CT of Patients With Hip Fracture: Muscle Size and Attenuation Help Predict Mortality

Abstract

OBJECTIVE Our objective was to determine the association between muscle cross-sectional area and attenuation, as measured on routine CT scans, and mortality in older patients with hip fracture. MATERIALS AND METHODS A retrospective 10-year study of patients with hip fracture was conducted with the following inclusion criteria: age 65 years or older, first-time hip fracture treated with surgery, and CT of the chest, abdomen, or pelvis. This yielded 274 patients (70.4% women; mean [± SD] age, 81.3 ± 8.3 years). On each CT scan, two readers independently measured the size (cross-sectional area, indexed for patient height) and attenuation of the paravertebral muscle at T12 and the psoas muscle at L4. We then determined the association between overall mortality and the muscle size and muscle attenuation, while adjusting for demographic variables (age, sex, ethnicity, and body mass index), American Society of Anesthesiologists (ASA) classification, and Charlson comorbidity index (CCI). RESULTS The overall mortality rate increased from 28.3% at 1 year to 79.5% at 5 years. Mortality was associated with decreased thoracic muscle size (odds ratio [OR], 0.66; 95% CI, 0.49–0.87). This association persisted after adjusting for demographic variables (OR, 0.69; 95% CI, 0.50–0.95), the ASA classification (OR, 0.70; CI, 0.51–0.97), and the CCI (OR, 0.72; 95% CI, 0.52–1.00). Similarly, decreased survival was associated with decreased thoracic muscle attenuation after adjusting for all of these combinations of covariates (OR, 0.67–0.72; 95% CI, 0.49–0.99). Decreased lumbar muscle size and attenuation trended with decreased survival but did not reach statistical significance. CONCLUSION In older adults with hip fractures, CT findings of decreased thoracic paravertebral muscle size and attenuation are associated with decreased overall survival.

Muscle Gain after Transjugular Intrahepatic Portosystemic Shunt Creation: Time Course and Prognostic Implications for Survival in Cirrhosis

“…Core muscle area was calculated by summing the psoas and paraspinal muscle area, and total muscle area was calculated by summing the core and abdominal wall muscle areas (7). Muscle attenuation (density) by CT was measured using Hounsfield units (HU) in the psoas, paraspinal, and abdominal wall muscles in the identified ROI from patients with an available unenhanced CT phase (12,13). Consensus for ROI measurement technique was determined by three radiologists with 5-8 years of experience.…”

Predicting Outcomes of Abdominal Surgical Emergencies in the Elderly Population Using a CT Muscle Gauge

“…However, muscle quality is also a key component affecting functional reserve (31,32). Fat cells replace skeletal muscle cells in the aging process, and a lower muscle intensity is detected on CT scans (11,(32)(33)(34). Both skeletal MI and density values have been reported to be inversely associated with clinical outcomes (8,13,35).…”

“…Traditional assessment tools (measuring grip strength, establishing walking speed, and administering detailed multi-item questionnaires) that are used to evaluate frailty are usually unavailable in the emergency setting (9). Recent evidence suggests that frailty, as indicated by low values for skeletal muscle area, skeletal muscle index, and skeletal muscle density, can be used to predict surgical outcomes (10)(11)(12)(13). Computed tomography (CT) images are often obtained in emergency settings to assist with preoperative diagnosis and advance surgical planning, and they can rapidly provide quantitative and qualitative measurements of skeletal muscle.…”

Sarcopenia: Beyond Muscle Atrophy and into the New Frontiers of Opportunistic Imaging, Precision Medicine, and Machine Learning

“…15 In our study of 274 hip fracture patients followed for 8 years, lower paraspinous muscle density at the T12 level on chest and abdomen CT was associated with increased all-cause mortality. 57 The consequences of syndromes associated with sarcopenia (e.g., frailty, cachexia, and dysmobility) are beyond the scope of this discussion. However, these syndromes combined with sarcopenia generally confer a worse prognosis for patients, compared with sarcopenia diagnosed by imaging alone.…”

“…But an increasing body of literature supports using PACS-based segmentation to measure intramuscular fat amount or density, without applying any tissue thresholds. 57,64 Such an approach is especially well suited to so-called opportunistic CT screenings.…”