Fast and Low Cost X-Ray Stereoradiography Displayed on a 3D Monitor

Conventional x-ray stereoradiography based on film radiography is not practical due to its inconvenient and time-consuming procedures. In this research, an image viewing system consisted of a 30 cm × 30 cm gadolinium oxy-sulfide (GOS) fluorescent screen and a Cannon 500D digital camera were designed and constructed for real-time and near real-time x-ray imaging. The camera was connected to a laptop computer via USB port to allow remote camera setting and control as well as view image on the computer. The system was tested with x-rays generated from a Rigaku x-ray tube for its response at various camera settings and exposure times. The image brightness increased with increasing of the camera ISO setting and with the exposure time as expected. To test the system performance, two test specimens were radiographed including a video camera and a floppy disk drive as well as two simulated specimens. Each of the test specimens was also radiographed at two positions by moving the specimens approximately 6 cm from the first position. The two radiographs of each specimen were then combined to make an anaglyph image that could be viewed in 3D on a normal LCD or LED monitor by using appropriate color glasses. When the two radiographs were combined to make MPO (multiple object) file format, it could be viewed in 3D on a 3D monitor with or without 3D glasses depending on type of the monitor. The developed system could be conveniently employed for routine inspection of a specimen both in 2D and 3D within a minute.

Radiation dose to patients during endoscopic retrograde cholangiopancreatography

Endoscopic retrograde cholangiopancreatography (ERCP) is an important tool for the diagnosis and treatment of the hepatobiliary system. The use of fluoroscopy to aid ERCP places both the patient and the endoscopy staff at risk of radiation-induced injury. Radiation dose to patients during ERCP depends on many factors, and the endoscopist cannot control some variables, such as patient size, procedure type, or fluoroscopic equipment used. Previous reports have demonstrated a linear relationship between radiation dose and fluoroscopy duration. When fluoroscopy is used to assist ERCP, the shortest fluoroscopy time possible is recommended. Pulsed fluoroscopy and monitoring the length of fluoroscopy have been suggested for an overall reduction in both radiation exposure and fluoroscopy times. Fluoroscopy time is shorter when ERCP is performed by an endoscopist who has many years experience of performing ERCP and carried out a large number of ERCPs in the preceding year. In general, radiation exposure is greater during therapeutic ERCP than during diagnostic ERCP. Factors associated with prolonged fluoroscopy have been delineated recently, but these have not been validated.

Rui Liao's work on patient-specific 3-D model guidance for interventional and hybrid-operating-room applications

Compared to surgery,interventional and hybrid-operating-room(OR) approaches diagnose or treat pathology with the most minimally invasive techniques possible.By minimizing the physical trauma to the patient,peripheral or hybrid approaches can reduce infection rates and recovery time as well as shorten hospital stays.Minimally invasive approaches therefore are the trend and often the preferred choice,and may even be the only option for the patients associated with high surgery risks.Common interventional imaging modalities include 2-D X-ray fluoroscopy and ultrasound.However,fluoroscopic images do not display the anatomic structures without a contrast agent,which on the other hand,needs to be minimized for patients' safety.Ultrasound images suffer from relatively low image quality and tissue contrast problems.To augment the doctor's view of the patient's anatomy and help doctors navigate the devices to the targeted area with more confidence and a higher accuracy,high-resolution pre-operative volumetric data such as computed tomography and/or magnetic resonance can be fused with intra-operative 2-D images during interventions.A seamless workflow and accurate 2-D/3-D registrationas well as cardiac and/or respiratory motion compensation are the key components for a successful image guidance system using a patient-specific 3-D model.Dr.Liao's research has been focused on developing methods and systems of 3-D model guidance for various interventions and hybrid-OR applications.Dr.Liao' s work has led to several Siemens products with high clinical and/or market impact and a good number of scientific publications in leading journals/conferences on medical imaging.