Rotator cuff tears in children and adolescents: experience at a large pediatric hospital.

BACKGROUND: Prior literature, limited to small case series and case reports, suggests that rotator cuff tears are rare in adolescents. However, we have identified rotator cuff tears in numerous children and adolescents who have undergone shoulder MRI evaluation. OBJECTIVE: The purpose of this study is to describe the prevalence and characteristics of rotator cuff tears in children and adolescents referred for MRI evaluation of the shoulder at a large pediatric hospital and to correlate the presence of rotator cuff tears with concurrent labral pathology, skeletal maturity and patient activity and outcomes. MATERIALS AND METHODS: We reviewed reports from 455 consecutive non-contrast MRI and magnetic resonance arthrogram examinations of the shoulder performed during a 2-year period, and following exclusions we yielded 205 examinations in 201 patients (ages 8-18 years; 75 girls, 126 boys). Rotator cuff tears were classified by tendon involved, tear thickness (partial or full), surface and location of tear (when partial) and presence of delamination. We recorded concurrent labral pathology when present. Physeal patency of the proximal humerus was considered open, closing or closed. Statistical analysis was performed to evaluate for a relationship between rotator cuff tears and degree of physeal patency. We obtained patient activity at the time of injury, surgical reports and outcomes from clinical records when available. RESULTS: Twenty-five (12.2%) rotator cuff tears were identified in 17 boys and 7 girls (ages 10-18 years; one patient had bilateral tears). The supraspinatus tendon was most frequently involved (56%). There were 2 full-thickness and 23 partial-thickness tears with articular-side partial-thickness tears most frequent (78%). Insertional partial-thickness tears were more common (78%) than critical zone tears (22%) and 10 (43%) partial-thickness tears were delamination tears. Nine (36%) patients with rotator cuff tears had concurrent labral pathology. There was no statistically significant relationship between rotator cuff tears and physeal patency (P > 0.05). Most patients were athletes (76%). Five tears were confirmed at surgery. Poor clinical follow-up limited evaluation of patient outcomes. CONCLUSION: Rotator cuff tears can be identified during MRI examination of symptomatic child and adolescent shoulders and often consist of tear patterns associated with repetitive microtrauma in overhead athletic activities or with single traumatic events. Rotator cuff tears are seen throughout the range of skeletal maturity, often coexist with labral tears and typically are found in athletes.

Comparison of radiation dose estimates and scan performance in pediatric high-resolution thoracic CT for volumetric 320-detector row, helical 64-detector row, and noncontiguous axial scan acquisitions.

RATIONALE AND OBJECTIVES: Efforts to decrease radiation exposure during pediatric high-resolution thoracic computed tomography (HRCT), while maintaining diagnostic image quality, are imperative. The objective of this investigation was to compare organ doses and scan performance for pediatric HRCT using volume, helical, and noncontiguous axial acquisitions. MATERIALS AND METHODS: Thoracic organ doses were measured using 20 metal oxide semiconductor field-effect transistor dosimeters. Mean and median organ doses and scan durations were determined and compared for three acquisition modes in a 5-year-old anthropomorphic phantom using similar clinical pediatric scan parameters. Image noise was measured and compared in identical regions within the thorax. RESULTS: There was a significantly lower dose in lung (1.8 vs 2.7 mGy, P < .02) and thymus (2.3 vs 2.7 mGy, P < .02) between volume and noncontiguous axial modes and in lung (1.8 vs 2.3 mGy, P < .02), breast (1.8 vs 2.6 mGy, P < .02), and thymus (2.3 vs 2.4 mGy, P < .02) between volume and helical modes. There was a significantly lower median image noise for volume compared to helical and axial modes in lung (55.6 vs 79.3 and 70.7) and soft tissue (76.0 vs 111.3 and 89.9). Scan times for volume, helical, and noncontiguous axial acquisitions were 0.35, 3.9, and 24.5 seconds, respectively. CONCLUSION: Volumetric HRCT provides an opportunity for thoracic organ dose and image noise reduction, at significantly faster scanning speeds, which may benefit pediatric patients undergoing surveillance studies for diffuse lung disease.

Comparison of radiation dose estimates, image noise, and scan duration in pediatric body imaging for volumetric and helical modes on 320-detector CT and helical mode on 64-detector CT.

