Defining our worth.

A recent article by Rodino et al. published in the Journal of Clinical Microbiology (K. G. Rodino, P. M. Luethy, A. N. Abbott, J. M. Bender, A. R. Eberly, M. Gitman, A. Leber, and J. Dien Bard, J Clin Microbiol 62:e00359-24, 2024, https://doi.org/10.1128/jcm.00359-24) hones in on clinical consultation as a way for clinical microbiology laboratory directors (CMLDs) to provide evidence of our worth. They relate that, unlike our physician colleagues, we are unable to generate billing for clinical consultations, relative value units, or other metrics that could assist to describe our import. Their study evaluated consultations performed by CMLDs as a way to underscore our importance as a key member of the healthcare team.

Reduced count pediatric whole-body 18F-FDG PET imaging reconstruction with a Bayesian penalized likelihood algorithm.

BACKGROUND: Advanced positron emission tomography (PET) image reconstruction methods promise to allow optimized PET/CT protocols with improved image quality, decreased administered activity and/or acquisition times. OBJECTIVE: To evaluate the impact of reducing counts (simulating reduced acquisition time) in block sequential regularized expectation maximization (BSREM) reconstructed pediatric whole-body 18F-fluorodeoxyglucose (FDG) PET images, and to compare BSERM with ordered-subset expectation maximization (OSEM) reconstructed reduced-count images. MATERIALS AND METHODS: Twenty children (16 male) underwent clinical whole-body 18F-FDG PET/CT examinations using a 25-cm axial field-of-view (FOV) digital PET/CT system at 90 s per bed (s/bed) with BSREM reconstruction (ß=700). Reduced count simulations with varied BSREM ß levels were generated from list-mode data: 60 s/bed, ß=800; 50 s/bed, ß=900; 40 s/bed, ß=1000; and 30 s/bed, ß=1300. In addition, a single OSEM reconstruction was created at 60 s/bed based on prior literature. Qualitative (Likert scores) and quantitative (standardized uptake value [SUV]) analyses were performed to evaluate image quality and quantitation across simulated reconstructions. RESULTS: The mean patient age was 9.0 ± 5.5 (SD) years, mean weight was 38.5 ± 24.5 kg, and mean administered 18F-FDG activity was 4.5 ± 0.7 (SD) MBq/kg. Between BSREM reconstructions, no qualitative measure showed a significant difference versus the 90 s/bed ß=700 standard (all P>0.05). SUVmax values for lesions were significantly lower from 90 s/bed, ß=700 only at a simulated acquisition time of 30 s/bed, ß=1300 (P=0.001). In a side-by-side comparison of BSREM versus OSEM reconstructions, 40 s/bed, ß=1000 images were generally preferred over 60 s/bed TOF OSEM images. CONCLUSION: In children who undergo whole-body 18F-FDG PET/CT on a 25-cm FOV digital PET/CT scanner, reductions in acquisition time or, by corollary, administered radiopharmaceutical activity of >50% from a clinical standard of 90 s/bed may be possible while maintaining diagnostic quality when a BSREM reconstruction algorithm is used.

Impact of upgrading from a 25-cm to a 30-cm z-axis field of view digital PET/CT in a pediatric hospital.

