Monitoring spinal muscular atrophy with three-dimensional optoacoustic imaging

BACKGROUND

Spinal muscular atrophy is a progressive neuromuscular disorder and among the most frequent genetic causes of infant mortality. While recent advancements in gene therapy provide the potential to ameliorate the disease severity, there is currently no modality in clinical use to visualize dynamic pathophysiological changes in disease progression and regression after therapy.

METHODS

In this prospective diagnostic clinical study, ten pediatric patients with spinal muscular atrophy and ten age- and sex-matched controls have been examined with three-dimensional optoacoustic imaging and clinical standard examinations to compare the spectral profile of muscle tissue and correlate it with motor function (ClinicalTrials.gov: NCT04115475).

FINDINGS

We observed a reduced optoacoustic signal in muscle tissue of pediatric patients with spinal muscular atrophy. The reduction in signal intensity correlated with disease severity as assessed by grayscale ultrasound and standard motor function tests. In a cohort of patients who received disease-modifying therapy prior to the study, the optoacoustic signal intensity was similar to healthy controls.

CONCLUSIONS

This translational study provides early evidence that three-dimensional optoacoustic imaging could have clinical implications in monitoring disease activity in spinal muscular atrophy. By visualizing and quantifying molecular changes in muscle tissue, disease progression and effects of gene therapy can be assessed in real time.

FUNDING

The project was funded by ELAN Fonds (P055) at the University Hospital of the Friedrich-Alexander-Universität (FAU) Erlangen-Nurnberg to A.P.R.

Multispectral optoacoustic tomography enables assessment of disease activity in paediatric inflammatory bowel disease

Multispectral optoacoustic tomography (MSOT) allows non-invasive molecular disease activity assessment in adults with inflammatory bowel disease (IBD). In this prospective pilot-study, we investigated, whether increased levels of MSOT haemoglobin parameters corresponded to inflammatory activity in paediatric IBD patients, too. 23 children with suspected IBD underwent MSOT of the terminal ileum and sigmoid colon with standard validation (e.g. endoscopy). In Crohn`s disease (CD) and ulcerative colitis (UC) patients with endoscopically confirmed disease activity, MSOT total haemoglobin (HbT) signals were increased in the terminal ileum of CD (72.1 ± 13.0 a.u. vs. 32.9 ± 15.4 a.u., p = 0.0049) and in the sigmoid colon of UC patients (62.9 ± 13.8 a.u. vs. 35.1 ± 16.3 a.u., p = 0.0311) as compared to controls, respectively. Furthermore, MSOT haemoglobin parameters correlated well with standard disease activity assessment (e.g. SES-CD and MSOT HbT (rs =0.69, p = 0.0075). Summarizing, MSOT is a novel technology for non-invasive molecular disease activity assessment in paediatric patients with inflammatory bowel disease.

Hybrid ultrasound and single wavelength optoacoustic imaging reveals muscle degeneration in peripheral artery disease

Peripheral arterial disease (PAD) leads to chronic vascular occlusion and results in end organ damage in critically perfused limbs. There are currently no clinical methods available to determine the muscular damage induced by chronic mal-perfusion. This monocentric prospective cross-sectional study investigated n = 193 adults, healthy to severe PAD, in order to quantify the degree of calf muscle degeneration caused by PAD using a non-invasive hybrid ultrasound and single wavelength optoacoustic imaging (US/SWL-OAI) approach. While US provides morphologic information, SWL-OAI visualizes the absorption of pulsed laser light and the resulting sound waves from molecules undergoing thermoelastic expansion. US/SWL-OAI was compared to multispectral data, clinical disease severity, angiographic findings, phantom experiments, and histological examinations from calf muscle biopsies. We were able to show that synergistic use of US/SWL-OAI is most likely to map clinical degeneration of the muscle and progressive PAD.

Contrast-Enhanced Multispectral Optoacoustic Tomography for Functional Assessment of the Gastrointestinal Tract

Real-time imaging and functional assessment of the intestinal tract and its transit pose a significant challenge to conventional clinical diagnostic methods. Multispectral optoacoustic tomography (MSOT), a molecular-sensitive imaging technology, offers the potential to visualize endogenous and exogenous chromophores in deep tissue. Herein, a novel approach using the orally administered clinical-approved fluorescent dye indocyanine green (ICG) for bedside, non-ionizing evaluation of gastrointestinal passage is presented. The authors are able to show the detectability and stability of ICG in phantom experiments. Furthermore, ten healthy subjects underwent MSOT imaging at multiple time points over eight hours after ingestion of a standardized meal with and without ICG. ICG signals can be visualized and quantified in different intestinal segments, while its excretion is confirmed by fluorescent imaging of stool samples. These findings indicate that contrast-enhanced MSOT (CE-MSOT) provides a translatable real-time imaging approach for functional assessment of the gastrointestinal tract.

