Andrew J Degnan1, Victor M Ho-Fung2, Dah-Jyuu Wang3, Can Ficicioglu4, Diego Jaramillo5. 1. Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA; Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Blvd., Philadelphia, PA 19104, USA. Electronic address: degnana@email.chop.edu. 2. Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA; Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Blvd., Philadelphia, PA 19104, USA. Electronic address: hov@email.chop.edu. 3. Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA. Electronic address: wangd@email.chop.edu. 4. Division of Human Genetics, The Children's Hospital of Philadelphia, Colket Translational Research Building, 3501 Civic Center Blvd, Floor 9, Philadelphia, PA 19104, USA; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Blvd., Philadelphia, PA 19104, USA. Electronic address: ficicioglu@email.chop.edu. 5. Department of Radiology, Columbia University Medical Center, 622 West 168th Street, PH1-301, New York, NY 10032, USA. Electronic address: diegjar1@gmail.com.
Abstract
OBJECTIVE: To assess magnetic resonance spectroscopy (MRS) bone marrow fat fractions' ability to discern between untreated Gaucher disease patients and healthy controls based on assessment of bone marrow infiltration and evaluate response to enzyme replacement therapy (ERT) on serial imaging. METHODS: This retrospective case-controlled study compared conventional MRI and bone marrow MRS findings in six pediatric and young adult Gaucher disease patients with age- and sex-matched controls, examining femoral neck and lumbar spine bone marrow fat fractions and bone marrow burden (BMB) scores. Separate analysis of six patients with serial imaging on ERT was performed with analysis of fat fractions, BMB scores, organ volumes, and serum chitotriosidase. RESULTS: Untreated patients had significantly lower femoral and lumbar spine fat fractions than controls (0.32 versus 0.67, p = 0.041 and 0.17 versus 0.34, p = 0.041, respectively). Total BMB scores were significantly higher in patients (8.0 versus 3.5, p = 0.015). In patients on ERT with average follow-up of 3.5 years, femoral neck fat fraction was the sole significant predictor of treatment duration (R square: 0.804, p < 0.001) when adjusted for age. Femoral neck fat fraction also correlated with lumbar spine fat fraction, liver volume and chitotriosidase (p < 0.05). MRS test-retest reliability was excellent (Pearson correlations: 0.96, 0.99; p-values <0.001). BMB inter-rater reliability was good overall with an intra-class correlation coefficient of 0.79 for total score, although lumbar spine score reliability was poor at 0.45. CONCLUSION: MRS-derived bone marrow fat fractions appear capable of detecting Gaucher disease severity and monitoring treatment-related changes as a predictor of ERT duration in pediatric and young adult patients.
OBJECTIVE: To assess magnetic resonance spectroscopy (MRS) bone marrow fat fractions' ability to discern between untreated Gaucher diseasepatients and healthy controls based on assessment of bone marrow infiltration and evaluate response to enzyme replacement therapy (ERT) on serial imaging. METHODS: This retrospective case-controlled study compared conventional MRI and bone marrow MRS findings in six pediatric and young adult Gaucher diseasepatients with age- and sex-matched controls, examining femoral neck and lumbar spine bone marrow fat fractions and bone marrow burden (BMB) scores. Separate analysis of six patients with serial imaging on ERT was performed with analysis of fat fractions, BMB scores, organ volumes, and serum chitotriosidase. RESULTS: Untreated patients had significantly lower femoral and lumbar spine fat fractions than controls (0.32 versus 0.67, p = 0.041 and 0.17 versus 0.34, p = 0.041, respectively). Total BMB scores were significantly higher in patients (8.0 versus 3.5, p = 0.015). In patients on ERT with average follow-up of 3.5 years, femoral neck fat fraction was the sole significant predictor of treatment duration (R square: 0.804, p < 0.001) when adjusted for age. Femoral neck fat fraction also correlated with lumbar spine fat fraction, liver volume and chitotriosidase (p < 0.05). MRS test-retest reliability was excellent (Pearson correlations: 0.96, 0.99; p-values <0.001). BMB inter-rater reliability was good overall with an intra-class correlation coefficient of 0.79 for total score, although lumbar spine score reliability was poor at 0.45. CONCLUSION: MRS-derived bone marrow fat fractions appear capable of detecting Gaucher disease severity and monitoring treatment-related changes as a predictor of ERT duration in pediatric and young adult patients.