Boaz Karmazyn

CT with a Computer-Simulated Dose Reduction Technique for Detection of Pediatric Nephroureterolithiasis: Comparison of Standard and Reduced Radiation Doses

OBJECTIVE The purpose of this study was to compare the diagnostic capabilities of standard- and reduced-dose CT in the detection of nephroureterolithiasis in children. MATERIALS AND METHODS Forty-five patients 20 years old or younger divided into two groups weighing 50 kg or less and more than 50 kg underwent unenhanced 16-MDCT in the evaluation of acute flank pain. An investigational computer-simulated tube current reduction tool was used to produce additional 80- and 40-mA examination sets (total number of image sets=135). Three independent blinded readers ranked random images for stones (confidence scale, 1-5, least to most), hydronephrosis, noise-based image quality, and presence of nonrenal lesions. RESULTS Compared with the standard tube current used for the original CT scans, there was no significant reduction (p=0.37) in detection of renal stones at the 80-mA setting (mean dose reduction, 67%; range, 43-81%); and at the 40-mA setting (mean dose reduction, 82%; range, 72-90%), the detection rate was significantly lower (p=0.05). At the 40-mA setting, there was no significant difference among the children weighing 50 kg or less (p=0.4). Detection of ureteral stones and hydronephrosis was not significantly different at 80 and 40 mA; however, disease frequency was low, and no definite conclusion can be made. CONCLUSION Simulated dose reduction is a useful tool for determining diagnostic thresholds for MDCT detection of renal stones in children. Use of the 80-mA setting for all children and 40 mA for children weighing 50 kg or less does not significantly affect the diagnosis of pediatric renal stones.

Community-associated methicillin-resistant Staphylococcus aureus in acute musculoskeletal infection in children: a game changer.

Background Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a virulent pathogen responsible for an increasing number of invasive musculoskeletal infections in healthy children. The purpose of this study is to characterize the presentation, clinical course, treatment, complications, and long-term morbidity of CA-MRSA musculoskeletal infection in children. Methods A retrospective study of children with CA-MRSA musculoskeletal infections from 2 institutions was conducted. Results The study group included 27 patients. Clinical presentation involved an extremity in 23 of 27 patients. Twelve patients required admission to the intensive care unit. Four of these patients developed acute multisystem failure. Magnetic resonance imaging was obtained in 21 patients and was diagnostic in all. Seven patients developed deep venous thrombosis and septic pulmonary emboli. All patients required surgical intervention, and 16 of 27 required multiple debridements. Conclusions CA-MRSA is limb and life threatening. Prompt recognition and treatment are critical. Aggressive surgical drainage/debridement in addition to long-term antibiotics is required. There is significant potential for long-term morbidity despite aggressive management. Level of Evidence Level IV, retrospective case series.

Anterior pericardial tracheoplasty for congenital tracheal stenosis: Intermediate to long-term outcomes

BACKGROUND Although several techniques for the treatment of long-segment stenosis of the trachea have been reported, including slide tracheoplasty, rib grafting, and use of a pericardial patch, the optimal repair remains controversial because of a lack of midterm to long-term follow-up data. METHODS To assess the intermediate and long-term outcomes of patients having repair with anterior pericardial tracheoplasty, we reviewed case histories of 12 patients (1984 to present). The median age was 6.7 months (range, 1 to 98 months), and the median weight was 6.0 kg (range, 0.97 to 42 kg). All patients underwent anterior pericardial tracheoplasty through a median sternotomy during partial normothermic cardiopulmonary bypass. An average of 13 tracheal rings (range, five to 23) were divided anteriorly, and a patch of fresh autologous pericardium was used to enlarge the trachea by 1.5 times the predicted diameter for patient age and weight. RESULTS There was one hospital death, and all but 2 patients are long-term survivors. All but 1 current survivor remain asymptomatic, with no bronchoscopic evidence of airway obstruction or granulation on the pericardial patch. All survivors examined have normal tracheal growth and development, with a median follow-up of 5.5 years (range, 1 to 11 years). CONCLUSIONS Anterior pericardial tracheoplasty for congenital tracheal stenosis provides excellent results at intermediate to long-term follow-up.

The prevalence of uncommon fractures on skeletal surveys performed to evaluate for suspected abuse in 930 children: Should practice guidelines change?

