Peter J. Strouse

Frequency and Severity of Acute Allergic-Like Reactions to Gadolinium-Containing IV Contrast Media in Children and Adults

OBJECTIVE. The purpose of our study was to determine the frequency and severity of acute allergic-like reactions to IV-administered gadolinium-containing contrast media in children and adults.MATERIALS AND METHODS. Pediatric (younger than 19 years) and adult department of radiology contrast material reaction forms involving patients who experienced acute allergic-like reactions to gadolinium-containing contrast media from January 1, 2001, through December 31, 2006, were retrospectively evaluated for the specific types of acute allergic-like reactions, reaction management, and patient outcomes. Relevant patient medical information, including documentation of prior gadolinium- or iodine-containing contrast material reaction, premedication before acute allergic-like reaction to IV gadolinium-containing contrast material, previous allergic reactions to substances other than contrast media, and history of asthma, was obtained by reviewing electronic medical records.RESULTS. Seventy-eight thousand three hundred...

Disorders of intestinal rotation and fixation (''malrotation'')

Malrotation with volvulus is one of the true surgical emergencies of childhood. Prompt radiological diagnosis is often paramount to achieving a good outcome. An understanding of the normal and anomalous development of the midgut provides a basis for understanding the pathophysiology and the clinical presentation of malrotation and malrotation complicated by volvulus. In this essay, the radiologic findings of malrotation and volvulus are reviewed and illustrated with particular attention to the child with equivocal imaging findings.

Incidence and Severity of Acute Allergic-Like Reactions to IV Nonionic Iodinated Contrast Material in Children

OBJECTIVE The purpose of this study was to evaluate the incidence and severity of acute allergic-like reactions related to i.v. administration of low-osmolality nonionic iodinated contrast material in children. MATERIALS AND METHODS Department of radiology contrast material reaction forms involving pediatric (younger than 19 years) imaging examinations performed from January 1, 1999, through June 30, 2006, were retrospectively evaluated for type of acute allergic-like reaction, severity of reaction, and patient outcome. The electronic medical record was reviewed for pertinent medical history related to each acute reaction, including previous contrast material reaction, premedication before administration of i.v. iodinated contrast material, previous allergic-like reaction to substances other than contrast material, and history of asthma. RESULTS In our department during the time period specified, 11,306 pediatric i.v. administrations of low-osmolality nonionic iodinated contrast material were performed. Acute allergic-like reactions to the contrast material were documented in 20 (0.18%) of the patients. Sixteen (80%) of the acute allergic-like reactions were categorized as mild, one (5%) as moderate, and three (15%) as severe. No deaths were attributed to i.v. nonionic iodinated contrast material. Six (30%) of the patients had a history of allergic-like reaction, including two patients who had a history of reaction to iodinated contrast material. Five (25%) of the patients had a history of asthma. CONCLUSION Acute allergic-like reactions to i.v. administration of low-osmolality nonionic iodinated contrast material in children are rare. As in the adult population, most pediatric reactions are mild; however, severe reactions do occur.

Autosomal dominant stapes ankylosis with broad thumbs and toes, hyperopia, and skeletal anomalies is caused by heterozygous nonsense and frameshift mutations in NOG, the gene encoding noggin.

Although fixation of the stapes is usually progressive and secondary to otosclerosis, it may present congenitally, with other skeletal manifestations, as an autosomal dominant syndrome-such as proximal symphalangism (SYM1) or multiple-synostoses syndrome (SYNS1), both of which are caused by mutations in NOG, the gene encoding noggin. We describe a family that was ascertained to have nonsyndromic otosclerosis but was subsequently found to have a congenital stapes ankylosis syndrome that included hyperopia, a hemicylindrical nose, broad thumbs and great toes, and other minor skeletal anomalies but lacked symphalangism. A heterozygous nonsense NOG mutation-c.328C-->T (Q110X), predicted to truncate the latter half of the protein-was identified, and a heterozygous insertion in NOG-c.252-253insC, in which the frameshift is predicted to result in 96 novel amino acids before premature truncation-was identified in a previously described second family with a similar phenotype. In contrast to most NOG mutations that have been reported in kindreds with SYM1 and SYNS1, the mutations observed in these families with stapes ankylosis without symphalangism are predicted to disrupt the cysteine-rich C-terminal domain. These clinical and molecular findings suggest that (1) a broader range of conductive hearing-loss phenotypes are associated with NOG mutations than had previously been recognized, (2) patients with sporadic or familial nonsyndromic otosclerosis should be evaluated for mild features of this syndrome, and (3) NOG alterations should be considered in conductive hearing loss with subtle clinical and skeletal features, even in the absence of symphalangism.

