Real-time probe tracking using EM-optical sensor for MRI-guided cryoablation

BACKGROUND

A method of real-time, accurate probe tracking at the entrance of the MRI bore is developed, which, fused with pre-procedural MR images, will enable clinicians to perform cryoablation efficiently in a large workspace with image guidance.

METHODS

Electromagnetic (EM) tracking coupled with optical tracking is used to track the probe. EM tracking is achieved with an MRI-safe EM sensor working under the scanner's magnetic field to compensate the line-of-sight issue of optical tracking. Unscented Kalman filter-based probe tracking is developed to smooth the EM sensor measurements when occlusion occurs and to improve the tracking accuracy by fusing the measurements of two sensors.

RESULTS

Experiments with a spine phantom show that the mean targeting errors using the EM sensor alone and using the proposed method are 2.21 mm and 1.80 mm, respectively.

CONCLUSION

The proposed method achieves more accurate probe tracking than using an EM sensor alone at the MRI scanner entrance.

Potential of Aqueous Humor as a Surrogate Tumor Biopsy for Retinoblastoma

Importance

Retinoblastoma (Rb) is one of the first tumors to have a known genetic etiology. However, because biopsy of this tumor is contraindicated, it has not been possible to define the effects of secondary genetic changes on the disease course.

Objective

To investigate whether the aqueous humor (AH) of Rb eyes has sufficient tumor-derived DNA to perform genetic analysis of the tumor, including DNA copy number alterations.

Design, Setting, and Participants

This investigation was a case series study at a tertiary care hospital (Children's Hospital Los Angeles) with a large Rb treatment center. Cell-free DNA (cfDNA) was isolated from 6 AH samples from 3 children with Rb, including 2 after primary enucleation and 1 undergoing multiple intravitreous injections of melphalan for vitreous seeding. Samples were taken between December 2014 and September 2015.

Main Outcomes and Measures

Measurable levels of nucleic acids in the AH and identification of tumor-derived DNA copy number variation in the AH. The AH was analyzed for DNA, RNA, and micro-RNA using Qubit high-sensitivity kits. Cell-free DNA was isolated from the AH, and sequencing library protocols were optimized. Shallow whole-genome sequencing was performed on an Illumina platform, followed by genome-wide chromosomal copy number variation profiling to assess the presence of tumor DNA fractions in the AH cfDNA of the 3 patients. One child's cfDNA from the AH and tumor DNA were subjected to Sanger sequencing to isolate the RB1 mutation.

Results

Six AH samples were obtained from 3 Rb eyes in 3 children (2 male and 1 female; diagnosed at ages 7, 20, and 28 months). A corroborative pattern between the chromosomal copy number variation profiles of the AH cfDNA and tumor-derived DNA from the enucleated samples was identified. In addition, a nonsense RB1 mutation (Lys→STOP) from 1 child was also identified from the AH samples obtained during intravitreous injection of melphalan, which matched the tumor sample postsecondary enucleation. Sanger sequencing of the AH cfDNA and tumor DNA with polymerase chain reaction primers targeting RB1 gene c.1075A demonstrated this same RB1 mutation.

Conclusions and Relevance

In this study evaluating nucleic acids in the AH from Rb eyes undergoing salvage therapy with intravitreous injection of melphalan, the results suggest that the AH can serve as a surrogate tumor biopsy when Rb tumor tissue is not available. This novel method will allow for analyses of tumor-derived DNA in Rb eyes undergoing salvage therapy that have not been enucleated.

Structural and Functional Characterization of Human Stem-Cell-Derived Retinal Organoids by Live Imaging

Purpose

Human pluripotent stem cell (hPSC)-derived retinal organoids are a platform for investigating retinal development, pathophysiology, and cellular therapies. In contrast to histologic analysis in which multiple specimens fixed at different times are used to reconstruct developmental processes, repeated analysis of the same living organoids provides a more direct means to characterize changes. New live imaging modalities can provide insights into retinal organoid structure and metabolic function during in vitro growth. This study employed live tissue imaging to characterize retinal organoid development, including metabolic changes accompanying photoreceptor differentiation.

Methods

Live hPSC-derived retinal organoids at different developmental stages were examined for microanatomic organization and metabolic function by phase contrast microscopy, optical coherence tomography (OCT), fluorescence lifetime imaging microscopy (FLIM), and hyperspectral imaging (HSpec). Features were compared to those revealed by histologic staining, immunostaining, and microcomputed tomography (micro-CT) of fixed organoid tissue.

Results

We used FLIM and HSpec to detect changes in metabolic activity as organoids differentiated into organized lamellae. FLIM detected increased glycolytic activity and HSpec detected retinol and retinoic acid accumulation in the organoid outer layer, coinciding with photoreceptor genesis. OCT enabled imaging of lamellae formed during organoid maturation. Micro-CT revealed three-dimensional structure, but failed to detect lamellae.

Conclusions

Live imaging modalities facilitate real-time and nondestructive imaging of retinal organoids as they organize into lamellar structures. FLIM and HSpec enable rapid detection of lamellar structure and photoreceptor metabolism. Live imaging techniques may aid in the continuous evaluation of retinal organoid development in diverse experimental and cell therapy settings.

Clinical Significance of Optic Nerve Enhancement on Magnetic Resonance Imaging in Enucleated Retinoblastoma Patients

PURPOSE

The aim of this 8-year retrospective review was to determine the clinical significance of gadolinium-enhanced magnetic resonance imaging (MRI) findings in retinoblastoma patients after enucleation, particularly the presence of abnormal contrast enhancement of the transected optic nerve.

DESIGN

Retrospective chart review.

SUBJECTS

A review was done on 88 patients with retinoblastoma undergoing 90 enucleations between January 2008 and December 2015.

METHODS

These patients underwent 233 MRI scans: 90 preoperative and 143 postoperative that were included for review.

MAIN OUTCOME MEASURE

The primary outcome measure assessed was abnormal MRI findings in the preoperative and postoperative MRI scans, specifically enhancement of the optic nerve and correlations between abnormal MRI findings and clinical outcomes for the 88 patients.

RESULTS

On the preoperative MRI, 4 optic nerves out of 90 scans showed positive enhancement. Fifty orbits had ≥1 postoperative MRI. Overall, 41 of 50 orbits (82%) of enucleated patients demonstrated postoperative contrast enhancement on MRI after enucleation, at a mean interval of 10 months after surgery. The percentage of MRI scans with optic nerve enhancement was 77% from 0 to 6 months after enucleation and 68% at >24 months after surgery. Postenucleation optic nerve enhancement did not correlate with preoperative optic nerve enhancement, chemotherapy administration, or the presence of optic nerve invasion on histopathology. No child required an orbital biopsy. None of the 88 patients were found to have subsequent orbital or metastatic disease at the last clinical follow-up visit (average, 29 months; range, 1-71).

CONCLUSION

Optic nerve contrast enhancement on follow-up MRI after enucleation for retinoblastoma seems to be a common, benign radiographic finding; none of the patients in this series developed extraocular tumor relapse. The presence of postenucleation enhancement on MRI did not correlate with preoperative chemotherapy or the presence of optic nerve invasion on histopathology. Based on our findings, intervention for isolated optic nerve enhancement on MRI is not indicated in the absence of other abnormal clinical or radiographic signs. A prospective trial with a validated radiographic grading system would be helpful to clarify the MRI features to differentiate orbital recurrence from benign postoperative enhancement.