Impact of oral Phytozen® EQ supplementation on plasma cortisol and behavior responses of young horses exposed to stressful stimuli

Calming supplements are common in the equine industry. This study tested the hypothesis that Phytozen® EQ, a blend of citrus botanical oils, magnesium, and yeast would reduce startle response as well as reduce behavioral and physiological signs of stress in young (1.5-6 years of age) horses (n = 14) when tied in isolation and when trailered in isolation. During the 59-day (d) trial, horses were assigned to either the control (CON; n=7) or treatment (PZEN; n=7) group that received 56 g of Phytozen® EQ daily. Horses underwent a 10 min isolation test on d 30 and a 15 min individual trailering test on day 52 or 55. For both tests, blood samples were obtained pre, immediately after, and 1-hour (h) post for analysis of plasma cortisol concentrations, which were analyzed by repeated measures ANOVA. On d 59, horses underwent a startle test, for which time to travel 3 m and total distance traveled were recorded. These data were analyzed using a T-test. During trailering, PZEN horses tended to have lower overall geometric mean (lower, upper 95% confidence interval) cortisol concentrations than CON (81 [67, 98] vs. 61 [48, 78] ng/mL; P = 0.071). For the startle test, PZEN horses tended to have longer geometric mean times to travel 3 m than CON horses (1.35 [0.39, 4.70] vs. 0.26 [0.07, 0.91 seconds [s], P = 0.064). Other data points were not different between treatments (P > 0.1). It is possible that this dietary supplement could have beneficial calming effects on horses undergoing trailering or in novel situations.

Multispectral optoacoustic tomography of the human intestine - temporal precision and the influence of postprandial gastrointestinal blood flow

Multispectral optoacoustic tomography (MSOT) holds great promise as a non-invasive diagnostic tool for inflammatory bowel diseases. Yet, reliability and the impact of physiological processes during fasting and after food intake on optoacoustic signals have not been studied. In the present investigator initiated trial (NCT05160077) the intestines of ten healthy subjects were examined by MSOT at eight timepoints on two days, one fasting and one after food intake. While within-timepoint and within-day reproducibility were good for single wavelength 800 nm and total hemoglobin (ICC 0.722-0.956), between-day reproducibility was inferior (ICC -0.137 to 0.438). However, temporal variability was smaller than variation between individuals (coefficients of variation 8.9%-33.7% vs. 17.0%-48.5%). After food intake and consecutive increased intestinal circulation, indicated by reduced resistance index of simultaneous Doppler ultrasound, optoacoustic signals did not alter significantly. In summary, this study demonstrates high reliability and temporal stability of MSOT for imaging the human intestine during fasting and after food intake.

Pulmonary Dysfunction after Pediatric COVID-19

Background Long COVID occurs at a lower frequency in children and adolescents than in adults. Morphologic and free-breathing phase-resolved functional low-field-strength MRI may help identify persistent pulmonary manifestations after SARS-CoV-2 infection. Purpose To characterize both morphologic and functional changes of lung parenchyma at low-field-strength MRI in children and adolescents with post-COVID-19 condition compared with healthy controls. Materials and Methods Between August and December 2021, a cross-sectional clinical trial using low-field-strength MRI was performed in children and adolescents from a single academic medical center. The primary outcome was the frequency of morphologic changes at MRI. Secondary outcomes included MRI-derived functional proton ventilation and perfusion parameters. Clinical symptoms, the duration from positive reverse transcriptase-polymerase chain reaction test result, and serologic parameters were compared with imaging results. Nonparametric tests for pairwise and corrected tests for groupwise comparisons were applied to assess differences in healthy controls, recovered participants, and those with long COVID. Results A total of 54 participants after COVID-19 infection (mean age, 11 years ± 3 [SD]; 30 boys [56%]) and nine healthy controls (mean age, 10 years ± 3; seven boys [78%]) were included: 29 (54%) in the COVID-19 group had recovered from infection and 25 (46%) were classified as having long COVID on the day of enrollment. Morphologic abnormality was identified in one recovered participant. Both ventilated and perfused lung parenchyma (ventilation-perfusion [V/Q] match) was higher in healthy controls (81% ± 6.1) compared with the recovered group (62% ± 19; P = .006) and the group with long COVID (60% ± 20; P = .003). V/Q match was lower in patients with time from COVID-19 infection to study participation of less than 180 days (63% ± 20; P = .03), 180-360 days (63% ± 18; P = .03), and 360 days (41% ± 12; P < .001) as compared with the never-infected healthy controls (81% ± 6.1). Conclusion Low-field-strength MRI showed persistent pulmonary dysfunction in children and adolescents who recovered from COVID-19 and those with long COVID. Clinical trial registration no. NCT04990531 © RSNA, 2022 Supplemental material is available for this article. See also the editorial by Paltiel in this issue.

Non-invasive metabolic profiling of inflammation in joints and entheses by multispectral optoacoustic tomography

OBJECTIVE

To explore the metabolic characteristics of arthritis and enthesitis using multispectral opto-acoustic tomography (MSOT), a technology using near-infrared multispectral laser to stimulate tissues and detect the emitted acoustic energy, enabling non-invasive quantification of tissue components in vivo based on differential absorbance at multiple wavelengths.

