PURPOSE: Vibration Response Imaging (VRIXP®) technology utilizes two arrays of pressure sensors to record vibration energy generated by airflow within the lungs. A digital image and quantitative data is then generated. The efficacy of VRIXP® in the diagnosis of pleural effusions has been presented in previous pilot data. A direct comparison with chest radiographs in the quantification of effusions was sought in this study.
METHODS: The reference gold standard was the amount of fluid drained via therapeutic thoarcentesis. Complete drainage was possible using pleural manometry. Radiologist's report of patients’ upright chest radiographs was used. Effusion size defined on a visual analogue scale was co-related against volume of fluid drained. A reader who was blinded to the chest radiograph findings assessed all VRIXP® recordings. Quantitative analysis of effusion size by VRIXP® technology involved calculation of pixels in the affected hemothorax and was also co-related against volume of effusion drained.
RESULTS: Twenty-nine patients (13 females) with a mean age 69 ± 13 years were recorded because of suspected pleural effusions. In qualitative analysis, the percentage of agreement between VRIXP® and chest radiograph for effusion location was 86% and effusion size was 72%. Quantitative analysis of effusion size showed a correlation between VRIXP® and chest radiograph in both the affected hemithorax (r=-0.81) and the affected region (r=-0.80). Thoracentesis was performed on 16 patients with a mean 1721 ± 1262 cc drained. The correlation between VRIXP® readings and volume of fluid drained (r=-0.68) was comparable to correlation between the chest radiograph reports and effusion drained (r=0.60).
CONCLUSION: This pilot study shows that VRIXP® performs as well as chest radiograph in quantifying pleural effusions.
CLINICAL IMPLICATIONS: VRIXP® may become a bedside tool in the diagnosis and monitoring of pleural effusions because it appears comparable to chest radiograph in quantifying the size of pleural effusions. It is also noninvasive and radiation free.
DISCLOSURE: Devanand Anantham, Grant monies (from industry related sources) This study was sponsored by Deep Breeze, Ltd.; Product/procedure/technique that is considered research and is NOT yet approved for any purpose. VRIXP® has been approved for clinical use in Europe but does not have FDA approval yet.