CT analysis of lung density changes in patients undergoing total body irradiation prior to bone marrow transplantation

• Published in: Journal of computer assisted tomography Vol. 8; no. 5; p. 885
• Main Authors: Lee, J Y, Shank, B, Bonfiglio, P, Reid, A
• Format: Journal Article
• Language: English
• Published: United States 01-10-1984
• Subjects: Adolescent; Adult; Bone Marrow Diseases - therapy; Bone Marrow Transplantation; Child; Child, Preschool; Combined Modality Therapy; Humans; Infant; Leukemia - therapy; Lung - diagnostic imaging; Lung - radiation effects; Mathematics; Respiration; Time Factors; Tomography, X-Ray Computed; Whole-Body Irradiation - adverse effects; Work of Breathing
• ISSN: 0363-8715
• DOI: 10.1097/00004728-198410000-00014

Sequential changes in lung density measured by CT are potentially sensitive and convenient monitors of lung abnormalities following total body irradiation (TBI). Methods have been developed to compare pre- and post-TBI CT of lung. The average local features of a cross-sectional lung slice are extracted from three peripheral regions of interest in the anterior, posterior, and lateral portions of the CT image. Also, density profiles across a specific region may be obtained. These may be compared first for verification of patient position and breathing status and then for changes between pre- and post-TBI. These may also be compared with radiation dose profiles through the lung. A preliminary study on 21 leukemia patients undergoing total body irradiation indicates the following: (a) Density gradients of patients' lungs in the antero-posterior direction show a marked heterogeneity before and after transplantation compared with normal lungs. The patients with departures from normal density gradients pre-TBI correlate with later pulmonary complications. (b) Measurements of average peripheral lung densities have demonstrated that the average lung density in the younger age group is substantially higher: pre-TBI, the average CT number (1,000 scale) is -638 +/- 39 Hounsfield unit (HU) for 0-10 years old and -739 +/- 53 HU for 21-40 years old. (c) Density profiles showed no post-TBI regional changes in lung density corresponding to the dose profile across the lung, so no differentiation of a radiation-specific effect has yet been possible. Computed tomographic density profiles in the antero-posterior direction are successfully used to verify positioning of the CT slice and the breathing level of the lung.