Utility of Pre-Hematopoietic Cell Transplantation Sinus CT Screening in Children and Adolescents.

BACKGROUND AND PURPOSE: The clinical benefit of pre-hematopoietic cell transplantation sinus CT screening remains uncertain, while the risks of CT radiation and anesthesia are increasingly evident. We sought to re-assess the impact of screening sinus CT on pretransplantation patient management and prediction of posttransplantation invasive fungal rhinosinusitis. MATERIALS AND METHODS: Pretransplantation noncontrast screening sinus CTs for 100 consecutive patients (mean age, 11.9 ± 5.5 years) were graded for mucosal thickening (Lund-Mackay score) and for signs of noninvasive or invasive fungal rhinosinusitis (sinus calcification, hyperattenuation, bone destruction, extrasinus inflammation, and nasal mucosal ulceration). Posttransplantation sinus CTs performed for sinus-related symptoms were similarly graded. Associations of Lund-Mackay scores, clinical assessments, changes in pretransplantation clinical management (additional antibiotic or fungal therapy, sinonasal surgery, delayed transplantation), and subsequent development of sinus-related symptoms or invasive fungal rhinosinusitis were tested (exact Wilcoxon rank sums, Fisher exact test, significance P < .05). RESULTS: Mean pretransplantation screening Lund-Mackay scores (n = 100) were greater in patients with clinical symptoms (8.07 ± 6.00 versus 2.48 ± 3.51, P < .001) but were not associated with pretransplantation management changes and did not predict posttransplantation sinus symptoms (n = 21, P = .47) or invasive fungal rhinosinusitis symptoms (n = 2, P = .59). CONCLUSIONS: Pre-hematopoietic cell transplantation sinus CT does not meaningfully contribute to pretransplantation patient management or prediction of posttransplantation sinus disease, including invasive fungal rhinosinusitis, in children. The risks associated with CT radiation and possible anesthesia are not warranted in this setting.

Full Dose-Reduction Potential of Statistical Iterative Reconstruction for Head CT Protocols in a Predominantly Pediatric Population.

BACKGROUND AND PURPOSE: A statistical iterative reconstruction algorithm provides an effective approach to reduce patient dose by compensating for increased image noise in CT due to reduced radiation output. However, after a point, the degree to which a statistical iterative algorithm is used for image reconstruction changes the image appearance. Our aim was to determine the maximum level of statistical iterative reconstruction that can be used to establish dose-reduced head CT protocols in a primarily pediatric population while maintaining similar appearance and level of image noise in the reconstructed image. MATERIALS AND METHODS: Select head examinations (brain, orbits, sinus, maxilla, and temporal bones) were investigated. Dose-reduced head protocols using an adaptive statistical iterative reconstruction were compared for image quality with the original filtered back-projection reconstructed protocols in a phantom by using the following metrics: image noise frequency (change in perceived appearance of noise texture), image noise magnitude, contrast-to-noise ratio, and spatial resolution. Dose-reduction estimates were based on CT dose index values. Patient volume CT dose index and image noise magnitude were assessed in 737 pre- and post-dose-reduced examinations. RESULTS: Image noise texture was acceptable for up to 60% adaptive statistical iterative reconstruction for the soft reconstruction kernel (at both 100 and 120 kV[peak]) and up to 40% adaptive statistical iterative reconstruction for the standard reconstruction kernel. Implementation of 40% and 60% adaptive statistical iterative reconstruction led to an average reduction in the volume CT dose index of 43% for brain, 41% for orbit, 30% for maxilla, 43% for sinus, and 42% for temporal bone protocols for patients between 1 month and 26 years of age, while maintaining an average noise magnitude difference of 0.1% (range, -3% to 5%), improving the contrast-to-noise ratio of low-contrast soft-tissue targets and the spatial resolution of high-contrast bony anatomy, compared with filtered back-projection. CONCLUSIONS: The methodology in this study demonstrates maximizing patient dose reduction and maintaining image quality by using statistical iterative reconstruction for a primarily pediatric population undergoing head CT examinations.

