Evaluation of intraventricular flow by multimodality imaging: a review and meta-analysis

Table 1 Comparison of left ventricle flow visualization modalities

	Echocardiographic particle image velocimetry	Vector flow mapping	4D flow Cardiovascular Magnetic Rensonce
Signal source	Contrast Echocardiography	Color Flow Doppler	Phase contrast MRI
Flow Analysis	2D	2D	3D
Temporal resolution	60 Hz	27–40 Hz	20–40 frames/cycle*
Spatial resolution	3²–4² mm²	2² mm2	1.5³–3³ mm3
Upper velocity limitation	40 cm/sec	2 x Nyquist limit	VENC ⁑
Low velocities	Accurate	Underestimation	Accurate†
Scan Time	< 5 min	< 5 min	5–15 min
Commercial hardware	+	+	+
Commercial software	+	+	–
Offline/online	Offline	Offline/Online ‡	Offline
Contrast	Required	Not required	Not required^✽
Cost	Lower	Lower	Higher
Availability	Higher	Higher	Lower
Dependence on Chest anatomy	+	+	–
Medical implants	§	§	§
Assessment of LV vortex	↑↑↑	↑	↑↑
Assessment of energetics	↑	↑↑	↑↑↑
Volume analysis	–	–	↑↑↑
Estimation of pressure fields	↑↑	↑↑	↑↑
Next generation	• High frame rate echocardiography • Blood speckle tracking • 3D-PIV	• 3D-iVFM • Doppler Vortography	• Multipoint 5D flow CMR

Abbreviations VENC velocity encoding, CHD congenital heart disease, 3D-PIV 3-dimensional particle image velocimetry, 3D-iVFM 3-dimensional vector flow mapping *number of reconstructed phases, this value is set by the operator ⁑ usually set 150,200 cm/sec. † underestimation of turbulent - nonlaminar flow ‡ the VFM analysis software is integrated on Hitachi echocardiography machines ✽ contrast is not strictly necessary but might increase signal to noise ratio,§. increased artifact with prosthetic material, difficulty in obtaining images in proper angles with assist device cannulae, increased artifact generation with resultant decrease in image quality as well as safety concerns, (−): not applicable/not available (+): present, objective strength in assessments (−) not applicable/not available, ↑: lower strength, ↑↑: moderate strength, ↑↑↑: higher strength

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