METHODS

We performed a cross-sectional study in patients with RA or PsA and healthy controls (HCs). Participants underwent clinical, ultrasonographic and MSOT examination of MCP and wrist joints as well as the entheses of the common extensor tendon at the lateral humeral epicondyles and of the patellar, quadriceps and Achilles tendon. MSOT-measured haemoglobin (Hb), oxygen saturation, collagen and lipid levels were quantified and scaled mean differences between affected and unaffected joints and entheses were calculated as defined by clinical examination or ultrasonography using linear mixed effects models.

RESULTS

We obtained 1535 MSOT and 982 ultrasonography scans from 87 participants (34 PsA, 17 RA, 36 HCs). Entheseal tenderness was not associated with significant metabolic changes, whereas enthesitis-related sonographic changes were associated with increased total Hb, oxygen saturation and collagen content. In contrast, the presence of arthritis-related clinical and sonographic findings showed increased Hb levels, reduced oxygen saturation and reduced collagen content. Synovial hypertrophy was associated with increased lipid content in the joints.

CONCLUSION

MSOT allows determination of distinct metabolic differences between arthritis and enthesitis in a non-invasive setting in humans in vivo.

Hybrid reflected-ultrasound computed tomography versus B-mode-ultrasound for muscle scoring in spinal muscular atrophy

BACKGROUND AND PURPOSE

Novel light- and sound-based technologies like multispectral optoacoustic tomography (MSOT) with co-registered reflected-ultrasound computed tomography (RUCT) could add additional value to conventional ultrasound (US) for disease phenotyping in pediatric spinal muscular atrophy (SMA). The aim of this study was to investigate the quality of RUCT compared to US for qualitative and quantitative assessment of imaging neuromuscular disorders.

METHODS

Subanalyzing the MSOT SMA study, 288 RUCT and 276 US images from 10 SMA patients (mean age 9.0 ± 3.7) and 10 gender- and age-matched healthy volunteers (HV; mean age 8.7 ± 4.3) were analyzed for quantitative (grayscale levels [GSLs]) and qualitative (echogenicity, distribution pattern, Heckmatt scale, and muscle texture) muscle changes. RUCT and US measures were further correlated with clinical standard motor outcomes.

RESULTS

Quantitative agreement using GSLs revealed significantly higher GSLs in muscles of SMA patients compared to healthy muscles in both techniques (US mean GSL [SD] SMA vs. HV: 110.70 [27.8] vs. 68.85 [19.2], p < .0001; RUCT mean GSL [SD] SMA vs. HV: 91.81 [21.8] vs. 59.86 [8.2], p < .0001) with good correlation with motor outcome tests, respectively. Qualitative agreement between methods for muscle composition was excellent for differentiation of pathological versus healthy muscles, echogenicity, and distribution pattern, moderate for Heckmatt scale, and poor for muscle texture.

CONCLUSIONS

The data suggest that RUCT may allow the assessment of basic qualitative and quantitative measures for muscular diseases with comparable results to conventional US.

COVID-19 vaccination and mask wearing behaviors in the United States, August 2020 - June 2021

BACKGROUND

During the rollout of COVID-19 vaccination, many states relaxed mask wearing guidance for those vaccinated. The aim of this study was to examine the association between vaccination status and mask wearing behaviors.

METHODS

Seven waves of surveys (n = 6721) were conducted between August 2020 and June 2021. Participants were asked about initiation of COVID-19 vaccination and mask wearing behavior at work/school or a grocery store. Odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regression were used to estimate associations between vaccination status and mask wearing at work/school and at the grocery store.

RESULTS

Between April and June 2021, mask wearing at work or school declined among both those vaccinated (74% to 49%) and unvaccinated (46% to 35%). There was a similar decline for mask wearing at grocery stores. The odds of wearing a mask were 2.35 times higher at work/school (95% CI: 1.82, 3.04) and 1.65 times at a grocery store (95% CI: 1.29, 2.11) among the vaccinated compared to unvaccinated.

CONCLUSION

Mask wearing decreased after mask guidelines were relaxed, with consistently lower mask wearing among the unvaccinated, indicating a reluctance among the unvaccinated to adopt COVID-19 risk reduction behaviors.

Pediatric Buried Bumper Syndrome: Diagnostic Validity of Transabdominal Ultrasound and Artificial Intelligence

PURPOSE

 Buried bumper syndrome (BBS) is a severe complication of percutaneous endoscopic gastrostomy (PEG) resulting from overgrowth of gastric mucosa and penetration of the inner holding plate into the gastric wall. The aim of this study was to evaluate the diagnostic value of transabdominal ultrasound (US) in comparison to an artificial intelligence (AI) model for the diagnosis of BBS in children.

MATERIALS AND METHODS

 In this monocentric retrospective study, pediatric US data concerning BBS from a ten-year period (2009-2019) were analyzed. US findings were compared to a clinical multiparameter-based AI model and reference standard endoscopy. Clinical risk factors for the occurrence of pediatric BBS were determined.

