Takeshi Johkoh MD, PhD, Presenter: Research Consultant, Bayer AG Research Consultant, F. Hoffman-La Roche Ltd

Fumikazu Sakai MD, PhD, Abstract Co-Author: Research Consultant, Bayer AG Research Consultant, F. Hoffman-La Roche Ltd Research Consultant, Takeda Pharmaceutical Company Limited Research Consultant, AstraZeneca PLC Research Consultant, Merck KGaA Research Consultant, Johnson & Johnson Research Consultant, Merck & Co, Inc Research Consultant, Kyowa-Kirin Co, Ltd Research Consultant, Bristol-Myers Squibb Company Research Consultant, Pfizer Inc Speaker, DAIICHI SANKYO Group Speaker, Eisai Co, Ltd Speaker, KYORIN Holdings, Inc Speaker, Shionogi & Co, Ltd Speaker, Dainippon Sumitomo Pharma Co, Ltd Research Grant, Bayer AG Research Grant, Eisai Co, Ltd Research Grant, LTT Bio-Pharma Co, Ltd

Takashi Ogura MD, Abstract Co-Author: Nothing to Disclose

Hiroyuki Taniguchi, Abstract Co-Author: Research Consultant, Bayer AG Research Consultant, F. Hoffmann-La Roche Ltd Research Consultant, Pfizer Inc

Tetsuo Yamaguchi, Abstract Co-Author: Nothing to Disclose

Masasho Bando MD, PhD, Abstract Co-Author: Nothing to Disclose

In the ATS-ERS-JRS-ALAT 2011 IPF/ UIP guideline, CT diagnostic criteria do not include CT findings corresponding to the two pathological hallmarks; lobular heterogeneity and perilobular predominance. The aims of the study were to describe CT findings of IPF/UIP without honeycombing and to clarify CT findings corresponding to lobular heterogeneity and perilobular predominance.

The study included 30 patients with IPF/UIP who had the multidisciplinary diagnosis and did not show honeycombing on CT. The patients ranged from 55 to 70 years of age (mean 64.3), and included 22 males and eight females. Two observers independently evaluated the existences, distributions, and extents of ground-glass attenuation, airspace consolidation, reticular shadow, nodules, and traction bronchiectasis on CT. The extent of each finding was graded as following 4-points scales; 0: no involvement, 1: less than 10% involvement of tortal lung, 2: 10-30% involvement, and 3: more than or equal to 30%. Moreover, the existences of lobular heterogeneity and perilobular　opacity were also evaluated. Lobular heterogeneity was defined as the existence of lobules which had more than four findings including normal appearance. Perilobular opacity was determined as either irregular pleural surface, irregular thickening of bronchovascular bundles, or irregular thickened interlobular septa. Furthermore, each case was incorporated into three categories（UIP, possible UIP, and inconsistent with UIP）in CT diagnostic criteria of ATS-ERS-JRS-ALAT guideline.

Lobular heterogeneity, perilobular opacity, reticular shadow, ground-glass attenuation, and traction bronchiectasis were seen in all 30 patients. Lower lobe predominance and peripheral predominance were found in 28（93%）and 27 patients（90%）, respectively. In 29 patients (97%), the extent of areas with ground-glass attenuation（Mean score; 2.2）was larger than that of reticular shadow (Mean score; 1.1)(paired t-test; p<0.01). These 29 cases were categorized into the inconsistent with UIP pattern on CT.

Perilobular opacity and lobular heterogeneity on CT are seen in all patients with IPF/UIP. Detection of both findings is feasible for the diagnosis of IPF/UIP.

The detection of either perilobular opacity or lobular heterogeneity on CT is the clue for the diagnosis of IPF/UIP.

Johkoh, T, Sakai, F, Ogura, T, Taniguchi, H, Yamaguchi, T, Bando, M, Idiopathic Pulmonary Fibrosis (IPF)/ Usual Interstitial Pneumonia (UIP) without Honeycombing on CT: CT findings in 30 Patients Diagnosed by Surgical Lung Biopsy.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013475.html