50 years old).DWI was done on a 1.5-T system using single-shot diffusion-weighted echo-planar imaging(b-values = 0,300,500 and 800 s/mm~2).ADC maps were calculated using the manufacturer's software.ROIs placed on peripheral zone contained,average,thirty pixels.Results When b-value was 300 s/mm~2,the ADC of peripheral zone in junior,middle-age and senior group were(2.03?0.29)?10~(-3) mm~2/s,(2.37?0.33)?10~(-3) mm~2/s,(2.75?0.29)?10~(-3) mm~2/s,respectively,and statistically significant different(F=36.66,P

0.05) except the patient’s age(P=0.00).Conclusion Follow-up of patients with non-tumoral lesions in prostate gland with MR imaging usually does not give useful informations in addition to the first MR examination.

Objective To evaluate three-dimensional reconstruction of MRI images in diagnosis and therapy of prostate cancer. Methods Twenty-eight patients with proven prostate cancers were recruited in this study. Seventeen of them were diagnosed as having prostate cancer according to the ultrasound guided systemic biopsy. Their MR examinations showed fourteen lesions in the peripheral zone and three in the central gland of the prostate. The other eleven patients underwent MR examination after a period of treatment, including endocrinetherapy and brachytherapy. Using endorectal coil, a series of T2-weighted images were acquired on the axial plane. These source images were processed by 3D-Doctor software to reconstruct into three-dimensional images. Results In the fourteen patients with peripheral zone cancer, reconstruction images could display the 3D regions of cancer and the involvement of capsular. The outspread of central gland and the compression of peripheral zone in patients with central gland cancer could be revealed in the same way. The volumetric changes of the lesion and the prostate after endocrinetherapy could also be perceived through these 3D images. Similarly, radioactive seeds were revealed in a spatial manner that could be easily evaluated. Conclusion Three-dimensional reconstruction images were obtained in all patients. They were able to provide stereotyped information about the lesions and their surrounding tissues. MRI three-dimensional reconstruction can be an adjunctive tool in the evaluation of prostate lesions.

Objective:To evaluate the variation of clinical data and referred purpose of prostate magnetic resonance(MR) examination in the past 12 years in Peking University First Hospital.Methods:One thousand and sixty-six patients underwent prostate MR examination(1 296 exams) from May 1992 to Sept.2004.The clinical data of the patients were retrospectively analyzed.The number of patients was counted and three groups were classified(diagnosing group,staging group and follow-up group) according to the purpose of prostate MR examination per year.For the diagnosing group, the clinical data of patient's age,symptom,level of serum prostate specific antigen(PSA),and the result of ultrasound or digital rectal examination(DRE) were evaluated.Results:(1)The number of patients increased year by year in the past 12 years,and the majority of the increased patients required differential diagnosis.(2) Diagnosing group: the percentage of patients with the symptom of BPH increased year by year.The average level of serum PSA dropped and the percentage of patients with elevated PSA or with nodules detected by ultrasound or DRE referred for detection of prostate cancer or with the symptom of metastasis decreased.Conclusion:With the widespread screening of prostate cancer,more patients of early prostate carcinoma and non-tumoral lesion in prostate gland are examined by MR imaging.

Objective To quantitatively analyze the ADC values of different types of benign prostatic hyperplasia(BPH) comparatively with ADC values of prostatic carcinoma(Pca).Methods Seventeen cases of BPH(mean age 69.1 years?4.3 years,ranged from 62 to 77 years) underwent transurethral resection of prostate(TURP) were scanned with the sequence of DWI.DWI(b-values = 0 s/mm2and 800 s/mm2) was performed at 1.5-T system.The hyperplasia tissues resected from central gland were divided into two types pathologically: glandular BPH and stromal BPH.According to the pathological results,ROIs were placed on central gland and the ADC values of two types of BPH were measured.In addition,fifteen patients with biopsy-proved Pca were evaluated and the ADC values of Pca regions were measured.Results The mean ADC values of glandular BPH,stromal BPH and Pca were(1.80?0.20)?10-3 mm2/s,(1.56?0.18)?10-3 mm2/s and(1.27?0.21)?10-3 mm2/s,respectively.Statistically significant difference(F=47.366,P

