Training Convolutional Networks for Prostate Segmentation With Limited Data.

Multi-zonal segmentation is a critical component of computer-aided diagnostic systems for detecting and staging prostate cancer. Previously, convolutional neural networks such as the U-Net have been used to produce fully automatic multi-zonal prostate segmentation on magnetic resonance images (MRIs) with performance comparable to human experts, but these often require large amounts of manually segmented training data to produce acceptable results. For institutions that have limited amounts of labeled MRI exams, it is not clear how much data is needed to train a segmentation model, and which training strategy should be used to maximize the value of the available data.

Prostatic peripheral zone thickness: what is normal on magnetic resonance imaging?

Purpose: To report the precision of a technique of measuring the PZ thickness on T2-weighted MRI and report normal parameters in patients with normal-sized prostates. We also wanted to establish the mean and second standard deviations (2SD) above and below the mean as criteria for abnormally narrow or expanded PZ thickness.

Methods: Of the initial 1566 consecutive cohort referred for evaluation for carcinoma based on elevated PSA (prostate specific antibody) or DRE (digital rectal examination), 132 separate subjects with normal-sized prostates were selected for this study.

Measurement of Prostate Volume with MRI (A Guide for the Perplexed): Biproximate Method with Analysis of Precision and Accuracy.

To review the anatomic basis of prostate boundary selection on T2-weighted magnetic resonance imaging (MRI). To introduce an alternative 3D ellipsoid measuring technique that maximizes precision, report the intra- and inter-observer reliability, and to advocate it's use for research involving multiple observers. We demonstrate prostate boundary anatomy using gross pathology and MRI examples.

Precision and accuracy of magnetic resonance imaging for lobar classification of benign prostatic hyperplasia.

Purpose: To validate the application of a magnetic resonance imaging (MRI)-based lobar classification of benign prostatic hyperplasia (BPH) for use in research and clinical management.

Methods: Two radiologists with 5 and 11 years post-fellowship experience were trained in the lobar classification of BPH using an internally developed atlas of prostate anatomy with example MRI images edited by a third senior radiologist designated as the "administrator" of the study. A study population of 140 patients referred to a tertiary academic medical center with known or suspected prostate cancer was selected by the administrator to test the interrater reliability (IRR; precision) of the classification as well as accuracy of the two readers compared to the administrator as the "gold" standard.

Use of MRI for Lobar Classification of Benign Prostatic Hyperplasia: Potential Phenotypic Biomarkers for Research on Treatment Strategies.

Objective: We present an MRI classification of benign prostatic hyperplasia (BPH) for use as a phenotype biomarker in the study of proposed therapeutic interventions.

Conclusion: Six patterns of BPH distribution were identified. Illustrations are provided for each classification type.

Imaging of non-neoplastic intratesticular masses.

The use of high-frequency ultrasound is increasing for the treatment of cystic, vascular, and solid non-neoplastic intratesticular masses. Cystic lesions examined include simple testicular cysts, tunica albuginea cysts, epidermoid cysts, tubular ectasia of rete testis, and intratesticular abscesses. Vascular lesions examined include intratesticular varicocele and intratesticular arteriovenous malformations.

Benign prostatic hyperplasia: a review and ultrasound classification.

Benign prostatic hyperplasia (BPH) is reviewed, including definition,natural history, diagnosis, and brief discussion of clinical management. Transrectal ultrasound is used to demonstrate the gross anatomy and natural history of BPH and its role in diagnosis and treatment strategies. A potentially useful ultrasound classification of BPH based on the gross anatomic classification of Randall is illustrated.

Elevation of dipeptidylpeptidase iv activities in the prostate peripheral zone and prostatic secretions of men with prostate cancer: possible prostate cancer disease marker.

Purpose: Dipeptidylpeptidase IV (DPIV) is a multifunctional type II plasma membrane glycoprotein with serine-type exopeptidase activity that is secreted by the prostate and increased in prostate cancer. We determined whether changes in DPIV activities in prostatic tissue zones and expressed secretions were associated with the presence of cancer.

Materials And Methods: Expressed prostatic secretion (EPS), and biopsy of the transition (TZ) and peripheral (PZ) zones were collected from men undergoing ultrasound guided prostate biopsy.

Imaging of urethral disease: a pictorial review.

Retrograde urethrography and voiding cystourethrography are the modalities of choice for imaging the urethra. Cross-sectional imaging modalities, including ultrasonography, magnetic resonance (MR) imaging, and computed tomography, are useful for evaluating periurethral structures. Retrograde urethrography is the primary imaging modality for evaluating traumatic injuries and inflammatory and stricture diseases of the male urethra.