3D Isotropic Super-resolution Prostate MRI Using Generative Adversarial Networks and Unpaired Multiplane Slices

We developed a deep learning–based super-resolution model for prostate MRI. 2D T2-weighted turbo spin echo (T2w-TSE) images are the core anatomical sequences in a multiparametric MRI (mpMRI) protocol. These images have coarse through-plane resolution, are non-isotropic, and have long acquisition times (approximately 10–15 min). The model we developed aims to preserve high-frequency details that are normally lost after 3D reconstruction. We propose a novel framework for generating isotropic volumes using generative adversarial networks (GAN) from anisotropic 2D T2w-TSE and single-shot fast spin echo (ssFSE) images. The CycleGAN model used in this study allows the unpaired dataset mapping to reconstruct super-resolution (SR) volumes. Fivefold cross-validation was performed. The improvements from patch-to-volume reconstruction (PVR) to SR are 80.17%, 63.77%, and 186% for perceptual index (PI), RMSE, and SSIM, respectively; the improvements from slice-to-volume reconstruction (SVR) to SR are 72.41%, 17.44%, and 7.5% for PI, RMSE, and SSIM, respectively. Five ssFSE cases were used to test for generalizability; the perceptual quality of SR images surpasses the in-plane ssFSE images by 37.5%, with 3.26% improvement in SSIM and a higher RMSE by 7.92%. SR images were quantitatively assessed with radiologist Likert scores. Our isotropic SR volumes are able to reproduce high-frequency detail, maintaining comparable image quality to in-plane TSE images in all planes without sacrificing perceptual accuracy. The SR reconstruction networks were also successfully applied to the ssFSE images, demonstrating that high-quality isotropic volume achieved from ultra-fast acquisition is feasible.

     

Reducing VAP with 6 Sigma

An Illinois medical center integrates a new solution to reducing ventilator-associated pneumonia.     

Alterations in Platelet Function and Cell-Derived Microvesicles in Recently Menopausal Women: Relationship to Metabolic Syndrome and Atherogenic Risk

A woman’s risk for metabolic syndrome (MS) increases at menopause, with an associated increase in risk for cardiovascular disease. We hypothesized that early menopause-related changes in platelet activity and concentrations of microvesicles derived from activated blood and vascular cells provide a mechanistic link to the early atherothrombotic process. Thus, platelet functions and cellular origin of blood-borne microvesicles in recently menopausal women (n = 118) enrolled in the Kronos Early Estrogen Prevention Study were correlated with components of MS and noninvasive measures of cardiovascular disease [carotid artery intima medial thickness (CIMT), coronary artery calcium (CAC) score, and endothelial reactive hyperemic index (RHI)]. Specific to individual components of the MS pentad, platelet number increased with increasing waist circumference, and platelet secretion of ATP and expression of P-selectin decreased with increasing blood glucose (p = 0.005) and blood pressure (p < 0.05), respectively. Waist circumference and systolic blood pressure were independently associated with monocyte- and endothelium-derived microvesicles (p < 0.05). Platelet-derived and total procoagulant phosphatidylserine-positive microvesicles, and systolic blood pressure correlated with CIMT (p < 0.05), but not with CAC or RHI. In summary, among recently menopausal women, specific platelet functions and concentrations of circulating activated cell membrane-derived procoagulant microvesicles change with individual components of MS. These cellular changes may explain in part how menopause contributes to MS and, eventually, to cardiovascular disease.     

Post-Prostatectomy incontinence and the Artificial Urinary Sphincter: A Long-Term Study of Patient Satisfaction and Criteria for Success

Purpose

We investigated patient satisfaction with the artificial urinary sphincter and established criteria for a successful outcome by inquiring about patient perceived satisfaction, continence achieved and comparison with the surgeon office records.

Materials and Methods

During 9 years 65 patients with post-prostatectomy incontinence underwent placement of the AMS800^* artificial urinary sphincter. Review of charts and a telephone questionnaire were conducted to determine patient perceived satisfaction.

Results

A total of 50 patients participated in the survey. Median followup was 23.4 months. Preoperative incontinence was severe. Of the patients 90 percent reported continuous leakage, and 70 percent wore an average of 6 diapers and 24 percent wore an average of 7.4 pads daily.The long-term complete continence rate was 20 percent. Of the patients with wetness 55 percent had leakage of a few drops daily and 22 percent had leakage of less than a teaspoon. Of all patients 50 percent had leakage daily, 24 percent had leakage 1 or more times a week and wore an average of 1.5 pads per day, and 6 percent reported changing clothes due to wetness. A total of 90 percent of the patients reported satisfaction with the artificial urinary sphincter and 96 percent stated that they would recommend or had recommended the artificial urinary sphincter to a friend. In retrospect, 92 percent of the patients would have the artificial urinary sphincter placed again, 90 percent of those undergoing revision reported no change in satisfaction and 14 percent reported improved sexual activity.