BACKGROUND: Advanced multidetector CT systems facilitate volumetric image acquisition, which offers theoretic dose savings over helical acquisition with shorter scan times. OBJECTIVE: Compare effective dose (ED), scan duration and image noise using 320- and 64-detector CT scanners in various acquisition modes for clinical chest, abdomen and pelvis protocols. MATERIALS AND METHODS: ED and scan durations were determined for 64-detector helical, 160-detector helical and volume modes under chest, abdomen and pelvis protocols on 320-detector CT with adaptive collimation and 64-detector helical mode on 64-detector CT without adaptive collimation in a phantom representing a 5-year-old child. Noise was measured as standard deviation of Hounsfield units. RESULTS: Compared to 64-detector helical CT, all acquisition modes on 320-detector CT resulted in lower ED and scan durations. Dose savings were greater for chest (27-46%) than abdomen/pelvis (18-28%) and chest/abdomen/pelvis imaging (8-14%). Noise was similar across scanning modes, although some protocols on 320-detector CT produced slightly higher noise. CONCLUSION: Dose savings can be achieved for chest, abdomen/pelvis and chest/abdomen/pelvis examinations on 320-detector CT compared to helical acquisition on 64-detector CT, with shorter scan durations. Although noise differences between some modes reached statistical significance, this is of doubtful diagnostic significance and will be studied further in a clinical setting.

Congenital lung lesions: prenatal MRI and postnatal findings.

BACKGROUND: Congenital lung lesions refer to a spectrum of malformations and developmental abnormalities of the foregut, pulmonary airways and vasculature. These lesions range from small, asymptomatic to large space-occupying masses that can increase risk of fetal death and respiratory compromise after birth. Prenatal sonography has been used for routine screening in pregnancy. The advent of prenatal magnetic resonance imaging leads to complementary use in the diagnosis of fetal anomalies, including in fetuses with congenital lung lesions. OBJECTIVE: To determine whether fetal MRI can differentiate congenital lung lesions by comparing prenatal diagnosis with postnatal imaging and pathology. MATERIALS AND METHODS: In a 4-year period, 76 fetuses with suspected lung lesions were referred for fetal MRI. We retrospectively reviewed the MR exams and assigned a specific diagnosis based on predetermined criteria. We then compared the prenatal diagnosis to postnatal imaging and pathology. RESULTS: Of 76 cases, 7 were excluded because of an alternative diagnosis. Of the 69 remaining patients, 3 died and 13 were lost to follow-up. Among the 53 patients, there were 56 lung lesions. Four of these lesions were difficult to diagnose because of size and location. Based on imaging records we gave the remaining 52 lesions a specific prenatal diagnosis: 28 congenital pulmonary airway malformations (CPAM), 4 bronchopulmonary sequestrations (BPS), 9 cases of overinflation, 9 hybrid lesions and 2 bronchogenic cysts. The prenatal diagnosis was concordant with postnatal evaluation in 51 of the 52 lung lesions. One fetus given the diagnosis of CPAM prenatally was diagnosed with a hybrid lesion postnatally. CONCLUSION: Prenatal MRI is highly accurate in defining congenital lung anomalies. When fetal MRI findings suggest a specific diagnosis, postnatal findings confirmed the prenatal MRI diagnosis in 98% of cases.

Radiation dose estimation for prospective and retrospective ECG-gated cardiac CT angiography in infants and small children using a 320-MDCT volume scanner.

OBJECTIVE: The purpose of this study is to determine patient dose estimates for clinical pediatric cardiac-gated CT angiography (CTA) protocols on a 320-MDCT volume scanner. MATERIALS AND METHODS: Organ doses were measured using 20 metal oxide semiconductor field effect transistor (MOSFET) dosimeters. Radiation dose was estimated for volumetrically acquired clinical pediatric prospectively and retrospectively ECG-gated cardiac CTA protocols in 5-year-old and 1-year-old anthropomorphic phantoms on a 320-MDCT scanner. Simulated heart rates of 60 beats/min (5-year-old phantom) and 120 beats/min (1- and 5-year-old phantoms) were used. Effective doses (EDs) were calculated using average measured organ doses and International Commission on Radiological Protection 103 tissue-weighting factors. Dose-length product (DLP) was recorded for each examination and was used to develop dose conversion factors for pediatric cardiac examinations acquired with volume scan mode. DLP was also used to estimate ED according to recently published dose conversion factors for pediatric helical chest examinations. Repeated measures and paired Student t test analyses were performed. RESULTS: For the 5-year-old phantom, at 60 beats/min, EDs ranged from 1.2 mSv for a prospectively gated examination to 4.5 mSv for a retrospectively gated examination. For the 5-year-old phantom, at 120 beats/min, EDs ranged from 3.0 mSv for a prospectively gated examination to 4.9 mSv for a retrospectively gated examination. For the 1-year-old phantom, at 120 beats/min, EDs ranged from 2.7 mSv for a prospectively gated examination to 4.5 mSv for a retrospectively gated examination. CONCLUSION: EDs for 320-MDCT volumetrically acquired ECG-gated pediatric cardiac CTA are lower than those published for conventional 16- and 64-MDCT scanners.

