Integration and Diagnostic Accuracy of 3T Nonendorectal coil Prostate Magnetic Resonance Imaging in the Context of Active Surveillance.

OBJECTIVE: To evaluate the integration of 3T nonendorectal coil multiparametric prostate magnetic resonance imaging (mpMRI) at 2 high-volume practices that routinely use mpMRI in the setting of active surveillance. MATERIALS AND METHODS: This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant, and dual-institution retrospective cohort study. Subjects undergoing 3T mpMRI without endorectal coil at either study institution over a 13-month period (August 1, 2015-August 31, 2016) were selected based on predefined criteria: clinical T1/T2 Gleason 6 prostate cancer, prostate-specific antigen <15 ng/mL, ≥40 years old, mpMRI within 2 years of prostate biopsy, and Prostate Imaging Reporting and Data System (PI-RADS) v2 score assigned. Subjects surveilled for Gleason ≥3 + 4 prostate cancer were excluded. The primary outcome was detection of Gleason ≥3 + 4 prostate cancer on magnetic resonance-ultrasound fusion biopsy, standard biopsy, or prostatectomy within 6 months following mpMRI. Positive predictive values (PPVs) were calculated. RESULTS: A total of 286 subjects (N = 193 from institution 1, N = 93 from institution 2) met the criteria. Most (87% [90 of 104]) with maximum PI-RADS v2 scores of 1-2 did not receive immediate biopsy or treatment and remained on active surveillance. Incidence and PPVs for PI-RADS v2 scores of ≥3 were the following: PI-RADS 3 (n = 57 [20%], PPV 21% [6 of 29]), PI-RADS 4 (n = 96 [34%], PPV 51% [39 of 77]), and PI-RADS 5 (n = 29 [13%], PPV 71% [20 of 28]). No Gleason ≥4 + 3 prostate cancer was identified for PI-RADS v2 scores of 1-3 (0 of 43 with histology). Following mpMRI and subsequent biopsy, 21% (61 of 286) of subjects were removed from active surveillance and underwent definitive therapy. CONCLUSION: The 3T nonendorectal coil mpMRI has been integrated into the care of patients on active surveillance and effectively stratifies risk of Gleason ≥3 + 4 prostate cancer in this population.

Continence outcomes after treatment of recalcitrant postprostatectomy bladder neck contracture and review of the literature.

OBJECTIVE: To present our experience with 2-stage management for recalcitrant refractory bladder neck contracture (BNC) after radical prostatectomy. METHODS: A 15-year retrospective medical record review was performed for patients referred for BNC using current procedural terminology code or by International Classification of Diseases-Ninth Revision code for bladder neck incision (BNI). Treatment consisted of deep cold-knife BNI, followed by cystoscopy at 3-4 months. If stable and healed, an artificial urethral sphincter (AUS) or male sling was placed depending on continence level. Recurrent BNC at 3 months was treated with a second BNI. RESULTS: Sixty-three patients were referred with median (range) age of 66 (41-82) years, body mass index 30.1 (21.9-64.8) kg/m(2), and follow-up of 11 (1-144) months. Seventeen (27%) underwent adjuvant radiation therapy. Of the 46 who had successful management of the BNC, 91.3% were satisfied with level of continence after BNI alone or with a single additional operation. Of the 33 who underwent AUS or sling, only 2 failures occurred: 1 ultimately required cystectomy after multiple urethral erosions, and 1 with mild incontinence was satisfied with a secondary sling procedure. Four patients progressed to permanent urinary diversion. Together, either BNI (n = 4) or the secondary incontinence procedure (n = 1) was not successful in a total of 5 patients and required permanent urinary diversion. Nine had concurrent severe membranous strictures with no coaptation of the external urethral sphincter and were treated with direct vision internal urethrotomy and AUS and were continent. CONCLUSION: This represents the largest known experience with BNC after radical prostatectomy. Patients can be managed with cold-knife incision, followed by AUS or sling, with 66% achieving continence.

Applications of nanoparticles in the detection and treatment of kidney diseases.

Nanoparticles have emerged in the medical field as a technology well suited for the diagnosis and treatment of various disease states. They have been heralded as efficacious in terms of improved therapeutic efficacy and reduction of treatment side effects in some cases. Various nanomaterials have been developed that can be tagged with targeting moieties as well as with drug delivery and imaging capability or a combination of both as a theranostic agent. These nanomaterials have been investigated for treatment and detection of various pathological conditions. The emphasis of this review is to demonstrate current research and clinical applications for nanoparticles in the diagnosis and treatment of kidney diseases.

