Steven C. Eberhardt

Urinary Continence After Radical Retropubic Prostatectomy: Relationship with Membranous Urethral Length on Preoperative Endorectal Magnetic Resonance Imaging

PURPOSE We determined whether membranous urethral length on preoperative magnetic resonance imaging (MRI) is predictive of urinary continence after radical retropubic prostatectomy. MATERIALS AND METHODS Membranous urethral length was measured on preoperative endorectal MRI in 211 consecutive patients with newly diagnosed prostate cancer before radical retropubic prostatectomy performed by a single surgeon. Neurovascular bundle resection was done in 60 cases. After surgery the time to stable postoperative continence was recorded in 180 cases and the level of stable continence was graded on a 5-point scale of 1-complete continence to 5-complete incontinence. RESULTS After controlling for age and surgical technique multivariate analysis showed that membranous urethral length was related to time to stable postoperative continence (p = 0.02), such that a longer membranous urethra was associated with a shorter time to stable continence. For example, 1 year after surgery 120 of the 134 patients (89%) with a preoperative membranous urethral length of greater than 12 mm. were completely continent compared with 35 of the 46 (77%) with a preoperative length of 12 mm. or less. CONCLUSIONS On endorectal MRI before radical prostatectomy a longer membranous urethra is associated with significantly more rapid return of urinary continence after surgery.

Prostate Magnetic Resonance Imaging and Magnetic Resonance Imaging Targeted Biopsy in Patients with a Prior Negative Biopsy: A Consensus Statement by AUA and SAR

PURPOSE After an initial negative biopsy there is an ongoing need for strategies to improve patient selection for repeat biopsy as well as the diagnostic yield from repeat biopsies. MATERIALS AND METHODS As a collaborative initiative of the AUA (American Urological Association) and SAR (Society of Abdominal Radiology) Prostate Cancer Disease Focused Panel, an expert panel of urologists and radiologists conducted a literature review and formed consensus statements regarding the role of prostate magnetic resonance imaging and magnetic resonance imaging targeted biopsy in patients with a negative biopsy, which are summarized in this review. RESULTS The panel recognizes that many options exist for men with a previously negative biopsy. If a biopsy is recommended, prostate magnetic resonance imaging and subsequent magnetic resonance imaging targeted cores appear to facilitate the detection of clinically significant disease over standardized repeat biopsy. Thus, when high quality prostate magnetic resonance imaging is available, it should be strongly considered for any patient with a prior negative biopsy who has persistent clinical suspicion for prostate cancer and who is under evaluation for a possible repeat biopsy. The decision of whether to perform magnetic resonance imaging in this setting must also take into account the results of any other biomarkers and the cost of the examination, as well as the availability of high quality prostate magnetic resonance imaging interpretation. If magnetic resonance imaging is done, it should be performed, interpreted and reported in accordance with PI-RADS version 2 (v2) guidelines. Experience of the reporting radiologist and biopsy operator are required to achieve optimal results and practices integrating prostate magnetic resonance imaging into patient care are advised to implement quality assurance programs to monitor targeted biopsy results. CONCLUSIONS Patients receiving a PI-RADS assessment category of 3 to 5 warrant repeat biopsy with image guided targeting. While transrectal ultrasound guided magnetic resonance imaging fusion or in-bore magnetic resonance imaging targeting may be valuable for more reliable targeting, especially for lesions that are small or in difficult locations, in the absence of such targeting technologies cognitive (visual) targeting remains a reasonable approach in skilled hands. At least 2 targeted cores should be obtained from each magnetic resonance imaging defined target. Given the number of studies showing a proportion of missed clinically significant cancers by magnetic resonance imaging targeted cores, a case specific decision must be made whether to also perform concurrent systematic sampling. However, performing solely targeted biopsy should only be considered once quality assurance efforts have validated the performance of prostate magnetic resonance imaging interpretations with results consistent with the published literature. In patients with negative or low suspicion magnetic resonance imaging (PI-RADS assessment category of 1 or 2, respectively), other ancillary markers (ie PSA, PSAD, PSAV, PCA3, PHI, 4K) may be of value in identifying patients warranting repeat systematic biopsy, although further data are needed on this topic. If a repeat biopsy is deferred on the basis of magnetic resonance imaging findings, then continued clinical and laboratory followup is advised and consideration should be given to incorporating repeat magnetic resonance imaging in this diagnostic surveillance regimen.

