Amy B. Kolbe

Radiological Response Is Associated With Better Long-Term Outcomes and Is a Potential Treatment Target in Patients With Small Bowel Crohn's Disease

OBJECTIVES:Crohns disease (CD) management targets mucosal healing on ileocolonoscopy as a treatment goal. We hypothesized that radiologic response is also associated with better long-term outcomes.METHODS:Small bowel CD patients between 1 January 2002 and 31 October 2014 were identified. All patients had pre-therapy computed tomography enterography (CTE)/magnetic resonance enterography (MRE) with follow-up CTE or MRE after 6 months, or 2 CTE/MREs≥6 months apart while on maintenance therapy. Radiologists characterized inflammation in up to five small bowel lesions per patient. At second CTE/MRE, complete responders had all improved lesions, non-responders had worsening or new lesions, and partial responders had other scenarios. CD-related outcomes of corticosteroid usage, hospitalization, and surgery were assessed using Kaplan–Meier survival analysis and multivariable Cox models.RESULTS:CD patients (n=150), with a median disease duration of 9 years, had 223 inflamed small bowel segments (76 with strictures and 62 with penetrating, non-perianal disease), 49% having ileal distribution. Fifty-five patients (37%) were complete radiologic responders, 39 partial (26%), and 56 non-responders (37%). In multivariable Cox models, complete and partial response decreased risk for steroid usage by over 50% (hazard ratio (HR)s: 0.37 (95% confidence interval (CI), 0.21–0.64); 0.45 (95% CI, 0.26–0.79)), and complete response decreased the risk of subsequent hospitalizations and surgery by over two-thirds (HRs: HR, 0.28 (95% CI, 0.15–0.50); HR, 0.34 (95% CI, 0.18–0.63)).CONCLUSIONS:Radiological response to medical therapy is associated with significant reductions in long-term risk of hospitalization, surgery, or corticosteroid usage among small bowel CD patients. These findings suggest the significance of radiological response as a treatment target.

Premedication of patients for prior urticarial reaction to iodinated contrast medium

PurposeThe purpose of this study was to determine whether premedication of patients with a history of urticaria after low osmolality contrast media (LOCM) results in fewer subsequent reactions, and if a benefit is seen, to determine which premedication regimen results in the fewest reactions.Materials and methodsThe subsequent contrast enhanced studies of patients who experienced urticaria after intravenous LOCM between 2002 and 2009 were reviewed to determine whether an additional reaction occurred. Patients undergoing subsequent studies received either no premedication, or premedication with diphenhydramine alone, corticosteroid alone, or corticosteroid plus diphenhydramine. Reactions occurring without premedication were termed repeat reactions and reactions occurring after premedication were termed breakthrough reactions.ResultsFifty patients with a history of urticaria after LOCM met the inclusion criteria and underwent 133 subsequent contrast enhanced studies. Repeat reactions occurred in 7.6% (5/66) of subsequent studies in patients receiving no premedication. Breakthrough reactions occurred in 8% (2/25), 46% (12/26), and 44% (7/16) of subsequent studies in patients receiving premedication with diphenhydramine, corticosteroid, and corticosteroid plus diphenhydramine, respectively. All subsequent reactions consisted of urticaria as the most severe manifestation; no hemodynamic instability or respiratory compromise occurred. In multivariate analysis, premedication with corticosteroid was significantly associated with higher rate of breakthrough reaction relative to no premedication (OR 14.3, 95% CI: 4.1–50.4), as was premedication with corticosteroid plus diphenhydramine (OR 8.3, 95% CI: 1.8–37.9).ConclusionThe results suggest that premedication of patients with a history of urticaria after LOCM may not be necessary.

Severe atrophy and fatty degeneration of the infraspinatus muscle due to isolated infraspinatus tendon tear.

Atrophy of both the supraspinatus and infraspinatus muscles is usually caused by chronic rotator cuff tear, but may also derive from suprascapular nerve entrapment at the spinoglenoid notch. Isolated infraspinatus muscle atrophy is uncommon, and typically associates with suprascapular nerve entrapment occurring distal to the spinoglenoid notch. However, isolated atrophy of the infraspinatus muscle due to insertional tear of the infraspinatus tendon may also occur. We present a case of a 43-year-old male with isolated infraspinatus muscle atrophy and fatty degeneration following an isolated full-thickness infraspinatus tendon tear at the insertion site on the humerus. While it is important to rule out other causes of infraspinatus muscle atrophy, such as concomitant rotator cuff tendon/muscle pathology or suprascapular nerve palsy, we present this case to increase awareness of this uncommon clinical presentation and the potential implications for treatment.

