title: Focal fatty sparing usually does not arise in preexisting nonalcoholic diffuse homogeneous fatty liver.
abstract: OBJECTIVE
  The purpose of this study was to investigate whether focal fatty sparing can arise in preexisting nonalcoholic diffuse homogeneous fatty liver and its clinical implications.
  
  
  METHODS
  This prospective study consisted of 2 parts. In the first part, 8598 people (5202 men and 3396 women; mean age ± SD, 43.4 ± 28.3 years; range, 18-82 years) were consecutively evaluated with sonography for abnormal liver findings; in the second part, participants with diffuse homogeneous fatty liver were followed over approximately 3 years. Sonographic findings of the participants in the first year and findings of the participants with diffuse homogeneous fatty liver in the first and third years were analyzed.
  
  
  RESULTS
  In the first part, 778 of 8598 participants (9.05%) were found to have fatty liver, including 752 cases of nonalcoholic diffuse fatty liver (8.75%) and 26 cases of alcoholic fatty liver (0.30%). Of the 752 cases of nonalcoholic diffuse fatty liver, 301 participants had nonalcoholic diffuse homogeneous fatty liver, and 68 (9.04%) had focal fatty sparing. In the second part, the 301 participants with nonalcoholic diffuse homogeneous fatty liver (205 men and 96 women; mean age, 39.6 ± 10.4 years; range, 18-60 years) were followed. In the third year, 2 cases of fatty liver (0.67%) had resolved, 2 cases (0.67%) had inflammatory pseudotumors, and no focal fatty sparing was found (P < .001).
  
  
  CONCLUSIONS
  The findings of this study suggest that focal fatty sparing usually does not arise in preexisting nonalcoholic diffuse homogeneous fatty liver, and a newly emerging abnormality is more likely a true lesion.
authors: Department of Medical Imaging, Affiliated Hospital of Hainan Medical College, Haikou, China. wsz074@aliyun.com.
authors: Size
authors: S
authors: Wu
authors: Department of Medical Imaging, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors: Rong
authors: R
authors: Tu
authors: Department of Medical Imaging, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors: Guangqing
authors: G
authors: Liu
authors: Department of Medical Imaging, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors: Li
authors: L
authors: Huang
authors: Department of Medical Imaging, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors: Ying
authors: Y
authors: Guan
authors: Department of Medical Imaging, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors: Enhai
authors: E
authors: Zheng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005234:Fatty Liver / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000000981:diagnostic imaging; D011446:Prospective Studies; D012307:Risk Factors; D018615:Ultrasonography, Doppler, Color / Q000379:methods; D055815:Young Adult
keywords: focal fatty sparing; gastrointestinal ultrasound; nonalcoholic fatty liver; sonography