Hounsfield unit measurements on computed tomography in elastofibroma dorsi: a patient-level comparison with adjacent skeletal muscle

Elastofibroma dorsi (ED) is a benign soft-tissue tumour typically located in the subscapular region. Hounsfield unit (HU) measurements on computed tomography (CT) may provide quantitative information on lesion attenuation. This study aimed to compare patient-level HU values of ED with those of adjacent skeletal muscle. This retrospective, single-centre study included 11 surgically treated patients with histopathologically confirmed ED. Preoperative CT examinations suitable for HU analysis were available for nine patients. For patients with bilateral measurements, right- and left-sided values were averaged to obtain one ED and one adjacent serratus anterior muscle value per patient. Paired differences were assessed for normality and compared using a paired-samples t test. Ten patients (90.9%) were female and one (9.1%) was male; the mean age was 59.0 ± 11.28 years. Pain and palpable swelling were reported by six (54.5%) and five (45.5%) patients, respectively. In the nine-patient imaging cohort, mean HU values were lower in ED than in adjacent muscle (27.89 ± 12.72 vs. 37.89 ± 10.46 HU). The mean paired difference was 10.0 HU (95% confidence interval, 4.36–15.64 HU; P = 0.003). ED demonstrated lower patient-level CT attenuation than adjacent skeletal muscle. HU measurement may provide complementary quantitative information when interpreted with characteristic lesion location and morphology; however, diagnostic specificity against other soft-tissue lesions and a role in surgical decision-making were not assessed.