Journal of Ultrasound in Medicine, Vol 18, Issue 6 403-410, Copyright © 1999 by American Institute of Ultrasound in Medicine
Ring-down artifacts posterior to the right hemidiaphragm on abdominal sonography: sign of pulmonary parenchymal abnormalities
J. H. Lim, K. S. Lee, T. S. Kim and M. P. Chung
Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
The aim of our study was to verify whether ring-down artifacts posterior to
the right hemidiaphragm on abdominal sonography reflected pulmonary
parenchymal abnormalities. Forty patients (group 1) with abdominal diseases
and 32 patients (group 2) with proved various pulmonary abnormalities
involving the right lung base underwent abdominal sonography with 2-4 MHz
transducers. In these two groups, the presence and number of ring-down
artifacts were assessed and correlated with peridiaphragmatic lung findings
on chest radiographs or computed tomographic scans. In 21 patients (group
3) with multiple (more than five) or numerous (10 or more) ring-down
artifacts, chest radiographs were reviewed to see if any peridiaphragmatic
pulmonary abnormalities were present. In group 1, one or several (less than
five) ring-down artifacts were shown in 27 of 40 (68%) patients. In these
patients, computed tomography showed insignificant focal intra- and
interlobular septal thickening in the peridiaphragmatic right lung. In
group 2, 31 of 32 (97%) patients showed multiple or numerous ring-down
artifacts. In group 3, chest radiographs showed various pulmonary
abnormalities in 20 of 21 (95%) patients, including emphysema, idiopathic
interstitial pneumonia, bronchopneumonia, and interstitial edema. Although
nonspecific, ring-down artifacts posterior to the right diaphragm on
abdominal sonography may be used to predict pulmonary abnormalities when
encountered on abdominal sonography in patients without specific pulmonary
symptoms.