Multimodality Predictive Diagnostic Characterization of Chronic Regional Pain Syndrome an Observational Study with Clinical and Imaging Correlation

Complex Regional Pain Syndrome or CRPS, its subtypes CRPS I: No nerve injury, CRPS II: Definitive nerve injury, characterized clinically by pain, vasomotor disturbances, trophic skin changes, and radio graphically by regional osteoporosis and bone resorption poses diagnostic challenges. Objective: Multimodality imaging characterization of CRPS, and clinical and imaging phenotypes. Materials & Methods: Fifty-seven patients in the age range of 33-65, the mean age of 49 men, 35 men (61.40%), 22 Women (38.60%) underwent this observational diagnostic accuracy study at Pratima Institute of Medical Sciences (Karimnagar Telangana, India). The multimodality imaging protocol on Radiography (Diagnox 302, Philips), Ultrasound Doppler (Infinity Philips), Low dose Multi-slice CT (Ingenuity), MRI (1.5 T Achieva, PHILIPS Health care) for characterization of CRPS phenotypes after IRB approval. The imaging findings from all the modalities were analyzed using descriptive statistics. Results: Patients with upper limb involvement (n=18), lower limb involvement (n=32), Pelvic involvement (6). CRPs Type 1:- 27, CRPS Type 2 :- 23, Mixed pattern: 7, 1. Juxta regional osteopenia (n=17) 2. Patterns of bone resorption on radiography and CT :Pattern A: Mild (n=31), B: Aggressive (19) Pattern C- No significant radiological changes (7); Locations of bone loss on radiography/CT. Periarticular: 18, Sub Periosteal: 8, subchondral/endosteal: 11-Intracortical : 7-Mixed pattern: 12, Bone marrow edema: 32, Soft tissue edema: 31, Pattern A: Positive Predictive Value (PPV) of 91%, a concordance rate of 94% with clinical diagnosis of CRPS. Pattern B: PPV of 98%, a concordance rate of 97%. Conclusion: The multimodality imaging approach predicts the accurate diagnosis of CRPS evolving from early acute to late atrophic stages.