Endoscopic skipping of the terminal ileum in pediatric Crohn disease

OBJECTIVE Pediatric small-bowel (SB) Crohn disease (CD) may be missed if the terminal ileum (TI) appears normal at endoscopy and SB imaging is not performed. We sought to estimate the prevalence and clinical characteristics of pediatric patients with CD and endoscopic skipping of the TI-that is, pediatric patients with active SB or upper gut inflammation and an endoscopically normal TI. MATERIALS AND METHODS This retrospective study included pediatric patients with CD who underwent both CT enterography (CTE) or MR enterography (MRE) and ileocolonoscopy within a 30-day period between July 2004 and April 2014. The physician global assessment was used as the reference standard for SB CD activity. Radiologists reviewed the CTE and MRE studies for inflammatory parameters; severity, length, and multifocality of SB inflammation; and the presence of penetrating complications. RESULTS Of 170 patients who underwent ileal intubation, the TI was macroscopically normal or showed nonspecific inflammation in 73 patients (43%). Nearly half (36/73, 49%) of the patients with normal or nonspecific findings at ileocolonoscopy had radiologically active disease with a median length of SB involvement of 20 cm (range, 1 to > 100 cm). Seventeen (47%) of these patients had multifocal SB involvement and five (14%) had penetrating complications. Overall, endoscopic TI skipping was present in 43 (59%) patients with normal or nonspecific ileocolonoscopic findings: 20 with histologic inflammation (17 with positive imaging findings), 14 with inflammation at imaging only, and nine with proximal disease (upper gut, jejunum, or proximal ileum). There were no significant differences in the clinical parameters of the patients with and those without endoscopic TI skipping. CONCLUSION Ileocolonoscopy may miss SB CD in pediatric patients that is due to isolated histologic, intramural, or proximal inflammation. Enterography is complementary to ileocolonoscopy in the evaluation of pediatric CD.

Upright Biplanar Slot Scanning in Pediatric Orthopedics: Applications, Advantages, and Artifacts

OBJECTIVE Digital slot scanning is a relatively new technology that has been used for imaging of pediatric orthopedic conditions such as scoliosis and leg-length discrepancies. This article will review the clinical applications, advantages, and unique artifacts of this new technology. CONCLUSION Upright biplanar slot scanners acquire high-resolution radiographs simultaneously in two orthogonal planes with reduced radiation dose. Other advantages include a more physiologic weightbearing imaging position, improved Cobb angle measurements, and 3D modeling.

Computed Tomography Enterography

Computed tomography (CT) enterography is a noninvasive imaging modality with superb spatial and temporal resolution, specifically tailored to evaluate the small bowel. It has several advantages over other radiologic and optical imaging modalities, all of which serve as complementary investigations to one another. This article describes CTE technique, including dose reduction techniques, special considerations for the pediatric population, common technical and interpretive pitfalls, and reviews some of the more common small bowel entities seen with CTE.

Pediatric ileocolic intussusception: new observations and unexpected implications

BackgroundIleocolic intussusception occurs when the terminal ileum “telescopes” into the colon. We observed that ileocolic intussusception lengths are similar regardless of location in the colon.ObjectiveTo examine the uniformity of ileocolic intussusception length and its relationship to colon location, symptom duration and reducibility.Materials and methodsWe retrospectively reviewed ultrasound-diagnosed pediatric ileocolic intussusceptions initially treated with pneumatic reduction at the Mayo Clinic or Texas Children’s Hospital. We recorded demographic, imaging and surgical findings including age, gender, symptom duration, location of the ileocolic intussusception, reducibility with air enema and, if fluoroscopically irreducible, surgical findings.ResultsWe identified 119 ileocolic intussusceptions (64% boys), with 81% in the right colon. There was no significant relationship between ileocolic intussusception length and colon location (P=0.15), nor ileocolic intussusception length and symptom duration (P=0.36). Ileocolic intussusceptions were more distal with increasing symptom duration (P=0.016). Successful reductions were unrelated to symptom duration (P=0.84) but were more likely with proximal versus distal locations (P=0.02).ConclusionIleocolic intussusception lengths are relatively uniform regardless of location along the course of the colon where they present. Our findings suggest that most of the apparent distal propagation of ileocolic intussusceptions is not caused by increasing telescoping of small bowel across the ileocecal valve but rather by foreshortening of the right colon. This implies poor cecal fixation and confirms fluoroscopic and surgical observations of cecal displacement from the right lower quadrant with ileocolic intussusceptions. The movement of the leading edge of the ileocolic intussusception during reduction is first due to “relocating” the cecum into the right lower quadrant after which the reduction of small bowel back across the ileocecal valve then occurs.

