S. C. S. Kao

Loss of Cystic Fibrosis Transmembrane Conductance Regulator Function Produces Abnormalities in Tracheal Development in Neonatal Pigs and Young Children

RATIONALE Although airway abnormalities are common in patients with cystic fibrosis (CF), it is unknown whether they are all secondary to postnatal infection and inflammation, which characterize the disease. OBJECTIVES To learn whether loss of the cystic fibrosis transmembrane conductance regulator (CFTR) might affect major airways early in life, before the onset of inflammation and infection. METHODS We studied newborn CFTR⁻(/)⁻ pig trachea, using computed tomography (CT) scans, pathology, and morphometry. We retrospectively analyzed trachea CT scans in young children with CF and also previously published data of infants with CF. MEASUREMENTS AND MAIN RESULTS We discovered three abnormalities in the porcine CF trachea. First, the trachea and mainstem bronchi had a uniformly small caliber and cross-sections of trachea were less circular than in controls. Second, trachealis smooth muscle had an altered bundle orientation and increased transcripts in a smooth muscle gene set. Third, submucosal gland units occurred with similar frequency in the mucosa of CF and control airways, but CF submucosal glands were hypoplastic and had global reductions in tissue-specific transcripts. To learn whether any of these changes occurred in young patients with CF, we examined CT scans from children 2 years of age and younger, and found that CF tracheas were less circular in cross-section, but lacked differences in lumen area. However, analysis of previously published morphometric data showed reduced tracheal lumen area in neonates with CF. CONCLUSIONS Our findings in newborn CF pigs and young patients with CF suggest that airway changes begin during fetal life and may contribute to CF pathogenesis and clinical disease during postnatal life.

Safety and efficacy of high-dose tamoxifen and sulindac for desmoid tumor in children: Results of a Children's Oncology Group (COG) Phase II Study

Desmoid fibromatosis (desmoid tumor, DT) is a soft tissue neoplasm prone to recurrence despite complete surgical resection. Numerous small retrospective reports suggest that non‐cytotoxic chemotherapy using tamoxifen and sulindac may be effective for DT. We evaluated the safety and efficacy of tamoxifen and sulindac in a prospective phase II study within the Childrens Oncology Group.

A survey of post-discharge side effects of conscious sedation using chloral hydrate in pediatric CT and MR imaging.

Background. Limited information is available on post-discharge side effects of chloral hydrate sedation in pediatric imaging. Objective. To prospectively study the post-discharge side effects of chloral hydrate sedation in pediatric CT and MR imaging. Materials and methods. A total of 119 children undergoing CT and MRI were sedated using chloral hydrate with 89 % success (mean initial dose, 72 mg/kg body weight) and 98 % success after augmentation (mean total, 78 mg/kg body weight). The frequency of each post-discharge side effect was correlated with other side effects and 12 patient/technical parameters. Results. The survey was completed in 80 children. Sleepiness lasted for > 4 h in 28 %. Unsteadiness occurred in 68 % and hyperactivity in 29 %. Appetite became poor in 14 % and vomiting occurred in 15 %. Normal activity was resumed after > 4 h in 54 %. Sleep deprivation did not result in increased success or earlier onset of sedation and might be associated with hyperactivity. A higher dose did not result in an increased success rate or earlier onset of sedation within the dose range used in this study. Conclusion. Data on the post-discharge side effects of chloral hydrate sedation will be useful to radiologists, technologists, and nurses explaining to parents about sedation using this agent.

Intracranial granulocytic sarcoma (chloroma): MR findings

Complications of the central nervous system are not uncommon in patients with a diagnosis of leukemia including infections and hemorrhage. We present the magnetic resonance (MR) findings of granulocytic sarcoma (chloroma) in two leukemic patients who presented with masses in the cerebellopontine angle and in the cavernous and the sphenoid sinuses. The MR signal displayed by these two lesions was isointense to the brain on both T1- and T2-weighted images. This signal intensity differs from that observed in cases of hemorrhage or infection.

Nonoperative treatment of simple meconium ileus : a survey of the Society for Pediatric Radiology

To determine the practice pattern regarding nonoperative treatment of simple meconium ileus, a survey was sent to directors of 66 pediatric radiology departments in the USA and Canada. Thirty-nine responses were received reporting 1,236 patients. A wide variation of enema techniques and contrast media were used. While the success rate did not correlate with osmolality, mode of administration, catheter size, or perforation rate there was a significantly higher overall success rate with the use of Gastrografin versus no-Gastrografin (p<0.00076) and the use of additives such as Tween-80 and Mucomyst versus techniques without additives (p<0.00001). Perforation did not correlate with success rate, osmolality, or type of contrast medium. The only two instances of rectal perforations were associated with the use of ballon-tip catheter.

Missed fractures resulting from satisfaction of search effect

This study assessed whether subtle fractures are mised in multitrauma patients because other fractures are detected. Sixty-five simulated trauma patients were each depicted in series of radiographs that were assembled from radiographs of several actual patients. The radiographs were selected to look like they belonged to a single patient. Forty-six cases included a radiograph showing a subtle fracture (which we called the “target”). In one experimental condition, none of the other radiographs in the patient’s series contained a fracture. In a second experimental condition, a radiograph containing an additional fracture (called the “distracter”) was substituted for a radiograph that had no fracture in the first experimental condition. The accuracy of detecting the target fractures was significantly reduced for cases in which the distracter fracture was reported. Awareness of the nature of this type of miss may lead to realistic strategies to avoid it.