BACKGROUND: Increased positron emission tomography (PET) scanner z-axis coverage provides an opportunity in pediatrics to reduce dose, anesthesia, or repeat scans due to motion. OBJECTIVE: Recently, our digital PET scanner was upgraded from a 25-cm to a 30-cm z-axis coverage. We compare the two systems through National Electrical Manufacturing Association (NEMA) testing and evaluation of paired images from patients scanned on both systems. MATERIALS AND METHODS: NEMA testing and a retrospective review of pediatric patients who underwent clinically indicated 18F-fluorodeoxyglucose (FDG) PET computed tomography (PET/CT) on both systems with unchanged acquisition parameters were performed. Image quality was assessed with liver signal to noise ratio (SNR-liver) and contrast to noise ratio (CNR) in the thigh muscle and liver with results compared with an unpaired t-test. Three readers independently reviewed paired (25 cm and 30 cm) images from the same patient, blinded to scanner configuration. RESULTS: Expansion to 30 cm increased system sensitivity to 29.8% (23.4 cps/kBq to 30.4 cps/kBq). Seventeen patients (6 male/11 female, median age 12.5 (IQR 8.3-15.0) years, median weight 53.7 (IQR 34.2-68.7) kg) were included. SNR-liver and CNR increased by 35.1% (IQR 19.0-48.4%) and 43.1% (IQR 6.2-50.2%) (P-value <0.001), respectively. All readers preferred images from the 30-cm configuration. A median of 1 (IQR 1-1) for fewer bed positions was required with the 30-cm configuration allowing a median of 91 (IQR 47-136) s for shorter scans. CONCLUSION: Increasing z-axis coverage from 25 to 30 cm on a current-generation digital PET scanner significantly improved PET system performance and patient image quality, and reduced scan duration.

Imaging of pediatric bone tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Malignant primary bone tumors are uncommon in the pediatric population, accounting for 3%-5% of all pediatric malignancies. Osteosarcoma and Ewing sarcoma comprise 90% of malignant primary bone tumors in children and adolescents. This paper provides consensus-based recommendations for imaging in children with osteosarcoma and Ewing sarcoma at diagnosis, during therapy, and after therapy.

Imaging of pediatric neuroblastoma: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Neuroblastoma is the most common extracranial solid neoplasm in children. This manuscript provides consensus-based imaging recommendations for pediatric neuroblastoma patients at diagnosis and during follow-up.

Ultrasound determination of pediatric thyroid mass.

BACKGROUND: Radioiodine therapy for Graves disease can be achieved with dosing based on estimated thyroid gland mass. Thyroid mass can be estimated using linear ultrasound measurements, and conversion factors for volume and density. The choice of conversion factors could impact estimated thyroid mass and thus administered radioiodine dose. OBJECTIVE: The objective of this study was to define the relationship between thyroid mass estimated by ultrasound and measured thyroid mass following thyroidectomy. MATERIALS AND METHODS: This was a retrospective, exempt study that included patients < 18 years of age with < 6 months between thyroid ultrasound and thyroidectomy January 2010-June 2020. Thyroid dimensions by ultrasound, thyroid mass at thyroidectomy and histopathological diagnosis were collected. Published conversion factors were used to estimate thyroid volume with conversion to mass using a density of 1.05 g/cm3. Pearson correlations and Bland-Altman difference analyses were used to define the relationship between estimated mass and specimen weight. Linear regression was used to calculate an optimal conversion factor for estimating thyroid mass. RESULTS: We included 86 patients, 67 female (78%), with a mean age of 14.5 ± 3.15 years. Mass estimated using all tested conversion factors had similar strong, positive correlation with specimen weight (r = 0.95). The mean difference between thyroid mass estimated by ultrasound and measured mass ranged from - 0.34 g (conversion factor = 0.523) to 1.69 g (conversion factor = 0.554). The optimal simplified factor for estimation of thyroid mass for the study sample was 0.537. CONCLUSION: All published conversion factors for estimating thyroid mass based on linear ultrasound measurements produce good estimates of thyroid mass. Errors in estimated mass are less than 2 g on average.

Radioiodine treatment of pediatric Graves disease: a multicenter review.