Quantification of humeral head deformity following neonatal brachial plexus palsy.

BACKGROUND: Neonatal brachial plexus palsy frequently leads to glenohumeral dysplasia if neurological recovery is incomplete. Although glenoid retroversion and glenohumeral subluxation have been well characterized, humeral head deformity has not previously been quantified. Nonetheless, humeral head flattening is described as a contraindication to joint contracture release and external rotation tendon transfers. This study describes a novel technique for objectively quantifying humeral head deformity with use of magnetic resonance (MR) imaging and correlates the humeral head deformity with clinical and radiographic outcomes following joint rebalancing surgery. METHODS: Magnetic resonance images of thirty-two children (age, 0.7 to 11.5 years) with neonatal brachial plexus palsy were retrospectively reviewed. Passive shoulder external rotation and Mallet scores were reviewed before joint rebalancing surgery and at a minimum clinical follow-up interval of two years. The humeral head skewness ratio on preoperative and postoperative axial MR images was defined as the ratio of anterior to posterior humeral head area, and this ratio was compared between affected and unaffected shoulders and with the glenoid version angle, posterior subluxation of the humeral head, and clinical parameters before and after surgery with use of paired t tests and Spearman correlation. Intraobserver and interobserver reliability of MR image measurements was determined. RESULTS: Measurements of the skewness ratio on the affected side had moderate to substantial intraobserver reliability (0.53 to 0.72) and substantial interobserver reliability (0.65 to 0.71). Preoperatively, the skewness ratio of the affected humeral head (mean, 0.76; range, 0.54 to 1.03) differed significantly from the ratio in the contralateral shoulder (p<0.05) and was significantly associated with the glenoid version angle (p<0.05) and posterior subluxation of the humeral head (p<0.05). Remodeling of the affected humeral head was observed postoperatively, with a significant improvement in the skewness ratio (p<0.05). However, there were no significant correlations between the preoperative skewness ratio and postoperative clinical outcomes. CONCLUSIONS: Humeral head deformity in neonatal brachial plexus palsy correlated with other measures of glenohumeral dysplasia and could be reliably and objectively quantified on MR imaging with use of the skewness ratio. The humeral head deformity can remodel following joint rebalancing surgery, and such a deformity alone does not preclude a successful outcome after surgical attempts to restore glenohumeral congruity.

Incidence and etiology of new liver lesions in pediatric patients previously treated for malignancy.

OBJECTIVE: The purpose of this study was to retrospectively evaluate the time course, cause, and imaging characteristics of all new liver lesions in pediatric patients with a previously treated malignancy. MATERIALS AND METHODS: Our hospital cancer registry was used to identify patients between 1980 and 2005 who met the following criteria: solid tumor, survival > 2 years after diagnosis, no liver lesions at a posttreatment baseline, and cross-sectional imaging follow-up of > 2 years. Final dictated reports of all cross-sectional imaging examinations including the abdomen were reviewed for any mention of new liver lesions. Positive reports were followed by consensus review of the images and clinical data. Patients were divided into three groups: those with suspected or proven focal nodular hyperplasia (FNH), those with suspected or proven metastases, and those with other lesions. An exact Wilcoxon test was used to evaluate the differences between the groups. RESULTS: Of 967 patients who met the initial inclusion criteria, 273 had adequate follow-up to be included in the study. Forty-six patients (16.8%) developed new liver lesions during the study period, and 14 of those 46 were classified into the FNH group (30.4%) and seven were classified into the metastasis group (15.2%). A significant difference was found in the median time to the development of FNH versus metastasis and other lesions (FNH, 92.9 months; metastasis, 43.2 months; other lesions, 18.5 months; p < 0.0001). A significant difference was also seen in the median length of follow-up between the groups (FNH, 115.6 months; metastasis, 57 months; other lesions, 50.8 months; p = 0.002). The imaging features of the groups also differed. CONCLUSION: The most common liver lesion encountered in pediatric patients previously treated for malignancy was FNH, which occurred farther from the time of diagnosis and had different imaging characteristics from both metastases and other liver lesions.

Inflammatory bowel disease in children and adolescents: assessing the diagnostic performance and interreader agreement of magnetic resonance enterography compared to histopathology.

