Magnetic Resonance Imaging Measure On Prostate

Objectiv:1.To measure the MRI volume datum of normal prostate and central gland and peripheral zone in different age and to establish the referent values of volume datum for further study of benign prostatic hyperplasia.2.To measure the volume datum of prostate and central gland and peripheral zone in different age with benign prostatic hyperplasia and to analyze the relationship between the volume datum and hyperplasia stages.3.To measure the T2 signal intensity of normal prostatic peripheral zone in different age and to evaluate the correlation between signal intensity and age .Materials and Methods:1.MRI study on normal prostate : 217 normal male adults without any urogenital symptoms were included in our study . The subjects were divided into seven groups according to their ages: group one (20-29years, n=22) , group two (30-39years,n=29) , group three (40-49years,n=47) ,group four (50-59years,n=45) , group five (60-69years,n=37) , group six (70-79years,n=22) , group seven (80yearsand more ,n=15) .The length ,width , height and area of the prostate and central gland were measured in MRI. the width and area of perpheral zone were measure in MRI.The volume and the peripheral zone to prostate proportion were calculated and compared in various age groups . Meanwhile, the MRI manifestations of normal prostate were observed.2. MRI study on BPH : 78 male adults with some urogenital symptoms were included in our study .The subjects were divided into five groups according to their ages: group one (40-49years,n=13), group two (50-59years,n=17), group three (60-69years,n=25) , group four(70-79years,n=15) , group five (80years and more ,n=8) . The length ,width , height and area of the prostate and central gland were measured in MRI. the width and area of perpheral zone were measured in MRI.The volume and the peripheral zone 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 datum were compared in various degree groups. Meanwhile, the MRI manifestions of BPH were observed.3.MRI study on normal prostate : 217 normal male adults without any urogenital symptoms were included in our study . The subjects were divided into seven groups according to their ages:(same 1).The T2 signal intensity of prostatic peripheral zone, gluteus and obturator internus were measured in MRI.The gluteus and obturator internus to the peripheral zone proportion were calculated and compared in various age groups .Results:1. The correlative study of various MRI volume datum in different age group: the average length of normal prostate is 4.15±0.48cm,the average width is 2.66±0.49cm, the average height is 2.53±0.43cm,and the average volume is 25.49±8.33cm3. There were significant difference in the value of length,the width,the height,and the volume in various age groups(p<0.000). the average length of central gland is 2.48c±0.45cm,the average width is 1.98±0.36cm, the average height is 2.04±0.33cm, and the average volume is 12.37±3.03cm3, There were significant difference in the value of length,the width , the height,and the volume in various age groups(p<0.000). the average left width of prostatic peripheral zone is 1.15±0.25cm,the average right width is 1.16±0.23cm, and the average volume is 14.14±4.10cm3. There were significant difference in the value of left width , the right width,and the volume in various age groups(p<0.000). the ratio of prostatic peripheral zone volume to whole prostate volume is 55.92±0.07%. the ratio of prostatic peripheral zone volume to whole prostate volume was significantly different in various age groups(P=0.000).2.The ratio of obturator internus and gluteus T2 signal intensity to prostatic peripheral zone T2 signal intensity is 4.97±1.33,2.80±0.68 respectively.T2 signal intensity of the peripheral zone increased with age and then decreased, Most of T2 signal intensity of peripheral zone are homogeneous.3.The thickness of the prostatic capsule is not even on the prostate surface of different places. The prostate capsule is thick at the back and two sides,thin at the body ,weak at the base,there is no obvious capsule at the bladder neck and the place where the seminal vesicle links the prostate. At the prostate apex, there is a defect in the capsule anteriorly .4.The correlative study of various MRI volume datum of BPH in different age and hyperplasia degree: the average length of prostate with BPH is 4.95±0.56cm,the average width is 3.30±0.81cm, the average height is 3.06±0.77cm,and the average volume is 42.44±22.78cm~3. the average length of central gland with BPH is 3.28±0.83cm,the average width is 2.62±0.70cm, the average height is 2.63±0.72cm, and the average volume is 24.21±17.78cm3. The length, width, height, and volume of prostate and central gland with BPH were large than those of normal prostate and central gland.There was significant difference in the width ,length, height, and volume between various ages groups(P<0.000). the average left width of prostatic peripheral zone with BPH is 1.18±0.28cm,the average right width is 1.17±0.31cm, and the average volume is 18.28±6.44 cm~3. There were significant difference in the value of left width , the right width,and the volume in various age groups(p=0.003,0.002,0.009 respectively). the ratio of prostatic peripheral zone volume to whole prostate volume is 46.40±10.25%. the ratio of prostatic peripheral zone volume to whole prostate volume was significantly different in various age groups(P=0.000).The width, length, height, and volume 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 of prostate between the degreeⅠhyperplasia and the normal group.5.The MRI manifestation of BPH: All the 78 patients with BPH developed in central gland. 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 .Conclusions:1,Normal prostate:1.1,There were significant difference in the value of length, width, height,and volume in various age groups(P<0.000).Positive correlation was found between the prostate volume and age ( r = 0. 695 , P < 0. 001). There were also significant differences in the value of length ,width ,height and volume of the central gland in various age groups(P<0.000).The volume of the central gland is positive correlation with the ages( r = 0. 796 , P < 0. 001). There were also significant differences in the value of prostatic peripheral zone volume in various age groups(P<0.000).The volume of the peripheral zone is negative correlation with the ages( r =-0.621 , P = 0. 000).1.2,MRI 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 .1.3,The peripheral zone enlarged with age and then became thin .T2 signal intensity of the peripheral zone increased with age and then decreased. 1.4,The thickness of the prostatic capsule is not even on the prostate surface of different places. The prostatic capsule is discontinuous.2,Begin prostate hyperplasia:2.1,The width ,length ,height and volume of hyperplastic prostate are larger than those of normal prostate. The hyperplastic degree in the volume of prostate and the central gland became worse along with the age older,especially after 70 years.2.2,The datum were not significantly different between theⅠdegree hyperplasia and the normal group ,the prostate size can be normal or little big in early begin prostate 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.2.3,Most of benign prostatic hyperplasia occurred in the transition zone ,so the central gland demonstrated enlargment in MRI .The ratio of central gland volume to whole prostate volume could de a target to estimate whether or not there is prostate hyperplasia and the degree.2.4,The benign prostate hyperplasia nodules showed different signal intensity because of different tissue elements. They showed high ,middle, or low signal intensity on T2WI. The width of peripheral zone became thin even may disappear,and the singal intensity of peripheral zone may decreased.