C Baunin1, D Sanmartin-Viron1, F Accadbled2, N Sans1, J Vial1, D Labarre1, C Domenech1, J Sales de Gauzy3. 1. Department of Paediatric Imaging, hôpital des Enfants, CHU de Toulouse, 31059 Toulouse, France. 2. Department of Paediatric Orthopaedic Surgery, hôpital des Enfants, CHU de Toulouse, 31059 Toulouse, France. Electronic address: faccadbled@wanadoo.fr. 3. Department of Paediatric Orthopaedic Surgery, hôpital des Enfants, CHU de Toulouse, 31059 Toulouse, France.
Abstract
PURPOSE: To evaluate diffusion MRI of the proximal femoral epiphysis and metaphysis as a prognosis factor in Legg Calvé Perthes (LCP) disease. METHODS: Thirty-one children (mean age 5.5 years, range 2.5-10.5) with unilateral LCP were included in a prospective, consecutive series. Radiographs were analysed and classified as per Herring criteriae. Mean follow-up was 19 months (range 6-30). Forty-nine MRI scans were performed at either the condensation or fragmentation stage. Apparent Diffusion Coefficient (ADC) of both the femoral epiphysis and metaphysis were measured bilaterally and ADC ratio were calculated, then compared to the Herring group. RESULTS: Sixteen hips were rated Herring A or B, 3 Herring B-C and 12 Herring C. ADC was increased in affected hips compared to unaffected sides, both at the femoral epiphysis (P<0.001) and metaphysis (P<0.0001). ADC ratio of the femoral metaphysis was positively correlated to Herring classification: if superior to 1.63, it was associated with a bad prognosis (Herring B-C or C) (P=0.0017, sensitivity=89%, specificity=58%). Interobserver reliability of ADC measurement was excellent. The 1.63 threshold could be determined as early as the condensation stage. CONCLUSIONS: Diffusion presents several advantages including being non radiating and non invasive. It does not need contrast medium administration and it can be performed without anaesthesia. The origin of the increased ADC remains unknown. Basically, it reflects molecular changes (true diffusion) but it is also influenced by the vascular supply (pseudo-diffusion). ADC ratio could provide an early prognosis before Herring classification is applicable. LEVEL OF EVIDENCE: Level III. Prospective uncontrolled study.
PURPOSE: To evaluate diffusion MRI of the proximal femoral epiphysis and metaphysis as a prognosis factor in Legg Calvé Perthes (LCP) disease. METHODS: Thirty-one children (mean age 5.5 years, range 2.5-10.5) with unilateral LCP were included in a prospective, consecutive series. Radiographs were analysed and classified as per Herring criteriae. Mean follow-up was 19 months (range 6-30). Forty-nine MRI scans were performed at either the condensation or fragmentation stage. Apparent Diffusion Coefficient (ADC) of both the femoral epiphysis and metaphysis were measured bilaterally and ADC ratio were calculated, then compared to the Herring group. RESULTS: Sixteen hips were rated Herring A or B, 3 Herring B-C and 12 Herring C. ADC was increased in affected hips compared to unaffected sides, both at the femoral epiphysis (P<0.001) and metaphysis (P<0.0001). ADC ratio of the femoral metaphysis was positively correlated to Herring classification: if superior to 1.63, it was associated with a bad prognosis (Herring B-C or C) (P=0.0017, sensitivity=89%, specificity=58%). Interobserver reliability of ADC measurement was excellent. The 1.63 threshold could be determined as early as the condensation stage. CONCLUSIONS: Diffusion presents several advantages including being non radiating and non invasive. It does not need contrast medium administration and it can be performed without anaesthesia. The origin of the increased ADC remains unknown. Basically, it reflects molecular changes (true diffusion) but it is also influenced by the vascular supply (pseudo-diffusion). ADC ratio could provide an early prognosis before Herring classification is applicable. LEVEL OF EVIDENCE: Level III. Prospective uncontrolled study.
Authors: Casey P Johnson; Luning Wang; Ferenc Tóth; Olumide Aruwajoye; Cathy S Carlson; Harry K W Kim; Jutta M Ellermann Journal: Radiology Date: 2018-07-31 Impact factor: 11.105
Authors: Casey P Johnson; Ferenc Tóth; Cathy S Carlson; Alexandra R Armstrong; Štefan Zbýň; Baolin Wu; Jutta M Ellermann; Harry K W Kim Journal: J Orthop Res Date: 2021-04-16 Impact factor: 3.102
Authors: Fernando Ruiz Santiago; Alicia Santiago Chinchilla; Afshin Ansari; Luis Guzmán Álvarez; Maria Del Mar Castellano García; Alberto Martínez Martínez; Juan Tercedor Sánchez Journal: Radiol Res Pract Date: 2016-01-13