Quantification of penile fat infiltration using the mDIXON quant sequence: a pilot study on the correlation with penis hardness and erectile dysfunction

Objective: The purpose of this study was to determine fat/water signal ratios using the mDIXON Quant sequence, quantitatively assess fat infiltration in the penis, and explore its possible relationship with penile hardness and erectile dysfunction. Methods: Routine pelvic magnetic resonance imaging with the mDIXON Quant sequence was performed in 62 subjects, including 22 people in the normal group, 20 people in the normal erectile hardness group, and 20 people in the ED group. The fat/water signal ratio in the penis was measured using the mDIXON Quant sequence. Shear wave elastography was used to evaluate the hardness of the corpus cavernosa of the penis. Results: The fat/water signal ratio of the corpus spongiosum was significantly lower than that of the corpus cavernosa in the normal group (p = 0.03) and ED group (p < 0.01). There was no significant difference in the fat/water signal ratios between the normal group and the normal erectile hardness group. Fat infiltration was significantly lower, and erectile hardness was significantly higher in the normal erectile hardness group than in the erectile dysfunction group, and the fat infiltration in the left and right corpus cavernosa was inversely proportional to the erectile hardness of the penis. Conclusion: This study suggests that mDIXON Quant can be used as a noninvasive, quantitative, and objective method for evaluating penile fat infiltration. This method could help diagnose penile fat infiltration in patients with erectile dysfunction and varying BMIs. Our results could also allow for a more accurate diagnosis and monitoring of erectile hardness function by quantitatively measuring penile fat infiltration. Advances in knowledge: (1) The proton density fat fraction (PDFF) technology is a new tool for the objective, quantitative and noninvasive evaluation of penile fat infiltration. (2) The quantitative measurement of fat infiltration in the corpora cavernosa might help diagnose and monitor penile erection hardness and its function more accurately.

Biomechanical Simulation of Peyronie’s Disease

A pathological disorder of human penile function, known as Peyronie’s disease, is characterized by the formation of plaque particles within the tunica albuginea. The plagues in the shape of rigid plate form in the scars as a result of the imperfect healing process. Due to high stiffness, plagues are the source of pain and anomalous deformations during erectile penis function. The authors simulate the biomechanical behavior of the penile structure by a 3D finite element model. The numerical model is based on the real geometrical shape and the tissue structure with consideration of large nonlinear deformations. The penile erection is modeled by the initial strains imposed on the corpus cavernosa. The stress analysis is performed in a case study of various plague locations. The Peyronie’s syndrome manifested by the penis angular deviation simulated by the analysis is compared with the clinical data. The computational simulations provide a rational explanation for the clinical observations on patients. The objective is to apply the proposed modeling approach for the development and validation of treatment methods based on the application of shock waves.

Degloving injury to groin, scrotum and penis due to low-velocity handlebar injury

Bicycles are a common cause of blunt abdominal trauma causing 5%–14% of injuries. However, impalement or shear injuries from low-velocity mechanism of injury are rare. We report a case of a 14-year-old boy presenting with an extensive left groin injury sustained while cycling one-handed along the pavement at walking pace. The laceration ran for 12–14 cm from the left groin across the pubis to the right and 10 cm inferiorly into the perineum. This inverted the left scrotum and partially degloved the penis. The corpus cavernosa and tunica vaginalis were exposed up to the level of the superficial inguinal ring. Literature on handlebar-impalement injuries is sparse and the majority of penile degloving injuries described in the literature result from alternative mechanisms. This unusual case demonstrates the potential forces involved, and potential damage resulting from handlebar injuries even at low velocity.

A Case Report of Hypertensive Emergency and Intracranial Hemorrhage Due to Intracavernosal Phenylephrine

Background: Intracavernosal injection of phenylephrine is a commonly used therapy for ischemic priapism and is typically well tolerated with few severe adverse side effects. We report a case of intracranial hemorrhage related to hypertensive emergency due to intracavernosal phenylephrine. Case Report: A 43-year-old Caucasian man with history of hypertension, diabetes mellitus type I, end-stage renal disease status post a combination kidney-pancreas transplant, and recurrent idiopathic priapism presented to emergency department with an episode of priapism. His home medications were lisinopril, metoprolol tartrate, mycophenolate mofetil, prednisone, sulfamethoxazole-trimethoprim, and tacrolimus. After local injection of 2 rounds (1 hour apart) of 100 µg phenylephrine into each corpus cavernosa, priapism resolved. Within 5 minutes, the patient had headaches, dyspnea, and excruciating chest pain. His blood pressure (BP) was noted to be 240/130 mm Hg but normalized spontaneously within few minutes. During this period, he developed new-onset right arm and leg weakness and found to have intracranial hemorrhage in the midbrain. Conclusion: A careful review for pharmacologic interactions should be performed prior to intracavernosal phenylephrine administration, and close monitoring should occur after its administration.