Ultrasonography and the American Thyroid Association Ultrasound-Based Risk Stratification Tool: Utility in Pediatric and Adolescent Thyroid Nodules

Background: Pediatric thyroid nodules are more likely to be malignant compared to those in adults and may have different concerning ultrasound (US) features. Recent adult guidelines stratify malignancy risk by US features. Our aim is to (1) describe and confirm US features that predict pediatric malignancy, and (2) apply the Adult American Thyroid Association (ATA) Risk Stratification Guidelines to a large pediatric cohort. Methods: We identified 112 children with 145 thyroid nodules from 1996 to 2015. Two blinded pediatric radiologists independently read all US images, described multiple features, and reported their overall impression: benign, indeterminate, or malignant. Each nodule was assigned an ATA risk stratification category. Radiologists’ impressions and ATA risk stratification were compared to histology and cytology results. Results: Multiple US features including a solid composition, presence of microcalcifications, irregular margins, increased blood flow, and hypoechogenicity were associated with increased odds of malignancy. ATA risk stratification correlated with the radiologists’ overall impression (p < 0.001). The sensitivity for detecting malignancy was comparable between both ATA stratification (91%) and the radiologists’ overall impression (90%). The specificity of the radiologists’ malignant overall impression (80%) was better compared to the ATA high risk stratification (54%). Conclusions: At our institution, pediatric radiologists’ overall impressions had similar sensitivity but better specificity for detecting malignancy than the ATA risk stratification tool by our convention. However, neither US-based methods perfectly discriminated benign from malignant nodules, supporting the continued need for fine needle aspiration for suspicious nodules. Further work is needed to develop an US-based scoring system specific to pediatric patients.

Diagnostic Accuracy of the McGill Thyroid Nodule Score in Pediatric Patients

Thyroid cancer is the most common paediatric endocrine cancer; accurate diagnosis and prompt management of paediatric thyroid nodules is critical. The McGill Thyroid Nodule Score (MTNS), based upon clinical, ultrasound (US) and cytology criteria, has recently been modified and studied in a pilot paediatric group with good results. We aim to describe the diagnostic accuracy of the paediatric modified MTNS (PMTNS) in a large paediatric cohort.

Appendiceal ultrasound: the importance of determinacy.

We appreciate the thoughtful comments of Drs. Trout and Larson [1] concerning our article in this issue of Pediatric Radiology and the opportunity to further this discussion with a few additional thoughts. There are striking similarities between our two studies with respect to design and results but there are substantial differences in the conclusions drawn [2, 3]. Patients referred for US evaluation for acute appendicitis have already been stratified into an indeterminate risk group based on their clinical data. Those thought to have a very high probability of acute appendicitis may be sent directly to surgery and those thought to have a very low probability of appendicitis often are not imaged at all. It is for those patients whose probability of acute appendicitis is indeterminate that clinicians seek our help with US imaging. When clinicians order an imaging test to assist in establishing or excluding the diagnosis of acute appendicitis, they should know the likelihood that the test will provide a determinate result and how accurate that result will be. We presented our appendiceal US data in two ways so as to clearly provide this information to our clinicians. The intention-to-diagnose analysis categorizes indeterminate results as missed cases based on the final outcome. Contrary to Trout and Larson’s statement, this analysis is specifically endorsed by Fedko et al. [4] because it allows for “transparent reporting of all results and determination of diagnostic yield” and likelihood ratios and informs physicians what proportion of appendiceal US examinations will not yield determinate results. The intention-to-diagnose method does underestimate measures of the diagnostic performance of US such as accuracy and sensitivity for the determinate results. To account for this, we performed a second analysis using the standard binary approach that excludes indeterminate studies because this analysis relates to clinicians the accuracy of appendiceal US when a determinate result is given. In our opinion, indeterminate results do not yield useful information. Trout and Larson think they do. They assert that indeterminate results reflect a range of probabilities that a given patient has appendicitis and that this information is meaningful to clinicians. While we did find a narrow range of prevalences of appendicitis in our three indeterminate groups, we disagree that this information is clinically useful. Our findings do not support their assertion on two grounds. First, the prevalence of appendicitis in our study group, children with abdominal pain referred for US, was 18.5%. This was the pretest probability for acute appendicitis. The overall prevalence of appendicitis in patients with positive and negative US results was 87% and 1%, respectively, and these are the post-test probabilities. They indicate that US is a very good test at discriminating the presence or absence of appendicitis when a definitive result is given. For indeterminate results, the prevalence of appendicitis was 14.2% overall. This is the post-test probability and it is not statistically different from the pre-test probability of 18.5% for the overall group or for each subset of indeterminate US results, P>0.05. Thus in our practice indeterminate US results do not change the likelihood that a patient does or does not have appendicitis * Larry A. Binkovitz binkovitz.larry@mayo.edu