OBJECTIVE The objective of our study was to evaluate the prevalence and site of fractures detected on skeletal surveys performed for suspected child abuse at a tertiary childrens hospital and to determine whether any survey images may be eliminated without affecting clinical care or the ability to make a diagnosis. MATERIALS AND METHODS We identified all skeletal surveys performed for suspected abuse from 2003 to 2009 of children younger than 2 years. Repeated studies were excluded, as were studies not performed to evaluate for suspected abuse. From the reports, we documented the sites of all the fractures. RESULTS. Nine hundred thirty children (515 boys and 415 girls) with a median age of 6 months met the entry criteria for the study. Fractures were detected in 317 children (34%), of whom 166 (18%) had multiple fractures. The most common sites for fractures were the long bones (21%), ribs (10%), skull (7%), and clavicle (2%). Ten children (1%) had fractures in the spine (n = 3), pelvis (n = 1), hands (n = 6), and feet (n = 2). All 10 children had other signs of physical abuse. CONCLUSION In skeletal surveys performed for suspected child abuse, fractures limited to sites other than the long bones, ribs, skull, and clavicles are rare. The additional radiation exposure and cost of obtaining radiographs of the spine, pelvis, hands, and feet may outweigh their potential benefit. Given the rarity of fractures of the spine, pelvis, hands, and feet, consideration may be given to eliminating those views from routine skeletal surveys performed to evaluate for suspected child abuse.

The Detection of Pulmonary Metastases by Helical Ct: A Clinicopathologic Study in Dogs

PURPOSE We sought to determine the accuracy of helical CT in the detection of pulmonary metastases. METHOD Four anesthetized dogs with metastatic osteosarcoma underwent helical CT with a collimation of 5 mm, a pitch of 2, and a reconstruction interval of 5 mm. All macroscopically evident metastases were recorded at autopsy. CT images were independently reviewed by 10 radiologists and compared with pathologic results. Alternate slices in the dog with the most metastases were microscopically examined in their entirety. RESULTS Pathologic examination of the lungs revealed 132 macroscopically evident pulmonary metastases, of which 74 (56%) were detected by at least one reader. Forty-four of the 99 (44%) metastases of < or = 5 mm in diameter were detected by at least one reader compared with 30 of 33 (91%) metastases of > 5 mm in diameter (p < 0.0001). The 10 readers reported a total of 107 false positives. Complete microscopy of alternate slices in the dog with the most metastases (n = 68) revealed an additional 38 micrometastases of < or = 3 mm in diameter. None of the 32 micrometastases of < or = 1 mm were detected by CT. CONCLUSION Helical CT has some limitations in the detection of pulmonary metastases.

Acute pyomyositis of the pelvis: the spectrum of clinical presentations and MR findings

Background: Acute pelvic pyomyositis is uncommon in non-tropical areas. Objective: To summarize the clinical and MR findings in children with acute pelvic pyomyositis. Materials and methods: We retrospectively identified 20 children (mean age 9.4 years) who were evaluated by MR and diagnosed with acute pelvis pyomyositis during the time period between January 2002 and June 2005. We reviewed clinical, laboratory, and imaging findings. Results: Fifteen of the 20 children had secondary pyomyositis associated with osteomyelitis (n=13), septic hip (n=4) or sacroiliitis (n=4); all were previously healthy except for one child with leukemia. Seven of the children with secondary pyomyositis underwent bone scintigraphy; three (43%) did not show pelvic abnormalities. Staphylococcus aureus was cultured in 13 of the 15 (87%) children. Five of the 20 children had primary pyomyositis. Three had underlying disease and two others were engaged in vigorous physical activity. Bone scintigraphies (n=2) were negative. Cultures were positive for S. aureus in three of the five (60%) children. Conclusion: Septic hip should be the first diagnostic consideration in children with fever and acute hip pain. Pyomyositis should be considered if art\hrocentesis is negative or there is clinical suspicion of infection outside the hip joint. MR is the preferred imaging modality for evaluating foci of pyomyositis, muscle abscesses, and additional foci of infection within the pelvis.

ACR Appropriateness Criteria® on Suspected Physical Abuse—Child

The appropriate imaging for pediatric patients being evaluated for suspected physical abuse depends on the age of the child, the presence of neurologic signs and symptoms, evidence of thoracic or abdominopelvic injuries, and whether the injuries are discrepant with the clinical history. The clinical presentations reviewed consider these factors and provide evidence-based consensus recommendations by the ACR Appropriateness Criteria(®) Expert Panel on Pediatric Imaging.

