Carcinoma of the prostate gland: MR imaging with pelvic phased-array coils versus integrated endorectal--pelvic phased-array coils.

Abstract

The integrated endorectal PPA coil is better for evaluation of local prostatic cancer than is the PPA coil.

Combined magnetic resonance imaging and spectroscopic imaging approach to molecular imaging of prostate cancer

“…1) (25,26). On T2-weighted MRI, regions of prostate cancer demonstrate decreased signal intensity relative to normal peripheral zone tissue due to increased cell density and a loss of the prostatic ducts ( Fig.…”

“…1) (23,26). Currently, the prostate is best imaged using an endorectal coil combined with four external coils (pelvic phased array) (26). The use of the body coil for excitation and an endorectal coil/pelvic phased array coil system for signal reception allows for the acquisition of high-spatial-resolution images of the prostate as well as coverage to the bifurcation for assessment of pelvic lymph node and bone metastases within the same exam.…”

“…The use of T2-weighted fast spin echo imaging (27) and a pelvic phased-array incorporating an endorectal coil can markedly improve the evaluation of extracapsular extension (ECE: accuracy ϭ 81%; sensitivity ϭ 84%; and specificity ϭ 80%) and seminal vesicle invasion (SVI: accuracy ϭ 96%; sensitivity ϭ 83%; and specificity ϭ 98%), thereby improving the staging of prostatic cancer (26). However, the detection of extracapsular extension by MRI is becoming more difficult since men are being diagnosed at earlier stages of disease, and because the microscopic spread of cancer through the prostatic capsule cannot be directly seen on MR images (23).…”

“…Studies evaluating clinical data (DRE, PSA, and PSA density), systematic biopsy, TRUS, and MRI alone have so far shown disappointing results for tumor localization within the prostate (30 -33). High-resolution endorectal/pelvic phased array MRI has demonstrated good sensitivity (78%) but low specificity (55%) in tumor location due to a large number of false-positives (26). These false-positives can be attributed to factors other than cancer, including post-biopsy hemorrhage, prostatitis, and therapeutic effects, which cause low signal intensity on T2-weighted images similar to that of prostate cancer (33,34).…”

“…3) (26). However, the assessment of cancer spread through the prostatic capsule is more difficult (81% accuracy) (26) and is becoming even harder to assess as fewer men demonstrate gross cancer spread (directly visible on MRI) due to earlier cancer detection. In a recent study of 53 patients with earlystage prostate cancer, tumor volume estimates based on MRSI findings were combined with high-specificity MRI criteria (74) in order to assess the ability of combined MRI/MRSI to predict extracapsular cancer spread.…”