The University of California San Francisco Brain Metastases Stereotactic Radiosurgery (UCSF-BMSR) MRI Dataset

Supplemental material is available for this article.

A machine learning approach for real-time cortical state estimation

Objective.Cortical function is under constant modulation by internally-driven, latent variables that regulate excitability, collectively known as 'cortical state'. Despite a vast literature in this area, the estimation of cortical state remains relatively ad hoc, and not amenable to real-time implementation. Here, we implement robust, data-driven, and fast algorithms that address several technical challenges for online cortical state estimation.Approach. We use unsupervised Gaussian mixture models to identify discrete, emergent clusters in spontaneous local field potential signals in cortex. We then extend our approach to a temporally-informed hidden semi-Markov model (HSMM) with Gaussian observations to better model and infer cortical state transitions. Finally, we implement our HSMM cortical state inference algorithms in a real-time system, evaluating their performance in emulation experiments.Main results. Unsupervised clustering approaches reveal emergent state-like structure in spontaneous electrophysiological data that recapitulate arousal-related cortical states as indexed by behavioral indicators. HSMMs enable cortical state inferences in a real-time context by modeling the temporal dynamics of cortical state switching. Using HSMMs provides robustness to state estimates arising from noisy, sequential electrophysiological data.Significance. To our knowledge, this work represents the first implementation of a real-time software tool for continuously decoding cortical states with high temporal resolution (40 ms). The software tools that we provide can facilitate our understanding of how cortical states dynamically modulate cortical function on a moment-by-moment basis and provide a basis for state-aware brain machine interfaces across health and disease.

3D U-Net for automated detection of multiple sclerosis lesions: utility of transfer learning from other pathologies

Background and purpose

Deep learning algorithms for segmentation of multiple sclerosis (MS) plaques generally require training on large datasets. This manuscript evaluates the effect of transfer learning from segmentation of another pathology to facilitate use of smaller MS-specific training datasets. That is, a model trained for detection of one type of pathology was re-trained to identify MS lesions and active demyelination.

Materials and methods

In this retrospective study using MRI exams from 149 patients spanning 4/18/2014 to 7/8/2021, 3D convolutional neural networks were trained with a variable number of manually-segmented MS studies. Models were trained for FLAIR lesion segmentation at a single timepoint, new FLAIR lesion segmentation comparing two timepoints, and enhancing (actively demyelinating) lesion segmentation on T1 post-contrast imaging. Models were trained either de-novo or fine-tuned with transfer learning applied to a pre-existing model initially trained on non-MS data. Performance was evaluated with lesionwise sensitivity and positive predictive value (PPV).

Results

For single timepoint FLAIR lesion segmentation with 10 training studies, a fine-tuned model demonstrated improved performance [lesionwise sensitivity 0.55 ± 0.02 (mean ± standard error), PPV 0.66 ± 0.02] compared to a de-novo model (sensitivity 0.49 ± 0.02, p = 0.001; PPV 0.32 ± 0.02, p < 0.001). For new lesion segmentation with 30 training studies and their prior comparisons, a fine-tuned model demonstrated similar sensitivity (0.49 ± 0.05) and significantly improved PPV (0.60 ± 0.05) compared to a de-novo model (sensitivity 0.51 ± 0.04, p = 0.437; PPV 0.43 ± 0.04, p = 0.002). For enhancement segmentation with 20 training studies, a fine-tuned model demonstrated significantly improved overall performance (sensitivity 0.74 ± 0.06, PPV 0.69 ± 0.05) compared to a de-novo model (sensitivity 0.44 ± 0.09, p = 0.001; PPV 0.37 ± 0.05, p = 0.001).

Conclusion

By fine-tuning models trained for other disease pathologies with MS-specific data, competitive models identifying existing MS plaques, new MS plaques, and active demyelination can be built with substantially smaller datasets than would otherwise be required to train new models.

Early urodynamic findings after complete primary repair of exstrophy

INTRODUCTION

Detrusor contraction in bladder exstrophy (BE) patients following reconstruction is poorly understood as there are few published studies assessing urodynamic findings in this population. Understanding the ability of the detrusor to contract in BE patients early after closure may be able to inform the longer-term management and potential for the development of future continence in this population.

OBJECTIVE

We sought to evaluate early detrusor contraction using urodynamic studies (UDS) in children who had previously undergone complete primary repair of bladder exstrophy (CPRE). We hypothesized that a majority of children with BE would display the presence of normal detrusor contractile function after CPRE.