RATIONALE AND OBJECTIVES: The purpose of this study was to determine the accuracy of magnetic resonance enterography (MRE) compared to histopathology in the evaluation of pediatric inflammatory bowel disease and to assess interreader reliability for image interpretation. MATERIALS AND METHODS: All magnetic resonance enterography studies performed for known or suspected inflammatory bowel disease between July 2009 and July 2010 were retrospectively reviewed by two pediatric radiologists. Exams were evaluated for signs of enteric inflammation and extraenteric disease. A five-point, Likert-type scale was used to assess the overall likelihood of active inflammation, with scores ≥ 3 considered positive. Cohen's κ coefficient was calculated to assess interreader agreement. A subset of patients who had undergone ileocolonoscopy or surgery with confirmed histopathology within 45 days of MRE were used to assess the accuracy of MRE for detecting active inflammation in the terminal ileum and large bowel. RESULTS: A total of 91 magnetic resonance enterography studies were reviewed. Of these, 45 had comparison histopathology within 45 days. The overall sensitivity of MRE for detecting active inflammation compared to ileocolonoscopy was 92% for both readers, while specificity was 100% for reader 1 and 75% for reader 2. Of the individual parameters evaluated, mucosal hyperenhancement and bowel wall thickening were the most sensitive indicators of active inflammation, each having sensitivity of 86% and specificity of 88%. Cohen's κ coefficient was 0.59, indicating moderate agreement between the readers. CONCLUSIONS: MRE has high overall diagnostic accuracy for detecting active bowel inflammation in pediatric patients compared to ileocolonoscopy and demonstrates moderate interreader reliability.

Outcomes of strabismus surgery for esotropia in children with Down syndrome compared with matched controls.

PURPOSE: Strabismus surgery dosages used in children with various neurodevelopmental disorders have been the subject of controversy. Few data have been reported regarding surgical results in individuals with Down syndrome (DS). METHODS: A retrospective, case-control study was performed in which children with DS and previous bilateral medial rectus recession surgery were matched with similar control patients without DS. Surgical results were compared using a random coefficients model for repeated measurements for each group. RESULTS: Sixteen patients with DS were matched with 16 control patients. Mean preoperative esotropia was 28.4 prism diopters (PD) in the DS group and 27.9 PD in the control group. No significant difference was found in surgical dosages between the two groups (P = .2402). Median surgical dosage was 4.4 mm in the DS group and 4.5 mm in the control group. Preoperative and 4-month and 24-month postoperative mean angles of esotropia were not different between groups (P = .8050). The 4-month postoperative mean angles of esotropia for the DS and control groups were 3.15 and 2.66 PD, respectively. The 24-month mean angles of esotropia for the DS and control groups were 7.09 and 6.60 PD, respectively. CONCLUSION: Standard bilateral medial rectus recession surgical dosages need not be modified for individuals with DS.

Comparison of standard, prone and cine MRI in the evaluation of tethered cord.

BACKGROUND: Tethered cord syndrome (TCS) is defined by abnormal traction on the spinal cord that confines its movement. Surgical cord release usually stops neurological deterioration; therefore, early and accurate neuroradiological diagnosis is important. Supine MRI is the imaging modality of choice, but prone MRI and cine MRI can demonstrate cord movement. OBJECTIVE: We compared the diagnostic accuracies of standard MRI, prone MRI and cine MRI in patients with clinical suspicion of TCS and evaluated inter-reader reliability for MR imaging. MATERIALS AND METHODS: Children who underwent MRI for suspicion of TCS were retrospectively identified. Supine, prone and cine MRI studies were re-read by two pediatric neuroradiologists. Conus level, filum appearance and cord movement were documented. RESULTS: Thirteen of 49 children had tethered cord documented at surgery. Conus level had the highest diagnostic accuracy (sensitivity 69-77%, specificity 94%, positive predictive value 82-83%, negative predictive value 89-92%, correct diagnosis 88-90%) and highest between-reader concordance (98%). Prone and cine MRI did not add to the accuracy of the supine imaging. CONCLUSION: Conus level provides the highest diagnostic accuracy and inter-reader reliability in TCS. Until a larger series is evaluated, it remains questionable whether prone or cine MRI provides enough additional diagnostic information to warrant routine use.

A comparison of inhalational inductions for children in the operating room vs the induction room.

