Magnetic Resonance Imaging Study On Normal Prostate,Benign Prostatic Hyperplasia And Prostatic Carcinoma

[Objective]1 .To quantitatively study the MRI volume parameters of normal prostate and central gland in different age and to establish the referent values of volume parameters for further study of benign prostatic hyperplasia.2.To quantitatively study the volume parameters of prostate and central gland in different age with benign prostatic hyperplasia and to analyze the relationship between the volume parameters and hyperplasia stages.3.To elucidate the manifestations and the values of MRI and dynamic MRI contrast scan in the diagnosis and differential diagnosis of normal prostate, benign prostatic hyperplasia and prostatic carcinoma.[Materials and Methods]1.MRI study on normal prostate: 30 normal male adults without any urogenital symptoms were included in our study.The subjects were divided into four groups according to their ages: group one(20-30years,n=5), group two(31-40years,n=9), group three(41-50years,n=5), group four(51-60years,n=11). The length, width and height of the prostate and central gland were measured in MRI. The volume, weight and the central gland to prostate proportion were calculated and compared in variousage groups. Meanwhile, the MRI manifestations of normal prostate were observed, and the contrast enhancement of central gland and peripheral zone were compared.2. MRI study on BPH: 25 patients with benign prostatic hyperplasia proved by pathology were studied. The subjects were divided into four groups according to their ages: group one(<60years,n = 6), group two(61-70years,n=8), group three(71-80years,n=9), group four(>81 years, n=2). The length, width and height of the prostate and central gland were measured in MRI. The volume and weight and the central gland to prostate proportion were calculated and compared in various age groups. At the same time, the subjects were divided into four groups according to clinic hyperplasia degrees, and the parameters were compared in various degree groups. Meanwhile, the MRI manifestions and the contrast enhancement of BPH were observed.3. MRI study on PC: 20 cases of prostatic carcinoma proved by pathology were retrospectively studied. The patients were divided into four stages according to Jewett and Whitmore stages.The signal intensity on dynamic contrast-enhancement were measured and time to signal intensity curve were painted. The characteristics in MRI plain and contrast enhancement scans of various stages were summerized.[Results]l.the correlateive study of various MRI volume parameters in different age group: the average width of normal prostate is 3.02±0.47cm, the average length is 4.19±0.52cm, the average height is 3.24±0.34cm, the volume is 22.01±7.48 cm3,and the weight is 23.11±7.86g. Except height, there were significant difference in the value of length, the width, the volume and the weight in various age groups(p=0.006,0.001,0.014 respectively), the width of central gland to normal prostate is 2.01±0.41cm, the length is 2.06±0.34cm, the height is 2.01±0.32cm, the volume is 4.46±1.74 cm3, the weight is 4.68±1.82g, the ratio of central gland volumto whole prostate volum is 20.4%. The volume and weight of central gland was significantly different in various age groups.2.the comparative study of contrast enhancement between central gland and peripheral zone: Using paired t-test statictical method, there were significantly difference between them(p=0.0001), and the enhancement of central gland was higher than that of peripheral zone.3. The correlative study of various MRI volume parameters of BPH in different age and hyperplasia degree: the width, length, height, volume and weight of prostate in BPH were larger than those in normal prostate. There was significant difference in height between various ages groups, however, there were not significant difference in the other parameters. The central gland to prostate proportion in BPH is 46.1%, which is much larger than the normal prostate. The width, length, height, volume and weight of prostate and central gland were significantly different in various hyperplasia degree groups(P<0.001). There was not significantly difference in the width, length, height, volume, weight of prostate between the degree I hyperplasia and the normal group.4. the MRI manifestations of BPH:A11 the 25 patients with BPH developed in central gland , and one case complicated with peripheral zone. The volume of prostate was increase, mainly in the central gland, with heterogeneous singal intensify. The hyperplastic nodules showed high, middle, or low singal intensify in T2WI with slight enhancement after Gd-DTPA injection.5.The manifestation of dynamic MRI contrast-enhanced of PC: The peak enhancement in 8 patients of PC in early stage, 1 in the middle stage, two cases presented gradually enhancement, and 1 case didn't show enhancement. Time-singal intensity curve showed that the signal intensity of carcinomaincreased rapidly, and then decreased gradually. The singal intensity of CG was increased slowly, and the peak value located in middle and late phase. The PZ was enhanced slowly and slightly. [Conclusions]normal prostate1. Except height, there were significant difference in the value of length, width, volume and the weight in various age groups(P<0. 05). With the ages increased, the prostate volume was enlarged. There were not significant difference in the value of length, width, height of central gland in different ages groups, but there were significant differences in the volume and weight of the central gland. The volum of the central gland is positive correlation with the ages.2.MR1 can clearly show the inside structure of the prostate, especially in T2WI. It can distinguish the central gland, the peripheral zone and the anterior fibromuscular stroma, that is very close to the normal prostate anatomy.3.the central gland and the peripheral zone showed different enhancement in the contrast scan, the enhancement of central gland was higher than that of peripheral zone. The T1WI contrast scan is superior to T1WI in zonal description of prostate anatomy. BPH1. The width, length, height, volume and weight of hyperplastic prostate are larger than those of the normal prostate. The hyperplastic degree in the volume of prostate and the peripheral zone became worse along with the age older, especially after 70 years.2. The parameters were not significantly different between the first degree hyperplasia and the normal group, the prostate size can be normal or little big in earlybenign prostatic hyperplasia, but MRI can show abnormal signal intensity of central gland which can not be found by DRE. There were significantly different in normal group and other hyperplasia groups.3.Most of benign prostatic hyperplasia occurred in the transition zone, so the central gland demonstrated enlargment in MRI. The ratio of central gland volum to whole prostate volum could be a target to estimate whether or not there is prostate hyperplasia and the degree.4.The benign prostatic hyperplasia nodules showed different signal intensity because of different tissue elements. They showed high, middle, or low signal intensity on T2WI.The central gland often demonstrated heterogenous enhancement after contrast scan. But the hyperplasia nodules demonstrated light enhancement, between the enhancement of central gland and the peripheral zone.PC1 .MRI was helpful in the location, extent, stage and choice to the therapy plan of the prostatic carcinoma. The contrast scan have some values in the differentation of BPH and PC.2.The signal intensity of carcinoma increased rapidly, and then decreased gradually in dynamic contrast scan. MRI dynamic contrast scan was helpful in evaluating the vascular structures of the lesions. So it is one of the most reliable and effective modality to evaluate the theraputic effect of prostate carcinoma.