Randheer Shailam

Dose reduction and compliance with pediatric CT protocols adapted to patient size, clinical indication, and number of prior studies.

PURPOSE To assess compliance and resultant radiation dose reduction with new pediatric chest and abdominal computed tomographic (CT) protocols based on patient weight, clinical indication, number of prior CT studies, and automatic exposure control. MATERIALS AND METHODS The study was institutional review board approved and HIPAA compliant. Informed consent was waived. The new pediatric CT protocols, which were organized into six color zones based on clinical indications and number of prior CT examinations in a given patient, were retrospectively assessed. Scanning parameters were adjusted on the basis of patient weight. For gradual dose reduction, pediatric CT (n = 692) examinations were performed in three phases of incremental stepwise dose reduction during a 17-month period. There were 245 male patients and 193 female patients (mean age, 12.6 years). Two radiologists independently reviewed CT images for image quality. Data were analyzed by using multivariate analysis of variance. RESULTS Compliance with the new protocols in the early stage of implementation (chest CT, 58.9%; abdominal CT, 65.2%) was lower than in the later stage (chest CT, 88%; abdominal CT, 82%) (P < .001). For chest CT, there was 52.6% (9.1 vs 19.2 mGy) to 85.4% (2.8 vs 19.2 mGy) dose reduction in the early stage of implementation and 73.5% (4.9 vs 18.5 mGy) to 83.2% (3.1 vs 18.5 mGy) dose reduction in the later stages compared with dose at noncompliant examinations (P < .001); there was no loss of clinically relevant image quality. For abdominal CT, there was 34.3% (9.0 vs 13.7 mGy) to 80.2% (2.7 vs 13.7 mGy) dose reduction in the early stage of implementation and 62.4% (6.5 vs 17.3) to 83.8% (2.8 vs 17.3 mGy) dose reduction in the later stage (P < .001). CONCLUSION Substantial dose reduction and high compliance can be obtained with pediatric CT protocols tailored to clinical indications, patient weight, and number of prior studies.

Role of MRI in the diagnosis and treatment of osteomyelitis in pediatric patients

Osteomyelitis is a significant cause of morbidity in children throughout the world. Multiple imaging modalities can be used to evaluate for suspected osteomyelitis, however magnetic resonance imaging (MRI) has distinct advantages over other modalities given its ability to detect early changes related to osteomyelitis, evaluate the true extent of disease, depict extraosseous spread of infection, and help guide surgical management. MRI has assumed a greater role in the evaluation of osteomyelitis with the increase in musculoskeletal infections caused by methicillin-resistant Staphylococcus aureus which have unique imaging features that are well-demonstrated with MRI. This review focuses primarily on the use of MRI in the evaluation of osteomyelitis in children and will include a discussion of the clinically important and characteristic findings on MRI of acute bacterial osteomyelitis and related conditions.

Relationship Between Radiologist Training Level and Fluoroscopy Time for Voiding Cystourethrography

OBJECTIVE The objective of our study was to determine whether voiding cystourethrography (VCUG) fluoroscopy time is related to the training level of the performing radiologist. MATERIALS AND METHODS VCUG reports with normal findings from 2008 to 2011 at one institution were retrospectively reviewed. The average fluoroscopy time was calculated for first-year radiology residents, senior radiology residents, pediatric radiology fellows, and attending pediatric radiologists. The average fluoroscopy time was also calculated for radiologist sex, patient sex, and patient age group. The analysis of variance was used to evaluate differences in average fluoroscopy times between training levels of radiologists, patient age groups, and patient sexes. RESULTS We reviewed 784 VCUG reports with normal findings: 340 (43.4%) were performed by first-year residents; 181 (23%), by senior residents; 161 (20.5%), by fellows; and 102 (13%), by attending pediatric radiologists. The overall average fluoroscopy time was 1.86 minutes (SD ± 0.98). The attending pediatric radiologists had the shortest average fluoroscopy time (1.63 ± 0.92 minutes), significantly shorter than senior residents (1.96 ± 1.09 minutes; p = 0.0070) and fellows (1.91 ± 0.85 minutes; p = 0.0255). There was no significant difference between attending radiologists and first-year residents (1.85 ± 1.00 minutes; p = 0.0550). The male-to-female ratio of radiologists was 54% versus 46%, with identical average fluoroscopy times: male radiologists, 1.86 ± 1.05 minutes; female radiologists, 1.86 ± 0.90 minutes. There was no significant difference in average fluoroscopy times among patient age groups: 1.93, 1.76, and 1.78 minutes, respectively, for groups A (0-1 years), B (> 1 to ≤ 5 years), and C (> 5 years) (p = 0.1750, 0.4605, 0.6303). The average fluoroscopy time for male patients (2.02 ± 1.00 minutes) was significantly longer than that for female patients (1.71 ± 0.95 minutes; p < 0.0001). CONCLUSION Attending pediatric radiologists have the shortest fluoroscopy time; the differences between their average time compared with the average times of pediatric radiology fellows and of senior radiology residents were statistically significant. The average fluoroscopy time is longer for male patients than for female patients.

