198 - Sensitivity and Specificity of Indocyanine Green Enhanced Optical Imaging (Xiralite) in Comparison to Magnetic Resonance Imaging and Ultrasonography

Sunday, November 6, 2011: 9:00 AM-6:00 PM
Hall F2 - Poster Hall (McCormick Place West)
Stephanie G. Werner1, Peter Schott2, Sarah Ohrndorf3, Carsten Schwenke4, Malte Bahner5, Bernward Kurtz2, Marina Backhaus6, Gerd R. Burmester3 and Hans-Eckhard Langer7, 1RHIO (Rheumatology, Immunology, Osteology) Duesseldorf, Duesseldorf, Germany, 2Evangelisches Krankenhaus Duesseldorf, Duesseldorf, Germany, 3Charité University Hospital, Berlin, Germany, 4SCOSSIS, statistical consulting, Berlin, Germany, 5mivenion GmbH, Berlin, Germany, 6Charite University Hospital, Berlin, Germany, 7Duesseldorf, Germany
Presentation Number: 198

Background/Purpose:Indocyanine green (ICG) enhanced fluorescence optical imaging (FOI) with the commercial available Xiralite system (mivenion GmbH, Berlin) is a novel imaging technology to assess inflammatory activity in arthritic conditions. We compared FOI with MRI and ultrasonography in patients with arthritis, arthralgia and healthy controls. 

Method: A total of 125 subjects was examined in 3 comparative studies. Cohort 1: 25 patients with rheumatoid or undifferentiated arthritis with high disease activity (DAS28 >3.2), cohort 2: 20 patients with early arthritis (disease duration≤24months) and cohort 3: 74 patients with arthritis or arthralgia in the hands. Six healthy individuals and 6 subjects with arthralgia without any sign of an inflammatory rheumatic disease served as control group. All patients received clinical examination (CE) and lab testing. In cohort 1 and 2 a contrast enhanced MRI of the clinically leading hand was performed. MRI was evaluated according to the OMERACT-criteria. Ultrasonography in grey-scale mode (GSUS) and power-Doppler Mode (PDUS) of the clinically leading hand was performed in cohort 3. All patients were examined by FOI using ICG as fluorophor (ICG-Pulsion® 0.1 mg/kg/BW bolus i.v., 6 minutes). Image interpretation was done on three defined phases of increased signal intensities (ISI) in the finger tips: early (P1, until strong ISI in the finger tips), intermediate (P2, during ISI in the finger tips), and late phase (P3, after decreasing of ISI in the finger tips) and for an automatically generated composite image (PrimaVista Mode, PVM). Sensitivity and specificity was calculated using MRI, GSUS or PDUS as reference.Result:With MRI or ultrasonography as reference, FOI was more sensitive than CE (Table 1). FOI had a high sensitivity and high specificity, depending on the evaluated phase. FOI did not detect any positive findings in 97.8%-100% of joints in controls, depending on the evaluated image or phase.

 
Table 1: Sensitivity and specificity of FOI and clinical examination with ultrasonography or MRI as reference
FOI MRI cohort 1 MRI cohort 1 MRI cohort 2 MRI cohort 2 PDUS cohort 3 PDUS cohort 3 GSUS cohort 3 GSUS cohort 3
sensitivity specificity sensitivity specificity sensitivity specificity sensitivity specificity
FOI PVM 51% 81% 55% 92% 67% 54% 56% 57%
FOI P1 27% 94% 34% 95% 33% 90% 22% 95%
FOI P2 72% 56% 83% 69% 72% 44% 68% 50%
FOI P3 47% 89% 60% 92% 60% 69% 51% 78%

Any phase (P1-3)

76% 54% 85% 65% 74% 42% 70% 48%
CE 59% 72% 58% 90% 50% 76% 35% 79%

Abbreviations: FOI: fluorescence optical imaging; PVM: PrimaVista mode; P1: phase 1; P2: phase 2; P3: phase 3; any phase: positive in P1 or P2 or P3; PDUS: ultrasonography in power-Doppler mode (synovitis or tenosynovitis); GSUS: ultrasonography in grey scale mode (synovitis or tenosynovitis); MRI: magnetic resonance imaging (synovitis or tenosynovitis); CE: clinical examination (swollen joints)

Conclusion: FOI appears to be a valuable tool for assessing inflammation in patients with rheumatoid, undifferentiated, early arthritis or arthralgia in the hands.  Sensitivity and specificity differed for PVM and P1-3. Therefore an adequate reading of a FOI sequence requires a separate reading of PVM and the phases. 


Keywords: imaging techniques, magnetic resonance imaging (MRI) and ultrasound

Disclosure: S. G. Werner, statistical analysis was funded by mivenion GmbH, 9 ; P. Schott, mivenion GmbH funded the statistical analysis, 9 ; S. Ohrndorf, mivenion GmbH funded the statistical analysis, 9 ; C. Schwenke, mivenion GmbH funded the statistical analysis, 9 ; M. Bahner, mivenion GmbH funded the statistical analysis, 9, shareholder of mivenion GmbH, 3 ; B. Kurtz, mivenion GmbH funded the statistical analysis, 9 ; M. Backhaus, mivenion GmbH funded the statistical analysis, 9 ; G. R. Burmester, mivenion GmbH funded the statistical analysis, 9 ; H. E. Langer, mivenion GmbH funded the statistical analysis, 9 .