BACKGROUND: There is no standardized approach to iodine-131 (I-131) therapy of hyperthyroidism in pediatric Graves disease. This prevents systematic study of outcomes. OBJECTIVE: To characterize current radioiodine dosing and define therapeutic outcomes at multiple institutions that use ultrasound to measure thyroid size to guide I-131 ablation of Graves disease. MATERIALS AND METHODS: This was a retrospective cohort study conducted at three institutions. The three sites collected demographic data, thyroid volume measured by ultrasound (mL), pre-ablation radioiodine uptake, I-131 activity administered, and outcomes at 6 and 12 months for children younger than 18 years of age treated with I-131 between November 2004 and October 2019. Comparisons of continuous variables were performed using the Mann-Whitney U test. RESULTS: Sixty-nine patients (mean age: 14.5±2.5 years) were included, 59 (85.5%) of whom were female. The mean administered I-131 radioiodine activity was 12.5 mCi (463 MBq) (range: 3.8-29.9 mCi [141-1,106 MBq]). At 6 months post-ablation, 54 (80.5% of 67) patients were hypothyroid, 8 (11.9% of 67) were euthyroid and 5 were hyperthyroid. Two of the five hyperthyroid patients had become euthyroid at 12 months. At 12 months, 1 previously euthyroid patient was hyperthyroid. Administered activity per mL of thyroid tissue adjusted for 24-h uptake was lower (0.18 mCi [6.7 MBq] x %/mL vs. 0.31 mCi [11.5 MBq] x %/mL, P=0.0054) for patients who remained hyperthyroid at 6 months. CONCLUSION: There is substantial variability in administered activity for radioiodine ablation of Graves disease in children. Efforts to standardize practice should start by standardizing administered activity guided by measurement of thyroid size by ultrasound. Our results and those of previous studies suggest the need for administered activities ≥0.25 mCi [9.3 MBq] x %/mL of thyroid tissue.

Simulated Reduced-Count Whole-Body FDG PET: Evaluation in Children and Young Adults Imaged on a Digital PET Scanner.

BACKGROUND. Digital PET scanners with increased sensitivity may allow shorter scan acquisition times or reductions in administered radiopharmaceutical activities. OBJECTIVE. The purpose of this study was to evaluate in children and young adults the impact of shorter simulated acquisition times on the quality of whole-body FDG PET images obtained using a digital PET/CT system. METHODS. This retrospective study included 27 children and young adults (nine male and 18 female patients) who underwent clinically indicated whole-body FDG PET/CT examinations performed using a 25-cm axial FOV PET/CT system at 90 s per bed position (expressed hereafter as seconds per bed). Raw list-mode data were reprocessed to simulate acquisition times of 60, 55, 50, 45, 40, and 30 s/bed. Three radiologists independently reviewed reconstructed images and assigned Likert scores for lesion conspicuity, normal structure conspicuity, image quality, and image noise. A separate observer recorded the SUVmax, SUVmean, and SD of the SUV (SUVSD) for liver, thigh, and the most FDG-avid lesion. The SUVSD/SUVmean (the SUVSD divided by the SUVmean) was calculated as a surrogate of image noise. ANOVA, the Friedman test, and the Dunn test were used to compare qualitative measures (combining reader scores) and SUV measurements. RESULTS. The mean patient age was 10.8 ± 8.3 (SD) years, mean BMI was 18.7 ± 2.9, and mean administered FDG activity was 4.44 ± 0.37 MBq/kg (0.12 ± 0.01 mCi/kg). No qualitative measure showed a significant difference versus 90 s/bed for the simulated acquisition at 60 s/bed (all p > .05). Significant differences (all p < .05) versus 90 s/bed were observed for lesion conspicuity at at most 40 s/bed, conspicuity of normal structures and overall image quality at at most 45 s/bed, and image noise at at most 55 s/bed. SUVmean was not significantly different from 90 s/bed for any site for any reduced-count simulation (all p > .05). SUVSD/SUVmean and SUVmax showed gradual increases with decreasing acquisition times and were significantly different from 90 s/bed only for liver at 60 s/bed (for SUVmax: 1.00 ± 0.00 vs 1.05 ± 0.03, p = .02; for SUVSD/SUVmean: 0.09 ± 0.02 vs 0.11 ± 0.02, p = .04). CONCLUSION. Favorable findings for the simulated acquisition at 60 s/bed suggest that, in children and young adults who undergo imaging performed using a 25-cm FOV digital PET scanner, acquisition time or administered FDG activity may be decreased by approximately 33% from the clinical standard without significantly impacting image quality. CLINICAL IMPACT. A 25-cm axial FOV digital scanner may allow FDG PET/CT examinations to be performed with reduced radiation exposure or faster scan acquisition times.

Agreement between serum estimates of glomerular filtration rate (GFR) and a reference standard of radioisotopic GFR in children with cancer.