Analyzing pepsin degradation assay conditions used for allergenicity assessments to ensure that pepsin susceptible and pepsin resistant dietary proteins are distinguishable

The susceptibility of a dietary protein to proteolytic degradation by digestive enzymes, such as gastric pepsin, provides information on the likelihood of systemic exposure to a structurally intact and biologically active macromolecule, thus informing on the safety of proteins for human and animal consumption. Therefore, the purpose of standardized in vitro degradation studies that are performed during protein safety assessments is to distinguish whether proteins of interest are susceptible or resistant to pepsin degradation via a study design that enables study-to-study comparison. Attempting to assess pepsin degradation under a wide-range of possible physiological conditions poses a problem because of the lack of robust and consistent data collected under a large-range of sub-optimal conditions, which undermines the needs to harmonize in vitro degradation conditions. This report systematically compares the effects of pH, incubation time, and pepsin-to-substrate protein ratio on the relative degradation of five dietary proteins: three pepsin susceptible proteins [ribulose 1,5-bisphosphate carboxylase-oxygenase (Rubisco), horseradish peroxidase (HRP), hemoglobin (Hb)], and two pepsin resistant proteins [lipid transfer protein (LTP) and soybean trypsin inhibitor (STI)]. The results indicate that proteins susceptible to pepsin degradation are readily distinguishable from pepsin-resistant proteins when the reaction conditions are within the well-characterized optima for pepsin. The current standardized in vitro pepsin resistant assay with low pH and high pepsin-to-substrate ratio fits this purpose. Using non-optimal pH and/or pepsin-to-substrate protein ratios resulted in susceptible proteins no longer being reliably degraded by this stomach enzyme, which compromises the ability of this in vitro assay to distinguish between resistant and susceptible proteins and, therefore, no longer providing useful data to an overall weight-of-evidence approach to assessing safety of proteins.

Temporal expression of CD184(CXCR4) and CD171(L1CAM) identifies distinct early developmental stages of human retinal ganglion cells in embryonic stem cell derived retina

Human retinal ganglion cells (RGCs) derived from pluripotent stem cells (PSCs) have anticipated value for human disease study, drug screening, and therapeutic applications; however, their full potential remains underdeveloped. To characterize RGCs in human embryonic stem cell (hESC) derived retinal organoids we examined RGC markers and surface antigen expression and made comparisons to human fetal retina. RGCs in both tissues exhibited CD184 and CD171 expression and distinct expression patterns of the RGC markers BRN3 and RBPMS. The retinal progenitor cells (RPCs) of retinal organoids expressed CD184, consistent with its expression in the neuroblastic layer in fetal retina. In retinal organoids CD184 expression was enhanced in RGC competent RPCs and high CD184 expression was retained on post-mitotic RGC precursors; CD171 was detected on maturing RGCs. The differential expression timing of CD184 and CD171 permits identification and enrichment of RGCs from retinal organoids at differing maturation states from committed progenitors to differentiating neurons. These observations will facilitate molecular characterization of PSC-derived RGCs during differentiation, critical knowledge for establishing the veracity of these in vitro produced cells. Furthermore, observations made in the retinal organoid model closely parallel those in human fetal retina further validating use of retinal organoid to model early retinal development.

Spine Cryoablation: A Multimodality Image-Guided Approach for Tumors Adjacent to Major Neural Elements

We report percutaneous cryoablation of spine tumors in 7 consecutive patients (5 men, 2 women [mean age, 47 years; range, 17-68 years]) by using intraprocedural image monitoring of ice ball margins to protect adjacent neural elements. Complete tumor ablation was achieved in all patients without neurologic complication. Pain relief was achieved in 4 of 5 (80%) patients; the patient with persistent pain was later found to have enlarging metastases at other sites.

Genomic Heterogeneity and Exceptional Response to Dual Pathway Inhibition in Anaplastic Thyroid Cancer

Purpose: Cancers may resist single-agent targeted therapies when the flux of cellular growth signals is shifted from one pathway to another. Blockade of multiple pathways may be necessary for effective inhibition of tumor growth. We document a case in which a patient with anaplastic thyroid carcinoma (ATC) failed to respond to either mTOR/PI3K or combined RAF/MEK inhibition but experienced a dramatic response when both drug regimens were combined.Experimental Design: Multi-region whole-exome sequencing of five diagnostic and four autopsy tumor biopsies was performed. Meta-analysis of DNA and RNA sequencing studies of ATC was performed.Results: Sequencing revealed truncal BRAF and PIK3CA mutations, which are known to activate the MAPK and PI3K/AKT pathways, respectively. Meta-analysis demonstrated 10.3% cooccurrence of MAPK and PI3K pathway alterations in ATC. These tumors display a separate transcriptional profile from other ATCs, consistent with a novel subgroup of ATC.Conclusions: BRAF and PIK3CA mutations define a distinct subset of ATC. Blockade of the MAPK and PI3K pathways appears necessary for tumor response in this subset of ATC. This identification of synergistic activity between targeted agents may inform clinical trial design in ATC. Clin Cancer Res; 23(9); 2367-73. ©2016 AACR.

The development of the Hong Kong Heat Index for enhancing the heat stress information service of the Hong Kong Observatory

This paper presents a study to develop a heat index, for use in hot and humid sub-tropical climate in Hong Kong. The study made use of hospitalization data and heat stress measurement data in Hong Kong from 2007 to 2011. The heat index, which is called Hong Kong Heat Index (HKHI), is calculated from the natural wet bulb temperature, the globe temperature, and the dry bulb temperature together with a set of coefficients applicable to the high humidity condition in the summer of Hong Kong. Analysis of the response of hospitalization rate to variation in HKHI and two other heat indices, namely Wet Bulb Globe Temperature (WBGT) and Net Effective Temperature (NET), revealed that HKHI performed generally better than WBGT and NET in reflecting the heat stress impact on excess hospitalization ratio in Hong Kong. Based on the study results, two reference criteria of HKHI were identified to establish a two-tier approach for the enhancement of the heat stress information service in Hong Kong.

Anterior chamber cholesterolosis in a patient with retinoblastoma

Anterior chamber cholesterolosis is a rare phenomenon typically associated with non-neoplastic conditions such as hyphema or Coats disease; it has never been reported to be associated with intraocular malignancy. We report a case of anterior chamber cholesterolosis presenting in the setting of retinoblastoma and discuss clinical features relevant for its differentiation from Coats disease.

