Michael B. Mazza

Imaging of pregnant and lactating patients: part 1, evidence-based review and recommendations.

OBJECTIVE The objectives of this article are to discuss the current evidence-based recommendations regarding radiation dose concerns, the use of iodinated and gadolinium-based contrast agents, and the comparative advantages of multimodality imaging (ultrasound, CT, and MRI) during pregnancy and lactation. We also discuss the use of imaging to evaluate pregnant trauma patients. CONCLUSION Maternal and fetal radiation exposure and dose are affected by gestational age, anatomic site, modality, and technique. The use of iodinated and gadolinium-based contrast agents during pregnancy and lactation has not been well studied in human subjects. Imaging should be used to evaluate pregnant trauma patients only when the benefits outweigh the risks.

Equivocal Pediatric Appendicitis: Unenhanced MR Imaging Protocol for Nonsedated Children—A Clinical Effectiveness Study

PURPOSE To determine retrospectively the clinical effectiveness of an unenhanced magnetic resonance (MR) imaging protocol for evaluation of equivocal appendicitis in children. MATERIALS AND METHODS Institutional review board approval was obtained. Pediatric patients (≤18 years old) underwent unenhanced MR imaging and contrast material-enhanced computed tomography (CT) of the appendix between December 2013 and November 2014 and December 2012 and November 2013, respectively, within 24 hours after an abdominal ultrasonographic examination with results equivocal for appendicitis. Pertinent MR imaging and CT reports were reviewed for visibility of the appendix, presence of appendicitis and appendiceal perforation, and establishment of an alternative diagnosis. Surgical reports, pathologic reports, and 30-day follow-up medical records were used as reference standards. Diagnostic performance with MR imaging and CT was calculated with 95% confidence intervals (CIs) for diagnosis of appendicitis and appendiceal perforation. The Fisher exact test was used to compare proportions; the Student t test was used to compare means. RESULTS Diagnostic performance with MR imaging was comparable to that with CT for equivocal pediatric appendicitis. For MR imaging (n = 103), sensitivity was 94.4% (95% CI: 72.7%, 99.9%) and specificity was 100% (95% CI: 95.8%, 100%); for CT [n = 58], sensitivity was 100% (95% CI: 71.5%, 100%), specificity was 97.9% (95% CI: 88.7%, 100%). Diagnostic performance with MR imaging and CT also was comparable for detection of appendiceal perforation, with MR imaging (n = 103) sensitivity of 90.0% (95% CI: 55.5%, 99.8%) and specificity of 85.7% (95% CI: 42.1%, 99.6%) and CT (n = 58) sensitivity of 75.0% (95% CI: 19.4%, 99.4%) and specificity of 85.7% (95% CI: 42.1%, 99.6%). The proportion of examinations with identifiable alternative diagnoses was similar at MR imaging to that at CT (19 of 103 [18.4%] vs eight of 58 [13.8%], respectively; P = .52). The proportion of appendixes seen at MR imaging and at CT also was similar (77 of 103 [74.8%] vs 50 of 58 [86.2%], respectively; P = .11). CONCLUSION Unenhanced MR imaging is sensitive and specific for the diagnosis of equivocal appendicitis in nonsedated pediatric patients.

Inter-radiologist agreement for CT scoring of pediatric splenic injuries and effect on an established clinical practice guideline