Pediatric Appendicitis: An Argument for US

Increased use of US in the evaluation of appendicitis represents one of the most substantial opportunities for reduction of CT radiation exposure to children in the United States.

Parenteral Nutrition–Associated Cholestasis in Neonates: Multivariate Analysis of the Potential Protective Effect of Taurine

BACKGROUND Neonates receiving parenteral nutrition (PN) are at risk for PN-associated cholestasis (PNAC); however, no preventive factors for PNAC have been clearly identified. Despite reports suggesting that taurine may prevent PNAC in neonates, such an effect of taurine has not yet been definitively demonstrated. We determined whether taurine supplementation reduces the incidence of PNAC in premature or critically ill neonates. METHODS This study was part of a prospective, randomized, multi-institutional trial designed to assess cholecystokinin vs placebo as a potential preventive therapy of PNAC. Taurine supplementation of PN varied between institutions. The presence or absence of taurine in PN was analyzed by multivariate analysis, with a primary outcome measure of serum conjugated bilirubin (CB) as a measure of PNAC. RESULTS Taurine reduced PNAC in premature infants (estimated maximum CB [95% confidence interval] 0.50 mg/dL [-0.17 to 1.18] for those receiving taurine, vs 3.45 mg/dL [1.79-5.11] for neonates not receiving taurine, approaching significance, p = .07). Taurine significantly reduced PNAC in infants with necrotizing enterocolitis (NEC; estimated maximum CB 4.04 mg/dL [2.85-5.23], NEC infants receiving taurine, vs 8.29 mg/dL [5.61-10.96], NEC infants not receiving taurine, p < .01). There were too few neonates with surgical anomalies to evaluate the effect of taurine in this group. CONCLUSIONS Within specific subgroups of neonatal patients, taurine supplementation does offer a very significant degree of protection against PNAC. Patients with NEC or severe prematurity are most likely to benefit substantially from taurine supplementation.

Use of Cholecystokinin-Octapeptide for the Prevention of Parenteral Nutrition-Associated Cholestasis

Objective. To determine whether cholecystokinin-octapeptide (CCK-OP) would prevent or ameliorate parenteral nutrition-associated cholestasis (PNAC) among high-risk neonates treated with total parenteral nutrition. Study Design. This was a multicenter, double-blind, randomized, controlled trial conducted between 1996 and 2001. Patients. Neonates at risk for the development of PNAC included very low birth weight neonates and those with major surgical conditions involving the gastrointestinal tract. Setting. Tertiary care hospitals. Intervention. Patients were randomized to receive CCK-OP (0.04 μg/kg per dose, twice daily) or placebo. Eligible infants were all <30 days of age. Patients were enrolled within 2 weeks after birth or within 7 days after surgery. Outcome Measures. The primary outcome measure was conjugated bilirubin (CB) levels, which were measured weekly. Secondary outcome measures included incidence of sepsis, times to achieve 50% and 100% of energy intake through the enteral route, number of ICU and hospital days, mortality rate, and incidences of biliary sludge and cholelithiasis. Results. A total of 243 neonates were enrolled in the study. CCK-OP administration did not significantly affect CB levels (1.76 ± 3.14 and 1.93 ± 3.31 mg/dL for CCK-OP and placebo groups, respectively; mean ± SD). Secondary outcome measures also were not significantly affected by the study drug. Conclusions. Use of CCK-OP failed to reduce significantly the incidence of PNAC or levels of CB. CCK-OP had no effect on other secondary measures and should not be recommended for the prevention of PNAC.

