The Value Of Bold-fMRI In Prostatic Disease And Preliminary Study Of Histologic Basis

Objective The different signal intensity-time curve (SI-TC) changes in normalprostate central zone tissue (CZ), peripheral zone tissue (PZ), benign prostatichyperplasia (BPH) and prostate cancer (PCa) using blood oxygen level-dependent(BOLD) induced by carbogen (95%O2/5%CO2) breathing were analyzed. Theobjectives of this study were (1) to explore the value of BOLD-fMRI in diagnosisand differential diagnosis in prostatic disease by comparing the average increasedsignal value and relative increase signal average rate of different tissue;(2) to explorethe relationship between relative increase signal average rate and different agegroups;(3) to analyze micro-vessels within BPH and PCa tissue for exploring thehistological basis of prostate BOLD-fMRI.Materials and Methods BOLD-fMRI was performed using a3.0Teslasuperconducting magnetic scanner (GE) equipped with a pelvic phased-arraymulti-coil in32healthy volunteers,35benign prostatic hyperplasia and24prostatecancer cases which proved by histopathology. BOLD imaging (T2*EPI sequence,15slices,4.0mm thickness) were acquired during5×1minute episodes alternatingbetween room air and carbogen (95%O2/5%CO2) breathing. All data weretransferred to GE Advantage Workstation and different regions of interests (ROI) ofCZ, PZ, BPH and PCa were drawn by a radiologist and then the signal intensity-timecurve (SI-TC) generated. The obturator internus were selected as internal references.The average signal value before/after carbogen breathing, the average increased signal value and relative increase signal average rate were computed. All data wereprocessed using SPSS17.0. The relative increase signal average rates of different agegroups were compared. The healthy volunteers were divided into three groupsaccording to the age: under30years old,30-50years old and above50years old.And MVD of tissue samples in BPH and PCa were counted. The ROC was draw tocompute the diagnosis sensitivity and specificity of BPH and PCa.Results The signal intensity of CZ, PZ, BPH and PCa during carbogen breathingwere higher than air breathing (P<0.05). The average increased signal value of CZ,PZ, BPH and PCa were51.83±11.81,40.84±12.17,64.34±15.73and24.02±8.58respectively, and the relative increase signal average rate of CZ, PZ, BPH and PCawere5.07±1.08%,2.78±1.13%,6.44±2.02%and1.77±0.40%respectively. Therewas statistical significance between every two groups. The relative increase signalaverage rate of CZ under30years old was higher than that of above50years old(P<0.05). The relative increase signal average rate of PZ under30years old washigher than that of between30-50years old, and that of above50years old (P<0.05).There was no apparent correlation with age in BPH and PCa (P>0.05). The bestdiagnosis threshold of relative increase signal average rate was2.36%in PCa, andthat in BPH was4.35%. The sensitivity and specificity were100%,62.5%and97.7%,39.1%in PCa and BPH respectively. The number of MVD of BPH and PCawas25.82±1.47and64.61±7.19respectively. The number of MVD of PCa washigher than that of BPH (P<0.05).Conclusion BOLD-fMRI during carbogen breathing contributes to the diagnosisand differential diagnosis of BPH and PCa. The relative increase signal average ratehas high sensitivity, but low specificity. BOLD-fMRI can reflect the signal change ofnormal prostate which may provide a new method to study the mechanism ofprostate disease. BOLD-fMRI can evaluate the conditions of micro-vessels in BPHand PCa.