BACKGROUND: There has been debate about the use of an induction room (IR) compared with an operating room (OR) for inhalational induction in children. The quality of the anesthesia induction between these two physical environments has not been studied previously. We sought to compare child distress, OR utilization and efficiency, and parental satisfaction and safety, between an IR and an OR. METHODS: In a prospective observational study, we studied 501 developmentally appropriate children ages 1-14 years, American Society of Anesthesiologists (ASA) physical status I-III, presenting for the inhalational induction of anesthesia, undergoing outpatient or outpatient-admit ENT surgery. Inductions were performed in an IR (IR group) or OR (OR group) with parent(s) present. Child behavioral compliance was assessed using the Induction Compliance Checklist (ICC), a validated observational scale from 0 to 10 consisting of 10 behaviors; an ICC score ≥4 was considered poor behavioral compliance. Times for transport, anesthesia start, ready for surgery, surgery finish, out of OR, and total case process times were recorded. OR utilization and OR efficiency was derived using these times. Data on number and experience of clinical providers were also collected. Parent satisfaction with the induction was measured using a satisfaction survey. Safety was measured by recording respiratory complications during induction. The chi-squared test was conducted to determine whether induction location was associated with level of behavioral compliance. A multivariable proportional odds model was used to control for risk factors. OR utilization and efficiency were analyzed using the Wilcoxon-Mann-Whitney test. RESULTS: There were no significant differences in ICC scores between the groups (P-value = 0.12). Anesthesia, nonoperative, and transport time were statistically less in the OR group when compared with the IR group, although total case process times were similar in both groups. While OR efficiency was significantly higher for the OR group (P-value = 0.0096), OR utilization did not differ between groups (P-value = 0.288). The OR group had a significantly higher number of anesthesia providers and a more experienced surgical team. Parents in the two groups were equally satisfied with their experience during induction, and none of the subjects had respiratory complications during the anesthesia induction. CONCLUSIONS: We found no differences in child distress, parent satisfaction, and respiratory complications between inductions conducted in the IR vs the OR. Differences in utilization, efficiency, and turnover were minimal and not operationally significant. Capital equipment, space, and staffing strategies should be key drivers in considerations for the use of IRs, and in the design of ORs with IRs.

Comparative analysis of tranexamic acid use in minimally invasive versus open craniosynostosis procedures.

BACKGROUND: Intraoperatively administered tranexamic acid (TXA) lessens blood loss during orthopedic and cardiovascular surgery. Its use for craniosynostosis surgery warrants investigation. Therefore, we analyzed our use of TXA during minimally invasive (MI) and open craniosynostosis procedures. METHODS: Fifty-six patients were retrospectively studied: 20 in the MI group, 10 receiving TXA; 36 in the open group, 16 receiving TXA. Study variables were weight-adjusted estimated blood loss (EBL) and calculated blood loss (CBL), transfusion and incidence, transfusion volume, and complications. Calculated blood loss was determined by a novel formula based on red cell mass. RESULTS: In the MI group, median EBL was significantly lower for TXA recipients (9.62 vs 15.94 mL/kg, P = 0.0231), whereas median CBL was not (36.59 vs 34.12 mL/kg, P = 0.7976). Transfusion incidences were 80% TXA versus 100% control (P = 0.4737). Median transfusion volume trended lower (10.76 vs 19.43 mL/kg, P = 0.0723).In the open group, median EBL and CBL for TXA recipients were lower but not significantly different than for nonrecipients (21.86 vs 23.40 mL/kg, P = 0.7416; 53.54 vs 80.13; P = 0.3137). All patients had a transfusion. Median transfusion volume for TXA recipients versus nonrecipients was 34.01 versus 40.35 mL/kg (P = 0.3137). Tranexamic acid greatly minimized the range of EBL and CBL in both surgical groups. There was a significant correlation between the CBL and EBL (P < 0.0001). There were no adverse events. CONCLUSIONS: Intraoperative TXA administration is safe with modest benefit suggested, especially in the MI group. Calculated blood loss correlated well with EBL at lower blood loss volumes, implicating it as a potential measurement of true blood loss.

Juvenile dermatomyositis: correlation of MRI at presentation with clinical outcome.

