging in pediatric fellowships has lagged.ObjectiveWe surveyed pediatric fellows and program directors regarding US scanning education to improve this experience moving forward.Materials and methodsWe conducted an online survey from February 2011 to March 2011 of all United States pediatric radiology body imaging fellows and fellowship program directors. Questions posed to fellows assessed their educational US experiences during their residencies and fellowships. Directors were asked to evaluate US educational opportunities in their programs.ResultsAmong the respondents, 43.9% of fellows undertook on-call US scanning without a sonographer during residency, 23.3% during fellowship; 41.8% of fellows and 58.6% of program directors reported that their fellowship had a dedicated curriculum to facilitate independent US scanning. Both fellows and program directors cited the volume of cases requiring immediate dictation as an obstacle to scanning. Fewer program directors than fellows identified lack of sufficient staffing as an obstacle, but more identified fellow disinterest. Program directors and fellows alike rated independent US scanning as highly important to pediatric radiologists’ future success.ConclusionPediatric radiology fellowship directors and fellows agree that technical US skills are crucial to the practice of pediatric radiology. However, the groups identify different obstacles to training. As US instruction is developing in undergraduate medicine and subspecialists are acquiring point-of-care US skills, pediatric radiology education should address the obstacles to US training and formalize a curriculum at the fellowship level.

Designing and testing an educational innovation

Technology provides an opportunity to develop innovations to improve the way we teach. Developing educational innovations must be approached in a methodical and thorough manner to identify the educational gap and validate the innovation’s success in filling the gap. A successful educational innovation requires a stepwise approach that includes needs assessment, design of intervention, testing and analysis, evaluation of intervention, and determination of learning retention.

Intestinal obstruction secondary to infantile polyarteritis nodosa

Polyarteritis Nodosa (PAN) is a rare systemic necrotising vasculitis of medium and small-sized arteries. Patients typically present with systemic symptoms. Obstructive intestinal symptoms are described but usually resolve with treatment of the underlying vascular disease. We report a case of a one year old boy with multiple ischemic small bowel strictures secondary to infantile PAN, who was treated with resection of the affected segments by single port laparoscopy.

Teaching and learning in the millennial age

Medical education has changed and evolved over the years and has been greatly influenced by advances in technology. While the learners have also changed and the information and skills to be learned and acquired have exponentially increased, the ultimate purpose of medical education has not changed. Our focus is and has always been to improve patient care. This minisymposium highlights selected specific topics that have the potential to enhance our ability to teach and pass along essential ideas and concepts to modern learners, thus improving the health and wellbeing of patients now and in the future.

MRI of the bowel — beyond inflammatory bowel disease

MR enterography is traditionally used to evaluate inflammatory bowel disease (IBD) both at initial presentation and at follow-up. MR enterography can also be used to evaluate non-IBD conditions such as polyps or other masses of the gastrointestinal tract. In this article, we emphasize how to recognize bowel conditions beyond IBD on conventional abdominal MRI without a specific enterographic technique. In this overview we discuss common and uncommon pediatric bowel conditions beyond IBD seen on MRI including infectious and inflammatory conditions, congenital diseases and tumor and tumor-like conditions. Radiologists should become familiar with the salient imaging features of these bowel conditions to help guide management.