Interventional MR Imaging for Deep-Brain Stimulation Electrode Placement

Purpose To investigate the safety and targeting errors of deep-brain stimulation (DBS) electrodes placed under interventional magnetic resonance (MR) imaging, which allows near real-time anatomic placement without physiologic mapping. Materials and Methods Retrospectively evaluated were 10 consecutive patients (five women, five men) with a mean age of 59.9 years (age range, 17-79 years). These patients underwent interventional MR imaging-guided DBS placement for movement disorders from September 2013 to August 2014 for placement of 19 DBS electrodes in cases where traditional frame-based surgery may be challenging because of the following: dystonia resulting in difficulty in placing the patients in frame, patient's inability or unwillingness to tolerate awake surgery, or anatomic anomaly or variant that could increase the risk of bleeding from microelectrode mapping. Outcomes measured included perioperative hemorrhage, death, and stroke, and electrode functionality assessed at 2 weeks after the operation. In addition, the mean radial error and mean trajectory error were calculated. Results No intraoperative neurologic complications (n = 10 [95% confidence interval: 0%, 31%]) were observed. One patient developed aspiration pneumonia in the postoperative period. Mean radial error was 0.7 mm ± 0.4 (standard deviation) and mean trajectory error was 0.5 mm ± 0.4. All leads delivered clinically effective stimulation. Conclusion Interventional MR imaging-guided DBS electrode placement may be a safe and effective alternative to conventional frame-based surgery in well-selected patients. ^© RSNA, 2016.

A Rapid and Sensitive Next-Generation Sequencing Method to Detect RB1 Mutations Improves Care for Retinoblastoma Patients and Their Families

Retinoblastoma is a childhood eye malignancy that can lead to the loss of vision, eye(s), and sometimes life. The tumors are initiated by inactivating mutations in both alleles of the tumor-suppressor gene, RB1, or, rarely, by MYCN amplification. Timely identification of a germline RB1 mutation in blood samples or either somatic RB1 mutation or MYCN amplification in tumors is important for effective care and management of retinoblastoma patients and their families. However, current procedures to thoroughly test RB1 mutations are complicated and lengthy. Herein, we report a next-generation sequencing-based method capable of detecting point mutations, small indels, and large deletions or duplications across the entire RB1 gene and amplification of MYCN gene on a single platform. From DNA extraction to clinical interpretation requires only 3 days, enabling early molecular diagnosis of retinoblastoma and optimal treatment outcomes. This method can also detect low-level mosaic mutations in blood samples that can be missed by routine Sanger sequencing. In addition, it can differentiate between RB1 mutation- and MYCN amplification-driven retinoblastomas. This rapid, comprehensive, and sensitive method for detecting RB1 mutations and MYCN amplification can readily identify RB1 mutation carriers and thus improve the management and genetic counseling for retinoblastoma patients and their families.

Three-dimensional printing of MRI-visible phantoms and MR image-guided therapy simulation

PURPOSE

To demonstrate the use of anatomic MRI-visible three-dimensional (3D)-printed phantoms and to assess process accuracy and material MR signal properties.

METHODS

A cervical spine model was generated from computed tomography (CT) data and 3D-printed using an MR signal-generating material. Printed phantom accuracy and signal characteristics were assessed using 120 kVp CT and 3 Tesla (T) MR imaging. The MR relaxation rates and diffusion coefficient of the fabricated phantom were measured and ¹ H spectra were acquired to provide insight into the nature of the proton signal. Finally, T₂ -weighted imaging was performed during cryoablation of the model.

RESULTS

The printed model produced a CT signal of 102 ± 8 Hounsfield unit, and an MR signal roughly 1/3^rd that of saline in short echo time/short repetition time GRE MRI (456 ± 36 versus 1526 ± 121 arbitrary signal units). Compared with the model designed from the in vivo CT scan, the printed model differed by 0.13 ± 0.11 mm in CT, and 0.62 ± 0.28 mm in MR. The printed material had T₂ ∼32 ms, T2*∼7 ms, T₁ ∼193 ms, and a very small diffusion coefficient less than olive oil. MRI monitoring of the cryoablation demonstrated iceball formation similar to an in vivo procedure.

CONCLUSION

Current 3D printing technology can be used to print anatomically accurate phantoms that can be imaged by both CT and MRI. Such models can be used to simulate MRI-guided interventions such as cryosurgeries. Future development of the proposed technique can potentially lead to printed models that depict different tissues and anatomical structures with different MR signal characteristics. Magn Reson Med 77:613-622, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Oral apixaban for the treatment of venous thromboembolism in cancer patients: results from the AMPLIFY trial

BACKGROUND

The AMPLIFY trial compared apixaban with enoxaparin followed by warfarin for the treatment of acute venous thromboembolism (VTE).

OBJECTIVE

To perform a subgroup analysis to compare the efficacy and safety of apixaban and enoxaparin followed by warfarin for the treatment of VTE in patients with cancer enrolled in AMPLIFY.

PATIENTS/METHODS

Patients with symptomatic VTE were randomized to a 6-month course of apixaban or enoxaparin followed by warfarin. The primary efficacy outcome and principal safety outcome were recurrent VTE or VTE-related death and major bleeding, respectively.

RESULTS

Of the 5395 patients randomized, 169 (3.1%) had active cancer at baseline, and 365 (6.8%) had a history of cancer without active cancer at baseline. Among patients with active cancer, recurrent VTE occurred in 3.7% and 6.4% of evaluable patients in the apixaban and enoxaparin/warfarin groups, respectively (relative risk [RR] 0.56, 95% confidence interval [CI] 0.13-2.37); major bleeding occurred in 2.3% and 5.0% of evaluable patients, respectively (RR 0.45, 95% CI 0.08-2.46). Among patients with a history of cancer, recurrent VTE occurred in 1.1% and 6.3% of evaluable patients in the apixaban and enoxaparin/warfarin groups, respectively (RR 0.17, 95% CI 0.04-0.78); major bleeding occurred in 0.5% and 2.8% of treated patients, respectively (RR 0.20, 95% CI 0.02-1.65).

CONCLUSIONS

The results of this subgroup analysis suggest that apixaban is a convenient option for cancer patients with VTE. However, additional studies are needed to confirm this concept and to compare apixaban with low molecular weight heparin in these patients.

The effect of bisphosphonate treatment on the biochemical and cellular events during bone remodelling in response to microinjury stimulation

Osteoporosis is one of the most prevalent bone diseases worldwide and is characterised by high levels of bone turnover, a marked loss in bone mass and accumulation of microdamage, which leads to an increased fracture incidence that places a huge burden on global health care systems. Bisphosphonates have been used to treat osteoporosis and have shown great success in conserving bone mass and reducing fracture incidence. In spite of the existing knowledge of the in vivo responses of bone to bisphosphonates, the cellular responses to these drugs have yet to be fully elucidated. In vitro model systems that allow the decoupling of complex highly integrated events, such as bone remodelling, provide a tool whereby these biological processes may be studied in a more simplified context. This study firstly utilised an in vitro model system of bone remodelling and comprising all three major cell types of the bone (osteocytes, osteoclasts and osteoblasts), which was representative of the bone's capacity to sense microdamage and subsequently initiate a basic multicellular unit response. Secondly, this system was used to study the effect of two commonly utilised aminobisphosphonate treatments for osteoporosis, alendronate and zoledronate. We demonstrated that microinjury to osteocyte networks being treated with bisphosphonates modulates receptor activator of nuclear factor kappa-B ligand and osteoprotegerin activity, and subsequently osteoclastogenesis. Furthermore, bisphosphonates increased the osteogenic potential following microinjury. Thus, we have shown for the first time that bisphosphonates act at all three stages of bone remodelling, from microinjury to osteoclastogenesis and ultimately osteogenesis.

Long-Term Outcomes of Group B Eyes in Patients with Retinoblastoma Treated with Short-Course Chemoreduction: Experience from Children's Hospital Los Angeles/University of Southern California

BACKGROUND/AIMS

Chemoreduction protocols for retinoblastoma vary widely across institutions. Herein, we compare a 3- versus 6-cycle chemotherapy approach for group B retinoblastoma.