The interaction of 'occupant factors' on the lower extremity fractures in frontal collision of motor vehicle crashes based on a level I trauma center.

BACKGROUND: To advance occupant protection through the improvement of safety countermeasures, it is necessary to understand the factors that affect human injury tolerance. This study investigated the effect of 'occupant factors' i.e. age, gender, height, weight, and body mass index (BMI) on the pattern of lower extremity injury after motor vehicle crashes (MVCs). The second objective was to identify factor(s) (including restraint systems and Delta V) that influence the severity of fractures (open versus close fractures) within the lower extremity area. The outcome of this study may have implications toward secondary prevention in MVCs. METHODS: One-hundred and thirty-seven front-seat occupants involved in MVCs with frontal impact admitted to the University of Michigan trauma center as part of the Crash Injury Research and Engineering Network (CIREN) project were evaluated. Injuries were classified according to location (knee, thigh, hip [KTH]; lower leg [LL], foot and ankle [FA]). All the relevant variables mentioned above were analyzed. RESULTS: KTH fractures were the most common region (49.5%) affected, followed by fractures to the FA (38.4%) and LL region (12.1%). Female occupants, being generally shorter than their male counterpart, sustained a significantly higher percentage of FA fractures (44% vs. 29.5%, p < 0.05). Male occupants sustained more KTH fractures (58.3% vs. 44%, p < 0.05). Results demonstrated that there were significantly higher percentages of 'open' fractures in the below knee area (FA [53.8%], LL [24.4%], and KTH [21.8%]; p < 0.05). Of all those variables tested (age, gender, height, weight, BMI, restraint systems, and Delta V), occupant's height had a significant effect on the severity of fractures sustained. CONCLUSION: The interactive effect observed for height and gender on the pattern of lower extremity fracture is principally related to the body habitus and that gender may be a 'proxy' variable. The 'human factor' plays a vital role in influencing the pattern of injury in a MVC. This study strongly supports the fact that occupants with dissimilar body habitus interact differently with the interior cabin of the vehicle, thus, the performance of the active and passive safety systems.

Structural and material changes in the aging thorax and their role in crash protection for older occupants.

The human body undergoes a variety of changes as it ages through adulthood. These include both morphological (structural) changes (e.g., increased thoracic kyphosis) and material changes (e.g., osteoporosis). The purpose of this study is to evaluate structural changes that occur in the aging bony thorax and to assess the importance of these changes relative to the well-established material changes. The study involved two primary components. First, full-thorax computed tomography (CT) scans of 161 patients, age 18 to 89 years, were analyzed to quantify the angle of the ribs in the sagittal plane. A significant association between the angle of the ribs and age was identified, with the ribs becoming more perpendicular to the spine as age increased (0.08 degrees/year, p=0.012). Next, a finite element model of the thorax was used to evaluate the importance of this rib angle change relative to other factors associated with aging. A three-factor, two-level factorial design was used to assess the relative importance of rib cage morphology ("young" and "old" rib angle), thickness of the cortical shell (thick = "young" and thin = "old"), and the bone material properties ("young" and "old") on the force-deflection response and injury tolerance of the thorax. The simulations showed that the structural and material changes played approximately equal roles in modulating the force-deflection response of the thorax. Changing the rib angle to be more perpendicular to the spine increased the effective thoracic stiffness, while the "old" material properties and the thin cortical shell decreased the effective stiffness. The offsetting effects of these traits resulted in similar effective thoracic stiffness for the "elderly" and baseline thoracic models, which is consistent with cadaver data available in the literature. All three effects tended to decrease chest deflection tolerance for rib fractures, though the material changes dominated (a four- to six-fold increase in elements eliminated using a maximum strain criterion). The primary conclusion, therefore, is that an older person's thorax, relative to a younger, does not necessarily deform more in response to an applied force. The tolerable sternal deflection level is, however, much less.

Gender differences in hip anatomy: possible implications for injury tolerance in frontal collisions.

Male occupants in frontal motor vehicle collisions have reduced tolerance for hip fractures than females in similar crashes. We studied 92 adult pelvic CT scans and found significant gender differences in bony pelvic geometry, including acetabular socket depth and femoral head width. Significant differences were also noted in the presentation angle of the acetabular socket to frontal loading. The observed differences provide biomechanical insight into why hip injury tolerance may differ with gender. These findings have implications for the future design of vehicle countermeasures as well as finite element models capable of more accurately predicting body tolerances to injury.