Estimating pediatric entrance skin dose from digital radiography examination using DICOM metadata: A quality assurance tool.

PURPOSE: To develop an automated methodology to estimate patient examination dose in digital radiography (DR) imaging using DICOM metadata as a quality assurance (QA) tool. METHODS: Patient examination and demographical information were gathered from metadata analysis of DICOM header data. The x-ray system radiation output (i.e., air KERMA) was characterized for all filter combinations used for patient examinations. Average patient thicknesses were measured for head, chest, abdomen, knees, and hands using volumetric images from CT. Backscatter factors (BSFs) were calculated from examination kVp. Patient entrance skin air KERMA (ESAK) was calculated by (1) looking up examination technique factors taken from DICOM header metadata (i.e., kVp and mA s) to derive an air KERMA (k air) value based on an x-ray characteristic radiation output curve; (2) scaling k air with a BSF value; and (3) correcting k air for patient thickness. Finally, patient entrance skin dose (ESD) was calculated by multiplying a mass-energy attenuation coefficient ratio by ESAK. Patient ESD calculations were computed for common DR examinations at our institution: dual view chest, anteroposterior (AP) abdomen, lateral (LAT) skull, dual view knee, and bone age (left hand only) examinations. RESULTS: ESD was calculated for a total of 3794 patients; mean age was 11 ± 8 yr (range: 2 months to 55 yr). The mean ESD range was 0.19-0.42 mGy for dual view chest, 0.28-1.2 mGy for AP abdomen, 0.18-0.65 mGy for LAT view skull, 0.15-0.63 mGy for dual view knee, and 0.10-0.12 mGy for bone age (left hand) examinations. CONCLUSIONS: A methodology combining DICOM header metadata and basic x-ray tube characterization curves was demonstrated. In a regulatory era where patient dose reporting has become increasingly in demand, this methodology will allow a knowledgeable user the means to establish an automatable dose reporting program for DR and perform patient dose related QA testing for digital x-ray imaging.

Characterization of adaptive statistical iterative reconstruction algorithm for dose reduction in CT: A pediatric oncology perspective.

PURPOSE: This study demonstrates a means of implementing an adaptive statistical iterative reconstruction (ASiR™) technique for dose reduction in computed tomography (CT) while maintaining similar noise levels in the reconstructed image. The effects of image quality and noise texture were assessed at all implementation levels of ASiR™. Empirically derived dose reduction limits were established for ASiR™ for imaging of the trunk for a pediatric oncology population ranging from 1 yr old through adolescence∕adulthood. METHODS: Image quality was assessed using metrics established by the American College of Radiology (ACR) CT accreditation program. Each image quality metric was tested using the ACR CT phantom with 0%-100% ASiR™ blended with filtered back projection (FBP) reconstructed images. Additionally, the noise power spectrum (NPS) was calculated for three common reconstruction filters of the trunk. The empirically derived limitations on ASiR™ implementation for dose reduction were assessed using (1, 5, 10) yr old and adolescent∕adult anthropomorphic phantoms. To assess dose reduction limits, the phantoms were scanned in increments of increased noise index (decrementing mA using automatic tube current modulation) balanced with ASiR™ reconstruction to maintain noise equivalence of the 0% ASiR™ image. RESULTS: The ASiR™ algorithm did not produce any unfavorable effects on image quality as assessed by ACR criteria. Conversely, low-contrast resolution was found to improve due to the reduction of noise in the reconstructed images. NPS calculations demonstrated that images with lower frequency noise had lower noise variance and coarser graininess at progressively higher percentages of ASiR™ reconstruction; and in spite of the similar magnitudes of noise, the image reconstructed with 50% or more ASiR™ presented a more smoothed appearance than the pre-ASiR™ 100% FBP image. Finally, relative to non-ASiR™ images with 100% of standard dose across the pediatric phantom age spectrum, similar noise levels were obtained in the images at a dose reduction of 48% with 40% ASIR™ and a dose reduction of 82% with 100% ASIR™. CONCLUSIONS: The authors' work was conducted to identify the dose reduction limits of ASiR™ for a pediatric oncology population using automatic tube current modulation. Improvements in noise levels from ASiR™ reconstruction were adapted to provide lower radiation exposure (i.e., lower mA) instead of improved image quality. We have demonstrated for the image quality standards required at our institution, a maximum dose reduction of 82% can be achieved using 100% ASiR™; however, to negate changes in the appearance of reconstructed images using ASiR™ with a medium to low frequency noise preserving reconstruction filter (i.e., standard), 40% ASiR™ was implemented in our clinic for 42%-48% dose reduction at all pediatric ages without a visually perceptible change in image quality or image noise.