STUDY DESIGN

A retrospective review of our prospectively collected database was performed for all patients with a diagnosis of classic BE who underwent primary CPRE between 2013 and 2017. From this cohort we identified patients with at least one post-operative UDS at 3 years of age or older who had undergone an initial CPRE. Our primary outcome was the presence of a detrusor contraction demonstrated on UDS.

RESULTS

There were 50 children (31 male, 19 female) with CBE who underwent CPRE between 2013 and 2017.There were 26 (13 male, 13 female) who met inclusion criteria. Median age was 3.5 (IQR: 3.2-4.7) years at the time of UDS Sixteen of the 26 (61.5%) generated a sustained detrusor contraction generating a void, with a median peak voiding pressure of 38 cm H20 (IQR: 28-51). The median bladder capacity reached was 48 ml, which represented a median of 30% of expected bladder capacity. The median post void residual (PVR) for the entire cohort was 26 ml (IQR: 9, 47) or 51% (IQR: 20%-98%) of their actual bladder capacity, while the median PVR for those children with a sustained detrusor contraction was 18 ml (IQR: 5, 46) or 33% (IQR: 27%, 98%) of their actual bladder capacity. Intraoperative bladder width and bladder dome to bladder neck length did not correlate with the presence of voiding via a detrusor contraction (p = 0.64).

DISCUSSION

We present the first study assessing early UDS finding of detrusor contraction in BE patients after CPRE. In our cohort, 61.5% of patients were able to generate a sustained detrusor contraction on UDS which is a higher percentage than has been reported in previous series. A difference in initial surgical management may account for these findings.

CONCLUSION

At short term follow up, the majority of children in our cohort were able to produce sustained detrusor contractions sufficient to generate a void per urethra with a modest post void residual volume. Long-term follow-up and repeated UDS will be needed to track detrusor contractility rates, bladder capacities, compliance, post void residuals and ultimately continence rates over time.

Development of Gestational Age-Based Fetal Brain and Intracranial Volume Reference Norms Using Deep Learning

BACKGROUND AND PURPOSE

Fetal brain MR imaging interpretations are subjective and require subspecialty expertise. We aimed to develop a deep learning algorithm for automatically measuring intracranial and brain volumes of fetal brain MRIs across gestational ages.

MATERIALS AND METHODS

This retrospective study included 246 patients with singleton pregnancies at 19-38 weeks gestation. A 3D U-Net was trained to segment the intracranial contents of 2D fetal brain MRIs in the axial, coronal, and sagittal planes. An additional 3D U-Net was trained to segment the brain from the output of the first model. Models were tested on MRIs of 10 patients (28 planes) via Dice coefficients and volume comparison with manual reference segmentations. Trained U-Nets were applied to 200 additional MRIs to develop normative reference intracranial and brain volumes across gestational ages and then to 9 pathologic fetal brains.

RESULTS

Fetal intracranial and brain compartments were automatically segmented in a mean of 6.8 (SD, 1.2) seconds with median Dices score of 0.95 and 0.90, respectively (interquartile ranges, 0.91-0.96/0.89-0.91) on the test set. Correlation with manual volume measurements was high (Pearson r = 0.996, P < .001). Normative samples of intracranial and brain volumes across gestational ages were developed. Eight of 9 pathologic fetal intracranial volumes were automatically predicted to be >2 SDs from this age-specific reference mean. There were no effects of fetal sex, maternal diabetes, or maternal age on intracranial or brain volumes across gestational ages.

CONCLUSIONS

Deep learning techniques can quickly and accurately quantify intracranial and brain volumes on clinical fetal brain MRIs and identify abnormal volumes on the basis of a normative reference standard.

Interinstitutional Portability of a Deep Learning Brain MRI Lesion Segmentation Algorithm

PURPOSE

To assess how well a brain MRI lesion segmentation algorithm trained at one institution performed at another institution, and to assess the effect of multi-institutional training datasets for mitigating performance loss.

MATERIALS AND METHODS

In this retrospective study, a three-dimensional U-Net for brain MRI abnormality segmentation was trained on data from 293 patients from one institution (IN1) (median age, 54 years; 165 women; patients treated between 2008 and 2018) and tested on data from 51 patients from a second institution (IN2) (median age, 46 years; 27 women; patients treated between 2003 and 2019). The model was then trained on additional data from various sources: (a) 285 multi-institution brain tumor segmentations, (b) 198 IN2 brain tumor segmentations, and (c) 34 IN2 lesion segmentations from various brain pathologic conditions. All trained models were tested on IN1 and external IN2 test datasets, assessing segmentation performance using Dice coefficients.