Conclusions

Patient satisfaction with the artificial urinary sphincter for post-prostatectomy incontinence is uniformly high. Although postoperative continence was not 100 percent, relative improvement in continence was the most significant factor affecting patient perceived outcome. Using these parameters criteria for a successful outcome can be established, and patient concerns regarding the artificial urinary sphincter can be dispelled.     

Vaginal Wall Sling: Long-Term Outcome Analysis of Factors Contributing to Patient Satisfaction and Surgical Success

Purpose

The clinical outcome of the vaginal wall sling was retrospectively evaluated to determine patient perception, satisfaction and factors contributing to postoperative success.

Materials and Methods

An outcome based study was conducted of 51 patients undergoing construction of a vaginal wall sling for genuine stress incontinence or intrinsic sphincteric deficiency. Preoperative symptoms, demographic parameters and video urodynamic studies were correlated with postoperative patient perception of symptoms to determine patient satisfaction and factors contributing to overall success.

Results

Of 42 patients (82%) available for followup 31 (74%) reported improvement in continence, 26 (62%) are currently satisfied with the urinary status, 72% in retrospect would repeat the procedure and 69% would recommend the vaginal wall sling to others. Despite long-term resolution of stress incontinence in 92% of those with genuine stress incontinence and 75% with intrinsic sphincter deficiency, postoperative urge incontinence was the single most important factor affecting patient satisfaction (p = 0.001). Patients without postoperative urge incontinence enjoyed the greatest levels of satisfaction, in excess of 90% (p = 0.001). Although preoperative leak point pressure correlated with resolution of stress incontinence, no preoperative demographic factors, symptoms or urodynamic parameters could reliably predict postoperative patient satisfaction.

Conclusions

The vaginal wall sling represents an excellent option for the treatment of genuine stress incontinence and an acceptable option for intrinsic sphincteric deficiency. Patient perception and satisfaction remain closely associated with presence or resolution of postoperative urge incontinence. However, prediction of postoperative urge incontinence remains a challenge and should be considered when counseling patients preoperatively.     

Monoclonal antibodies to human vitamin K-dependent protein S

Monoclonal antibodies to human protein S have been prepared using established hybridoma technology. One antibody was isolated that binds protein S only when Ca2+ is present; others bind antigen equally well in the presence or absence of EDTA. Other antibodies display a diminished affinity for protein S in the presence of EDTA. Purified immunoglobulins from cell lines displaying Ca2+ dependence were immobilized and used to purify protein S from fractions obtained by barium precipitation of citrated plasma, ammonium sulfate fractionation, and chromatography on diethylaminoethanol (DEAE)- Sephadex and dextran sulfate agarose. Essentially homogeneous protein S was isolated from the barium-citrate-adsorbed, 35% ammonium-sulfate- soluble proteins using a totally Ca2+-dependent antibody and EDTA elution. Protein S and several substances of higher mol wt were bound directly from plasma by a partially Ca2+-dependent antibody and were eluted partially with EDTA and NaCl and finally with NaSCN. The largest and most abundant of the high mol wt materials is likely protein S- complement C4b-binding protein complex. The immunoaffinity-isolated protein S was found to be indistinguishable from conventionally isolated protein S in terms of activity, sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) mobility, and by high- performance liquid chromatography (HPLC). These studies establish reagents that can probe the structure of protein S and isolate protein S in its free and complexed forms.     

Multiple sclerosis and the urologist

PURPOSE: We provide an updated reference detailing the neurological and urological state of the art approach to multiple sclerosis (MS) with special emphasis on the pathology and physiology, effects on the genitourinary tract, diagnostic evaluation, and treatment of neurological and urological manifestations. MATERIALS AND METHODS: A MEDLINE computerized reference search and manual bibliography review were performed to find pertinent peer reviewed articles on the neurological and urological manifestations and treatment of MS. A meta-analysis was performed on the urodynamic findings of 22 studies involving 1,882 patients from well-defined MS populations. RESULTS: The majority of patients with MS have genitourinary symptoms ranging from urgency, urge incontinence and frequency to urinary retention. Symptoms do not accurately reflect the underlying urological pathology but parallel pyramidal tract dysfunction. Urodynamic evaluation has an important role in determining proper bladder management. The most common urodynamic finding is detrusor hyperreflexia in 62% of these patients, followed by detrusor-sphincter dyssynergia in 25% and hypocontractility in 20%. Less than 1% of patients has renal deterioration and most may be treated with conservative measures. If conservative measures fail, new forms of bladder reconstruction and diversion may be effectively used. The incidence of sexual dysfunction is up to 80% in men and 72% in women, and treatment focuses on improvement of overall disability and erectile or orgasmic function. CONCLUSIONS: Although the genitourinary consequences of MS are rarely life threatening, they can cause significant morbidity and patient frustration. With the rapid advances in the medical management of MS the urologist should be actively involved in multispecialty treatment of these patients.     