METHODS

A nonrandomized, retrospective review of patients diagnosed with group B retinoblastoma from 1991-2011 at Children's Hospital Los Angeles was performed. A total of 72 eyes of 63 patients were analyzed. Mean follow-up time was 82 months (range 6-272 months). Main outcome measures were globe salvage and need for external beam radiation.

RESULTS

Forty-six patients (55 eyes) were treated upfront with 3 cycles of carboplatin, etoposide, and vincristine; 17 patients (17 eyes) received 6 cycles. Thirty-seven eyes (67%) in the 3-cycle group were cured with initial chemoreduction alone. An additional 10 eyes with persistent or recurrent tumors were rescued with 3 more cycles for a total salvage rate of 85% (47/55 eyes). In the 6-cycle group, 16 of 17 eyes (94%) avoided radiation and enucleation.

CONCLUSION

The initial recurrence rate was higher for the 3-cycle group (p = 0.03). However, eyes failing short-course chemoreduction were rescued with 3 additional cycles and achieved a similar overall event-free survival rate (p = 0.16). In our cohort, this short-course approach spared 63% (29/46) of patients with group B retinoblastoma the extra 3 cycles of systemic chemotherapy.

Quantification of liver herniation in fetuses with isolated congenital diaphragmatic hernia using two-dimensional ultrasonography

OBJECTIVES

To describe a method of quantifying the amount of liver herniation in fetuses with isolated congenital diaphragmatic hernia (CDH) using two-dimensional ultrasonography and to correlate this finding with neonatal outcome.

METHODS

Ultrasound images obtained from 77 consecutive fetuses that presented with isolated CDH between January 2004 and July 2012 were reviewed. Liver herniation and thoracic area were measured in a cross-sectional plane of the fetal chest at the level of the four-chamber view of the heart (the same section as is used to measure the lung area-to-head circumference ratio) and the ultrasound-derived liver-to-thoracic area ratio (US-LiTR) was calculated by dividing the liver herniation area by the thoracic area. Receiver-operating characteristics (ROC) curve analysis was used to evaluate the performance of US-LiTR in predicting neonatal outcome (survival to 6 months after delivery and need for extracorporeal membrane oxygenation (ECMO)). In addition, the US-LiTR was compared with the magnetic resonance imaging (MRI)-derived volume ratio (MRI-LiTR) and percentage of liver herniation (MRI-%LH).

RESULTS

The overall neonatal mortality in the 77 cases with isolated CDH was 20.8% (16/77). ECMO was needed in 35.5% (27/76) of the newborns, with a survival rate of 52%. The US-LiTR was associated statistically with mortality (P < 0.01) and with the need for ECMO (P < 0.01). Good correlations were observed between US-LiTR and MRI-LiTR (r = 0.87; P < 0.001) and between US-LiTR and MRI-%LH (r = 0.90; P < 0.001). Based on ROC curve analysis, all three parameters had similar accuracy in predicting mortality (US-LiTR: area under the ROC curve (AUC), 0.78 (95% CI, 0.65-0.92), P < 0.01; MRI-LiTR: AUC, 0.77 (95% CI, 0.63-0.90), P < 0.01; MRI-%LH: AUC, 0.79 (95% CI, 0.65-0.92), P < 0.01, respectively) as well as the need for ECMO (US-LiTR: AUC, 0.72 (95% CI, 0.60-0.84), P < 0.01; MRI-LiTR: AUC, 0.73 (95% CI, 0.60-0.88), P < 0.01; MRI-%LH: AUC, 0.77 (95% CI, 0.64-0.89), P < 0.01, respectively).

CONCLUSIONS

Two-dimensional ultrasound measurement of the amount of liver herniation in fetuses with isolated CDH is feasible and demonstrates a predictive accuracy for neonatal outcome similar to that of MRI.

Magnetic Resonance Imaging-Guided Spine Interventions

MR imaging-guided interventions for treatment of low back pain and for diagnosis and treatment of soft tissue and bony spinal lesions have been shown to be feasible, effective, and safe. Advantages of this technique include the absence of ionizing radiation, the high tissue contrast, and multiplanar imaging options. Recent advancements in MR imaging systems allow improved image qualities and real-time guidance. One exciting application is MR imaging-guided cryotherapy of spinal lesions, including treating such lesions as benign osteoid osteomas and malignant metastatic disease in patients who are not good surgical candidates. This particular technique shows promise for local tumor control and pain relief in appropriate patients.

Outcomes of medium choroidal melanomas treated with ruthenium brachytherapy guided by three-dimensional pretreatment modeling

PURPOSE

The Collaborative Ocular Melanoma Study (COMS) established iodine-125 (I-125) plaque brachytherapy for eye preserving treatment of medium-sized choroidal melanomas in the United States. Eye Physics I-125 plaque treatment modeled with Plaque Simulator (PS) software yields similar results to COMS. Herein, we report results from a series of 15 patients treated with ruthenium-106 (Ru-106) plaque brachytherapy using PS pretreatment modeling for plaque localization and dosimetry.

METHODS AND MATERIALS

Fifteen patients with medium-sized choroidal melanomas (2.84-5.5 mm in apical height and a basal diameter of 7.8-12.6 mm) treated with ruthenium brachytherapy from 2003 to 2005 were evaluated retrospectively. Baseline and followup data were evaluated for tumor height, best corrected visual acuity, radiation retinopathy, radiation optic neuropathy, postradiation cataract formation, diplopia, and ptosis. Tumor response for both Ru-106 and I-125 plaques planned using the same PS pretreatment modeling was evaluated and compared.

RESULTS

Isotope-specific radiation profiles were compared, and rates of local treatment failure (0%), optic neuropathy (6.7%), retinopathy (20%), and cataracts (33%) were evaluated. Five year-treated tumor heights were approximately 0.61 ± 0.29 (I-125, n = 16) and 0.53 ± 0.17 (Ru-106, n = 6) of their heights at diagnosis.

CONCLUSIONS

This patient subset had background characteristics very similar to those of the COMS and patients treated at our institution with I-125 plaques. Treatment response was equivalent although radiation complications occurred slightly less frequently in the Ru-106 group compared with those treated with I-125. Image-guided three-dimensional pretreatment modeling for plaque localization and dosimetry seems to work equally as well for Ru as for I-125 plaques and justifies more extensive investigation.

Congenital heart anomaly in newborns with congenital diaphragmatic hernia: a single-center experience

OBJECTIVE

To evaluate the impact of the presence of a congenital heart anomaly (CHA) and its potential contribution to morbidity and mortality in infants with congenital diaphragmatic hernia (CDH).

METHODS

In this retrospective cohort study, prenatal and postnatal data of all newborns diagnosed with CDH between January 2004 and December 2012 in a single center were reviewed. Cases were classified into two groups: those with 'isolated' CDH and those with both CDH and CHA. Patients with CHA were further subclassified into those with a major or minor CHA based on the Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1), and the Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery (STS-EACTS) scoring systems. Patients with associated non-cardiac anomalies, including 'syndromic cases', were excluded from the analysis. Primary and secondary outcomes were survival up to 1 year of age and a need for extracorporeal membrane oxygenation (ECMO), respectively.