RESULTS

 In n = 121 independent examinations of n = 82 patients, the placement of the inner holding plate of the PEG was assessed by US. In n = 18 cases BBS was confirmed. Recall and precision rates were 100 % for US and 88 % for the AI-based assessment. Risk factors for the occurrence of BBS were mobilization problems of the PEG (r_s = 0.66, p < 0.001), secretion/exudation (r_s = 0.29, p = 0.002), time between 1^st PEG placement and US (r_s = 0.38, p < 0.001), and elevated leukocyte count (r_s = 0.24, p = 0.016).

CONCLUSION

 Transabdominal US enables correct, rapid, and noninvasive diagnosis of BBS in pediatric patients. Preceding AI models could aid during diagnostic workup. To avoid unnecessary invasive procedures, US could be considered as a primary diagnostic procedure in suspected BBS. .

High-resolution label-free mapping of murine kidney vasculature by raster-scanning optoacoustic mesoscopy: an ex vivo study

BACKGROUND

Chronic kidney disease (CKD) is a global burden affecting both children and adults. Novel imaging modalities hold great promise to visualize and quantify structural, functional, and molecular organ damage. The aim of the study was to visualize and quantify murine renal vasculature using label-free raster scanning optoacoustic mesoscopy (RSOM) in explanted organs from mice with renal injury.

MATERIAL AND METHODS

For the experiments, freshly bisected kidneys of alpha 8 integrin knock-out (KO) and wildtype mice (WT) were used. A total of n=7 female (n=4 KO, n=3 WT) and n=6 male animals (n=2 KO, n=4 WT) aged 6 weeks were examined with RSOM optoacoustic imaging systems (RSOM Explorer P50 at SWL 532nm and/or ms-P50 imaging system at 532 nm, 555 nm, 579 nm, and 606 nm). Images were reconstructed using a dedicated software, analyzed for size and vascular area and compared to standard histologic sections.

RESULTS

RSOM enabled mapping of murine kidney size and vascular area, revealing differences between kidney sizes of male (m) and female (f) mice (merged frequencies (MF) f vs. m: 52.42±6.24 mm² vs. 69.18±15.96 mm², p=0.0156) and absolute vascular area (MF f vs. m: 35.67±4.22 mm² vs. 49.07±13.48 mm², p=0.0036). Without respect to sex, the absolute kidney area was found to be smaller in knock-out (KO) than in wildtype (WT) mice (WT vs. KO: MF: p=0.0255) and showed a similar trend for the relative vessel area (WT vs. KO: MF p=0.0031). Also the absolute vessel areas of KO compared to WT were found significantly different (MF p=0.0089). A significant decrease in absolute vessel area was found in KO compared to WT male mice (MF WT vs. KO: 54.37±9.35 mm² vs. 34.93±13.82 mm², p=0.0232). In addition, multispectral RSOM allowed visualization of oxygenated and deoxygenated parenchymal regions by spectral unmixing.

CONCLUSION

This study demonstrates the capability of RSOM for label-free visualization of differences in vascular morphology in ex vivo murine renal tissue at high resolution. Due to its scalability optoacoustic imaging provides an emerging modality with potential for further preclinical and clinical imaging applications.

Transfontanellar Contrast-enhanced US for Intraoperative Imaging of Cerebral Perfusion during Neonatal Arterial Switch Operation

Background Brain injury and subsequent neurodevelopmental disorders are major determinants for later-life outcomes in neonates with transposition of the great arteries (TGA). Purpose To quantitatively assess cerebral perfusion in neonates with TGA undergoing arterial switch operation (ASO) using transfontanellar contrast-enhanced US (T-CEUS). Materials and Methods In a prospective single-center cross-sectional diagnostic study, neonates with TGA scheduled for ASO were recruited from February 2018 to February 2020. Measurements were performed at five time points before, during, and after surgery (T₁-T₅), and 11 perfusion parameters were derived per cerebral hemisphere. Neonate clinical characteristics, heart rate, mean arterial pressure, central venous pressure, near-infrared spectroscopy, blood gas analyses, ventilation time, time spent in the pediatric intensive care unit, and time in hospital were correlated with imaging parameters. Analysis of variance or a mixed-effects model were used for groupwise comparisons. Results A total of 12 neonates (mean gestational age, 39 6/7 weeks ± 1/7 [SD]) were included and underwent ASO a mean of 6.9 days ± 3.4 after birth. When compared with baseline values, T-CEUS revealed a longer mean time-to-peak (right hemisphere, 4.3 seconds ± 2.1 vs 17 seconds ± 6.4 [P < .001]; left hemisphere, 4.0 seconds ± 2.3 vs 21 seconds ± 8.7 [P < .001]) and rise time (right hemisphere, 3.5 seconds ± 1.7 vs 11 seconds ± 5.1 [P = .002]; left hemisphere, 3.4 seconds ± 2.0 vs 22 seconds ± 7.8 [P = .004]) in both cerebral hemispheres during low-flow cardiopulmonary bypass and hypothermia (T₄) for all neonates. Neonate age at surgery negatively correlated with T-CEUS parameters during ASO, as calculated with the area under the flow curve (AUC) during wash-in (R = -0.60, P = .020), washout (R = -0.82, P = .002), and both wash-in and washout (R = -0.79, P = .004). Mean AUC values were lower in neonates older than 7 days compared with younger neonates during wash-in ([87 arbitrary units {au} ± 77] × 10² vs [270 au ± 164] × 10², P = .049]), washout ([15 au ± 11] × 10³ vs [65 au ± 38] × 10³, P = .020]) and both wash-in and washout ([24 au ± 18] × 10³ vs [92 au ± 53] × 10³, P = .023). Conclusion Low-flow hypothermic conditions resulted in reduced cerebral perfusion, as measured with transfontanellar contrast-enhanced US, which inversely correlated with age at surgery. Clinical trial registration no. NCT03215628 © RSNA, 2022 Online supplemental material is available for this article.