BackgroundThe American Pediatric Surgical Association (APSA) advocates for the use of a clinical practice guideline to direct management of hemodynamically stable pediatric spleen injuries. The clinical practice guideline is based on the CT score of the spleen injury according to the American Association for the Surgery of Trauma (AAST) CT scoring system.ObjectiveTo determine the potential effect of radiologist agreement for CT scoring of pediatric spleen injuries on an established APSA clinical practice guideline.Materials and methodsWe retrospectively analyzed blunt splenic injuries occurring in children from January 2007 to January 2012 at a single level 1 trauma center (n = 90). Abdominal CT exams performed at clinical presentation were reviewed by four radiologists who documented the following: (1) splenic injury grade (AAST system), (2) arterial extravasation and (3) pseudoaneurysm. Inter-rater agreement for AAST injury grade was assessed using the multi-rater Fleiss kappa and Kendall coefficient of concordance. Inter-rater agreement was assessed using weighted (AAST injury grade) or prevalence-adjusted bias-adjusted (binary measures) kappa statistics; 95% confidence intervals were calculated. We evaluated the hypothetical effect of radiologist disagreement on an established APSA clinical practice guideline.ResultsInter-rater agreement was good for absolute AAST injury grade (kappa: 0.64 [0.59–0.69]) and excellent for relative AAST injury grade (Kendall w: 0.90). All radiologists agreed on the AAST grade in 52% of cases. Based on an established clinical practice guideline, radiologist disagreement could have changed the decision for intensive care management in 11% (10/90) of children, changed the length of hospital stay in 44% (40/90), and changed the time to return to normal activity in 44% (40/90).ConclusionRadiologist agreement when assigning splenic AAST injury grades is less than perfect, and disagreements have the potential to change management in a substantial number of pediatric patients.

Normal and Variant Abdominal Anatomy on Magnetic Resonance Imaging

The diagnostic usefulness of abdominal magnetic resonance (MR) imaging lies in the improved contrast resolution and ability to qualify several tissue characteristics of a specific organ or lesion. Our institution uses organ-specific protocols to facilitate technical reproducibility and optimize scan duration. These protocols are discussed individually in this article when applicable, noting that many build on a basic protocol with slight variations. Because most abdominal MR imaging studies are targeted toward an organ or area of interest, this article discusses the protocol strategies and relevant anatomy in a segmented/organ-specific manner.

MR Imaging of Pelvic Emergencies in Women

MR imaging is a useful adjunct imaging modality for evaluating women presenting with acute lower abdominal/pelvic pain who have negative or inconclusive sonographic findings. In pregnant women, although obstetric complications are of prime concern, gastrointestinal pathologies also warrant careful attention, and MR imaging is often useful in refining the diagnosis. In nonpregnant women, gynecologic pathologies and gastrointestinal pathologies are of major concern, and may necessitate evaluation with MR imaging. Knowledge of imaging features in the appropriate clinical setting helps in early and accurate diagnosis, enabling timely management for better clinical outcomes.

Clearing the Posttraumatic Adult Cervical Spine

More than 13 million patients with trauma at risk for cervical spine (c-spine) injury are treated in emergency departments in the United States and Canada each year.1 C-spine injuries are present in approximately 2% to 10% of trauma cases, with more than 10,000 new patients per year.2 Given the potential for disastrous consequences in delayed or missed diagnosis, clearance of the c-spine in a trauma patient is of paramount importance. Clearance of the c-spine is defined as the determination of the absence of c-spine injury and is an important task that must be performed accurately and expeditiously. Today, with the advent of and dramatic improvement in cross-sectional imaging, the diagnostic radiologist has become an important member of the management team of patients with c-spine and multitrauma injuries.

Post-traumatic penile pseudoaneurysm causing high-flow priapism

A 7-year-old boy presented to the ED with an 8-day history of continuous, painless priapism which began following a straddle-type injury to the groin during a bicycle accident. On physical exam, the patient’s phallus was fully erect and straight. Mild swelling was noted at the penoscrotal junction but no perineal ecchymosis or swelling was present. The testicles were unremarkable, without tenderness or visible signs of injury such as swelling or bruising. The patient denied hematuria or any difficulty with urination. Ultrasonography of the penis was performed which demonstrated the presence of color Doppler flow in the cavernosal arteries. A small, contained outpouching of color Doppler flow along the left cavernosal artery demonstrated arterial flow on spectral analysis, consistent with a pseudoaneurysm (Figs. 1 and 2). Based on the history of perineal straddle injury and the duplex ultrasonography findings, the diagnosis of high-flow priapism was made. It was elected to treat the patient conservatively with close observation alone. Over the course of a month, the priapism subsided with full resolution of penile tumescence. Follow-up color duplex ultrasonography was normal, demonstrating resolution of the cavernosal pseudoaneurysm. Discussion