Characterization of prostate size,PSA and endocrine profiles in patients with spinal cord injuries

Aims of this study: From cross-sectional and longitudinal population based studies as well as from autopsy studies it is well documented that total prostate volume increases with advancing age. However, it is not well known (1) which factors are ultimately responsible for this growth phenomenon; or (2) at what time in a persons life the growth tends to occur. At present at least a permissive role for testicular androgens is assumed to be involved in growth regulation. Other factors such as growth factors, epithelial-mesenchymal interaction, and the role of intact neural pathways are still poorly understood. We aimed to study a group of men with spinal cord injuries to determine whether the pattern of prostate enlargement would be different in men with partially or completely interrupted innervation of the pelvis and the prostate gland. Materials and methods: Forty-three men from the Spinal Cord Injury (SCI) Service at the VA North Texas Health Care System ranging in age from 27-73 y (mean 51 y) were recruited to participate in this study. Time since SCI ranged from 2-47 (mean 19 y). All patients underwent standardized questionnaire, physical examination, transrectal ultrasonography (TRUS) measurements of total and transition zone volume of the prostate, serum PSA, testosterone (T), dihydrotestosterone (DHT), FSH and LH measurements, some had TRUS guided biopsies taken. Results: By all the measured criteria there were no abnormalities regarding the pituitary-gonadal axis observed in these men. Testicular volume, serum T, DHT and LH were within normal ranges, and when the patients were stratified by age, no differences were identified. There was an age related increase in FSH which has been described in neurologically intact men. Serum PSA increased slightly with advancing age. While total (TPV) and transition zone (TZV) prostate volume increased with age, the groupwise differences by decades of life were not significant. Moreover, when compared to a group of community dwelling men without known prostatic diseases and a clinic cohort of men with BPH, TPV was substantially lower for each decade of life except for men in their 40s, while TZV was substantially lower for men in their 60s. Conclusions: We observed normal age related changes regarding serum PSA and serum FSH without significant changes in other hormonal parameters. All parameters behaved consistent with changes described in neurologically intact populations. However, we did not observe the typical increase in TPV and TZV of the prostate as seen in population, autopsy and clinic patient studies. This interesting finding indicates that factors other than an intact pituitary-gonadal axis and male steroid hormones may be responsible for the normal age related growth of the prostate. Further studies in larger cohorts are needed to corroborate our findings.     

MRI accurately detects chronic exertional compartment syndrome: a validation study

Objective

To validate the diagnostic performance of an in-scanner exercise-based magnetic resonance imaging (MRI) examination used to screen for chronic exertional compartment syndrome (CECS). Final clinical impression and intracompartmental needle manometry (INM) served as the reference standards.

Materials and methods

Consecutive patients, referred by a sports medicine physician or orthopedic surgeon, underwent the MRI examination for lower extremity pain over the past 4 years and 9 months. Utilizing a diagnostic T2-weighted intensity ratio threshold of 1.54, established by a prior cohort of patients, sensitivity, specificity, predictive value, and diagnostic odds ratio were calculated for the anterior compartments. The means of the T2-weighted intensity ratios were compared using the Wilcoxon rank sum test.

Results

A total of 79 patients were identified, and 76 met the inclusion criteria and were evaluated. Of these, 23 met clinical diagnostic criteria. Sensitivity and specificity were 96% (95% CI: 79–99%) and 87% (95% CI: 75–94%) using the established threshold of 1.54. T2-weighted intensity ratio provided excellent discrimination with a concordance statistic of 0.96 (95% CI: 0.91–1.00). In the subset of 36 patients with INM results, 23 patients met criteria for CECS, although only 19 patients met both INM and clinical criteria. The sensitivity and specificity of the MRI examination relative to INM results were 87% (95%: 70–96%) and 62% (95% CI: 36–82%) respectively.

Conclusion

In-scanner exercise-based MRI demonstrated reliability and reproducibility as a non-invasive screening test for CECS, thus reducing the need for invasive INM.