Multispectral optoacoustic tomography for non-invasive disease phenotyping in pediatric spinal muscular atrophy patients

Proximal spinal muscular atrophy (SMA) is a rare progressive, life limiting genetic motor neuron disease. While promising causal therapies are available, meaningful prognostic biomarkers for therapeutic monitoring are missing. We demonstrate handheld Multispectral Optoacoustic Tomography (MSOT) as a novel non-invasive imaging approach to visualize and quantify muscle wasting in pediatric SMA. While MSOT signals were distributed homogeneously in muscles of healthy volunteers (HVs), SMA patients showed moth-eaten optoacoustic signal patterns. Further signal quantification revealed greatest differences between groups at the isosbestic point for hemoglobin (SWL 800 nm). The SWL 800 nm signal intensities further correlated with clinical phenotype tested by standard motor outcome measures. Therefore, handheld MSOT could enable non-invasive assessment of disease burden in SMA patients.

Continuous monitoring of SARS-CoV-2 seroprevalence in children using residual blood samples from routine clinical chemistry

OBJECTIVES

The assessment of SARS-CoV-2 infections in children is still challenging, but essential for appropriate political decisions. The aim of this study was to investigate whether residual blood samples can be used for SARS-CoV-2 seroprevalence monitoring in pediatrics.

METHODS

In this repeated cross-sectional cohort study, anonymous residual blood samples from pediatric patients aged 0-17 years were collected in three time-periods (Oct.-Nov. 2020, April 2021, and June-July 2021) and analyzed for SARS-CoV-2 Spike protein (anti-S) and nucleocapsid (anti-N) antibodies using commercial antibody assays. 28 reactive samples were used to compare antibody levels with a pseudotyped neutralization assay. The results were further compared to the official national COVID-19 surveillance data to calculate the number of unreported cases.

RESULTS

In total, n=2,626 individual blood samples were analyzed. In this unvaccinated pediatric cohort anti-S and anti-N antibody seroprevalence increased over the three time periods (anti-S: 1.38-9.16%, and 14.59%; anti-N: 1.26%, to 6.19%, and 8.56%). Compared to the national surveillance data this leads to a 3.93-5.66-fold increase in the number of unreported cases. However, a correlation between the cumulative incidence of the individual provinces and our assigned data was found (r=0.74, p=0.0151). In addition, reactive samples with anti-S and anti-N and samples with only anti-S showed neutralization capabilities (11/14 and 8/14, respectively). Anti-S levels were not significantly different between age groups and sexes (all p>0.05).

CONCLUSIONS

The present study suggests that residual blood samples from routine laboratory chemistry could be included in the estimation of the total SARS-CoV-2 seroprevalence in children.

Precision of handheld multispectral optoacoustic tomography for muscle imaging

Photo-or optoacoustic imaging (OAI) allows quantitative imaging of target tissues. Using multi-wavelength illumination with subsequent ultrasound detection, it may visualize a variety of different chromophores at centimeter depth. Despite its non-invasive, label-free advantages, the precision of repeated measurements for clinical applications is still elusive. We present a multilayer analysis of n = 1920 imaging datasets obtained from a prospective clinical trial (NCT03979157) in n = 10 healthy adult volunteers. All datasets were analyzed for 13 single wavelengths (SWL) between 660 nm-1210 nm and five MSOT-parameters (deoxygenated/oxygenated/total hemoglobin, collagen and lipid) by a semi-automated batch mode software. Intraclass correlation coefficients (ICC) were good to excellent for intrarater (SWL: 0.82-0.92; MSOT-parameter: 0.72-0.92) and interrater reproducibility (SWL: 0.79-0.87; MSOT-parameter: 0.78-0.86), with the exception for MSOT-parameter lipid (interrater ICC: 0.56). Results were stable over time, but exercise-related effects as well as inter-and intramuscular variability were observed. The findings of this study provide a framework for further clinical OAI implementation.