RESULTS

Of the 180 infants with CDH, 41 were excluded because of the presence of non-cardiac associated anomalies, 118 had isolated CDH and 21 had CDH with CHA (16 with minor and five with major CHA). Receiver-operating characteristics curve analysis demonstrated that the best cut-off for survival was when the score for CHA was ≤ 2 for both RACHS-1 (area under the curve (AUC), 0.74 (P = 0.04); sensitivity, 80.0%; specificity, 87.5%) and STS-EACTS (AUC, 0.83 (P = 0.03); sensitivity, 100%; specificity, 87.5%). Survival rate at 1 year was significantly lower in those with CHD and a major CHA (40.0%; P = 0.04) than in those with isolated CDH (77.1%) and those with CDH and a minor CHA (81.3%). We found no significant differences among the groups with regard to the need for ECMO.

CONCLUSIONS

In general, a milder form of CHA does not appear to have a negative impact on the survival of infants with CDH. However, mortality appears to be significantly higher in infants with CDH and a major form of CHA. The scoring systems appear to be useful as predictors for classifying the effects of CHA in this population of patients.

Realgar (As4S4) nanoparticles and arsenic trioxide (As2O3) induced autophagy and apoptosis in human melanoma cells in vitro

The aim of the present study was to compare the effect of realgar nanoparticles and arsenic trioxide (ATO) on viability, DNA damage, proliferation, autophagy and apoptosis in the human melanoma cell lines BOWES and A375. The application of various flow cytometric methods for measurements cell viability, DNA cell cycle, mitochondrial potential, lysosomal activity, and intracellular content of glutathione was used. In addition, quantitative PCR, western blotting and multiplex bead array analyses were applied for evaluation of redox stress, autophagic flux, and cell signaling alterations.The results showed that realgar treatment of studied cells caused modulation of cell proliferation, induced a block in G2/M phase of the cell cycle and altered phosphorylation of IκB, Akt, ERK1/2, p38, and JNK kinases, as well as decreased mitochondrial membrane potential. Additionally, it appeared that induction of cell death by both realgar and ATO was dose-dependent, when lower (0.3 µM) dosage increased lysosomal activity and induced autophagy and higher (1.25 µM) concentration resulted in the appearance of apoptosis, while pan-caspase inhibitor attenuated more efficiently realgar- than ATO-induced cell death. Furthermore, low concentrations of ATO and realgar nanoparticles increased the content of intracellular glutathione and elevated γ-H2AX expression confirmed DNA damage preferentially at higher concentrations of both drugs used. Further analysis revealed slight differences in time-dependent phosphorylation pattern due to both realgar and ATO treatments, while significant differences were noticed between cell lines. In conclusion, realgar nanoparticles and ATO treatment induced dose-dependent activation of autophagy and apoptosis in both melanoma cell lines, when autophagy flux was determined at lower drug concentrations and the switch to apoptosis occurred at higher concentrations of both arsenic forms.

CT guided method for access to extremely difficult disc spaces without bony penetration or local anesthesia deeper than skin

Gaining needle access to the intervertebral discs for discography has been performed with fluoroscopic guidance but can be challenging when sedation cannot be used. Avoidance of the exiting L5 nerve roots is particularly challenging when the disc space is severely narrowed with overhanging endplates or osteophytes. We describe our experience on 28 discs in 10 consecutive patients referred for presurgical evaluation using low-dose computed tomography oblique axial and sagittal reformats aligned to the needle for guidance into the disc.

Cholesterol Granuloma of the Petrous Apex: A 5-Year Review of Radiology Reports with Follow-Up of Progression and Treatment

Objectives To assess the stability and outcomes of patients with cholesterol granulomas at Brigham and Women's Hospital. Design A retrospective review of neuroradiology magnetic resonance imaging (MRI) studies was performed. The number of newly diagnosed cases of cholesterol granuloma per year was determined. Additional data included age and gender, clinical presentation if applicable, growth on imaging follow-up, and recurrence on postoperative follow-up if applicable. Participants Inclusion criteria included patients who underwent MRI studies between January 1, 2009 and July 1, 2013. Upon review of imaging of these patients, 18 patients had findings compatible with cholesterol granuloma. Results During the study period, an average of three cases of cholesterol granuloma were diagnosed on MRI per year. Three of 18 patients underwent treatment. Two underwent surgery, both of whom demonstrated recurrence on postoperative follow-up imaging. One patient who underwent computed tomography-guided percutaneous aspiration and Gelfoam (Pfizer, New York, United States) embolization had no recurrence on imaging follow-up of up to 23 months. Among the patients who were observed without intervention, growth was identified in only one patient. Conclusions Cholesterol granulomas are a rare entity; however, their appearance on imaging may be greater than previously reported. Most of the lesions demonstrate stability and can be observed.

Low-Dose Chemoreduction for Infants Diagnosed with Retinoblastoma before 6 Months of Age

AIM

The purpose of this study was to evaluate the outcomes of infants diagnosed with retinoblastoma before 6 months of age, including the need for chemoreduction (CRD). In this age group, dosage of CRD was reduced due to its potential for toxicity.

METHODS

This is a retrospective review from 2000 to 2009 that includes 126 eyes of 72 infants (18 unilateral, 54 bilateral). Systemic CRD was administered when local modalities failed or were considered inadequate. Primary outcome measures were the need for CRD and globe salvage.

RESULTS

Of the 72 infants diagnosed before 6 months of age, 48 (67%) ultimately required CRD for globe salvage, 40 (56%) patients before 6 months of age. Globe salvage was achieved in 62% (78/126) of eyes overall and in 93% (68/73) of eyes with Group A-C disease. No patient was hospitalized for CRD-related illness; survival was 100%. The mean follow-up was 52.9 months (range 1-148 months).

CONCLUSION

Utilizing a combination of focal modalities and reduced-dose CRD, children diagnosed with retinoblastoma before 6 months of age attain globe salvage rates comparable to those of older age groups. Two thirds of the infants ultimately required CRD for globe salvage. Bilateral disease as well as Group D and E classification in at least one eye at presentation increased the chance of requiring CRD (p < 0.0001 and p < 0.016, respectively).

Development and Evaluation of Reference Standards for Image-based Telemedicine Diagnosis and Clinical Research Studies in Ophthalmology

Information systems managing image-based data for telemedicine or clinical research applications require a reference standard representing the correct diagnosis. Accurate reference standards are difficult to establish because of imperfect agreement among physicians, and discrepancies between clinical vs. image-based diagnosis. This study is designed to describe the development and evaluation of reference standards for image-based diagnosis, which combine diagnostic impressions of multiple image readers with the actual clinical diagnoses. We show that agreement between image reading and clinical examinations was imperfect (689 [32%] discrepancies in 2148 image readings), as was inter-reader agreement (kappa 0.490-0.652). This was improved by establishing an image-based reference standard defined as the majority diagnosis given by three readers (13% discrepancies with image readers). It was further improved by establishing an overall reference standard that incorporated the clinical diagnosis (10% discrepancies with image readers). These principles of establishing reference standards may be applied to improve robustness of real-world systems supporting image-based diagnosis.