RESULTS

The U-Net accurately segmented brain MRI lesions across various pathologic conditions. Performance was lower when tested at an external institution (median Dice score, 0.70 [IN2] vs 0.76 [IN1]). Addition of 483 training cases of a single pathologic condition, including from IN2, did not raise performance (median Dice score, 0.72; P = .10). Addition of IN2 training data with heterogeneous pathologic features, representing only 10% (34 of 329) of total training data, increased performance to baseline (Dice score, 0.77; P < .001). This final model produced total lesion volumes with a high correlation to the reference standard (Spearman r = 0.98).

CONCLUSION

For brain MRI lesion segmentation, adding a modest amount of relevant training data from an external institution to a previously trained model supported successful application of the model to this external institution.Keywords: Neural Networks, Brain/Brain Stem, Segmentation Supplemental material is available for this article. © RSNA, 2021.

Automated multiclass tissue segmentation of clinical brain MRIs with lesions

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A U-Net incorporating spatial prior information can successfully segment 6 brain tissue types.

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The U-Net was able to segment gray and white matter in the presence of lesions.

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The U-Net surpassed the performance of its source algorithm in an external dataset.

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Segmentations were produced in a hundredth of the time of its predecessor algorithm.

Delineation and quantification of normal and abnormal brain tissues on Magnetic Resonance Images is fundamental to the diagnosis and longitudinal assessment of neurological diseases. Here we sought to develop a convolutional neural network for automated multiclass tissue segmentation of brain MRIs that was robust at typical clinical resolutions and in the presence of a variety of lesions. We trained a 3D U-Net for full brain multiclass tissue segmentation from a prior atlas-based segmentation method on an internal dataset that consisted of 558 clinical T1-weighted brain MRIs (453/52/53; training/validation/test) of patients with one of 50 different diagnostic entities (n = 362) or with a normal brain MRI (n = 196). We then used transfer learning to refine our model on an external dataset that consisted of 7 patients with hand-labeled tissue types. We evaluated the tissue-wise and intra-lesion performance with different loss functions and spatial prior information in the validation set and applied the best performing model to the internal and external test sets. The network achieved an average overall Dice score of 0.87 and volume similarity of 0.97 in the internal test set. Further, the network achieved a median intra-lesion tissue segmentation accuracy of 0.85 inside lesions within white matter and 0.61 inside lesions within gray matter. After transfer learning, the network achieved an average overall Dice score of 0.77 and volume similarity of 0.96 in the external dataset compared to human raters. The network had equivalent or better performance than the original atlas-based method on which it was trained across all metrics and produced segmentations in a hundredth of the time. We anticipate that this pipeline will be a useful tool for clinical decision support and quantitative analysis of clinical brain MRIs in the presence of lesions.

Three-dimensional U-Net Convolutional Neural Network for Detection and Segmentation of Intracranial Metastases

PURPOSE

To develop and validate a neural network for automated detection and segmentation of intracranial metastases on brain MRI studies obtained for stereotactic radiosurgery treatment planning.

MATERIALS AND METHODS

In this retrospective study, 413 patients (average age, 61 years ± 12 [standard deviation]; 238 women) with a total of 5202 intracranial metastases (median volume, 0.05 cm³; interquartile range, 0.02-0.18 cm³) undergoing stereotactic radiosurgery at one institution were included (January 2017 to February 2020). A total of 563 MRI examinations were performed among the patients, and studies were split into training (n = 413), validation (n = 50), and test (n = 100) datasets. A three-dimensional (3D) U-Net convolutional network was trained and validated on 413 T1 postcontrast or subtraction scans, and several loss functions were evaluated. After model validation, 100 discrete test patients, who underwent imaging after the training and validation patients, were used for final model evaluation. Performance for detection and segmentation of metastases was evaluated using Dice scores, false discovery rates, and false-negative rates, and a comparison with neuroradiologist interrater reliability was performed.

RESULTS

The median Dice score for segmenting enhancing metastases in the test set was 0.75 (interquartile range, 0.63-0.84). There were strong correlations between manually segmented and predicted metastasis volumes (r = 0.98, P < .001) and between the number of manually segmented and predicted metastases (R = 0.95, P < .001). Higher Dice scores were strongly correlated with larger metastasis volumes on a logarithmically transformed scale (r = 0.71). Sensitivity across the whole test sample was 70.0% overall and 96.4% for metastases larger than 6 mm. There was an average of 0.46 false-positive results per scan, with the positive predictive value being 91.5%. In comparison, the median Dice score between two neuroradiologists was 0.85 (interquartile range, 0.80-0.89), with sensitivity across the test sample being 87.9% overall and 98.4% for metastases larger than 6 mm.

