Michael A. Hulse

An implemented MRI program to eliminate radiation from the evaluation of pediatric appendicitis

BACKGROUND Recent efforts have been directed at reducing ionizing radiation delivered by CT scans to children in the evaluation of appendicitis. MRI has emerged as an alternative diagnostic modality. The clinical outcomes associated with MRI in this setting are not well-described. METHODS Review of a 30-month institutional experience with MRI as the primary diagnostic evaluation for suspected appendicitis (n=510). No intravenous contrast, oral contrast, or sedation was administered. Radiologic and clinical outcomes were abstracted. RESULTS MRI diagnostic characteristics were: sensitivity 96.8% (95% CI: 92.1%-99.1%), specificity 97.4% (95% CI: 95.3-98.7), positive predictive value 92.4% (95% CI: 86.5-96.3), and negative predictive value 98.9% (95% CI: 97.3%-99.7%). Radiologic time parameters included: median time from request to scan, 71 minutes (IQR: 51-102), imaging duration, 11 minutes (IQR: 8-17), and request to interpretation, 2.0 hours (IQR: 1.6-2.6). Clinical time parameters included: median time from initial assessment to admit order, 4.1 hours (IQR: 3.1-5.1), assessment to antibiotic administration 4.7 hours (IQR: 3.9-6.7), and assessment to operating room 9.1 hours (IQR: 5.8-12.7). Median length of stay was 1.2 days (range: 0.2-19.5). CONCLUSION Given the diagnostic accuracy and favorable clinical outcomes, without the potential risks of ionizing radiation, MRI may supplant the role of CT scans in pediatric appendicitis imaging.

A randomized controlled trial comparing three different techniques of nasojejunal feeding tube placement in critically ill children.

BACKGROUND The goal of this study was to compare 3 different techniques used to place nasojejunal (NJ) feeding tubes in the critically ill or injured pediatric patients. This was a randomized, prospective trial in a university-affiliated 12-bed pediatric intensive care unit. Patients were critically ill children requiring placement of an NJ feeding tube. Patient age, weight, medications, use of mechanical ventilation, and patient tolerance were recorded. An abdominal radiograph obtained immediately after the placement determined correct placement. The final placement was recorded, as was the number of placement attempts. METHODS Patients were randomized to 1 of 3 groups: standard technique, standard technique facilitated with gastric insufflation, and standard technique facilitated with the use of preinsertion erythromycin. To ensure equal distribution, all patients were stratified by weight (<10 kg vs > or =10 kg) before randomization. All NJ tubes were placed by one of the investigators. If unsuccessful, a second attempt by the same investigator was allowed. Successful placement of the NJ tube was defined by confirmation of the tip of the tube in the first part of the duodenum or beyond by a pediatric radiologist blinded to the treatment groups. RESULTS Seventy-five pediatric patients were enrolled in the study; 94.6% (71/75) of tubes were passed successfully into the small bowel on the first or second attempt. Evaluation of the data revealed no significant association with a specific technique and successful placement (p = .1999). CONCLUSIONS When placed by a core group of experienced operators, the majority of NJ feeding tubes can be placed in critically ill or injured children on the first or second attempt, regardless of the technique used.

Alternative diagnoses at paediatric appendicitis MRI

As the utilization of MRI in the assessment for paediatric appendicitis increases in clinical practice, it is important to recognize alternative diagnoses as the cause of abdominal pain. The purpose of this review is to share our institutions experience using MRI in the evaluation of 510 paediatric patients presenting with suspected appendicitis over a 30 month interval (July 2011 to December 2013). An alternative diagnosis was documented in 98/510 (19.2%) patients; adnexal pathology (6.3%, n = 32), enteritis-colitis (6.3%, n = 32), and mesenteric adenitis (2.2%, n = 11) comprised the majority of cases. These common entities and other less frequent illustrative cases obtained during our overall institutional experience with MRI for suspected appendicitis are reviewed.

MRI for clinically suspected pediatric appendicitis: case interpretation

As utilization of MRI for clinically suspected pediatric appendicitis becomes more common, there will be increased focus on case interpretation. The purpose of this pictorial essay is to share our institution’s case interpretation experience. MRI findings of appendicitis include appendicoliths, tip appendicitis, intraluminal fluid–debris level, pitfalls of size measurements, and complications including abscesses. The normal appendix and inguinal appendix are also discussed.

Single injection, inspiratory/expiratory high-pitch dual-source CT angiography for median arcuate ligament syndrome: Novel technique for a classic diagnosis

This article discusses a novel technique for dynamic imaging of median arcuate ligament syndrome utilizing low dose CT technology and a single contrast injection.

A quality improvement project to reduce hypothermia in infants undergoing MRI scanning

BackgroundHypothermia prevention strategies during MRI scanning under general anesthesia in infants may pose a challenge due to the MRI scanner’s technical constraints. Previous studies have demonstrated conflicting results related to increase or decrease in post-scan temperatures in children. We noted occurrences of post-scan hypothermia in anesthetized infants despite the use of routine passive warming techniques.ObjectiveThe aims of our quality improvement project were (a) to identify variables associated with post-scan hypothermia in infants and (b) to develop and implement processes to reduce occurrence of hypothermia in neonatal intensive care unit (NICU) infants undergoing MRI.Materials and methodsOne hundred sixty-four infants undergoing MRI scanning were prospectively audited for post-scan body temperatures. A multidisciplinary team identified potential variables associated with post-scan hypothermia and designed preventative strategies: protocol development, risk factor identification, vigilance and use of a vacuum immobilizer. Another audit was performed, specifically focusing on NICU infants.ResultsIn the initial phase, we found that younger age (P = 0.002), lower weight (P = 0.005), lower pre-scan temperature (P < 0.01), primary anesthetic technique with propofol (P < 0.01), advanced airway devices (P = 0.02) and being in the NICU (P < 0.01) were associated with higher odds for developing post-scan decrease in body temperature. Quality improvement processes decreased the occurrence of hypothermia in NICU infants undergoing MRI scanning from 65% to 18% (95% confidence interval for the difference, 26-70%, P < 0.001).ConclusionSeveral variables, including being in the NICU, are associated with a decrease in post-scan temperature in infants undergoing MRI scanning under sedation/general anesthesia. Implementation of strategies to prevent hypothermia in infants may be challenging in the high-risk MRI environment. We were able to minimize this problem in clinical practice by applying quality improvement principles.

Combination of traumatic thoracic aortic pseudoaneurysm and myocardial contusion leading to left ventricular aneurysm

The combination of thoracic aortic pseudoaneurysm and left ventricular aneurysm resulting from a single traumatic incident is an exceedingly rare occurrence. We present a case of a 10-year-old girl who sustained significant blunt trauma to the chest after being involved in a rollover motor vehicle accident. The child underwent immediate repair of a transected aortic arch. An inferior wall left ventricular aneurysm developed 3 weeks later, and the patient underwent successful repair of the left ventricular aneurysm and a damaged mitral valve. The use of fast multidetector row CT, cardiac MRI, and echocardiography have improved our ability to diagnose these types of injuries and accurately image their anatomic relationships in the acute and perioperative settings.

Testicular ascent as a mechanism for intra-abdominal torsion.

Testicular ascent, while uncommon, can occur. A testicle that has ascended out of the scrotum can torse and may present as an acute inguinal mass or acute abdomen. Testicle ascent can occur even if previous intra-scrotal location has been documented.