Establishing a standard calibration methodology for MOSFET detectors in computed tomography dosimetry.

PURPOSE: The use of metal-oxide-semiconductor field-effect transistor (MOSFET) detectors for patient dosimetry has increased by ~25% since 2005. Despite this increase, no standard calibration methodology has been identified nor calibration uncertainty quantified for the use of MOSFET dosimetry in CT. This work compares three MOSFET calibration methodologies proposed in the literature, and additionally investigates questions relating to optimal time for signal equilibration and exposure levels for maximum calibration precision. METHODS: The calibration methodologies tested were (1) free in-air (FIA) with radiographic x-ray tube, (2) FIA with stationary CT x-ray tube, and (3) within scatter phantom with rotational CT x-ray tube. Each calibration was performed at absorbed dose levels of 10, 23, and 35 mGy. Times of 0 min or 5 min were investigated for signal equilibration before or after signal read out. RESULTS: Calibration precision was measured to be better than 5%-7%, 3%-5%, and 2%-4% for the 10, 23, and 35 mGy respective dose levels, and independent of calibration methodology. No correlation was demonstrated for precision and signal equilibration time when allowing 5 min before or after signal read out. Differences in average calibration coefficients were demonstrated between the FIA with CT calibration methodology 26.7 ± 1.1 mV cGy(-1) versus the CT scatter phantom 29.2 ± 1.0 mV cGy(-1) and FIA with x-ray 29.9 ± 1.1 mV cGy(-1) methodologies. A decrease in MOSFET sensitivity was seen at an average change in read out voltage of ~3000 mV. CONCLUSIONS: The best measured calibration precision was obtained by exposing the MOSFET detectors to 23 mGy. No signal equilibration time is necessary to improve calibration precision. A significant difference between calibration outcomes was demonstrated for FIA with CT compared to the other two methodologies. If the FIA with a CT calibration methodology was used to create calibration coefficients for the eventual use for phantom dosimetry, a measurement error ~12% will be reflected in the dosimetry results. The calibration process must emulate the eventual CT dosimetry process by matching or excluding scatter when calibrating the MOSFETs. Finally, the authors recommend that the MOSFETs are energy calibrated approximately every 2500-3000 mV.

Neonatal progeroid (Wiedemann-Rautenstrauch) syndrome: report of five new cases and review.

The neonatal progeroid syndrome (NPS), or Wiedemann-Rautenstrauch, is a rare autosomal recessive disorder comprised of generalized lipoatrophy except for fat pads in the suprabuttock areas, hypotrichosis of the scalp hair, eyebrows, and eyelashes, relative macrocephaly, triangular face, natal teeth, and micrognathia. We report on 5 new patients who demonstrate phenotypic variability and who represent the single largest series of NPS reported to date. Two of the patients are from an African-American kindred, an ethnic occurrence not reported previously. The fact that there are 2 pairs of sibs among the 5 patients further supports that NPS is an autosomal recessive condition. This report also includes a review of the previously reported 16 patients and compares them with the 5 new patients. Abnormalities in endocrine and lipid metabolism were found in 3 of 5 patients. Skeletal findings in 2 of our patients demonstrated some new findings as well as the typical radiological abnormalities previously noted in NPS. It is apparent, based on the 21 cases, that mild to moderate mental retardation is common in NPS. Long term follow-up of patients with NPS should provide more information relative to their ultimate psychomotor development. NPS is usually lethal by 7 months; however, on rare occasions, patients have survived into the teens. Our 3 surviving patients range in age from 16-23 months. Variability in the phenotype of NPS is clear; however, the phenotype remains distinct enough to allow a secure diagnosis.