CONCLUSION

A 3D U-Net-based convolutional neural network was able to segment brain metastases with high accuracy and perform detection at the level of human interrater reliability for metastases larger than 6 mm.Keywords: Adults, Brain/Brain Stem, CNS, Feature detection, MR-Imaging, Neural Networks, Neuro-Oncology, Quantification, Segmentation© RSNA, 2021.

Multi-Disease Segmentation of Gliomas and White Matter Hyperintensities in the BraTS Data Using a 3D Convolutional Neural Network

An important challenge in segmenting real-world biomedical imaging data is the presence of multiple disease processes within individual subjects. Most adults above age 60 exhibit a variable degree of small vessel ischemic disease, as well as chronic infarcts, which will manifest as white matter hyperintensities (WMH) on brain MRIs. Subjects diagnosed with gliomas will also typically exhibit some degree of abnormal T2 signal due to WMH, rather than just due to tumor. We sought to develop a fully automated algorithm to distinguish and quantify these distinct disease processes within individual subjects’ brain MRIs. To address this multi-disease problem, we trained a 3D U-Net to distinguish between abnormal signal arising from tumors vs. WMH in the 3D multi-parametric MRI (mpMRI, i.e., native T1-weighted, T1-post-contrast, T2, T2-FLAIR) scans of the International Brain Tumor Segmentation (BraTS) 2018 dataset (n_training = 285, n_validation = 66). Our trained neuroradiologist manually annotated WMH on the BraTS training subjects, finding that 69% of subjects had WMH. Our 3D U-Net model had a 4-channel 3D input patch (80 × 80 × 80) from mpMRI, four encoding and decoding layers, and an output of either four [background, active tumor (AT), necrotic core (NCR), peritumoral edematous/infiltrated tissue (ED)] or five classes (adding WMH as the fifth class). For both the four- and five-class output models, the median Dice for whole tumor (WT) extent (i.e., union of AT, ED, NCR) was 0.92 in both training and validation sets. Notably, the five-class model achieved significantly (p = 0.002) lower/better Hausdorff distances for WT extent in the training subjects. There was strong positive correlation between manually segmented and predicted volumes for WT (r = 0.96) and WMH (r = 0.89). Larger lesion volumes were positively correlated with higher/better Dice scores for WT (r = 0.33), WMH (r = 0.34), and across all lesions (r = 0.89) on a log(10) transformed scale. While the median Dice for WMH was 0.42 across training subjects with WMH, the median Dice was 0.62 for those with at least 5 cm³ of WMH. We anticipate the development of computational algorithms that are able to model multiple diseases within a single subject will be a critical step toward translating and integrating artificial intelligence systems into the heterogeneous real-world clinical workflow.

Outcomes of externalized pyeloureteral versus internal ureteral stent in pediatric robotic-assisted laparoscopic pyeloplasty

INTRODUCTION

After pyeloplasty, urinary drainage options include internal double-J (DJ) ureteral stents or externalized pyeloureteral (EPU) stents, which can avoid bladder symptoms and additional anesthetic exposure from stent removal. Comparative outcome studies, however, are lacking following primary pediatric robotic-assisted laparoscopic pyeloplasty (RALP).

OBJECTIVE

To compare operative success, operative time, hospitalization, and postoperative complications of EPU versus DJ stents following RALP.

STUDY DESIGN

Consecutive children undergoing primary RALP from 10/2013 to 9/2015 were retrospectively identified. Data collected included patient demographics, stent type and duration, postoperative complications, and operative success. To control for confounding by indication for EPU stent, propensity score weighting was used to balance baseline covariates. Weighted regression analyses compared between-group differences in study outcomes.

RESULTS

At median follow-up of 12.3 months, 44 and 17 patients underwent DJ and EPU stenting, respectively. At baseline, DJ stent patients were older than EPU stent patients (median 7.7 vs 1.2 years, P = 0.01) and were less likely to be on postoperative antibiotic prophylaxis (25 vs 76%, P < 0.001). After weighting, these differences disappeared. All EPU stents were removed in the outpatient clinic; all DJ stents were removed under anesthesia. On weighted regression analyses (Summary Fig.), EPU stents had no different associations than DJ stents with operative success (95 vs 94%, between-group difference 1%, 95% CI -11, 13; P = 0.86), complications, or operative time, but did have 0.6 of a day more hospitalization (95% CI 0.04, 1.2; P = 0.04).