Avascular necrosis of the metacarpal head: a report of two cases and review of literature

BackgroundAvascular necrosis (AVN) of the metacarpal head is a rare condition that can go unrecognized on radiography and progress to degenerative arthritis. Few reports describe the association with trauma, steroid use and systemic lupus erythematosus (SLE). Optimal treatment for this condition has not been established and long-term prognosis is unknown.ObjectiveWe present two cases of children with AVN of the fourth metacarpal head with a relatively recent history of indirect hand trauma.Materials and methodsBoth of our cases had radiographs and MRI of the hand.ResultsMRI was diagnostic in both cases; however, radiographs were reported as normal in the early stage in one case.ConclusionAVN of the metacarpal head is rare but can occur in children. Pediatric radiologists should be aware of this uncommon clinical entity, especially in light of increased involvement of children in sporting activities. Active children with hand trauma and children treated with steroids for a variety of conditions are particularly at risk.

Case 10-2008: A 10-Year-Old Girl with Dyspnea on Exertion

From the Pediatric Pulmonary Unit (K.E.H.) and the Departments of Pediatric Surgery (D.P.R.), Radiology (R.S.), and Pathology (E.J.M.), Massachusetts General Hospital; Pediatric Otolaryngology, Massachusetts Eye and Ear Infirmary (C.J.H.); and the Departments of Pediatrics (K.E.H.), Otology and Laryngology (C.J.H.), Surgery (D.P.R.), Radiology (R.S.), and Pathology (E.J.M.), Harvard Medical School.

Case 10-2008

From the Pediatric Pulmonary Unit (K.E.H.) and the Departments of Pediatric Surgery (D.P.R.), Radiology (R.S.), and Pathology (E.J.M.), Massachusetts General Hospital; Pediatric Otolaryngology, Massachusetts Eye and Ear Infirmary (C.J.H.); and the Departments of Pediatrics (K.E.H.), Otology and Laryngology (C.J.H.), Surgery (D.P.R.), Radiology (R.S.), and Pathology (E.J.M.), Harvard Medical School.

Oxygen Saturation Can Predict Pediatric Pneumonia in a Resource-Limited Setting

BACKGROUND The World Health Organization (WHO) recommends using age-specific respiratory rates for diagnosing pneumonia in children. Past studies have evaluated the WHO criteria with mixed results. OBJECTIVE We examined the accuracy of clinical and laboratory factors for diagnosing pediatric pneumonia in resource-limited settings. METHODS We conducted a retrospective chart review of children under 5 years of age presenting with respiratory complaints to three rural hospitals in Rwanda who had received a chest radiograph. Data were collected on the presence or absence of 31 historical, clinical, and laboratory signs. Chest radiographs were interpreted by pediatric radiologists as the gold standard for diagnosing pneumonia. Overall correlation and test characteristics were calculated for each categorical variable as compared to the gold standard. For continuous variables, we created receiver operating characteristic (ROC) curves to determine their accuracy for predicting pneumonia. RESULTS Between May 2011 and April 2012, data were collected from 147 charts of children with respiratory complaints. Approximately 58% of our sample had radiologist-diagnosed pneumonia. Of the categorical variables, a negative blood smear for malaria (χ(2) = 6.21, p = 0.013) and the absence of history of asthma (χ(2) = 4.48, p = 0.034) were statistically associated with pneumonia. Of the continuous variables, only oxygen saturation had a statistically significant area under the ROC curve (AUC) of 0.675 (95% confidence interval [CI] 0.581-0.769 and p = 0.001). Respiratory rate had an AUC of 0.528 (95% CI 0.428-0.627 and p = 0.588). CONCLUSION Oxygen saturation was the best clinical predictor for pediatric pneumonia and should be further studied in a prospective sample of children with respiratory symptoms in a resource-limited setting.

Case records of the Massachusetts General Hospital. Case 26-2011. A 7-year-old boy with a complex cyst in the kidney.

A 7-year-old boy was seen in an outpatient clinic at this hospital because of a complex cyst in the kidney. The patient was born by vaginal delivery after an uncomplicated 38-week gestation. His birth weight was 3.04 kg. A diagnosis of tuberous sclerosis complex (TSC) was made at age 4 months, when he was admitted to this hospital with respiratory distress due to bronchiolitis associated with short episodes of apnea and cyanosis. An electrocardiogram (ECG) showed a shortened PR interval. Transthoracic echocardiography revealed multiple intracardiac masses involving the right ventricle, right atrium, septum, and possibly the left ventricle, features consistent with rhabdomyomas. Magnetic resonance imaging (MRI) of the brain revealed multiple subependymal nodules along the lateral ventricular margins, innumerable cortical tubers, and multiple linear areas of increased T1-weighted signal and decreased T2-weighted signal within the white matter, findings that are typical of tuberous sclerosis. A renal ultrasound examination revealed enlarged kidneys (right kidney, 7.5 cm in length; left kidney, 9.3 cm) with multiple large bilateral cysts (up to 4 cm in diameter) and no evidence of a solid mass. An electroencephalogram showed attenuation of the background amplitude and slowing in the left hemisphere as compared with the right, and focal spikes in the right temporal region at T4 during drowsiness and sleep. Examination with a Wood’s lamp revealed 12 small hypopigmented cutaneous macules; an ophthalmologic examination was normal. Discussion with the parents revealed that the patient’s father had received a diagnosis of tuberous sclerosis during adolescence, manifested by renal cysts, hypopigmented macules, and a facial angiofibroma; he reportedly had no abnormalities on brain-imaging studies but had learning disabilities. The patient had three older maternal half siblings, none of whom had the disease. The infant was discharged on the fourth hospital day, after initiation of treatment with oral amoxicillin and nebulized albuterol. When the patient was 6 months of age, seizure activity developed and was treated with divalproex sodium. At 12 months of age, infantile spasms began, which were treated with vigabatrin. At 13 months of age, hypertension developed and was treated first with nifedipine and later with amlodipine. Repeat renal ultrasonography Case 26-2011: A 7-Year-Old Boy with a Complex Cyst in the Kidney