Early postoperative imaging and image-guided procedures on patients with face transplants

Face transplantation is being performed with increasing frequency. Facial edema, fluid collections, and lymphadenopathy are common postoperative findings and may be due to various etiologies, some of which are particular to face transplantation. The purpose of this study was to demonstrate how postoperative imaging and image-guided minimally invasive procedures can assist in diagnosing and treating complications arising from face transplantation. Retrospective evaluation of 6 consecutive cases of face transplantation performed at Brigham and Women's Hospital between April 2009 and March 2014 was performed with assessment of postoperative imaging and image-guided procedures, including aspiration of postoperative fluid collection, lymph node biopsy, and treatment of salivary gland leak. Through these cases, we demonstrate that early postoperative imaging and image-guided procedures are key components for the management of complications following face transplantation.

23-Gauge endoscopic vitrectomy

Vitreoretinal diseases are exemplified by a wide spectrum of complexities. The purpose of this review is to highlight the potential role of endoscopic vitrectomy in modern microincision vitreoretinal surgery. This is related to the clinically relevant optical properties that are exclusive to endoscopy, namely the ability to bypass anterior segment opacities, visualization of difficult-to-access regions of the retina, the unique surgeon's perspective, and the use of reflected (coaxial) versus transmitted (dissociated) illumination. Indications for endoscopy include posterior pathology with limited-to-no view secondary to anterior segment pathology, difficult-to-assess retroirideal pathologies involving the sclerotomy, pars plana, pars plicata, ciliary sulcus, ciliary body, or peripheral lens, and complex anterior retinal detachments, particularly in pediatric vitreoretinopathies and anterior proliferation. The recent advent of the 23-gauge endoscope significantly increases the utility of endoscopic vitrectomy, making it a potentially important part of the surgical armamentarium alongside conventional viewing systems.

Fetal lung volume and quantification of liver herniation by magnetic resonance imaging in isolated congenital diaphragmatic hernia

OBJECTIVE

To determine associations between fetal lung and liver herniation volumes measured by magnetic resonance imaging (MRI) and mortality/need for extracorporeal membrane oxygenation (ECMO) in cases of isolated congenital diaphragmatic hernia (CDH). A secondary objective was to compare prenatal MRI parameters with two-dimensional ultrasound lung measurements.

METHODS

A retrospective review of medical records of all fetuses with isolated CDH evaluated between January 2004 and July 2012 was performed. The following MRI parameters were measured at 20-32 weeks: observed/expected total fetal lung volume (o/e-TLV), predicted pulmonary volume (PPV), percentage of liver herniated into the fetal thorax (%LH) and the liver/thoracic volume ratio (LiTR). These were compared with the ultrasound-determined lung-to-head ratio (LHR) and the observed/expected LHR (o/e-LHR) in the same cohort. The predictive value of MRI and ultrasound parameters for mortality and the need for ECMO was evaluated by univariate, multivariate and factor analysis and by receiver-operating characteristics curves.

RESULTS

Eighty fetuses with isolated CDH were evaluated. Overall mortality was 18/80 (22.5%). Two newborns died a few hours after birth. ECMO was performed in 29/78 (37.2%) newborns, with a survival rate of 48.3% (14/29). The side of the diaphragmatic defect was not associated with mortality (P = 0.99) or the need for ECMO (P = 0.48). Good correlation was observed among o/e-TLV, PPV, LHR and o/e-LHR as well as between %LH and LiTR (r = 0.89; P < 0.01); however, fetal lung measurements and measures of liver herniation were not correlated (all P > 0.05). All parameters were statistically associated with mortality or the need for ECMO. The best combination of measurements to predict mortality was o/e-TLV and %LH, with 83% accuracy.

CONCLUSION

Mortality and the need for ECMO in neonates with isolated CDH can be best predicted using a combination of MRI o/e-TLV and %LH.

Systematic review with network meta-analysis: the efficacy of anti-TNF agents for the treatment of Crohn's disease

BACKGROUND

Anti-tumour necrosis factor-alpha agents (anti-TNF) are effective therapies for the treatment of Crohn's disease (CD), but their comparative efficacy is unknown.

AIM

To perform a network meta-analysis comparing the efficacy of anti-TNF therapies in CD.

METHODS

After screening 506 studies, reviewers extracted information on 10 studies. Traditional meta-analysis (TMA) was used to compare each anti-TNF agent to placebo. Bayesian network meta-analysis (NMA) was performed to compare the effects of anti-TNF agents to placebo. In addition, sample sizes for comparative efficacy trials were calculated.

RESULTS

Compared to placebo, TMA revealed that anti-TNF agents result in a higher likelihood of induction of remission and response (RR: 1.66, 95% CI: 1.17-2.36 and RR: 1.43, 95% CI: 1.17-1.73, respectively) as well as maintenance of remission and response (RR: 1.78, 95% CI: 1.51-2.09 and RR: 1.68, 95% CI: 1.46-1.93, respectively). NMA found nonsignificant trends between infliximab and adalimumab or certolizumab pegol. Among subcutaneous therapies, NMA demonstrated superiority of adalimumab to certolizumab pegol for induction of remission (RR: 2.93, 95% CrI: 1.21-7.75). Sample size calculations suggest that adequately powered head-to-head comparative efficacy trials would require greater than 3000 patients.

CONCLUSIONS

All anti-TNF agents are effective for induction and maintenance of response and remission in the treatment of CD. Although adalimumab is superior to certolizumab pegol for induction of remission, there is no evidence of clinical superiority among anti-TNF agents. Head-to-head trials among the anti-TNF agents are impractical in terms of size and cost.

Factors predictive of long-term visual outcomes of Group D eyes treated with chemoreduction and low-dose IMRT salvage: the Children's Hospital Los Angeles experience

AIM

To evaluate clinical factors predictive of visual outcomes in Group D retinoblastoma eyes.

METHODS

Retrospective chart review of patients with Group D retinoblastoma from January 2000 to December 2009. All patients were treated with systemic chemoreduction and external beam radiation as salvage therapy when indicated. Primary outcome measure was visual acuity. Clinical factors evaluated include quadrants of subretinal fluid, extent of vitreous seeding, involvement of more/less than 50% of the macula, endophytic/exophytic tumour classification, and presence of tumour behind the lens at diagnosis.

RESULTS

Fifty-two Group D eyes of 41 patients were included; 10 eyes with visual acuity better than 20/80, 32 eyes with vision worse than 20/100 and 10 eyes with indeterminate vision (fix and follow). Complete retinal detachment (p=0.002), involvement of >50% of the macula (p=0.01), and seeding >3 quadrants (p=0.05) were associated with worse visual outcome. Average follow-up was 50.0 months (range: 10-118 months).

CONCLUSIONS

At presentation, it is difficult to predict which Group D eyes will be salvaged with useful vision following systemic chemotherapy. The presence of complete retinal detachment, macular involvement and extensive seeding on presentation were factors associated with a worse visual prognosis in this study. These findings can guide the ophthalmologist in clinical decision making, as well as in counselling parents.

