Masaaki Hirata MD, Presenter: Nothing to Disclose

Hiroaki Tanaka MD, Abstract Co-Author: Nothing to Disclose

Naoki Fukuyama, Abstract Co-Author: Nothing to Disclose

Gen Koiwahara, Abstract Co-Author: Nothing to Disclose

Naoto Kawaguchi MD, Abstract Co-Author: Nothing to Disclose

Takaharu Tsuda MD, PhD, Abstract Co-Author: Nothing to Disclose

Teruhito Mochizuki MD, Abstract Co-Author: Nothing to Disclose

CT-guided puncture is a well-established minimally-invasive technique applied to biopsy, drainage, percutaneous osteoplasty, etc. On this procedure, in case of nonuse of CT fluoroscope, physicians have to define the angle of puncture needle as planned on the reference images by eye measurement. This uncertain process can be the cause of inaccurate puncture with large angle error. To overcome this, we developed a smartphone application to support CT guided puncture.

Function of the application After definition of the appropriate puncture site and needle angle, planning puncture line is drawn on the reference image. Then the reference image is transferred to the smartphone as jpeg data. While holding smartphone at any angle, this application automatically rotate and keep the image horizontal by the function of gyroscope. All physicians have to do is just to advance the needle along the puncture line shown on the device. Puncture test In order to evaluate the accuracy of this application, experimental puncture test was carried out. Vertical, horizontal and curved plane was defined on the puncture target which was made from melamine sponge. On the scanned CT image of this target, puncture line of 30°, 50°and 70° was drawn. The reference image was transferred to the smartphone. Then, nine times of test puncture was performed using this application (i.e. 30°, 50°and 70°respectively for vertical, horizontal and curved plane). As a result, the maximum angle error was only 1° (average angle error was 0.6°).

Most of smartphones have vibrating structure gyroscope inside in order to recognize the movement of the device itself. This application makes smartphone into a handy tool which present appropriate puncture angle in real time with high accuracy. Other advantages are as follows: 1. Recognition of anatomy around the puncture site from the image on the device without eye movement. 2. High availability of devices. 3. Easy preparation. (Just put the smartphone into sterilized nylon bag.) 4. Easy to complete procedure without assistant.

We developed an application to support CT guided puncture. This application makes smartphone into beneficial tool for accurate puncture.  

http://abstract.rsna.org/uploads/2014/14001129/14001129_sstw.jpg

Hirata, M, Tanaka, H, Fukuyama, N, Koiwahara, G, Kawaguchi, N, Tsuda, T, Mochizuki, T, CT Guided Puncture Navigated by Gyroscope Equipped Smartphone.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14001129.html