DISCUSSION

Patients receiving EPU stents were different at baseline from those receiving DJ stents. After propensity score weighting balanced these covariates, EPU stents were associated with similar operative success, complications, and operative time to DJ stents. Further study is warranted in larger prospective cohorts.

CONCLUSION

Use of EPU stents provided a viable alternative, particularly in younger patients, to DJ stenting with comparable success and complications, while avoiding the need for an additional anesthetic.

Back to the future: The Cecil-Culp technique for salvage penile reconstructive procedures

INTRODUCTION

Re-operative penile reconstruction is challenging and requires tension-free skin closure. The repair popularized by Cecil and Culp in the 1940s, using the scrotum to provide a temporary vascularized bed for complex hypospadias repairs, fell out of favor due to temporal trends towards single-stage repairs and concern for utilizing hair-bearing skin on the penile shaft.

OBJECTIVE

It was hypothesized that a modified Cecil-Culp (CC) concept of penile scrotalization, leaving the penis attached to the scrotum for 1 year rather than 6 weeks as originally described, improves outcomes with this reconstruction for ventral skin deficiency or poor vascular support.

METHODS

Institutional Review Board-approved registries were reviewed to identify patients who underwent a CC repair during 1987-2016 at two institutions. Cecil-Culp technique was utilized in multi-stage hypospadias complication repairs or for insufficient ventral penile shaft skin coverage. Anatomic abnormality, number and type of prior surgeries, and complications before and after CC were recorded.

RESULTS

Thirty-nine patients underwent CC: 23 failed hypospadias repairs, three hypospadias after bladder exstrophy, 10 penile curvature following circumcision, and three with skin loss from trauma. Mean age at CC was 61.8 months (hypospadias), and 59.8 months (non-hypospadias). Hypospadias patients underwent a mean of 3.6 surgeries (range 1-9) prior to CC. Four of the 39 patients (10.3%) had perioperative complications after CC, including scrotal abscess, skin infections, and difficulty removing the urethral stent. Eight of 37 (21.6%) patients had longer-term complications related to their hypospadias repair, including fistulae, diverticula, dehiscence, and stricture. Mean time from CC placement to release was 345 and 473 days for hypospadias and non-hypospadias cases, respectively. There was no apparent scrotal skin transferred to the penile shaft at the final take-down. Mean follow-up was 22.3 months.

DISCUSSION

Embedding the penis into the scrotum for added vascularity and ventral skin coverage has been used effectively in cases of the most tenacious fistulas and for significant skin loss and trauma. Limitations of this study were its retrospective approach at two institutions over an extended period of time by multiple surgeons, so patient selection and procedure may have varied.

CONCLUSIONS

Modification of CC repair by delaying 9-12 months before CC take-down enhanced the benefits of a robust vascular bed for wound healing, and helped to avoid transfer of hair-bearing scrotal skin to the penile shaft. The CC technique is an important tool for penile reconstructive surgery of complex hypospadias repairs with inadequate skin, and for traumatic injuries.

Tunica vaginalis flap for salvaging testicular torsion: A matched cohort analysis

INTRODUCTION

In testicular torsion, ischemia time from pain onset impacts testicular salvage. A tunica albuginea fasciotomy to relieve compartment pressure followed by a tunica vaginalis flap (TVF) may enhance salvage.

OBJECTIVE

To define the optimal window of ischemia time during which TVF may be most beneficial to avoid orchiectomy.

STUDY DESIGN

A retrospective cohort study of males presenting with testicular torsion at a single tertiary-care institution from January, 2003 to March, 2017. Ischemia time was defined as duration of pain from onset to surgery. Because TVF would be an option to orchiectomy, and it was found that ischemia time was longer in testicles that underwent orchiectomy, matching was performed. Cases of torsion treated with TVF were matched 1:1 with cases treated with orchiectomy on age at surgery, and ischemia time. Outcomes included postoperative viability, defined as palpable testicular tissue with normal consistency, and atrophy, defined as palpable decrease in size relative to contralateral testicle. Sensitivity analyses were performed restricting to the subgroups with postoperative ultrasound, >6 months' follow-up, and additionally matching for degrees of twist.