Prognostic Significance of Tumor Response at the End of Therapy in Group III Rhabdomyosarcoma: A Report From the Children's Oncology Group

PURPOSE Some patients with rhabdomyosarcoma (RMS) achieve less than a complete response (CR) despite receiving all planned therapy. We assessed the impact of best response at the completion of all therapy on patient outcome. PATIENTS AND METHODS We studied 419 clinical group III participants who completed all protocol therapy without developing progressive disease for Intergroup Rhabdomyosarcoma Study (IRS) IV. Response (complete resolution [CR], partial response [PR; > or = 50% decrease], or no response [NR; < 50% decrease and < 25% increase]) was determined by radiographic measurement and categorized by the best response. RESULTS At the end of therapy, 341 participants (81%) achieved a best response of CR and 78 (19%) had a best response of PR/NR. Five-year failure-free survival was similar for participants achieving CR (80%) and PR/NR (78%). After adjustment for age, nodal status, primary site, and histology, there was no significant indication of lower risk of failure (hazard ratio [HR], 0.77; 95% CI, 0.46 to 1.27; P = .3) nor death (HR, 0.63; 95% CI, 0.36 to 1.09; P = .1) for CR versus PR/NR participants. Seventeen participants with a best response of PR/NR had surgical procedures; eight (50%) of 16 with available pathology reports had residual viable tumor and only three achieved a complete resection. Resection of residual masses was not associated with improved outcome. CONCLUSION CR status at the end of protocol therapy in clinical group III participants was not associated with a reduction of disease recurrence and death. Aggressive alternative therapy may not be warranted for RMS patients with a residual mass at the end of planned therapy.

Evaluation of a digital workstation for interpreting neonatal examinations. A receiver operating characteristic study.

RATIONALE AND OBJECTIVES The purpose of this study is to compare the diagnostic accuracy of interpreting clinical neonatal radiographs using a commercially available digital workstation versus conventional radiographic images. METHODS The case sample consists of 100 chest or abdominal radiographs from the neonatal intensive care unit in which diagnosis was confirmed. Four radiologists served as observers. During two initial reading sessions, half of the studies were viewed on digital radiography monitors and the other half by plain film. Observers indicated whether each patient had normal or abnormal findings and their degree of confidence in this judgment. Six weeks later, observers viewed cases on the alternate presentation system. Two statistical analyses were performed: the data from each observer were treated as a separate experiment in the first analysis; the data from all observers were combined using a new method in the second analysis. RESULTS No differences between areas under receiver operating characteristic (ROC) curves for viewing on the picture archiving and communication system (PACS) console and plain film were found for any observer (0.86 versus 0.86, 0.89 versus 0.86, 0.88 versus 0.85, 0.83 versus 0.82). CONCLUSIONS The study suggests that for pediatric plain film images, video images offer diagnostic information comparable with that of conventional radiographs for neonatal examinations.

Gastric volvulus and wandering spleen.

Although rare in childhood, gastric volvulus and wandering spleen share a common etiology: congenital absence of intraperitoneal visceral attachments. We report an unusual case of a patient who presented with three episodes of intractable vomiting and abdominal mass but no abdominal pain. A diagnosis could not be made until the third episode because the gastric volvulus resolved each time on placement of a nasogastric (NG) tube before any further tests could be done. During the third episode, diagnostic imaging was performed before inserting an NG tube, and the diagnosis of a mesenteroaxial gastric volvulus and an abnormally positioned spleen was made. Although both conditions are caused by abnormalities of fixation, the association of gastric volvulus and wandering spleen has been reported only once before.

Utility of Tc-99m mebrofenin scintigraphy in the assessment of infantile jaundice.

Technetium-99m mebrofenin hepatobillary excretory patterns were assessed in 36 infants with hyperbilirubhnemia. Phenobarbital was administered to 22 patients before imaging. Final diagnoses included: intrahepatic chotestasis (14 patients), neonatal hepatitis (nine patients), biliary atresia (eight patients), alpha-1-antitrypsin deficiency (two patients), Ategilles syndrome (two patients), and cystic fibrosis (one patient). No patient with biliary atresia showed bowel activity by 24 hours. Of the 28 infants without biliary atresia, 23 (82%) had bowel activity visualized by 6–8 hours and 26 (90%) had bowel activity by 24 hours. Two had no bowel activity at 24 hours: one had cystic fibrosis and one had neonatal hepatitis. Of the 26 patients with bowel visualization, the time to visualize bowel did not differ between patient groups with and without phenobarbital induction. All of the patients with hepatitis, including those with marked dysfunction, showed good hepatic uptake. Mebrofenin scintigraphy is an important imaging technique in the diagnostic evaluation of infants with hyperbilirubinemia. In addition to biliary atresia, intrahepatic chotestasis due to cystic fibrosis and severe neonatal hepatitis may also cause bowel nonvisualization up to 24 hours. The results of this study suggest phenobarbital induction may not be needed when Tc-99m mebrofenin scintigraphy is used for the assessment of infantile jaundice.