OBJECTIVE: The clinical course of juvenile dermatomyositis (JDMS) is unpredictable. MRI is used to determine muscle biopsy site and to monitor disease activity. It is unknown whether soft-tissue features on MRI obtained at diagnosis correlate with clinical outcome. The purpose of our study is to determine whether initial MRI findings in the pelvis and thighs in children with JDMS can predict clinical disease course. MATERIALS AND METHODS: Forty-five children (31 girls and 14 boys; median age, 6 years; range, 1-18 years) with clinically diagnosed biopsy-proven JDMS and at least 24 months of clinical follow-up were included. Clinical outcome was categorized as limited or chronic disease, according to the established Crowe clinical classification scheme. Pretreatment MRI examinations of the pelvis and thighs were evaluated for signal abnormalities of muscle and fascia and reticulated signal changes in subcutaneous fat; associations with clinical outcome were examined. RESULTS: Twenty-two patients had limited disease and 23 had chronic disease. Signal intensity ranged from normal (n = 3) to floridly increased in all muscle compartments (n = 17). Muscle and fascial involvement were not associated with clinical outcome. Controlling for duration of symptoms, the adjusted odds of progressing to chronic disease were higher for patients with abnormal subcutaneous fat signal than for those with normal fat signal (odds ratio, 9.0; 95% CI, 1.5-53.5; p < 0.02). CONCLUSION: MRI findings of muscle or fascia involvement do not predict clinical outcome in children with newly diagnosed JDMS. Abnormal subcutaneous fat signal appears to have a significant association with a more aggressive chronic disease course.

Operating room traffic: is there any role of monitoring it?

BACKGROUND: Operating room (OR) human traffic has been implicated as a cause of surgical site infection. We first observed the normal human traffic pattern in our Pediatric Orthopedic ORs, and then examined the effect of surveillance on that traffic pattern. METHODS: This study consisted of 2 phases: phase I sought to observe the OR traffic pattern (number of door swings, maximum and minimum number of OR personnel, number of OR personnel at 30-minute intervals, or changes in nursing, anesthesia, or surgeon staff) during surgical cases without OR personnel being notified, and for phase II, the same traffic pattern was monitored with their knowledge. RESULTS: Two thousand four hundred forty-two minutes of surgical time were observed in phase I, and 1908 minutes were observed in phase II. There was no difference (P=0.06) in the time between door swings between phase I (1.39 min) and phase II (1.70 min), no difference (P=1.000) in the maximum number of people in the OR between phase I (11.5 people, range: 7-15 people) and phase II (11.5 people, range: 8-20 people), and no difference (P=1.000) in the minimum number of people in the OR between phase I (4.67 people, range: 4-6 people) and phase II (4.71 people, range: 3-6 people). There was a difference in the time between door swings (P=0.03) and maximum number of people in the OR (P=0.005) based on the length of the surgery (less or more than 120 min). There was no difference in the time between door swings (P=0.11), but there was a difference in the maximum number of people in the OR (P=0.002) based on type of surgery (spine vs. others). CONCLUSIONS: There was no role of surveillance of human traffic in the OR. To achieve any change in the OR traffic pattern, monitoring alone may not be sufficient; other novel techniques or incentives may need to be considered.

Susceptibility of transcranial electric motor-evoked potentials to varying targeted blood levels of dexmedetomidine during spine surgery.

BACKGROUND: Dexmedetomidine has been increasingly used as an adjunct to opioid-propofol total intravenous anesthesia (TIVA). The authors tested the hypothesis and found that clinically relevant blood levels of dexmedetomidine do not produce significant attenuation of the amplitude of transcranial electric motor-evoked potentials either independently or by interaction with propofol in a dose-dependent manner. METHODS: The authors planned to recruit 72 patients with idiopathic scoliosis who had posterior spine fusion surgery during propofol and remifentanil TIVA with dexmedetomidine as an adjunct. However, the authors terminated the study after enrolling 44 patients because of change in surgical technique. Before administering dexmedetomidine, baseline transcranial electric motor-evoked potentials were acquired during TIVA with remifentanil and propofol. Patients were randomized to varying targeted blood levels of dexmedetomidine (0.4, 0.6, and 0.8 ng/ml) and propofol (2.5, 3.75, and 5 microg/ml) using a factorial design. The primary outcome variable was amplitude of transcranial electric motor-evoked potential. The secondary outcome was amplitude of cortical somatosensory-evoked potentials. RESULTS: Of the 44 recruited patients, 40 completed the study, and their data were analyzed. The administration of dexmedetomidine in increasing doses as an adjunct to propofol-based TIVA caused a clinically and statistically significant attenuation of amplitudes of transcranial electric motor-evoked potentials. CONCLUSION: The authors conclude that under the stimulation conditions used, dexmedetomidine as an anesthetic adjunct to propofol-based TIVA at clinically relevant target plasma concentrations (0.6-0.8 ng/ml) can significantly attenuate the amplitude of transcranial electric motor-evoked potentials.

Prenatal pulmonary hypertension index: novel prenatal predictor of severe postnatal pulmonary artery hypertension in antenatally diagnosed congenital diaphragmatic hernia.