Initial Clinical Experience With Extremity Cone-Beam CT of the Foot and Ankle in Pediatric Patients

OBJECTIVE Extremity cone-beam CT (CBCT) scanners have become available for clinical use in the United States. The purpose of this study was to review an initial clinical experience with CBCT of the foot and ankle in pediatric patients. MATERIALS AND METHODS A retrospective review was conducted of all foot or ankle CBCT examinations performed on patients 18 years old and younger at one institution from August 1, 2013, through February 28, 2015. A t test was used to compare mean effective dose for CBCT with that for MDCT foot or ankle examinations of age-matched control subjects. To assess changes in utilization, a t test also was used to compare the mean numbers of foot or ankle CT examinations per month before and after installation of the CBCT scanner at the institution. RESULTS Thirty-four CBCT examinations were performed. The mean effective dose was 0.013 ± 0.003 mSv compared with 0.023 ± 0.020 mSv for MDCT of age-matched control subjects (p < 0.005). The mean numbers of foot or ankle CT examinations per month were 3.4 in the 18 months before and 3.8 in the 18 months after installation of the CBCT scanner (p = 0.28). The mean number of foot or ankle MDCT examinations per month decreased significantly (3.4 vs 1.9, p = 0.03) over the same period. In 56% of patients, CBCT revealed important findings that were not visible on contemporaneous radiographs. In 68% of patients, the CBCT findings affected clinical management. CONCLUSION CBCT of the foot or ankle of pediatric patients is a viable lower-dose alternative to MDCT that provides important information that may affect clinical management.

Case 25-2015

Dr. Jessica M. Rosenthal (Pediatrics): An 8-year-old girl who had required long-term tracheostomy because of airway stenosis caused by an injury in infancy was admitted to this hospital because of a chest-wall mass and a large pleural effusion. The patient was born in China. At 7 months of age, she underwent emergency tracheostomy after a caustic injury from either ingestion or inhalation. At 2.5 years of age, she was adopted by an American family and moved to the United States. Her adoptive parents noted that she had stridor and snoring, and her pediatrician referred her to an otolaryngologist at the Massachusetts Eye and Ear Infirmary (MEEI) at 2 years 10 months of age. On examination, the nasopharynx was completely obstructed; there was fusion of the posterior tongue and hard palate and of the hard palate and epiglottis, with a narrow opening in the oropharynx. The supraglottic passage was normal beyond the stenosis; the subglottic airway was not evaluated. A tracheostomy was performed, and the left nasal choanal obstruction was opened with a laser. Repeat bronchoscopy revealed that the larynx and subglottic trachea were normal. On two occasions, esophagogastroduodenoscopy revealed no evidence of gastroesophageal reflux. The tracheostomy tube was removed when the patient was 5.5 years of age; there was a residual tracheal–cutaneous fistula. When she was 7.5 years of age (7 months before this admission), another tracheostomy was performed because of worsening oropharyngeal stenosis that precluded intubation and because of concern about possible obstruction. The patient had been in her usual state of health until approximately 6.5 weeks before this admission; during a 10-day period, her mother noted recurrent bloodtinged sputum in the tracheostomy tube, and an episode of bleeding at the tracheostomy site occurred at school. The patient was seen in the emergency department of the MEEI, where a flexible tracheoscopy, which was performed at the bedside after removal of the tracheostomy tube, revealed no exposed blood vessels or granulation tissue in the trachea or stoma. A chest radiograph showed consolidation in the right lower lobe, which was thought to be due to aspiration, pneumonia, or atelectasis. Gram’s staining of the sputum showed abundant neutrophils, abundant gram-positive cocci in pairs and a few chains, abundant gram-negative diplococci, a few gram-positive rods, and a few thin gram-negative rods. Culture From the Departments of Pediatrics (S.M.M.), Radiology (R.S.), and Patholo‐ gy (E.J.M.), Massachusetts General Hos‐ pital; and the Departments of Pediatrics (S.M.M.), Radiology (R.S.), and Pathology (E.J.M.), Harvard Medical School — both in Boston.