1Department of Clinical Laboratory, Toranomon Hospital, 2Department of Hepatology, Toranomon Hospital, 3Department of Gastroenterology, Toranomon Hospital, 4Department of Diagnostic Pathology, Japan Community Health care Organization Tokyo Shinjuku Medical Center
Purpose: Due to advances in the technology, the frequencies of appearance of each of the B-mode findings that are characteristic to the fatty liver are changing. In addition, because fatty changes in tissues are classified as a surface area of 5% or greater according to the non-alcoholic fatty liver disease activity score (NAS). we investigated each of the fatty change findings observed during the B-mode imaging. Patients and Methods: We investigated 75 patients who underwent a hepatic cytology and an ultrasound (US) imaging using a Toshiba Aplio XG. We performed a comparative investigation between the frequency of fatty change findings on B-mode images, such as hepato-renal echo contrast, bright liver, enhanced deep attenuation, vascular blurring, and focal spared area, and NAS fatty change classification. Results: A comparison between NAS and fatty liver on US imaging showed that if subjects had both hepato-renal echo contrast and bright liver or if these findings were mild and when the fatty liver on US imaging showed aforementioned findings along with focal spared area, then the NAS fatty change classification of grade 0/1/2/3 (S 0-3) corresponded to 0%/52%/100%/100% of the fatty liver tissue observed, respectively. In addition, in subjects with mild fatty changes of 5%-33% or less, fatty changes in tissues were subdivided into 5%-10%/11%-20%/21%-33%, which corresponded to 21%/88%/100% of the fatty liver tissue observed, respectively. The presence of each fatty change finding on B-mode images is as follows: Enhanced deep attenuation, a finding indicative of high-grade fatty liver, was present in S2: 10%/S3: 75%, while vascular blurring was observed in S2: 0%/S3: 38% and focal spared area was observed in S1/2/3 in 32%/70%/88%, respectively. Conclusion: The frequency of observation of enhanced deep attenuation and vascular blurring has decreased. In addition, the findings such as bright liver and hepato-renal echo contrast as well as focal spared area are important because these findings can indicate mild fatty changes involving 10% of the liver.