BACKGROUND: Accurate assessment of renal function is important in the care of children with cancer because renal function has implications for anti-tumor medication dosing and eligibility for clinical trials. OBJECTIVE: To characterize agreement between serum estimates of glomerular filtration rate (GFR) and a reference standard of radioisotopic GFR in a large pediatric oncology cohort. MATERIALS AND METHODS: We conducted a retrospective cross-sectional study of children who had both radioisotopic GFR (99mTc-diethylenetriaminepentaacetic acid, or 99mTc-DTPA) and serum labs (creatinine, cystatin C) obtained <7 days apart between January 2017 and August 2019. We calculated estimated GFR from serum labs using published equations and calculated agreement using intraclass correlation coefficient (ICC) and Bland-Altman analysis with univariate regression to define predictors of agreement. RESULTS: We included 272 pairs of data. Mean patient age was (mean ± standard deviation) 7.8±5.7 years. Mean radioisotopic GFR was 112±33 mL/min/1.73 m2. Absolute agreement between radioisotopic GFR and serum estimates was only fair (ICC=0.46-0.58) with a mean difference of -26.6 to +0.12 mL/min/1.73 m2. For radioisotopic GFR measurements <60 mL/min/1.73 m2, mean differences were greater, with serum estimates overestimating GFR by a mean of 21.5-39.6 mL/min/1.73 m2. In multivariable modeling, significant predictors of agreement included age, height, acute kidney injury and tumor type. Sensitivity of serum estimates was 14-29% for a GFR <60 mL/min/1.73 m2. CONCLUSION: Agreement between radioisotopic GFR and serum estimates of GFR is only fair and serum estimates of GFR have poor sensitivity for clinically relevant GFR <60 mL/min/1.73 m2. Radioisotopic measurement of GFR likely remains necessary to assess renal function in pediatric oncology patients with decreased renal function.

Clinical Laboratory Perspective on Streptococcus halichoeri, an Unusual Nonhemolytic, Lancefield Group B Streptococcus Causing Human Infections.

Streptococcus halichoeri is a relatively newly identified species of pyogenic streptococci that causes zoonotic infection in humans. S. halichoeri was first described in 2004 as indigenous to seals, and only 8 reports of human S. halichoeri infection have been published. S. halichoeri grows as small, white, nonhemolytic colonies and may be strongly catalase-positive on routine blood agar media, which can lead to isolates being misidentified as coagulase-negative staphylococci. S. halichoeri tests positive for Lancefield group B antigen, like S. agalactiae, but can be identified with matrix-assisted laser desorption/ionization time of flight mass spectrometry or partial 16S rRNA sequencing. We describe 3 cases of S. halichoeri bone and joint infections in patients in the United States with underlying health conditions. In addition, we examine the microbiologic characteristics of S. halichoeri and discuss the importance of fully identifying this organism that might otherwise be disregarded as a skin commensal.

Artificial Intelligence Algorithm Improves Radiologist Performance in Skeletal Age Assessment: A Prospective Multicenter Randomized Controlled Trial.

Background Previous studies suggest that use of artificial intelligence (AI) algorithms as diagnostic aids may improve the quality of skeletal age assessment, though these studies lack evidence from clinical practice. Purpose To compare the accuracy and interpretation time of skeletal age assessment on hand radiograph examinations with and without the use of an AI algorithm as a diagnostic aid. Materials and Methods In this prospective randomized controlled trial, the accuracy of skeletal age assessment on hand radiograph examinations was performed with (n = 792) and without (n = 739) the AI algorithm as a diagnostic aid. For examinations with the AI algorithm, the radiologist was shown the AI interpretation as part of their routine clinical work and was permitted to accept or modify it. Hand radiographs were interpreted by 93 radiologists from six centers. The primary efficacy outcome was the mean absolute difference between the skeletal age dictated into the radiologists' signed report and the average interpretation of a panel of four radiologists not using a diagnostic aid. The secondary outcome was the interpretation time. A linear mixed-effects regression model with random center- and radiologist-level effects was used to compare the two experimental groups. Results Overall mean absolute difference was lower when radiologists used the AI algorithm compared with when they did not (5.36 months vs 5.95 months; P = .04). The proportions at which the absolute difference exceeded 12 months (9.3% vs 13.0%, P = .02) and 24 months (0.5% vs 1.8%, P = .02) were lower with the AI algorithm than without it. Median radiologist interpretation time was lower with the AI algorithm than without it (102 seconds vs 142 seconds, P = .001). Conclusion Use of an artificial intelligence algorithm improved skeletal age assessment accuracy and reduced interpretation times for radiologists, although differences were observed between centers. Clinical trial registration no. NCT03530098 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Rubin in this issue.