Successful medical therapy for deeply invasive facial infection due to Pythium insidiosum in a child.

Pythiosis occurs in animals and humans who encounter aquatic habitats that harbor Pythium insidiosum. Drug therapy for deeply invasive infections with this organism has been ineffective in humans and animals; patients have been cured only by radical surgical debridement. A 2-year-old boy developed periorbital cellulitis unresponsive to antibiotic and antifungal therapy. The cellulitis extended to the nasopharynx, compromising the airway and necessitating a gastrostomy for feeding. P. insidiosum was isolated from surgical biopsy specimens of the affected tissue. On the basis of in vitro susceptibility studies of the isolate, the patient was treated with a combination of terbinafine and itraconazole. The infection resolved over a period of a few months. The patient remained well 1.5 years after completing a 1-year course of therapy. Cure of deep P. insidiosum infection is feasible with drug therapy.

Infant with midline thoracoabdominal schisis and limb defects.

An infant presented with multiple congenital anomalies including a midline thoracoabdominal defect, absence of the sternum, ectopia cordis, right diaphragmatic hernia, right anophthalmia, left microphthalmia, incomplete bilateral cleft lip, and various limb defects including ectrodactyly of the right hand and left foot, and phocomelia of the right lower extremity. The infant expired soon after birth. The radiological findings included absence of the sternum, 11 right-sided ribs, absence of the middle third of the right clavicle, opaque right hemithorax, hypoplastic right tibia, absent right fibula and foot, and ectrodactyly of the right hand and left foot. In addition, the autopsy revealed two distinct diaphragmatic defects, an anterior midline defect of the diaphragm beneath the ectopic heart, and a large Bochdalek hernia, with abdominal contents in the chest. Our case has overlapping features with conditions such as thoracoabdominal syndrome, pentalogy of Cantrell, and limb-body wall complex, but the concurrence of midline body wall defect and ectrodactyly has not been described previously.

Type 3 Pfeiffer syndrome with normal thumbs.

We report on a male infant with extremely shallow orbits, spontaneous luxation of the eyes out of the eyelids, hypoplastic midface, broad, medially rotated great toes, and respiratory distress due to severe bilateral posterior choanal stenosis. At 4 days he had open cranial sutures (both by palpation and radiological examination). Subsequent radiologic studies demonstrated: thickening of the skull base, vertebral anomalies, flattening of the olecranon fossae with dislocated radii, and triangular shape of the proximal phalanx of the first toes. Our patient had manifestations of type 3 Pfeiffer syndrome (PS). However, the finding of normal thumbs has not been reported in type 3 PS. Point mutations in fibroblast growth factor receptor-1 (FGFR1) and fibroblast growth factor receptor-2 (FGFR2) have been reported in familial and sporadic cases of PS, but were not found in this patient. Recognizing type 3 PS, despite variability in expression, is important for genetic counseling, prognosis, and decision-making regarding craniofacial surgery.

Cocultured blastocyst cryopreservation: experience of more than 500 transfer cycles.

OBJECTIVE: To present our experience using cocultured cryopreserved and transferred blastocysts. DESIGN: Retrospective study of patients undergoing transfer of cryopreserved blastocysts. SETTING: Three different IVF centers. PATIENTS: Four hundred sixty-seven thawed cycles from January 1991 to June 1994. MAIN OUTCOME MEASURE: Pregnancy rate per cycle after transfer of pre-embryos developed from thawed blastocysts. RESULTS: One thousand two hundred thirty-nine blastocysts were thawed. Of these, 1,033 (83%) survived thawing and were transferred. Five hundred sixty-three thawed cycles resulted in 516 (92%) receiving intrauterine transfer. One hundred twelve clinical pregnancies were established, resulting in a 21.7% pregnancy per transfer with a 19% ongoing rate. The implantation rate of 13.4% results from 138 implanted pre-embryos. There was a higher PR in the programmed cycle (79/302; 26.2%) compared with the natural cycle (6/47;13%). CONCLUSIONS: Freezing at the blastocyst stage is a proven and reliable method in IVF technology. Although there may be fewer pre-embryos, their ability to implant appears to approach the potential of a fresh transfer.