Objective To investigate the changes of apparent diffusion coefficient(ADC) values after endocrinotherapy in cancerous and noncancerous regions of prostate peripheral zone.Methods 28 patients with prostate cancer proved by pathology were retrospectively evaluated in this study.The prostate peripheral zone was divided into two regions(cancerous and noncancerous regions).All patients were examined by single-shot diffusion-weighted echo-planar imaging before and after 3~6 months endocrinotherapy.ADC values of noncancerous and cancerous regions in peripheral zone were calculated and statistical analysis was performed on the data by applying either paired or independent t-test.Results Before treatment, the average ADC values in noncancerous ( n=107 ) and cancerous ( n=61 ) regions were (2.21?0.61)?10-3 mm2/s and (1.65?0.46)?10-3mm2/s, respectively, and statistic significant difference could be detected between them (t=4.36, P=0.039, independent t-test). After 3~6 months treatment, the ADC values in noncancerous and cancerous regions decreased to(1.33?0.48)?10-3 mm2/s and (1.28?0.53)?10-3mm2/s, respectively, significantly lower than those before treatment(t=5.28, P=0.024 and t=7.39, P=0.015, paired t-test),but no significant difference between noncancerous and cancerous regions was detected after endocrinotherapy (t=0.58, P=0.639, independent t-test). Conclusion After endocrinotherapy, the ADC value of cancerous and noncancerous prostate tissues both decreased. This change was more significant in noncancerous tissue and the difference of ADC values between them diminished after endocrinotherapy.

0.05,Friedman Test).When b-value increased from 300 s/mm2 up to 500 s/mm2 and 800 s/mm2,the decreased rates of ADC value were 14% and 21% respectively in carcinous regions,5% and 11% respectively in non-carcinous regions respectively.Conclusion The ADC values are different when b-values changed in both prostatic non-carcinous and carcinous regions,but the difference of ADC between the non-carcinous and carcinous tissues seems to be stable in spite of the change of b-value(range 300-800 s/mm2).

40 years, old group) without prostate diseases, underwent MRI and MRS examinations. The peripheral zone (PZ) and central gland (CG) of the prostate were distinctly demonstrated on MRI, the right and left side of PZ and CG were divided into bottom, middle and tip regions,totally 12 samples were obtained from each case. The levels of (Cho+Cre)/Cit ratios were calculated on the basis of the MRS metabolic map. Results ①The mean level of (Cho+Cre)/Cit ratios in PZs and CGs of different regions in young group and old group was not significantly different. Statistically significant variation of the (Cho+Cre)/Cit ratio in PZs and CGs in the two groups was detected. ②The mean level of (Cho+Cre)/Cit ratios of PZs between young group and old group was not significantly different. Only Statistically significant variation of (Cho+Cre)/Cit ratios in CGs between two groups was detected. Conclusion The normal levels of prostatic metabolites fluctuate dramatically among individuals. There is metabolic difference between the peripheral and central zone and that of young and old group.

Objective To investigate MRI characteristics of recurrent prostate cancer after endocrinotherapy.Methods Recurrent prostate cancer after endocrinotherapy was diagnosed clinically in 10 cases.MRI examinations were performed before and after recurrence of tumors.T_2 signal intensity and morphological changes of the prostate,involvement of pelvic tissues,metastasis of bone and lymph metastasiswere analyzed.Results The prostates enlarged in 7 patients after recurrence and maintained the same size in the other three.The pelvictissues,including seminal vesicle,bladder,rectal and obturator internus,were involved in 7 patients after recurrence.Metastasis of bone and lymph node progressed in 7 and 9 patients,respectively,but T_2 signal differences were unremarkable between recurrent regions and otherregions.Conclusion MRI examination can provide sufficient radiologic information in the diagnosis of recurrence of prostate cancer afterendocrinotherapy.

Objective To evaluate the diagnostic efficacy of MRS in prostate cancer based on sextant localization. Methods There were 110 patients, 54 patients with pathologically confirmed prostate cancer and 56 patients confirmed non-prostate cancer proved by ultrasound guided systemic biopsy. The (choline + creatine)/citrate (CC/C) value in each voxel and ratio of positive voxel (PVR) in sextant localization were measured. The ROC analysis was used to evaluate the diagnostic efficacy of CC/C in single voxel and PVR in sextant localization. Results There are 1673 and 2426 voxel in prostate cancer and non-prostate cancer respectively. The median of CC/C in cancer sextants was 2. 137; the median of CC/C in noncancer sextants was 0. 600. The difference of these two groups was statistically significant (Z = -41.7, P < 0. 01 ). The diagnostic sensitivity was 81.4% ( 1362/1673 ), the specificity was 83.1% (2018/2426), and the accuracy was 82.4% [ (1362+2018)/4099] for prostatic cancer with the cutoff point 0. 911 of the CC/C value. The median of PVR in cancer sextants and noncancer sextants were 1 and 0 respectively, the difference of PVR was statistically significant (Z = -11.7,P < 0.01 ). The diagnostic sensitivity was 77. 5% (148/191), the specificity was 76. 9% (247/321), and the accuracy was 77. 1% [ ( 148 + 247 )/ 512] for prostatic cancer with the cutoff point 0. 519 of the PVR. Conclusion Detecting the cutoff point of the CC/C value in single voxel and the PVR in sextant localization may be valuable in the diagnosis of prostate cancer.