RESULTS

A total of 182 patients met eligibility criteria, of whom 49, 36, and 97 underwent orchiectomy, TVF, and septopexy alone, respectively. Median follow-up was 2.7 months; 26% of patients had postoperative ultrasound (61% of TVF group). In the orchiectomy, TVF, and septopexy groups, respectively, median ischemia times were 51, 11, and 8 h, postoperative viability rates were 0, 86, and 95%, and postoperative atrophy rates were 0, 68, and 24%. After matching, 32 patients with TVF were matched to 32 patients who underwent orchiectomy. In the TVF group, postoperative viability occurred in 95% (19/20) vs 67% (8/12) of patients with ischemia times ≤24 and >24 h, respectively. Atrophy occurred in 67% (12/18) vs 83% (10/12) of these same respective patients. Sensitivity analysis by ultrasound and longer follow-up found similar viability results, although atrophy rates were higher. Additional matching for degrees of twist showed lower viability and higher atrophy rates for increasing ischemia times.

DISCUSSION

Patients who presented with testicular torsion with ischemia times ≤24 h and who were being considered for orchiectomy may have benefitted most from TVF, albeit at high risk of atrophy. However, for ischemia times >24 h, TVF may still have preserved testicular viability in two-thirds of cases. A limitation was short follow-up.

CONCLUSION

A TVF was a valid alternative to orchiectomy for torsed testicles, albeit with high testicular atrophy rates.

Genitourinary involvement and management in children with Stevens-Johnson syndrome and toxic epidermal necrolysis

BACKGROUND

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are devastating hypersensitivity disorders that cause epidermal cell death and can affect all epidermal surfaces, including the urethra, vagina, labial and scrotal skin. Despite the well-described ocular and orofacial manifestations of SJS/TEN, there is a paucity of reports on the genitourinary (GU) symptoms and their management. Specifically, consulting services often ask the pediatric urology team if it is safe to place a urethral catheter, but there is no data in the literature to help guide management. The present study sought to review all pediatric cases of SJS/TEN in a tertiary care hospital to determine the incidence and optimal management of GU manifestations, including the use of urethral catheters.

METHODS

With IRB approval, cases of SJS and TEN that were managed as an inpatient between January 2008 and June 2015 were retrospectively reviewed in order to identify the extent of GU involvement/manifestations, the treatment provided, use of urethral catheterization and long-term follow-up or complications.

RESULTS

Thirty-one patients (15 female, 16 male; age range 2-18 years) presented with SJS or TEN over the study period. Etiologies for SJS/TEN included mycoplasma infection (48%) and medications (45%). Incidences of GU manifestations at presentation and their management are shown in Summary Table. Overall, 74% of patients had genital involvement of skin lesions. In 12 cases (39%), urology consultation was obtained. Twenty patients (61%) complained of dysuria and one child had gross hematuria in the setting of meatal lesion. Petroleum jelly was used in the majority of patients. A urethral catheter was placed in eight patients (25.8%, four female, four male) with a range of duration of 7-23 days. No patient developed hematuria or any other complications (i.e. strictures or urinary symptoms) after catheter removal. One boy required lysis of penile adhesions in the short-term. One of each gender developed penile and labial adhesions on long-term follow-up that self-resolved.

CONCLUSIONS

GU involvement in SJS/TEN occurred in almost three-quarters of patients and was managed conservatively like other skin/mucosal manifestations. Long-term sequelae were rare and urethral catheterization appeared to be safe, without any short-term or long-term complications.

How do they get here: Does the method of transportation impact salvage for patients with testicular torsion?

INTRODUCTION

A growing number of patients are arriving at our tertiary care center for evaluation of possible testicular torsion using ambulance or helicopter transport. In many cases the parents arrive by car before the patient arrives. Are these advanced methods of medical transport worth the expense and risk in the case of suspected testicular torsion?

OBJECTIVE

We evaluated the total number of patients presenting to our emergency room for suspected testicular torsion to see if the means of transport affected testicular survival.

STUDY DESIGN

Retrospective.

RESULTS

As shown below in the table, the means of transport did not impact on testicular salvage.

DISCUSSION

It is understandable that many patients with scrotal pain seek treatment closer to home because of their pediatrician's recommendation and/or family preference. However once evaluated many patients are transferred because of a lack of urologists willing to evaluate and treat the pediatric patients in community settings or because of a lack of anesthesia support. These patients are often transported by ambulance or helicopter. Our data would suggest that there is no improvement in the testicular salvage rate seen with these more advanced means of medical transportation compared with transfer by private car even when we restrict the analysis to patients traveling from over 40 miles away. We suspect that important time is lost while waiting to make such transfer arrangements. Furthermore transfer by ambulance or helicopter is more expensive and these costs are often passed on to families. Transfer by helicopter is also riskier. While an argument can be made in favor of medical transport over long distances or long driving times, this data suggests that many of these transfers could be accomplished by car with no effect on testicular salvage rates.