Model-based Iterative Reconstruction: Effect on Patient Radiation Dose and Image Quality in Pediatric Body CT

PURPOSE To retrospectively compare image quality and radiation dose between a reduced-dose computed tomographic (CT) protocol that uses model-based iterative reconstruction (MBIR) and a standard-dose CT protocol that uses 30% adaptive statistical iterative reconstruction (ASIR) with filtered back projection. MATERIALS AND METHODS Institutional review board approval was obtained. Clinical CT images of the chest, abdomen, and pelvis obtained with a reduced-dose protocol were identified. Images were reconstructed with two algorithms: MBIR and 100% ASIR. All subjects had undergone standard-dose CT within the prior year, and the images were reconstructed with 30% ASIR. Reduced- and standard-dose images were evaluated objectively and subjectively. Reduced-dose images were evaluated for lesion detectability. Spatial resolution was assessed in a phantom. Radiation dose was estimated by using volumetric CT dose index (CTDI(vol)) and calculated size-specific dose estimates (SSDE). A combination of descriptive statistics, analysis of variance, and t tests was used for statistical analysis. RESULTS In the 25 patients who underwent the reduced-dose protocol, mean decrease in CTDI(vol) was 46% (range, 19%-65%) and mean decrease in SSDE was 44% (range, 19%-64%). Reduced-dose MBIR images had less noise (P > .004). Spatial resolution was superior for reduced-dose MBIR images. Reduced-dose MBIR images were equivalent to standard-dose images for lungs and soft tissues (P > .05) but were inferior for bones (P = .004). Reduced-dose 100% ASIR images were inferior for soft tissues (P < .002), lungs (P < .001), and bones (P < .001). By using the same reduced-dose acquisition, lesion detectability was better (38% [32 of 84 rated lesions]) or the same (62% [52 of 84 rated lesions]) with MBIR as compared with 100% ASIR. CONCLUSION CT performed with a reduced-dose protocol and MBIR is feasible in the pediatric population, and it maintains diagnostic quality.

A critical evaluation of US for the diagnosis of pediatric acute appendicitis in a real-life setting: how can we improve the diagnostic value of sonography?

BackgroundWe have observed that day-to-day use of US for acute appendicitis does not perform as well as described in the literature.ObjectiveReview the diagnostic performance of US in acute appendicitis with attention to factors that influence performance.Materials and methodsRetrospective review of all sonograms for acute appendicitis in children from May 2005 to May 2010 with attention to the rate of identification of the appendix, training of personnel involved and diagnostic accuracy.ResultsThe appendix was identified in 246/1,009 cases (24.4%), with identification increasing over time. The accuracy of US was 85–91% with 35 false-positives and 54 false-negatives. Pediatric sonographers were significantly better at identifying the appendix than non-pediatric sonographers (P < 0.0001). Increased weight was the only patient factor that influenced identification of the appendix (P = 0.006). CT use was stable over the 5 years but declined in cases where the appendix was identified by US.ConclusionIn day-to-day use, US does not perform as purported in the literature. We do not visualize the appendix as often as we should and false-negative and false-positive exams are too common. To improve the diagnostic performance of this modality, involvement by experienced personnel and/or additional training is needed.

Transient small-bowel intussusception in children on CT.

ObjectiveTo determine the frequency and significance of small-bowel intussusception identified in children on CT.Materials and methodsAll abdomen CT reports between July 1995 and April 2002 were reviewed to identify patients with small-bowel intussusception. Intussusceptions were identified as an intraluminal mass with a characteristic layered appearance and/or continuity with adjacent mesenteric fat. Ileocolic intussusceptions and intussusceptions related to feeding tubes were excluded. Imaging studies and medical records were reviewed.ResultsTwenty-five pediatric patients (16 boys, 9 girls; mean age 11.2 years) were identified with small-bowel intussusception on CT. No patient had a persistent intussusception requiring surgery. Fourteen had limited immediate repeat CT images as part of the same examination, ten of which demonstrated resolution of the CT abnormality. Follow-up CT [n=13 (6 within 24 h)], ultrasound (n=3), small-bowel follow-through (n=4) and surgery (n=3) showed no intussusception. In four patients with persistent symptoms, underlying pathology was identified requiring treatment (giardiasis, 2; small-bowel inflammation/strictures, 1; abscess and partial small-bowel obstruction after perforated appendicitis, 1). In 21 other patients, direct correlation of symptoms to CT abnormality was absent or questionable, no treatment was required, and there was no clinical or imaging evidence of persistence or recurrence.ConclusionMost small-bowel intussusceptions identified in children by CT are transient and of no clinical significance.