Evaluation of Antimicrobial Susceptibility Testing Methods for Burkholderia cenocepacia and Burkholderia multivorans Isolates from Cystic Fibrosis Patients.

The Burkholderia cepacia complex (BCC) is known for causing serious lung infections in people with cystic fibrosis (CF). These infections can require lung transplantation, eligibility for which may be guided by antimicrobial susceptibility testing (AST). While the Clinical and Laboratory Standards Institute recommends AST for BCC, the European Committee on Antimicrobial Susceptibility Testing (EUCAST) does not, due to poor method performance and correlation with clinical outcomes. Furthermore, limited data exist on the performance of automated AST methods for BCC. To address these issues, reproducibility and accuracy were evaluated for disk diffusion (DD), broth microdilution (BMD), and MicroScan WalkAway using 50 B. cenocepacia and 50 B. multivorans isolates collected from people with CF. The following drugs were evaluated in triplicate: chloramphenicol (CAM), ceftazidime (CAZ), meropenem (MEM), trimethoprim-sulfamethoxazole (TMP-SMX), minocycline (MIN), levofloxacin (LVX), ciprofloxacin (CIP), and piperacillin-tazobactam (PIP-TAZ). BMD reproducibility was ≥ 95% for MEM and MIN only, and MicroScan WalkAway reproducibility was similar to BMD. DD reproducibility was < 90% for all drugs tested when a 3 mm cut-off was applied. When comparing the accuracy of DD to BMD, only MEM met all acceptance criteria. TMP-SMX and LVX had high minor errors, CAZ had unacceptable very major errors (VME), and MIN, PIP-TAZ, and CIP had both unacceptable minor errors and VMEs. For MicroScan WalkAway, no drugs met acceptance criteria. Analyses also showed that errors were not attributed to one species. In general, our data agree with EUCAST recommendations.

Prognostic significance of pretreatment 18F-FDG positron emission tomography/computed tomography in pediatric neuroblastoma.

BACKGROUND: 18F-2-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) shows tumor activity in most neuroblastomas, but the role of 18F-FDG PET/CT in neuroblastoma remains to be defined. OBJECTIVE: This study explored the prognostic significance of 18F-FDG PET in newly diagnosed neuroblastic tumors. MATERIALS AND METHODS: This retrospective study reviewed all 18F-FDG PET/CT examinations performed for a new diagnosis of suspected neuroblastoma. MYCN amplification status, tumor recurrence and survival were abstracted from the medical record. Primary tumors were manually segmented to measure maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), tumor volume and total lesion glycolysis. Univariate and multivariable analyses using Cox proportional hazards regression testing assessed the predictive performance of PET indices for event-free survival and overall survival with thresholds determined using receiver operating characteristic curve analysis. RESULTS: Fifty-five children were included, with a median age of 2.9 years (interquartile range [IQR] 1.8-3.0 years). SUVmax, tumor volume and total lesion glycolysis were higher in MYCN-amplified tumors (P=0.012, P<0.0001, P<0.0001, respectively) and in higher International Neuroblastoma Risk Group (INRG) stages (P=0.0008, P=0.0017, P=0.0017, respectively). After adjusting for age, tumor SUVmax (P=0.028) and SUVmean (P=0.045) were associated with overall survival. An SUVmax threshold of 4.77 (P=0.028) best predicted overall survival, with median overall survival of 2,604 days (SUVmax>4.77) vs. >2,957 days (SUVmax≤4.77). No PET parameters were independently significantly associated with overall survival or event-free survival after controlling for MYCN status, stage or treatment risk stratification. CONCLUSION: Tumor metabolic activity is higher in higher-stage MYCN-amplified neuroblastic tumors. Higher SUVmax and SUVmean were associated with worse overall survival but were not independent of other prognostic markers.

