Pancreatic Consistency and Hounsfield Unit on CT Scan in Mature (65+) Subjects
Yuichi Kitagawa*
Surgery, National Center for Geriatrics and Gerontology, Obu, Japan
Introduction: Consistency of the pancreas is one of the most important prognostic factors for pancreatic anastomosis. However, pancreatic stiffness had been evaluated, subjectively. We introduce a tactile sensor for digitize the consistency of the pancreas. Materials and methods: A material has its own resonance frequency. If material touches an oscillated object, a shift of the resonance frequency will be observed. The difference between the frequencies under pre and post oscillate conditions depends on the stiffness of the object. So, the consistency of material can be measured by monitoring the shift in the frequency. The tactile sensor system is composed of a sensor probe, an amplifier and a filter; the probe is connected to a piezoelectric transducer with a resonance frequency of 57 kHz. Measurements were made 200 times per second, and the magnitude of frequency change was processed by connected computer with original software. 85 patients with mean age 70.1 +- 9.5 were registered with this study. These patients did not have any clinical sign of pancreatitis. 35 patients were excluded from this study, because of high serum amylase level. And mean serum amylase level was 92.9 +- 21.5 IU/L. Patients were divided two groups into over and under 65 years old. Consistency of the pancreas was measured with a tactile sensor system (Venous Handy Biosensor system TM, AXIOM, Fukushima, Japan). Pancreas head and body (neck) were measured 2 or 3 times on the same point. If the patients had pancreatic tumor, the measurement was performed far from the tumor. Hounsfield Unit (HU) on CT scan was measured in head and neck of the pancreas. HU was measured on SOMATOME Sensation Cardiac-64 (SIEMENS Japan, Tokyo, Japan) CT system with SIEMENS image server using the original software. Results: The consistency of the pancreas head was 670.0 +- 172.9 Hz in mature and 708.0 +- 239.3 Hz in younger, respectively. The consistency of the pancreas neck was 737.1 +- 178.4 Hz in mature and 684.2 +- 174.7 Hz in younger, respectively. The HU of the pancreas head was 42.9 +- 4.9 HU in mature and 43.0 +- 4.3 HU in younger, respectively. The HU of the pancreas neck was 43.7+- 5.4 HU in mature and 44.4 +- 5.7 HU in younger, respectively. There was no correlation between age and hardness of the pancreas. Also, there was no relation with hardness and HU in each age group. Conclusion: This method is easily maintained the consistency of pancreas non-invasively. Further investigation will be needed for elucidate the relationship between consistency and Hounsfield Unit of pancreas.
Back to 2011 Program