Cobas Integra: clinical laboratory instrument with continuous and random-access capabilities.

The Cobas Integra from Roche Diagnostic Systems is a new clinical laboratory analyzer with continuous and random-access features for routine chemistries, specific proteins, electrolytes, hormones, therapeutic drugs, and drugs of abuse. The system maintains 68 test-specific reagent cassettes on board, along with multiple ion-selective electrodes (ISEs) for electrolyte determinations. This gives the Cobas Integra the capability of analyzing as many as 72 analytes without having to load additional reagents. We describe the basic analyzer configuration and the subsystems for absorbance, fluorescence polarization, and ISE measurements. Performance characteristics for precision, methods comparison, and on-board stability are given for assays representative of the various test groups. The 29 Cobas Integra tests evaluated in the present study show good agreement (r > or = 0.98 and slopes generally 0.90 to 1.12) with the respective methods available on either the Olympus AU5000, Hitachi 911 or 717, Behring BNA, or Abbott TDx systems. Total assay precision (CV) ranged from 0.8% to 8.5%, and calibration curves were stable for as long as 20 weeks. Test throughput, which is dependent on pipetting sequence, was determined to be up to 600 tests per hour without ISE and up to 750 tests per hour with ISE; the time to first result was 2.0-10.0 min.

Rickets secondary to phosphate depletion. A sequela of antacid use in infancy.

Two infants presented with growth failure and were found to have generalized osteomalacia (rickets) due to phosphate depletion from prolonged administration of an aluminum-containing antacid given for the symptoms of colic. One of the infants developed bilateral proptosis due to craniosynostosis related to the underlying metabolic bone disease. The chronic use of aluminum-containing antacids in infants has potential risk for the growing skeleton and is not innocuous. Therefore, antacid therapy should be used in low doses and very cautiously, with routine monitoring of serum calcium and phosphorus in children taking medications which reduce gastrointestinal phosphate absorption.

Commentary: sonography in the evaluation of children following blunt trauma: is it to be or not to be?

Over the past decade CT scanning has become generally accepted in North America as the diagnostic modality of choice for the evaluation of abdominal injury in children following blunt trauma [1-5]. Recently, there has been increasing interest in the use of sonography as the primary screening examination in this area. Initial studies utilizing sonography in the evaluation of trauma patients focused primarily on identifying hemoperitoneum in adults [6-8]. More recent studies have also attempted to evaluate the accuracy of sonography for the diagnosis of solid viscus injury [9-14]. Filiatraut and colleagues recently reported a long and successful experience using sonography for the investigation of blunt abdominal trauma in children [12]. Their work in this area should be applauded. However, whether widespread application of this modality can be successful remains uncertain. In the space below a critical evaluation of sonography and CT in the assessment of injured children is presented.

Active hemorrhage in children after thoracoabdominal trauma: clinical and CT features.

