The Relationship Of Age And CT Imaging Anatomy Of The Inguinal Canal In Normal Male

1. Backgrounds and ObjectiveAn inguinal hernia is a protrusion of abdominal-cavity contents through the inguinal canal. There are two types of inguinal hernia, direct and indirect, which are defined by their relationship to the inferior epigastric vessels. The indirect hernia is the most common, and accounts for about 95%. The epidemiological data showed that the male is significantly more than female, and the elderly are more common than young and middle–aged in inguinal hernia. In the clinical, it is found that most elderly patients with inguinal hernia in one side, have a significantly widened inguinal canal in the opposite side, in which were filled with low density fat. With this background, the aims of this study are to explore the relationship between age and groin fat, through observation of inguinal canal CT value in different ages groups of male, situation of inguinal ligament and the inferior spermatic artery and spermatic cord, the broadening of the inguinal canal and inside composition changes associated with age, and to provide the possible medical evidence why the inguinal hernia has a high incidence in the elderly.2. Reasarch methods2.1.In this study, GE lightspeed 16 row CT or TOSHIBA Aquilion ONE 320 row CT scanners were used with 7.5 mm slice, and 7.5 mm layer spacing, 1.25 mm alignment, 512×512 matrix; 260 m A and 120 KV, pitch automatic matching; Scan range included bilateral inguinal region, window width with 300-350 Hu, window center with 3-50 Hu. CT value in groin in all cases measured on plain CT scan imaging. Image post-processing and reconstruction were made in AW4.3 workstation after scans.2.2.The imaging data of 913 male patients who had inguinal region CT scan in Qing Yuan people’s hospital were analyzed, including the CT value and CT imaging anatomy at the groin area. The change of surrounding structure and the morphology of inguinal canal and various anatomical structures were observed respectively in transverse, coronal and saggittal plane. The region of interest(ROI) were selected at the level of pubic bone nodule in the transverse plane for measuring the CT value and area of inguinal canal area in both left and right sides, which is drawing along the inside edge of the inguinal canal.2.3 Epi Data3.0 is adopted to establish the database, all data for double entry. SPSS 18.0 statistical package were used for Statistical analysis.3. Results3.1. Out of all 913 cases, 108 cases in group 1(11-30 years), whose CT average value of left and right inguinal canal are 29.9 Hu 31.34 Hu, respectively; 264 cases in group 2(31-50 years), whose CT average value of left and right inguinal canal are 17.72 Hu and 20.72 Hu, respectively; 319 cases in group 3(51-70 years), whose CT average value of left and right inguinal canal are 6.08 Hu and 9.61 Hu, respectively; 222 cases in group 4(71-92 years), whose CT average value of left and right inguinal canal are-4.91 Hu and 1.54 Hu, respectively.3.2. The CT value of fat is between-20 Hu and-80 Hu. In this study,-10 Hu is as a upper limit value of fat CT density, due to the measurement of the inguinal canal CT values which cannot be avoided Including some inguinal canal structure.The cases with fat density(under-10 Hu) of the left inguinal canal in group 1(11-30 years), group 2(31-50 years), group 3(51-70 years), and group 4(71-92 years) were 4/108, 18/264, 76/319, 80/222, respectively. The cases with fat density(under-10 Hu) of the right inguinal canal in group 1(11-30 years), group 2(31-50 years), group 3(51-70 years), and group 4(71-92 years) were 3/108, 19/264, 60/319, 68/222, respectively.3.3 The average area of left inguinal canal in group 1(11-30 years), group 2(31-50 years), group 3(51-70 years), and group 4(71-92 years) were 54.82mm2, 109.57mm2, 129.41mm2, 152.38mm2, respectively. The average area of right inguinal canal in group 1(11-30 years), group 2(31-50 years), group 3(51-70 years), and group 4(71-92 years) were 52.39mm2, 105.76mm2, 114.86mm2, 155.42mm2, respectively.4. ConclusionsThe male inguinal canal cross sectional area increases with the growth of the age, and the CT value show a downward trend. This is to say, the adipose tissue composition in inguinal canal is increased with the age increase in normal male, which resulting in decreased the density. The increases of fat content in the inguinal canal in older men lead to the wakening of the abdominal wall strength. There is a correlation between the anatomical structural changes and the incidence of inguinal hernia in elderly patients. The distribution of fat in the inguinal canal has a certain rule, which is of certain significance to the judgment of the fat in inguinal canal or inguinal hernia containing fat.