CONCLUSION

The rate of testicular salvage was not affected by the means of transport to our tertiary facility. Only 4 patients would have required advanced of medical transport if this were limited to those facilities over 100 miles or 1.5 hours driving time away. This would achieve a substantial cost savings with no measurable change in outcome.

Pediatric calyceal diverticulum treatment: An experience with endoscopic and laparoscopic approaches

INTRODUCTION

The symptomatic calyceal diverticulum is a rare event in the pediatric population. In adults, surgical options include ureteroscopy, percutaneous ablation, and laparoscopic decortication but there is a lack of experience in the literature with these techniques.

OBJECTIVE

We present our experience with both the ureteroscopic and laparoscopic approach to treating the pediatric calyceal diverticulum.

STUDY DESIGN

We performed a retrospective case series looking at patients who underwent treatment for calyceal diverticulum at our institution from January 2009 to May 2014. We reviewed patient demographics, indications for intervention, radiographic appearance, type of intervention, and perioperative outcomes. Ureteroscopic approach included dilation of infundibulum and ablation of diverticular cavity. Laparoscopic approach included ablation of the diverticulum with argon diathermy with or without surgical closure of the ostium.

RESULTS

There were 13 patients who underwent 15 procedures for symptomatic calyceal diverticulum (Table). Median age was 11 years. Indications for intervention were: pain and increasing size of diverticulum (8/15, 55%), hematuria (3/15, 20%), UTI (3/15, 20%), and calculi (1/15, 5%). 11/15 (73%) procedures were managed endoscopically and 4/15 (27%) were managed with laparoscopic decortication. Ureteral stent was left in all patients for a mean duration of 51 days (15-120 days). Follow up imaging at median of 2.1 years (0.5-4 years) revealed an initial success rate of 85% (11/13 patients). Two patients failed initial intervention (persistent pain/increasing size) necessitating successful secondary minimally invasive procedures. There were 2 (13%) complications: a perinephric hematoma post endoscopic ablation which resolved spontaneously and a deep venous thrombosis in a patient with a coagulation disorder in the laparoscopic group.

DISCUSSION

Limitations of our study include its retrospective design, lack of standardization of the treatment approach amongst the four treating surgeons, and the small number of patients requiring intervention for this relatively rare diagnosis. Our study is the largest to date in the pediatric population and is the first to report outcomes with ureteroscopic management of the calyceal diverticulum.

CONCLUSIONS

We found that the pediatric calyceal diverticulum can be successfully treated in a minimally invasive manner. The endoscopic approach should be the first line option for patients with small, endophytic diverticula, particularly those located in the upper and mid pole. The laparoscopic approach is more invasive but should be considered for large diverticula that are exophytic with thin overlying parenchyma.

Genetic evidence for different male and female roles during cultural transitions in the British Isles

Human history is punctuated by periods of rapid cultural change. Although archeologists have developed a range of models to describe cultural transitions, in most real examples we do not know whether the processes involved the movement of people or the movement of culture only. With a series of relatively well defined cultural transitions, the British Isles present an ideal opportunity to assess the demographic context of cultural change. Important transitions after the first Paleolithic settlements include the Neolithic, the development of Iron Age cultures, and various historical invasions from continental Europe. Here we show that patterns of Y-chromosome variation indicate that the Neolithic and Iron Age transitions in the British Isles occurred without large-scale male movements. The more recent invasions from Scandinavia, on the other hand, appear to have left a significant paternal genetic legacy. In contrast, patterns of mtDNA and X-chromosome variation indicate that one or more of these pre-Anglo-Saxon cultural revolutions had a major effect on the maternal genetic heritage of the British Isles.

PCR-based microsatellite analysis for differentiation and genetic monitoring of nine inbred SENCAR mouse strains

Sixteen DNA microsatellites or simple sequence length polymorphisms (SSLPs), generated by polymerase chain reaction (PCR) were selected for use in the genetic quality control of the nine inbred SENCAR strains currently available. The SENCAR strains constitute a powerful tool for mechanistic studies of multi-stage skin carcinogenesis, as well as for studies to understand the underlying genetic basis of resistance to tumour promotion and progression. SSLP analysis is a fast and economical way for detecting genetic contamination (unexpected outcrosses) among these closely-related albino strains, where standard immunological and biochemical markers have been shown to be insufficient.