Fatigue failure of osteocyte cellular processes: implications for the repair of bone

The physical effects of fatigue failure caused by cyclic strain are important and for most materials well understood. However, nothing is known about this mode of failure in living cells. We developed a novel method that allowed us to apply controlled levels of cyclic displacement to networks of osteocytes in bone. We showed that under cyclic loading, fatigue failure takes place in the dendritic processes of osteocytes at cyclic strain levels as low as one tenth of the strain needed for instantaneous rupture. The number of cycles to failure was inversely correlated with the strain level. Further experiments demonstrated that these failures were not artefacts of our methods of sample preparation and testing, and that fatigue failure of cell processes also occurs in vivo. This work is significant as it is the first time it has been possible to conduct fatigue testing on cellular material of any kind. Many types of cells experience repetitive loading which may cause failure or damage requiring repair. It is clinically important to determine how cyclic strain affects cells and how they respond in order to gain a deeper understanding of the physiological processes stimulated in this manner. The more we understand about the natural repair process in bone the more targeted the intervention methods may become if disruption of the repair process occurred. Our results will help to understand how the osteocyte cell network is disrupted in the vicinity of matrix damage, a crucial step in bone remodelling.

Image-guided percutaneous aspiration and gelfoam treatment of petrous apex cholesterol granuloma: a new theory and method for diagnosis and treatment

Although diagnosis of cholesterol granulomas of the skull base can be straightforward with computed tomography (CT) and magnetic resonance imaging (MRI) appearance, treatment is controversial with various skull base approaches described in the literature. This report describes a 35-year-old man who presented with a symptomatic, enlarging cystic lesion in the left petrous apex and clivus that had imaging features of a cholesterol granuloma (cholesterol cyst). Due to a prior history of treated mediastinal germ cell tumor, pathologic confirmation of the lesion was requested. A CT-guided percutaneous aspiration revealed dark used motor oil-like fluid. Continued aspiration yielded a change in the character of the fluid to marrow red. Injection of contrast revealed no communication with cerebrospinal fluid. Gelfoam (Pfizer, New York, New York, USA) was subsequently injected percutaneously into the residual cavity. Histopathology showed no evidence of malignancy and follow-up MRI at 1 month, 3 months, 6 months, and 1 year demonstrated continued decrease in size and signal of the lesion.

Holistic management of venous ulcers especially with endovenous laser treatment using 980nm laser in an ethnically diverse society

AIM

Chronic venous ulcers usually occur as an occupational hazard due to venous insufficiency with venous hypertension. Endovenous laser treatment (EVT) is used to treat varicose veins with venous ulcers and outcome including demography assessed in the different races.

PROCEDURE

145 lower limbs(right 39.3%, left 60.7%) with venous ulcers involving reflux of the great saphenous (132 cases) and / or small saphenous (57 cases) veins underwent EVT with 980 nm diode laser for single (123 cases) or both (11 cases) legs intervention. Supplementary procedures required multiple avulsions and / or sclerotherapy. Holistic advice of multilayered bandaging, graduated compression stockings, weight reduction and lifestyle changes enforced.

RESULT

The average age with venous ulcers was 53.6 years.The mean BMI was 26.8 : the Chinese, Indian and Malay BMIs were 25.1, 28.1 and 31.3 respectively. Symptoms that included pain, swelling, heaviness and cramps assessed pre- and postsurgically were significantly reduced (<0.0001), using the Wilcoxan signed rank test. Of the occupations involved by race, the Chinese were mostly salespersons, Indians blue collar workers and Malays foodrelated workers. Young overweight Indians with sedentary occupations were most predisposed to venous ulcers. Gram negative organisms 63.4% and gram positive organisms 36.6% were isolated in the ulcers. Most ulcers 63.5% measured <2 cm and majority 73.8% localised in the gaiter area.

DISCUSSION

Results of EVT in healing ulcers with no recurrences more than 2 years were successful in 89.7% (130/145). Complications included numbness foot 7.5% and DVT 1.4%. 10.3% (15 cases) had recurrence of venous ulcers within 2 years. In terms of satisfaction 32.3% experienced as very satisfied while 63.4% were satisfied and 4.3% unsatisfied. In conclusion EVT is a useful adjunct with with minimal invasion in managing venous ulcers holistically.

The use of digital imaging in the identification of skip areas after laser treatment for retinopathy of prematurity and its implications for education and patient care

PURPOSE

To describe the utility of using wide-angle digital imaging in the training for retinopathy of prematurity with laser and in identifying common locations of skip areas that were present after initial panretinal photocoagulation with indirect ophthalmoscopy by ophthalmologists-in-training.

METHODS

Retrospective review of digital retinal images of 22 eyes of 12 infants who had undergone laser treatment for retinopathy of prematurity performed by ophthalmologists-in-training. Presence of skip areas was determined by masked review of photographs. The location of skip areas was classified based on two axes: 1) circumferential (in one of six clock-hour regions) and 2) radial (adjacent to the retinal ridge, adjacent to the ora serrata, or isolated patches of greater than one laser burn width).

RESULTS

A total of 30 skip areas were identified in the 22 eyes treated with laser photocoagulation. Based on the circumferential location, a significant difference in skip area distribution was found (P = 0.02). Regions with the highest percentage of skip areas were between the clock hours 11:00 to 1:00 (45%) and 5:00 to 7:00 (41%). Based on the radial location, 40% of all skip areas were found near the ora serrata, 17% near the ridge, and 43% as isolated patches (P = 0.14).

CONCLUSION

Skip areas after indirect panretinal laser photocoagulation by ophthalmologists-in-training were easily visualized by wide-angle digital imaging, after being missed by the trainee during the initial treatment procedure. Most skip areas in this study occurred in the superior or inferior retina. Digital imaging can assist ophthalmologists in visualizing all regions of the retina, can identify inadequate areas of laser treatment, and may reduce the need for retreatment after initial laser for retinopathy of prematurity.

Retinal angiogenesis suppression through small molecule activation of p53

Neovascular age-related macular degeneration is a leading cause of irreversible vision loss in the Western world. Cytokine-targeted therapies (such as anti-vascular endothelial growth factor) are effective in treating pathologic ocular angiogenesis, but have not led to a durable effect and often require indefinite treatment. Here, we show that Nutlin-3, a small molecule antagonist of the E3 ubiquitin protein ligase MDM2, inhibited angiogenesis in several model systems. We found that a functional p53 pathway was essential for Nutlin-3-mediated retinal antiangiogenesis and disruption of the p53 transcriptional network abolished the antiangiogenic activity of Nutlin-3. Nutlin-3 did not inhibit established, mature blood vessels in the adult mouse retina, suggesting that only proliferating retinal vessels are sensitive to Nutlin-3. Furthermore, Nutlin-3 inhibited angiogenesis in nonretinal models such as the hind limb ischemia model. Our work demonstrates that Nutlin-3 functions through an antiproliferative pathway with conceivable advantages over existing cytokine-targeted antiangiogenesis therapies.