Point-Counterpoint: Differences between the European Committee on Antimicrobial Susceptibility Testing and Clinical and Laboratory Standards Institute Recommendations for Reporting Antimicrobial Susceptibility Results.

INTRODUCTIONAntibiotic susceptibility test results are among the most important results issued by clinical microbiology laboratories because they routinely guide critical treatment decisions. Interpretations of MIC or disk diffusion test results, such as "susceptible" or "resistant," are easily understood. Clinical laboratories also need to determine whether and how their reports will reflect more complex situations. Such situations include, first, whether there is need to administer higher or more frequent doses of antibiotic than usual for clinical efficacy; second, whether an antimicrobial is likely to be effective at a body site where it concentrates; and third, whether there is some uncertainty in the test results due to technical variability that cannot be eliminated. Two leading organizations that set standards for antimicrobial susceptibility testing, the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI), have taken different strategies to deal with these challenges. In this Point-Counterpoint, Gunnar Kahlmeter and Christian Giske discuss how EUCAST is addressing these issues, and Thomas Kirn and Susan Sharp discuss the CLSI approach.

Detection of lymph node metastases in pediatric and adolescent/young adult sarcoma: Sentinel lymph node biopsy versus fludeoxyglucose positron emission tomography imaging-A prospective trial.

BACKGROUND: Lymph node metastases are an important cause of treatment failure for pediatric and adolescent/young adult (AYA) sarcoma patients. Nodal sampling is recommended for certain sarcoma subtypes that have a predilection for lymphatic spread. Sentinel lymph node biopsy (SLNB) may improve the diagnostic yield of nodal sampling, particularly when single-photon emission computed tomography/computed tomography (SPECT-CT) is used to facilitate anatomic localization. Functional imaging with positron emission tomography/computed tomography (PET-CT) is increasingly used for sarcoma staging and is a less invasive alternative to SLNB. To assess the utility of these 2 staging methods, this study prospectively compared SLNB plus SPECT-CT with PET-CT for the identification of nodal metastases in pediatric and AYA patients. METHODS: Twenty-eight pediatric and AYA sarcoma patients underwent SLNB with SPECT-CT. The histological findings of the excised lymph nodes were then correlated with preoperative PET-CT imaging. RESULTS: A median of 2.4 sentinel nodes were sampled per patient. No wound infections or chronic lymphedema occurred. SLNB identified tumors in 7 of the 28 patients (25%), including 3 patients who had normal PET-CT imaging of the nodal basin. In contrast, PET-CT demonstrated hypermetabolic regional nodes in 14 patients, and this resulted in a positive predictive value of only 29%. The sensitivity and specificity of PET-CT for detecting histologically confirmed nodal metastases were only 57% and 52%, respectively. CONCLUSIONS: SLNB can safely guide the rational selection of nodes for biopsy in pediatric and AYA sarcoma patients and can identify therapy-changing nodal disease not appreciated with PET-CT. Cancer 2017;155-160. © 2016 American Cancer Society.

FDG PET/CT appearance of local osteosarcoma recurrences in pediatric patients.