PURPOSE: This study aim to assess the potential of prenatal predictors of postnatal severe pulmonary artery hypertension (PAH) in isolated left congenital diaphragmatic hernia (CDH) and to define a new prenatal pulmonary hypertension index (PPHI). METHODS: A retrospective chart review of CDH patients between May 2005 and October 2008 was conducted. Ten patients with systemic/suprasystemic and 9 patients with subsystemic pulmonary hypertension at 3 weeks of age were identified. Diameters of the right pulmonary artery, left pulmonary artery (LPA(d)), aorta, and the length of vermis of the cerebellum were obtained from prenatal magnetic resonance imaging to calculate the PPHI [=(LPA(d)/length of vermis of the cerebellum) x 10] and the modified McGoon index (MGI) [=(diameter of the right pulmonary artery + LPA(d))/diameter of aorta]. Prenatal pulmonary hypertension index and MGI were compared with lung-to-head ratio, percent predicted lung volume, and total lung volume for pulmonary hypertension and survival. RESULTS: The PPHI and MGI had a significant, negative correlation with pulmonary hypertension (r = -0.61, P = .005, and r = -0.72, P < .005, respectively). The PPHI and MGI are significantly lower in the systemic/suprasystemic PAH group compared with the subsystemic PAH group (1.11 +/- 0.32 versus 1.63 +/- 0.28, P = .004, and 0.71 +/- 0.15 versus 1.05 +/- 0.11, P < .001, respectively). There were no significant differences between the groups comparing the lung-to-head ratio, percent predicted lung volume, and total lung volume. CONCLUSION: Both PPHI and MGI accurately predict the severity of postnatal PAH in isolated left CDH.

Medial collateral ligament of the knee on magnetic resonance imaging: does the site of the femoral origin change at different patient ages in children and young adults?

BACKGROUND: The medial patellofemoral ligament (MPFL), a chief medial restraint preventing lateral patellar dislocation, often is reconstructed in children with recurrent dislocation. The femoral MPFL attachment can be difficult to delineate at surgery. Therefore, the origin of the medial collateral ligament (MCL) frequently is used to approximate the reattachment site. The purpose of our study was to compile normative data from MR imaging examinations over different patient ages, to determine the effect of growth on the relationship of the MCL origin site to the distal femoral physis and medial femoral condyle (MFC). SUBJECTS AND METHODS: This HIPAA-compliant study was IRB approved. Informed consent requirement was waived. Three hundred knee MR imaging examinations (143 boys, 157 girls, 0-20 y) were evaluated. MCL origin to femoral physis distance, MFC height, and MCL origin-physis distance: MFC height ratio (MCL:MFC ratio) were calculated. Relationships between these values and age, gender, and physeal patency were assessed using linear regression models. RESULTS: With physeal patency, MCL origin-physis distance was significantly associated with increasing age in boys (P=0.0394), and trended toward significance in girls (P=0.0557). Distance increased 0.01 cm/y in both genders. MFC height increased 0.15 cm/y in boys and 0.13 cm/y in girls (P<0.0001). MCL:MFC ratio decreased 0.01/y (P<0.0001). With physeal closure, no significant change was measured for any variable. CONCLUSIONS: During growth, there are statistically significant, albeit minimal, changes of the MCL origin-physis distance and MFC height. As these changes are essentially negligible, no adjustment for age is needed during restorative MPFL surgery in growing children. CLINICAL RELEVANCE: As there is neglible change in location of the origin of the MCL relative to the distal femoral physis during skeletal growth in both boys and girls, no adjustment for patient age is necessary when using the origin of the MCL as a landmark to locate the site of femoral reattachment of a disrupted MPFL.

Bare spot of the glenoid fossa in children: incidence and MRI features.

BACKGROUND: The bare spot of the glenoid fossa is a normal cartilage defect seen frequently in adults. It has been used on arthroscopy as a landmark for the center of the glenoid fossa. There are no reports of this variant in children, but we have noted it on some pediatric clinical shoulder MRI studies. OBJECTIVE: Our main purpose is to evaluate the incidence of the bare spot in children and define location and MRI features. MATERIALS AND METHODS: Shoulder MRI studies (total 570) from 2004 to 2008 were reviewed. Children were divided into two age groups: group 1, 0-10 years (n = 200), group 2, 11-20 years (n = 370). RESULTS: A total of 12 bare spots (2.1%) were identified; all were seen in group 2. Eight (67%) were central and four were eccentric in the glenoid fossa. All showed a well-marginated focal cartilage defect containing hyperintense joint fluid or contrast agent. Three also had air. CONCLUSION: The bare spot is seen in children. The absence in children younger than 10 years and the low incidence in the second decade support the proposed acquired nature. Familiarity with this finding is important so as not to misinterpret it as a pathologic condition.