Advances in Imaging in the Postoperative Patient with a Rising Prostate-Specific Antigen Level

Imaging prostate cancer continues to represent a clinical challenge for both primary and recurrent disease. In the evaluation of the persistent/recurrent/metastatic prostate cancer, knowledge of cancer location (local v distant), size, and extent are essential in order to design a treatment, tailored to each patients needs. There are evidence-based guidelines for the use of imaging in assessing the presence of distant spread of prostate cancer. Radionuclide bone scans and computed tomography (CT), magnetic resonance imaging (MRI), and/or positron emission tomography (PET) supplement clinical and biochemical evaluations (prostate-specific antigen [PSA]) for suspected metastatic disease to bones and lymph nodes. There is no consensus about the use of imaging in the evaluation of local tumor recurrence. The use of ultrasound has been limited to biopsy guidance of the prostatic bed, or percutaneous biopsy of enlarged lymph nodes detected on CT or MRI. The use of MRI is evolving. Recent studies indicate that the use of MRI provides valuable information in the evaluation of local tumor recurrence, and nodal and bony metastases. In a patient post-radiation therapy, the method of combining MRI anatomic information with MR spectroscopic metabolic information is evolving. Another modality offering information about anatomy and metabolism of the local disease is PET/CT. The value of PET/CT at present is controversial, but new studies exploring the role of PET/CT in aggressive prostate cancer are promising.

ACR Appropriateness Criteria prostate cancer--pretreatment detection, staging, and surveillance.

Prostate cancer is the most common noncutaneous male malignancy in the United States. The use of serum prostate-specific antigen as a screening tool is complicated by a significant fraction of nonlethal cancers diagnosed by biopsy. Ultrasound is used predominately as a biopsy guidance tool. Combined rectal examination, prostate-specific antigen testing, and histology from ultrasound-guided biopsy provide risk stratification for locally advanced and metastatic disease. Imaging in low-risk patients is unlikely to guide management for patients electing up-front treatment. MRI, CT, and bone scans are appropriate in intermediate-risk to high-risk patients to better assess the extent of disease, guide therapy decisions, and predict outcomes. MRI (particularly with an endorectal coil and multiparametric functional imaging) provides the best imaging for cancer detection and staging. There may be a role for prostate MRI in the context of active surveillance for low-risk patients and in cancer detection for undiagnosed clinically suspected cancer after negative biopsy results. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Blood loss during radical retropubic prostatectomy: relationship to morphologic features on preoperative endorectal magnetic resonance imaging

OBJECTIVES To determine whether morphologic features at preoperative magnetic resonance imaging (MRI) are related to intraoperative blood loss during radical retropubic prostatectomy. METHODS Endorectal MRI was performed in 143 patients with newly diagnosed prostate cancer before radical retropubic prostatectomy. Two independent readers rated the prominence of the periprostatic veins (on the basis of number and size) at four anatomic sites on a 3-point scale. Other features analyzed were prostate volume and interspinous diameter. RESULTS A prominence of the anterior and posterior apical periprostatic veins was positively associated with blood loss (correlation coefficient = 0.22 and 0.17 and P <0.01 and <0.05, respectively). Blood loss was not related to prostate volume (correlation coefficient = 0.02, P = 0.8) or interspinous diameter (correlation coefficient = 0.01, P = 0.9). The site-specific scores of both readers demonstrated positive agreement, with Pearsons correlation coefficients of 0.51 to 0.65 (P <0.01). CONCLUSIONS A marked prominence of the apical periprostatic veins on preoperative MRI is associated with greater intraoperative blood loss during radical retropubic prostatectomy. Other morphologic factors appear unrelated to the amount of intraoperative blood loss.

Iron-Based Superparamagnetic Nanoparticle Contrast Agents for MRI of Infection and Inflammation

OBJECTIVE. In this article, we summarize the progress to date on the use of superparamagnetic iron oxide nanoparticles (SPIONs) as contrast agents for MRI of inflammatory processes. CONCLUSION. Phagocytosis by macrophages of injected SPIONs results in a prolonged shortening of both T2 and T2* leading to hypointensity of macrophage-infiltrated tissues in contrast-enhanced MR images. SPIONs as contrast agents are therefore useful for the in vivo MRI detection of macrophage infiltration, and there is substantial research and clinical interest in the use of SPION-based contrast agents for MRI of infection and inflammation. This technique has been used to identify active infection in patients with septic arthritis and osteomyelitis; importantly, the MRI signal intensity of the tissue has been found to return to its unenhanced value on successful treatment of the infection. In SPION contrast-enhanced MRI of vascular inflammation, animal studies have shown decreased macrophage uptake in atherosclerotic plaques after treatment with statin drugs. Human studies have shown that both coronary and carotid plaques that take up SPIONs are more prone to rupture and that abdominal aneurysms with increased SPION uptake are more likely to grow. Studies of patients with multiple sclerosis suggest that MRI using SPIONs may have increased sensitivity over gadolinium for plaque detection. Finally, SPIONs have enabled the tracking and imaging of transplanted stem cells in a recipient host.