The role of pelvic magnetic resonance in evaluating nonhip sources of infection in children with acute nontraumatic hip pain.

We retrospectively identified all children with acute hip pain who underwent pelvic magnetic resonance (MR). Children with septic hip or history of trauma were excluded; the remaining children with signs of infection (fever, >38°C; leukocytosis, >12 × 109/L; or elevated erythrocyte sedimentation rate [ESR], >30 mm/h) comprised the study group. Thirty-three children (9 girls; age, 0.8-15.8 years) were identified. On MR examination, 18 (55%) of 33 children had hip joint effusion, whereas 19 (58%) of 33 children had other abnormalities, including pyomyositis (n = 15), osteomyelitis (n = 12), and sacroiliitis (n = 3). Staphylococcus aureus was cultured from 13 (68%) of these 19 children. Compared with MR, sensitivity for bone and soft tissue abnormalities was 30% for pelvic radiography (n = 26) and 71% for bone scintigraphy (n = 8). Elevated ESR (>30 mm/h) was the clinical finding that best predicted pelvic osteomyelitis or pyomyositis. Pelvic MR should be performed to rule out pelvic osteomyelitis or pyomyositis in children with acute hip pain, ESR of more than 30 mm/h, and no evidence of septic hip.

Testicular Microlithiasis in Children and Associated Testicular Cancer

PURPOSE To evaluate the prevalence of testicular microlithiasis (TM) in children who have undergone scrotal ultrasonography (US) and their association with testicular tumors. MATERIALS AND METHODS This HIPAA-compliant study with waiver of informed consent was approved by the institutional review board. From 2003 to 2012, all patients with scrotal US and report mentioning calcifications or microlithiasis and all patients with testicular tumors from pathology database were identified. US studies were evaluated for the type of TM (classic ≥5 microliths or limited <5 microliths in a single view) and change in follow-up studies if available. Medical charts were reviewed for US indication, underlying medical conditions, and pathologic abnormalities, when available. Fisher exact test was used to analyze the association of testicular tumors and TM. RESULTS A total of 3370 boys had scrotal US, 83 (2%) of whom had TM or microcalcifications in the report. TM was usually bilateral (n = 62, 75%) and classic (n = 59, 71%) type.TM was significantly less common in those younger than 2 years of age than in older age groups (0.1% vs 3.1%, P < .0001). The most common indication for US was scrotal pain (40 of 83 patients, 48%), and the most common associated medical condition was cryptorchidism (nine of 83 patients, 11%). Testicular tumor was significantly more likely in boys with TM (12% vs 0.3%, P < .01). Five (83%) of six patients with premalignant or benign tumors had a premalignant condition (cryptochydism in two and Peutz-Jeghers syndrome in three). Four patients with TM had malignant testicular tumors, all diagnosed after the age of 16 years. CONCLUSION TM has a prevalence of 2% in boys who undergo scrotal US. It is most commonly bilateral, classic type, and stable at follow-up studies. There is a significant association of TM and testicular tumors. Malignant tumors were seen only in adolescent boys.

ACR Appropriateness Criteria ® on Developmental Dysplasia of the Hip—Child

Developmental dysplasia of the hip (DDH) affects 1.5 of every 1,000 caucasian Americans and less frequently affects African Americans. Developmental dysplasia of the hip comprises a spectrum of abnormalities, ranging from laxity of the joint and mild subluxation to fixed dislocation. Early diagnosis of DDH usually leads to low-risk treatment with a harness. Late diagnosis of DDH in children may lead to increased surgical intervention and complications. Late diagnosis of DDH in adults can result in debilitating end-stage degenerative hip joint disease. Screening decreases the incidence of late diagnosis of DDH. Clinical evaluation for DDH should be performed periodically at each well-baby visit until the age of 12 months. There is no consensus on imaging screening for DDH. Consideration for screening with ultrasound is balanced between the benefits of early detection of DDH and the increased treatment and cost factors. In addition, randomized trials evaluating primary ultrasound screening did not find significant decrease in late diagnosis of DDH. In the United States, hip ultrasound is selectively performed in infants with risk factors, such as family history of DDH, breech presentation, and inconclusive findings on physical examination. Ultrasound for DDH should be performed after 2 weeks of age because laxity is common after birth and often resolves itself. A pelvic radiograph can optimally be performed after the age of 4 months, when most infants will have ossification centers of the femoral heads.