Shedding light on pediatric diseases: multispectral optoacoustic tomography at the doorway to clinical applications

Optoacoustic imaging (OAI), or photoacoustic imaging (PAI), has fundamentally influenced basic science by providing high-resolution visualization of biological mechanisms. With the introduction of multispectral optoacoustic tomography (MSOT), these technologies have now moved closer to clinical applications. MSOT utilizes short-pulsed near-infrared laser light to induce thermoelastic expansion in targeted tissues. This results in acoustic pressure waves, which are used to resolve specific endo- and exogenous chromophores. Especially in the pediatric population, this non-invasive imaging approach might hold fundamental advantages compared to conventional cross-sectional imaging modalities. As this technology allows the visualization of quantitative molecular tissue composition at high spatial resolution non-invasively in sufficient penetration depth, it paves the way to personalized medicine in pediatric diseases.

Risk factors for measles among infants in Tianjin, China

OBJECTIVES

Infants aged <8 months are ineligible for measles vaccination in China but represent a disproportionate number of cases. We examined the risk factors for measles among infants in Tianjin, China.

STUDY DESIGN

Case-control study.

METHODS

Cases were enrolled from a surveillance system, and IgG-negative controls were sampled from registries at immunization clinics. A logistic regression model assessed for risk factors.

RESULTS

Among 82 cases and 485 controls, exposure to a municipal hospital (OR [odds ratio]: 5.21; 95% confidence interval [CI]: 1.19-22.82) or a specialty hospital (OR: 13.22; 95% CI: 6.13-28.51) was associated with the disease, whereas visiting a township or district hospitals was not associated with increased odds of measles.

CONCLUSIONS

Hospitals were an important focal point of measles transmission for infants. Hospitals, particularly higher-level municipal and specialty hospitals, should enforce infection control programs to separate infants with highly communicable diseases to prevent transmission.

"Emplotted Narratives" and Structured "Behavioral Observations" Supporting the Diagnosis of Willis-Ekbom Disease/Restless Legs Syndrome in Children with Neurodevelopmental Conditions

Background

Willis‐Ekbom disease/restless legs syndrome (WED/RLS) seems to be a frequent cause of intractable chronic insomnia (ICI) but is under‐recognized in children/adolescents with neurodevelopmental conditions (NDCs), as many patients do not have the ability to express the underlying “urge‐to‐move”. In light of this, we aim to develop a protocol for behavioral observations supporting the diagnosis of WED/RLS.

Methods

We investigated 26 pediatric patients (age 1–16 years, median 8) with NDCs, ICI and evidence of familial WED/RLS employing (1) “emplotted narratives” for description of the various “urge‐to‐move” presentations and (2) self‐description and “behavioral observations” during a “suggested clinical immobilization test” (SCIT).

Results

Parental narratives reflected typical WED/RLS‐related “urge‐to‐move” symptoms during day‐, bed‐, and nighttime in all patients. Fifteen out of 26 patients could describe the “urge‐to‐move” during the SCIT. Ten out of 26 patients, unable to describe their symptoms due to cognitive disabilities, showed patterns of “relieving‐movements” upon observation. Sensory processing abnormalities were reported in all patients, with tactile sensitivities (26/26) (including shifted pain threshold) as the most common sensory domain.

Conclusion

“Emplotted narratives” and structured “behavioral observations” support recognition of familial WED/RLS associated movement patterns and provide a useful tool for the diagnosis of WED/RLS in children with NDCs in a clinical office setting.

Exercise influences circadian gene expression in equine skeletal muscle

Circadian rhythms are endogenously generated 24-h oscillations that coordinate numerous aspects of mammalian physiology, metabolism and behaviour. The existence of a molecular circadian clock in equine skeletal muscle has previously been demonstrated. This study investigates how the circadian 24-h expression of exercise-relevant genes in skeletal muscle is influenced by a regular exercise regime. Mid-gluteal, percutaneous muscle biopsies were obtained over a 24-h period from six Thoroughbred mares before and after an 8-week exercise programme. Real-time qPCR assays were used to assess the expression patterns of core clock genes ARNTL, PER2, NR1D1, clock-controlled gene DBP, and muscle genes MYF6, UCP3, VEGFA, FOXO1, MYOD1, PPARGC1A, PPARGC1B, FBXO32 and PDK4. Two-way repeated measures ANOVA revealed a significant interaction between circadian time and exercise for muscle genes MYF6, UCP3, MYOD1 and PDK4. A significant effect of time was observed for all genes with the exception of VEGFA, where a main effect of exercise was observed. By cosinor analysis, the core clock genes, ARNTL (P <0.01) and NR1D1 (P <0.05), showed 24-h rhythmicity both pre- and post-exercise, while PER2 expression was rhythmic post-exercise (P <0.05) but not pre-exercise. The expression profiles of muscle genes MYOD1 and MYF6 showed significant fits to a 24-h cosine waveform indicative of circadian rhythmicity post-exercise only (P <0.01). This study suggests that the metabolic capacity of muscle is influenced by scheduled exercise and that optimal athletic performance may be achieved when exercise times and competition times coincide.

Refracture with cement extrusion following percutaneous vertebroplasty of a large interbody cleft

We present a case report of a patient on long-term dialysis who underwent percutaneous vertebroplasty to treat a painful intrabody vertebral cleft and who subsequently experienced a refracture of the posterior portion of the same vertebral body, resulting in anterior displacement of the cement through the anterior cortex. The case raises the question whether, in some patients, the marrow space should be filled with cement in addition to the cleft.