OBJECTIVE: We reviewed the clinical features and CT evidence of active hemorrhage in children undergoing CT studies because of closed thoracoabdominal trauma. Our purpose was to evaluate the hypothesis that children with this CT finding have uniformly poor clinical outcomes. MATERIALS AND METHODS: The CT records of approximately 3000 children undergoing CT evaluation for trauma at four geographically distinct pediatric trauma centers were reviewed for the presence of active hemorrhage on CT scans. The location and severity of active hemorrhage, accompanying organ injury, initial clinical information, type of treatment (surgical or nonsurgical), and clinical outcome were recorded. RESULTS: Seven CT studies showing acute extravasation of intravascular contrast material in the abdomen (six) or chest (one) were identified. Hemorrhage was caused by severe solid organ injury in four children (three with hepatic injury and one with splenic injury) and by vascular injury to the internal iliac artery, segmental pulmonary artery, and descending colon in one child each. Every child with abdominal injuries had large collections of intraperitoneal fluid, and three children had abdominal CT signs of hypoperfusion. Although all patients were hemodynamically stable initially, four children became hypotensive during CT examination. Six children required surgical intervention because of ongoing blood loss, and two children died. CONCLUSION: Our results suggest that children with CT evidence of active hemorrhage have a different spectrum of injuries than that seen in adults. Despite the high rate of hemodynamic instability and need for urgent surgical intervention, most children with this CT finding survive.

Childhood survival of atlantooccipital dislocation: underdiagnosis, recognition, treatment, and review of the literature.

Traumatic childhood atlantooccipital dislocation (AOD) may be overlooked, especially in patients with concomitant closed head injury and multiple trauma. We diagnosed and treated 4 children with traumatic AOD seen in less than a 2-year period. We found published descriptions of only 15 other survivors of childhood traumatic AOD in the literature. Clinical histories, radiographic findings, treatment, outcome, and complications in these 15 children as well as our 4 patients were reviewed. The age distribution of childhood AOD survivors (average age 6.8 years) closely resembles that of pediatric multiple trauma patients. Early diagnosis of traumatic AOD hinges on precise interpretation of the lateral cervical radiograph. Longitudinal AOD was seen most often. Usually these children presented with cranial nerve palsies, major motor deficits, and depressed level of consciousness. Most underwent posterior atlantooccipital fusion. Outcome varied from normal neurological function to prolonged ventilator dependency and delayed demise. AOD must be diagnosed early to avoid attributing potentially reversible neurologic changes to irreversible injuries since closed head injury and high spinal cord dysfunction may be confused clinically and the outcome of a patient with AOD is unpredictable.

Is cystic mesenchymal hamartoma of the liver similar to infantile hemangioendothelioma and cavernous hemangioma on dynamic computed tomography?

Dynamic incremental contrast CT of a cystic mesenchymal hamartoma of the liver in a 10 year old boy demonstrated peripheral and septal enhancement with partial centripetal fill-in during the next sixty minutes, not unlike that which occurs in hemangioendothelioma and hemangioma. Histologic similarities among these mesenchymal lesions may explain the similar CT and angiographic characteristics of such malformations.

Hallermann-Streiff syndrome with hypopituitarism contributing to growth failure.

A 35-month-old black boy with Hallermann-Streiff syndrome (HSS) was evaluated for anterior hypopituitarism when he presented with ketotic hypoglycemia, microgenitalia, and short stature. Endocrine evaluation showed a low T4 and TSH levels, suggesting hypothalamic hypothyroidism; this was confirmed by TRH stimulation. Metyrapone test confirmed ACTH deficiency as a contributing factor to the ketotic hypoglycemia. A superagonist GnRH test suggested hypothalamic GnRH deficiency. Growth hormone provocative testing conclusively demonstrated complete growth hormone deficiency. MRI investigation of the brain suggested hypopituitarism. Although facial findings were not completely classical of the HSS, we suggest these may be somewhat altered due to his racial back-ground. We recommend endocrine evaluation of HSS patients with manifestations suggesting hypopituitarism since treatment of this condition will improve the quality of life of these patients.

Epithelioid hemangioendothelioma of the lung (intravascular bronchioloalveolar tumor) in a young girl.

This report describes a 7 year old girl who presented with scoliosis and a small right hemithorax. Findings on spine roentgenographs were pleural thickening on the right and parenchymal densities. Computed tomography of the chest and abdomen revealed multiple pulmonary nodules and two hypervascular lesions within the liver. The diagnosis established by lung biopsy was intravascular bronchioloalveolar tumor (epithelioid hemangioendothelioma of the lung). This is the youngest reported case of this rare tumor.