BACKGROUND: Osteosarcoma is the most common pediatric malignant bone tumor, frequently surgically managed with limb salvage rather than amputation. Local recurrences are seen in up to 9% of osteosarcoma patients, with CT and MRI imaging often limited by metal artifacts. OBJECTIVE: To describe the [F-18]2-fluoro-2-deoxyglucose (FDG) PET/CT appearance of local osteosarcoma recurrences with correlation to findings on other imaging modalities. MATERIALS AND METHODS: A retrospective review of pediatric osteosarcoma patients imaged with FDG PET/CT was performed in patients with pathologically proven local recurrences. FDG PET/CT findings were reviewed and correlated with available comparison imaging studies. RESULTS: Ten local osteosarcoma recurrences in eight pediatric osteosarcoma patients were imaged with FDG PET/CT. All eight patients had a local recurrence after limb salvage; two patients had a second local recurrence after amputation. All local recurrences were seen with FDG PET/CT, demonstrating solid (n=5) or peripheral/nodular (n=5) FDG uptake patterns. Maximum standard uptake values (SUVs) ranged from 3.0 to 15.7. In five recurrences imaged with FDG PET/CT and MRI, MRI was limited or nondiagnostic in three. In four recurrences imaged with FDG PET/CT and bone scan, the bone scan was negative in three. CONCLUSION: Local osteosarcoma recurrences are well visualized by FDG PET/CT, demonstrating either solid or peripheral/nodular FDG uptake with a wide range of maximum SUVs. FDG PET/CT demonstrates the full extent of local recurrences, while MRI can be limited by artifact from metallic hardware. PET/CT appears to be more sensitive than bone scan in detecting local osteosarcoma recurrences.

MIBG in Neuroblastoma Diagnostic Imaging and Therapy.

Neuroblastoma is a common malignancy observed in infants and young children. It has a varied prognosis, ranging from spontaneous regression to aggressive metastatic tumors with fatal outcomes despite multimodality therapy. Patients are divided into risk groups on the basis of age, stage, and biologic tumor factors. Multiple clinical and imaging tests are needed for accurate patient assessment. Iodine 123 ((123)I) metaiodobenzylguanidine (MIBG) is the first-line functional imaging agent used in neuroblastoma imaging. MIBG uptake is seen in 90% of neuroblastomas, identifying both the primary tumor and sites of metastatic disease. The addition of single photon emission computed tomography (SPECT) and SPECT/computed tomography to (123)I-MIBG planar images can improve identification and characterization of sites of uptake. During scan interpretation, use of MIBG semiquantitative scoring systems improves description of disease extent and distribution and may be helpful in defining prognosis. Therapeutic use of MIBG labeled with iodine 131 ((131)I) is being investigated as part of research trials, both as a single agent and in conjunction with other therapies. (131)I-MIBG therapy has been studied in patients with newly diagnosed neuroblastoma and those with relapsed disease. Development and implementation of an institutional (131)I-MIBG therapy research program requires extensive preparation with a focus on radiation protection.

Individualized Quality Control Plan (IQCP): Is It Value-Added for Clinical Microbiology?

The Center for Medicaid and Medicare Services (CMS) recently published their Individualized Quality Control Plan (IQCP [https://www.cms.gov/regulations-and-guidance/legislation/CLIA/Individualized_Quality_Control_Plan_IQCP.html]), which will be the only option for quality control (QC) starting in January 2016 if laboratories choose not to perform Clinical Laboratory Improvement Act (CLIA) [U.S. Statutes at Large 81(1967):533] default QC. Laboratories will no longer be able to use "equivalent QC" (EQC) or the Clinical and Laboratory Standards Institute (CLSI) standards alone for quality control of their microbiology systems. The implementation of IQCP in clinical microbiology laboratories will most certainly be an added burden, the benefits of which are currently unknown.

Spondylolysis and Beyond: Value of SPECT/CT in Evaluation of Low Back Pain in Children and Young Adults.

Single photon emission computed tomography (SPECT)/computed tomography (CT) is ideally suited for assessment of low back pain in children and young adults. Spondylolysis is one of the most common structural causes of low back pain and is readily identified and characterized in terms of its chronicity and likelihood to heal. The value of SPECT/CT extends to identification and characterization of other causes of low back pain, including abnormalities of the posterior elements, developing vertebral endplate, transverse processes, and sacrum and sacroiliac joint. Some of the disease processes that are identifiable at SPECT/CT are similar to those that occur in adults (eg, facet hypertrophy) but may be accelerated in young patients by high-level athletic activities. Other processes (eg, limbus vertebrae) are more unique to children, related to injury of the developing spine. The authors review the spectrum of pars interarticularis abnormalities with emphasis on the imaging features of causes of pediatric low back pain other than spondylolysis.