Rotavirus activity and meteorological variations in an Asian subtropical city, Hong Kong, 1995-2009

Rotavirus is a leading cause of severe infectious diarrhea in infants and young children aged <5 years. Rotavirus infections have minimal to strong seasonality depending on geographical locations. In this study, a comprehensive retrospective analysis was performed to evaluate the association between rotavirus admission and multiple key meteorological variables, including air temperature, relative humidity, atmospheric pressure, and solar radiation over a 15-year period from 1995 to 2009 in Hong Kong. Rotavirus infections were found to show a distinct cyclical pattern with an annual peak in cold season. The weekly number of cases showed the strongest correlation with average air temperature of the previous 7 days (rho=-0.69; P<0.0001), followed by atmospheric pressure (rho=+0.67; P<0.0001); whereas only weak correlation with relative humidity (rho=-0.252; P<0.0001) and solar radiation (rho=-0.312; P<0.0001) was observed. Curve fitting regression analysis suggested that the correlation was nonlinear in nature in which the effect was more profound towards lower air temperature and higher atmospheric pressure conditions. In binary logistic regression analysis, a final model that included air temperature (≤ 20°C) and atmospheric pressure (≥ 1,013 hPa) predicted correctly 85.3% and 82.6% of weeks with rotavirus activity above and below the baseline level, respectively. In multivariate Poisson model, air temperature and solar radiation were independent factors associated with the weekly number of rotavirus cases, adjusted for seasonal variation. In summary, the current study provides evidence suggesting that local seasonal activity of rotavirus correlated strongly with air temperature, followed by atmospheric pressure but only minimally with relative humidity in pre-vaccine era.

Effect of region-of-interest placement in bolus tracking cerebral computed tomography angiography

INTRODUCTION

Premature or delayed triggering of semiautomatic contrast tracking during intracranial computed tomographic angiography can occur due to artifact from dense contrast in the superior vena cava or brachiocephalic veins near the anterior aortic arch. We determine if placement of bolus tracking region-of-interest in the posterior thoracic aorta can prevent suboptimal intracranial arterial opacification.

METHODS

Intracranial computed tomography angiographies from 80 patients performed on the same scanner were retrospectively evaluated. Thirty-seven consecutive patients with bolus tracking region-of-interest (ROI) placed in the anterior thoracic aorta (group A) and 43 consecutive patients with ROI placed in the posterior thoracic arch (group B) were identified. Two neuroradiologists scored the quality of intracranial computed tomography angiography on a four-point scale. Quantitative measurement of intracranial arterial opacification was also performed. The proportions of patients with poorest quality score as well as the proportions of the patients with the worst degree of intracranial arterial opacification (<10th percentile) were compared between groups A and B using two-sample proportion test.

RESULTS

Qualitative evaluation of the intracranial computed tomography angiography showed 4 (11%) patients in group A with poor quality (score of 1), while all patients in group B scored 2 or higher (p = 0.028). Seven (19%) patients in group A had the lowest quantitative score (mean arterial opacification < 10th percentile) while 1 (2.5%) patient in group B had the lowest score (p = 0.018).

CONCLUSION

Bolus tracking in the posterior thoracic aorta reduces the chance of suboptimal intracranial computed tomography angiography.

Malignant teratoid medulloepithelioma with retinoblastic and rhabdomyoblastic differentiation

We describe an unusual case of malignant teratoid medulloepithelioma in which distinct populations of tumor cells with different immunohistochemical staining patterns existed within the same eye. A neuroblastic population exhibited atypical features of retinoblastoma, including organization into pseudo-Flexner-Wintersteiner and Homer-Wright rosettes. Other populations evolved in strikingly different patterns, with large fields of cells resembling astrocytes and intervening streams of spindle cells that suggested smooth muscle. The spindle cell population was negative for smooth muscle antigen but stained positively for desmin, myoglobin, and myogenin. Under high magnification, the desmin, myoglobin, and myogenin-staining cells exhibited striations consistent with skeletal muscle differentiation.

Examination of osteoarthritis and subchondral bone alterations within the stifle joint of an ovariectomised ovine model

The exact relationship between osteoporosis and osteoarthritis is still a matter for debate for many. The ovariectomised ewe is frequently used as a model for osteoporosis, resulting in significant alterations in bone morphometry and turnover in both trabecular and subchondral bone after 1 year. This study examines whether ovariectomy has any impact on development of osteoarthritis within the ovine stifle joint at the same time point. In addition, we investigate whether there are any significant correlations present between articular cartilage degeneration and alterations in microstructural parameters or turnover rates in the underlying bone. Twenty-two sheep were examined in this study; 10 of the sheep underwent ovariectomy and 12 were kept as controls. Five distinctive fluorochrome dyes were administered intravenously at 12-week intervals to both groups, to label sites of bone turnover. All animals were then sacrificed 12 months postoperatively. Although most specimens showed some evidence of osteoarthritis, no measurable difference between the two study groups was detected. Osteoarthritis was associated with a thinning of the subchondral plate, specifically the subchondral cortical bone; however, whereas previous studies have suggested a link between trabecular thinning and osteoarthritis, this was not confirmed. No correlation was found between osteoarthritis and bone turnover rates of either the subchondral trabecular bone or bone plate. In conclusion, despite the fact that ovariectomy results in marked morphological and structural changes in the ovine stifle joint at 1-year postoperatively, no evidence was found to suggest that it plays a direct role in the aetiology of osteoarthritis.

Long-term outcomes of Group D eyes in bilateral retinoblastoma patients treated with chemoreduction and low-dose IMRT salvage

BACKGROUND

To evaluate outcomes of Group D eyes of bilateral retinoblastoma patients treated with primary chemoreduction and external beam radiation as salvage.

PROCEDURE

Retrospective chart review of patients diagnosed with bilateral retinoblastoma and designated Group D in at least one eye from January 1, 2000 to December 31, 2009. Overall, 62 Group D eyes of 49 patients were included; 13 had bilateral Group D disease. Primary chemoreduction with vincristine, etoposide, and carboplatin with local consolidation was administered, followed by external beam radiation in the form of intensity-modulated radiation therapy (IMRT) as salvage for recurrent tumor. Primary outcome measure was globe salvage.

RESULTS

Of 62 Group D eyes, 7 were enucleated primarily; 55 were treated with systemic chemoreduction, and local therapy. Chemoreduction cured 26 of 55 eyes (47%). Recurrences were found in 29 eyes; 5 underwent enucleation and 24 were treated with IMRT at a dose of 24 Gy (2 eyes) or 36 Gy (22 eyes). Of the 24 irradiated eyes, 19 (79%) were salvaged and 5 required enucleation. Final visual acuity ranged from 20/20 to light perception with 10 eyes having 20/80 or better visual acuity. Average follow-up was 54.2 months.

CONCLUSION

Kaplan-Meier estimates of eye survival of Group D eyes in bilateral patients at 12 months is 82% (95% confidence interval [CI] 70.1-89.7%); at 60 months eye survival is estimated to be 68% (95% confidence interval [CI] 55.4-82.8%). Systemic treatment for retinoblastoma demonstrated a high rate of globe preservation with acceptable complications and many eyes retaining functional vision.

Spontaneous intracranial hypotension from calcified thoracic disc protrusions causing CSF leak successfully treated with targeted epidural blood patch

Spontaneous spinal cerebrospinal fluid (CSF) leaks are increasingly recognized in patients presenting with orthostatic headache and ultimately diagnosed with intracranial hypotension. While the precise cause of these spontaneous leaks is unknown, it is thought to result from underlying weakness in the spinal meninges and may be associated with meningeal diverticula or Tarlov cysts. Rarely, calcified intervertebral discs or bony osteophytes can result in CSF leakage, which has been described in the surgery literature but not well recognized in the radiology literature. The authors present three cases of patients presenting with CSF leaks from calcified thoracic disc protrusions that were successfully treated with epidural blood patches.