High-resolution Y chromosome haplotypes of Israeli and Palestinian Arabs reveal geographic substructure and substantial overlap with haplotypes of Jews

High-resolution Y chromosome haplotype analysis was performed in 143 paternally unrelated Israeli and Palestinian Moslem Arabs (I&P Arabs) by screening for 11 binary polymorphisms and six microsatellite loci. Two frequent haplotypes were found among the 83 detected: the modal haplotype of the I&P Arabs (approximately 14%) was spread throughout the region, while its one-step microsatellite neighbor, the modal haplotype of the Galilee sample (approximately 8%), was mainly restricted to the north. Geographic substructuring within the Arabs was observed in the highlands of Samaria and Judea. Y chromosome variation in the I&P Arabs was compared to that of Ashkenazi and Sephardic Jews, and to that of North Welsh individuals. At the haplogroup level, defined by the binary polymorphisms only, the Y chromosome distribution in Arabs and Jews was similar but not identical. At the haplotype level, determined by both binary and microsatellite markers, a more detailed pattern was observed. Single-step microsatellite networks of Arab and Jewish haplotypes revealed a common pool for a large portion of Y chromosomes, suggesting a relatively recent common ancestry. The two modal haplotypes in the I&P Arabs were closely related to the most frequent haplotype of Jews (the Cohen modal haplotype). However, the I&P Arab clade that includes the two Arab modal haplotypes (and makes up 32% of Arab chromosomes) is found at only very low frequency among Jews, reflecting divergence and/or admixture from other populations.

Difference-quotient turbulence model: analytical solutions for the core region of plane poiseuille flow

The difference-quotient turbulence model and an explanation in terms of fluid dynamics is presented. With this model an analytical theory for the symmetric core region of turbulent plane Poiseuille flow is derived. The equations and the solutions reveal an order/disorder transition with analogies in other scientific fields where statistical physics applies. At moderate Reynolds numbers the time-averaged profile of the downstream mean velocity and a second-order fluctuation correlation are described in terms of Bessel functions of the first type. At the infinite Reynolds number limit these solutions converge toward functions which can be described by simple geometric figures. Experimental data confirm the model results.

See the light: Project Spectrum solves some of healthcare's most challenging IT problems

BJC Health System, St. Louis.

PROBLEM

Changes in healthcare, including the growth of managed care forced administrators at BJC to find new ways to address patients' needs across the entire continuum of care. To meet this challenge, disparate legacy information systems had to begin communicating.

SOLUTION

BJC officials turned to IBM, along with Kodak, Southwestern Bell and Motorola, for the creation of Project Spectrum--a system that reaches beyond the boundaries of this acute care facility.

RESULTS

Project Spectrum accomplishes three goals: allows access to clinical data from anywhere in the health system; is user friendly and fast; and provides the tools for better and efficient care.

KEYS TO SUCCESS

"There is no quick fix. True integration means a long-term, institutional commitment to information system objectives."

The CIO's position in today's emerging health care system: lessons learned

The integrated delivery network is a new concept. Using information technology as a rallying point has allowed people to come together in a non-threatening way. They discuss new ideas and possibilities for improving the performance of their individual institution and thus, the entire Network. How quickly and how well business adapts to this new model will dictate long-term viability in the marketplace. Technology will not be the limiting factor to success in this new endeavor. It will be a facilitator that can help the organizational transition from single institutions to an IDN. The challenge is in managing how well personnel accept this change and seek ways to work together in this new endeavor. The ability to perform competently at these new levels comes from the ability to perform as a senior executive, acting in partnership and peer relationships as a facilitator and leader. To manage the change required in these new organizations, there must be common vision, the creation of new roles, agreed upon priorities, flexibility, and standardization when necessary. While there is not one right solution, leadership and shared vision and the ability to deliver are key success factors.

Hospital saves with bedside point-of-care system

Do bedside and point-of-care systems actually deliver on their promise of reducing operating expenses while helping improve the overall quality of healthcare? And how does a healthcare facility quantify associated "productivity" improvements to prove cost savings? These are two critical issues that healthcare providers face in implementing a bedside or point-of-care (POC) system. Barnes Hospital, St. Louis, is a 1,000 bed member facility of the Barnes-Jewish Inc./Christian Health Services integrated health system. Barnes Hospital has indeed seen significant cost savings as a result of a POC project.