123I-MIBG scintigraphy and 18F-FDG PET in neuroblastoma.

UNLABELLED: The purpose of this study was to compare the diagnostic utility of (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy and (18)F-FDG PET in neuroblastoma. METHODS: A total of 113 paired (123)I-MIBG and (18)F-FDG PET scans in 60 patients with neuroblastoma were retrospectively reviewed. Paired scans were acquired within 14 days of each other. RESULTS: For stage 1 and 2 neuroblastoma (13 scans, 10 patients), (18)F-FDG depicted more extensive primary or residual neuroblastoma in 9 of 13 scans. (123)I-MIBG and (18)F-FDG showed equal numbers of lesions in 1 of 13 scans, and 3 of 13 scan results were normal. For stage 3 neuroblastoma (15 scans, 10 patients), (123)I-MIBG depicted more extensive primary neuroblastoma or local or regional metastases in 5 of 15 scans. (18)F-FDG depicted more extensive primary neuroblastoma or local or regional metastases in 4 of 15 scans. (123)I-MIBG and (18)F-FDG were equal in 2 of 15 scans, and 4 of 15 scan results were normal. For stage 4 neuroblastoma (85 scans, 40 patients), (123)I-MIBG depicted more neuroblastoma sites in 44 of 85 scans. (18)F-FDG depicted more neuroblastoma sites in 11 of 85 scans. (123)I-MIBG and (18)F-FDG were equivalent or complementary in 13 of 85 scans, and 17 of 85 scan results were normal. CONCLUSION: (18)F-FDG is superior in depicting stage 1 and 2 neuroblastoma, although (123)I-MIBG may be needed to exclude higher-stage disease. (18)F-FDG also provides important information for patients with tumors that weakly accumulate (123)I-MIBG and at major decision points during therapy (i.e., before stem cell transplantation or before surgery). (18)F-FDG can also better delineate disease extent in the chest, abdomen, and pelvis. (123)I-MIBG is overall superior in the evaluation of stage 4 neuroblastoma, especially during initial chemotherapy, primarily because of the better detection of bone or marrow metastases.

Sirolimus for angiomyolipoma in tuberous sclerosis complex or lymphangioleiomyomatosis.

BACKGROUND: Angiomyolipomas in patients with the tuberous sclerosis complex or sporadic lymphangioleiomyomatosis are associated with mutations in tuberous sclerosis genes resulting in constitutive activation of the mammalian target of rapamycin (mTOR). The drug sirolimus suppresses mTOR signaling. METHODS: We conducted a 24-month, nonrandomized, open-label trial to determine whether sirolimus reduces the angiomyolipoma volume in patients with the tuberous sclerosis complex or sporadic lymphangioleiomyomatosis. Sirolimus was administered for the first 12 months only. Serial magnetic resonance imaging of angiomyolipomas and brain lesions, computed tomography of lung cysts, and pulmonary-function tests were performed. RESULTS: Of the 25 patients enrolled, 20 completed the 12-month evaluation, and 18 completed the 24-month evaluation. The mean (+/-SD) angiomyolipoma volume at 12 months was 53.2+/-26.6% of the baseline value (P<0.001) and at 24 months was 85.9+/-28.5% of the baseline value (P=0.005). At 24 months, five patients had a persistent reduction in the angiomyolipoma volume of 30% or more. During the period of sirolimus therapy, among patients with lymphangioleiomyomatosis, the mean forced expiratory volume in 1 second (FEV1) increased by 118+/-330 ml (P=0.06), the forced vital capacity (FVC) increased by 390+/-570 ml (P<0.001), and the residual volume decreased by 439+/-493 ml (P=0.02), as compared with baseline values. One year after sirolimus was discontinued, the FEV1 was 62+/-411 ml above the baseline value, the FVC was 346+/-712 ml above the baseline value, and the residual volume was 333+/-570 ml below the baseline value; cerebral lesions were unchanged. Five patients had six serious adverse events while receiving sirolimus, including diarrhea, pyelonephritis, stomatitis, and respiratory infections. CONCLUSIONS: Angiomyolipomas regressed somewhat during sirolimus therapy but tended to increase in volume after the therapy was stopped. Some patients with lymphangioleiomyomatosis had improvement in spirometric measurements and gas trapping that persisted after treatment. Suppression of mTOR signaling might constitute an ameliorative treatment in patients with the tuberous sclerosis complex or sporadic lymphangioleiomyomatosis. (ClinicalTrials.gov number, NCT00457808.)