TABLE 3

New noninvasive imaging techniques for pulmonary hypertension (PH)

Variable	Comments
Echo
Speckle tracking-derived RV strain and strain rate	RV longitudinal peak systolic strain of ≥ −19% is significantly associated with all-cause mortality [72]
RV automated systolic index	Semi-automated and reproducible [73]
Three-dimensional echo	Excellent correlation with CMRI, but can underestimate LV volumes [74]; real-time three-dimensional echo could be a time-saving and low-cost alternative to MRI [75]
CMRI
RV strain	Systolic strain and strain rate are predictors of right-sided heart failure, clinical deterioration and mortality in patients with PAH [76]
Contrast-enhanced CMRI	LGE at the right ventricle insertion point is a marker for advanced disease in PH and is related to clinical worsening [55]
Wall sheer stress	Being investigated [77]
Exercise CMRI	RV stroke volume does not increase on exercise in patients with PAH (unlike healthy individuals) [78], indicating that these patients need to raise their heart rate to cope with exercise
Fast SENC imaging	A through-plane CMRI tagging technique that allows direct measurement of regional function by using a free-breathing single-heartbeat real-time image acquisition [79]
Myocardial T1 mapping	Enables quantification of myocardial extracellular volume; may be useful for detecting the early stages of chronic PH, prior to the onset of macroscopic fibrosis [80]
PET
Right ventricle ¹⁸F-FDG	Higher uptake is associated with greater severity or clinical worsening of PH [81–83]
Same-day scanning with ¹³N-NH₃ and ¹⁸F-FDG	Feasible for quantifying RV blood flow and metabolism in patients with idiopathic PAH [84]

Echo: echocardiography; RV: right ventricular; CMRI: cardiac magnetic resonance imaging; SENC: strain-encoded; PET: positron emission tomography; FDG: fluorodeoxyglucose; LV: left ventricular; MRI: magnetic resonance imaging; PAH: pulmonary arterial hypertension; LGE: late gadolinium enhancement.