Avoiding bias in measuring 'hemisphere radius' in echocardiographic mitral regurgitation quantification: Mona Lisa PISA

摘要

The conventional "Proximal Isovelocity Surface Area" (PISA) technique is the standard clinical method to quantify the effective regur-gitant orifice area (EROA) in mitral regurgitation (MR) [1-4]. Using conventional PISA, the operator must measure the distance r ("radius") between the flow convergence zone and the orifice. Traditionally the teaching is that the radius should be measured perpendicularly to the valve plane. In the 4 chamber-view this is typically vertical, towards the probe. However in some cases the valve plane unavoidably has a different orientation and operators may not be sure whether to measure (as advised) or towards the probe. Lack of guidance on this question is compounded by the assumption that the distance to the aliasing point in the two directions should be roughly the same so that the choice does not matter. We tested these experimentally to remove doubt.