An Exploratory Study of Endorectal Magnetic Resonance Imaging and Spectroscopy of the Prostate as Preoperative Predictive Biomarkers of Biochemical Relapse After Radical Prostatectomy

PURPOSE Radical prostatectomy has significant side effects. Preoperative information predicting its long-term outcome would be valuable to patients and physicians. We determined whether pretreatment endorectal magnetic resonance imaging/magnetic resonance spectroscopic imaging predicts biochemical recurrence after radical prostatectomy. MATERIALS AND METHODS Of 202 patients who underwent endorectal magnetic resonance imaging/magnetic resonance spectroscopic imaging from January 2000 to December 2002 before radical prostatectomy 130 satisfied study inclusion criteria and were included in analysis. We compared imaging factors with potential predictive capability to biochemical recurrence data, including magnetic resonance imaging risk score based on local disease extent and magnetic resonance spectroscopic imaging index lesion characteristics, such as the number of voxels and degree of metabolic abnormality (magnetic resonance spectroscopic imaging grade). We evaluated associations of these imaging variables with time to biochemical recurrence by Cox proportional hazards regression adjusted for known predictors of biochemical recurrence, such as stage, grade and prostate specific antigen. RESULTS At a median 68-month followup there were 26 biochemical failures. Risk score, lesion volume and high grade voxels each correlated with time to biochemical recurrence. In a model combining clinical parameters risk score, lesion volume and at least 1 high grade voxel the magnetic resonance spectroscopic imaging variables remained significant but the magnetic resonance imaging score dropped out. CONCLUSIONS Index lesion volume on magnetic resonance spectroscopic imaging and high grade magnetic resonance spectroscopic imaging voxels correlate with time to biochemical recurrence after radical prostatectomy even when adjusted for clinical data. Results suggest the preoperative predictive usefulness of endorectal magnetic resonance imaging/magnetic resonance spectroscopic imaging in patients considering radical prostatectomy.

Radiology of epiploic appendages: acute appendagitis, post-infarcted appendages, and imaging natural history

Our aim was to demonstrate the imaging characteristics of epiploic appendages in native, acute inflamed/ischemic and post-infarcted states through retrospective imaging analysis, with clinical and pathologic correlation, and to discuss clinical implications. Cases were gathered mostly retrospectively and reviewed for inclusion based on established diagnostic criteria. Radiology report text search was used to find cases, using terms “epiploic,” “appendage,” “appendagitis,” and “peritoneal body.” Data records included patient demographics, relevant clinical data, lesion size, location and apparent imaging composition, and the presence of change or stability in features over multiple studies. Pathologic and clinical data were sought and assessed for correlation. Imaging studies of 198 individuals were included (mean age 50, range 9–95), with a total of 228 lesions: 63 acute and 165 non-acute presentations. All included subjects had CT imaging and some had lesions visible on radiographs, MRI, PET/CT, and sonography. 23 subjects had more than one studied lesion. In addition to classic acute appendagitis, more frequently encountered are post-infarcted appendages either in situ along the colon, adhered to peritoneal or serosal surfaces, or freely mobile in the peritoneum as loose bodies. The majority of the non-acute varieties are recognizable due to peripheral calcification that develops over time following ischemic insult. Multiple cases demonstrated the imaging natural history and confirmed pathologic basis for imaging findings. In summary, acute and post-infarcted epiploic appendages have characteristic imaging appearances and natural history which should provide correct diagnosis in most cases. Incidental post-infarcted epiploica are more commonly encountered than acute presentations.

Quantitative mapping of total choline in healthy human breast using proton echo planar spectroscopic imaging (PEPSI) at 3 Tesla

To quantitatively measure tCho levels in healthy breasts using Proton‐Echo‐Planar‐Spectroscopic‐Imaging (PEPSI).

The Current State of MR Imaging–targeted Biopsy Techniques for Detection of Prostate Cancer

Systematic transrectal ultrasonography (US)-guided biopsy is the standard approach for histopathologic diagnosis of prostate cancer. However, this technique has multiple limitations because of its inability to accurately visualize and target prostate lesions. Multiparametric magnetic resonance (MR) imaging of the prostate is more reliably able to localize significant prostate cancer. Targeted prostate biopsy by using MR imaging may thus help to reduce false-negative results and improve risk assessment. Several commercial devices are now available for targeted prostate biopsy, including in-gantry MR imaging-targeted biopsy and real-time transrectal US-MR imaging fusion biopsy systems. This article reviews the current status of MR imaging-targeted biopsy platforms, including technical considerations, as well as advantages and challenges of each technique.