Isolated stenosis of a persistent hypoglossal artery visualized at 3D CT angiography

The persistent hypoglossal artery is a rare perseverance of an embryonic vessel connecting the anterior and posterior circulations and is generally considered to be an incidental finding. This is a case of a patient with an atherosclerotic narrowing at the origin of the persistent hypoglossal artery seen at 3D CT angiography. The pertinent findings and clinical implications of this anomalous vessel are discussed.

Outcome comparison of patients receiving oral or depot neuroleptic medication

Three outcome measures of psychiatric treatment were retrospectively compared between two groups of acutely hospitalized psychotic patients who had been prescribed either oral haloperidol (n = 58) or depot haloperidol (n = 95) as the only medication at the time of discharge. There were no significant differences between the groups on demographic variables, including sex, age, and ethnicity. There were no significant differences between the groups on keeping the initial outpatient appointment, in readmission history over a 4-yr. follow-up, or in length of time to subsequent readmission, if any. It appears that there is no benefit in choosing one form of medication over the other from a clinical perspective, as neither appears more clinically efficacious when examined on these outcome variables. However, there is a significant difference in cost of the two forms of the medication in favor of the oral form, making the oral form more favorable if cost is to be minimized.

Laser excisional conization in an office environment

Use of the laser as an excisional tool in the treatment of cervical disease is an established technique. A study was constructed to determine whether laser excisional conization could be done safely and effectively in an office environment. The subjects of the study were 104 sequential patients who underwent laser excisional cone in an office environment. The average cone size was 16.5 mm by 12.5 mm. The average operating time was 15 minutes. Margins of the cone specimen were adequate for interpretation in 100 patients (96%). Of patients available for complete posttherapy follow-up, 96/98 (98%) achieved initial cure of their lesion. Complications included bleeding requiring revisit in 7.7%, relocation of the SCJ out of colposcopic view in 7%, and cervical stenosis/occlusion in 2 patients. Four pregnancies have occurred and have either been delivered or are progressing satisfactorily. We believe that laser excisional conization may safely and effectively be moved out of the operating room environment.

Relationship of Schmorl's nodes to vertebral body endplate fractures and acute endplate disk extrusions

BACKGROUND AND PURPOSE

Literature regarding clinical pain syndromes associated with acute, traumatic Schmorl's nodes (SNs) is limited. Our purpose was to determine whether an SN could be related to a previous traumatic event producing either acute SN or a vertebral endplate fracture.

METHODS

Two neuroradiologists independently reviewed initial and follow-up MR examinations of 14 patients with a clinical diagnosis of acute, symptomatic thoracolumbar SNs or vertebral body endplate fractures that evolved into SNs to evaluate marrow edema, signal intensity, margin definition, presence of intravertebral extruded disk material, and pattern of contrast enhancement.

RESULTS

Edema of the affected vertebral body, adjacent to an endplate without wedging or collapse, was observed on the initial MR images in all cases. The initial MR images of six (43%) of 14 patients exhibited only edema of the marrow immediately adjacent to the endplate without wedging or collapse. The MR images obtained at the time of follow-up showed subsequent formation of a chronic and eventually asymptomatic SN for all six patients. The initial MR images of eight (57%) of the 14 patients showed the typical appearance of acute SNs with marrow edema of the affected vertebra. The contrast-enhanced images of three patients manifested enhancement of the invaginated disk material in three (100%) of three cases and enhancement of the surrounding vertebral body in one case (33%). Six (43%) of 14 patients had acute typical compression fracture of a vertebral body of at least one additional level.

CONCLUSION

Most (57%) of the SNs in this series could be traced to episodes of significant, sudden-onset, localized, nonradiating back pain and tenderness for which the MR images showed SNs surrounded by vertebral body marrow edema. The remaining SNs (43%) were not immediately apparent as SNs and manifested only as vertebral body edema representing endplate fracture but did evolve into classical chronic SNs that follow-up imaging revealed.

Radiologic manifestations of round pneumonia in adults

Round pneumonia, a benign cause of coin lesions seen on chest radiography, can often be difficult to distinguish from bronchogenic carcinoma. Although relatively uncommon in adults, this entity will probably be seen in most radiology practices and may lead to CT and biopsy. Because round pneumonia is easily treated with antibiotics, this diagnosis should be considered in all patients with a coin lesion, keeping in mind that bronchogenic carcinoma is much more frequent. A recent chest radiograph with normal findings or a history of cough and fever can aid in the diagnosis. A trial of antibiotics followed by a second chest radiograph in 2-3 weeks may be indicated in symptomatic or younger patients but should be considered in all patients with a solitary pulmonary nodule, because round pneumonia can occur in patients of any age and may be clinically silent. Any patient with a pulmonary nodule that does not decrease in size or resolution after antibiotic treatment should be further assessed with bronchoscopy, transthoracic needle biopsy, or other diagnostic procedures.

