Takeshi Yoshikawa MD, Abstract Co-Author: Research Grant, Toshiba Corporation

Tomonori Kanda, Abstract Co-Author: Nothing to Disclose

Yoshiharu Ohno MD, PhD, Abstract Co-Author: Research Grant, Toshiba Coporation Research Grant, Koninklijke Philips Electronics NV Research Grant, Bayer AG Research Grant, DAIICHI SANKYO Group Research Grant, Eisai Co, Ltd Research Grant, Terumo Corporation Research Grant, Covidien AG Research Grant, FUJIFILM Holdings Corporation

Keitaro Sofue, Presenter: Nothing to Disclose

Noriyuki Negi RT, Abstract Co-Author: Nothing to Disclose

Yasuko Fujisawa MS, Abstract Co-Author: Employee, Toshiba Corporation

Tohru Murakami, Abstract Co-Author: Nothing to Disclose

Hisanobu Koyama MD, Abstract Co-Author: Nothing to Disclose

Mizuho Nishio MD, Abstract Co-Author: Research Grant, Toshiba Corporation

Naoki Kanata MD, Abstract Co-Author: Nothing to Disclose

Kazuro Sugimura MD, PhD, Abstract Co-Author: Research Grant, Toshiba Corporation Research Grant, Koninklijke Philips Electronics NV Research Grant, Bayer AG Research Grant, Eisai Co, Ltd Research Grant, DAIICHI SANKYO Group

To assess effects of breath control technique on CT perfusion values in the abdomen

One hundred eight patients (male: 69, female: 39, mean age: 70.6 years) underwent upper abdominal CT perfusion. Scans (0.5mm x 320, 80kV, AEC) were conducted 7 to 120 seconds after administration of contrast medium (CM) and 25-ml saline chaser. The patients were randomly divided into two groups; breathhold and free breathing groups. Demographic features and scan parameters (FOV, CTDI, and DLP) for CT perfusion were recorded and compared. CT images were analyzed using prototype software for perfusion analysis, which also compensated first manually, then automatically for respiratory misregistrations before perfusion analysis. Maximum length of manual compensation (mm) (usually z-direction) was recorded for each patient and compared between the groups. Hepatic arterial and portal perfusion (HAP and HPP, ml/min/100ml), arterial perfusion fraction (APF, %), mean transit time (MTT, s), and distribution volume (DV, ml/100ml) were calculated using dual-input maximum slope (dMS), deconvolution (dDC), and compartment model (dCM) methods using the same ROIs. Arterial perfusions (AP), MTT, and DV of pancreas, spleen, gastric wall were calculated using single-input MS, DC, and CM (sMS, sDC, sCM) methods. The values were compared between the groups.

There was no significant difference in demographic features or scan parameters. Mean manual compensation length had a trend toward larger in free breathing group (13.5 ± 7.7) than breathhold (11.3 ± 7.9). HAP with dCM (p<0.05) and HPPs with dMS, dDC (p<0.05), and dCM (<0.005) were significantly lower in breathhold group. MTTs in the liver with dDC (<0.0001) and dCM (<0.0005) were significantly higher in breathhold group. There was no significant difference in pancreatic, splenic, or gastric perfusion values.

Even after careful compensations for respiratory misregistrations, CT perfusion values in the liver are affected by breath control technique. Changes in portal perfusion values were possibly due to structure distortions, which made vessel tracking process in analysis difficult. CM transit time changes might be caused by intra-thoracic or inferior vena caval pressure changes.

CT perfusion values in the liver are affected by breath control technique. When measuring hepatic portal perfusion or CM transit time, breathhold technique is recommended

Yoshikawa, T, Kanda, T, Ohno, Y, Sofue, K, Negi, N, Fujisawa, Y, Murakami, T, Koyama, H, Nishio, M, Kanata, N, Sugimura, K, Abdominal CT Perfusion: Breathhold or Free Breathing?.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13018125.html