Measurement of the normal optic chiasm on coronal MR images

PURPOSE

To develop an objective method for measuring the optic chiasm and to document its normal range in size.

METHODS

Measurements of the height and area of the optic chiasm, made on coronal T1-weighted MR images with the use of commercially available region-of-interest software, were obtained in 114 healthy subjects who had a total of 123 MR studies. A normal range and standard deviation were calculated, and the information was broken down by age and sex.

RESULTS

The mean area of the optic chiasm was 43.7 mm2, with a standard deviation of 5.21. The mean width was 14.0 mm, with a standard deviation of 1.68.

CONCLUSION

The area and width of the optic chiasm can be measured with the use of commercially available software, which allows an objective estimate of the chiasm's size. Knowledge of the normal size range of the optic chiasm can be helpful in the early detection of some disorders.

Indocyanine green videoangiography of hemorrhagic retinal arterial macroaneurysms

We examined 3 patients with isolated retinal macroaneurysms and secondary hemorrhage by standard fluorescein angiography (FA) and indocyanine green (ICG) angiography. In contrast to standard FA, ICG videoangiography clearly demonstrated the lesion to be pulsatile, contiguous with the arterial wall and pathognomonic of an isolated retinal artery macroaneurysm. ICG with its absorption and emission peak in the near-infrared range penetrates hemorrhage to a greater degree than does blue or green light of conventional FA. ICG can be essential in delineating the specific cause of the bleeding and allow the physician to choose the correct specific form of treatment needed.

Can the Yale-Brown Obsessive Compulsive Scale be used to assess trichotillomania? A preliminary report

Given recent conceptualizations of trichotillomania (TM) as a variant of obsessive compulsive disorder (OCD), clinician-rated measures of obsessive compulsive symptoms have been adapted for use in the assessment of TM. Although the reliability and validity of these instruments have been well-documented in patients with OCD, psychometric properties have not been examined systematically in patients with TM. Here, we evaluate the reliability and validity of the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) in a sample of 11 patients with a primary diagnosis of TM. Data addressed the utility of the Y-BOCS for evaluating symptoms of TM, and provided information regarding the proposed overlap between OCD and TM. Initial analyses suggested that interrater reliability, internal consistency, and test-retest reliability for the total score were adequate. However, the range of scores was somewhat restricted, and suggested in particular that interference in daily functioning from TM symptoms is quite low. Both internal consistency and test-retest reliability for the Target Behaviors subscale were inadequate, suggesting that this combined score is inappropriate for use with TM patients. Concurrent validity data using the total score were mixed, although the Y-BOCS did appear to be sensitive to change in TM symptoms over treatment. Implications for the use of the Y-BOCS with TM patients and hypothesized phenomenological differences between TM and OCD are discussed.

Acute orbital pseudotumor with iatrogenic intraorbital air: a diagnostic dilemma

A 13-year-old black female was referred with unilateral granulomatous uveitis and orbital inflammation of sudden onset. Hematologic, serologic, bacteriologic, and ultrasonographic studies along with high resolution CT scans of the orbits were employed to determine the diagnosis and appropriate treatment. Subconjunctival corticosteroid injection containing air prior to referral obfuscated the ultimate diagnosis of pseudotumor. The Pediatric Infectious Disease service delayed definitive treatment with systemic steroids. Differential diagnosis of granulomatous uveitis with orbital inflammation are discussed. CT scan has significantly advanced the diagnosis and management of orbital pseudotumor.

Kinetics of [99mTc]heparin, venous scintigraphy with [99mTc]fibrinogen and beta-thromboglobulin assay in the diagnosis of deep-vein thrombosis

The information provided by three examinations: [99mTc]heparin kinetics (KH), venous scintigraphy with [99mTc]fibrinogen (VSF) and plasmatic assay of beta-thromboglobulin (beta TG), are studied on 23 patients separated into two groups on the basis of phlebographic results. VSF which could provide to a certain extent the same kind of information as phlebography, proves to have insufficient sensitivity. KH has high specificity but low sensitivity, while beta TG performance is the opposite. The authors discuss the mechanisms responsible for these discordant results. They observe that in cases where the KH and beta TG correspond, the diagnostic value is very satisfactory, so that a double positive can replace phlebography in cases where the latter is contra-indicated or difficult to perform.

Influence of counting statistics on borderline detection of hepatitis B antigen by a solid-phase radioimmunoassay

The detection of hepatitis B antigen by a solid-phase radioimmunoassay technique is by now well established, particularly where transfusions are concerned. However, it would appear that the use of systematic procedures leading to positive detection, such as the "cutoff" method (mean counts per minute of the negative controls multiplied by a coefficient of 2.1), are open to criticism if elementary precautions concerning the time span and the statistical accuracy of radioactivity counting are not taken. The method may even prove inaccurate in a certain number of borderline cases studies in relation to plasma and different sera, especially if subjected to a single screening process over a large number of samples analyzed by computer. These deficiencies can be avoided by correcting the positive coefficient in relation to the mean counts per minute of negative controls, the statistical accuracy (relative standard deviation) and the distribution of counting times.