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Cardiac image foreshortening occurs when a cardiac view represents a shorter apparent base-to-apex extent than the intended anatomical chamber length, often because the imaging plane misses the true cardiac apex. It can create an apparently thick false apex and affect derived ejection fraction and deformation measurements.

A primary echocardiography study acquired optimal and deliberately foreshortened views in 72 participants using a GE Vivid E9 system. The altered acquisition window was one rib-space above the optimal window; two analysis systems were used to compare derived quantities.^[ref] This tests acquisition geometry while keeping the participant the same, rather than interpreting every shorter-looking chamber as a biological change.

An original ellipsoid model distinguishes a missed apex from a simple projected length. Letwith the true cardiac long axis along $z$. The central long-axis plane $y=0$ includes both axial tips and has full length $2a$. A parallel offset plane $y=d$ instead intersects an ellipse whose apparent axial extent isAt $d=0.6b$, $L(d)=0.8(2a)$. A 10 cm true extent therefore appears as 8 cm in this model even though the slice was translated rather than rotated. Its apparent tips are not the original chamber tips.

This model is a geometrical explanation, not a clinical correction formula. A shorter outline can alter measured volume differently at end-diastolic volume and end-systolic volume; the ejection fraction error need not follow the length error by one fixed percentage. Consistent anatomical landmarks and independent views help distinguish actual chamber shape from the chosen section. Improving the repeatability of an outline inside an incorrect plane does not recover anatomy that was never acquired.

Serkan Ünlü investigates cardiac imaging and the dependence of measured heart function on image acquisition. His official institutional profile identifies cardiology as his unit and lists cardiac and cardiovascular research areas.^[ref]

Ünlü is first author of a primary study testing cardiac image foreshortening in echocardiography. The investigators imaged 72 participants using a GE Vivid E9 system and deliberately collected altered apical views from a window one rib-space above the optimal position. They compared ejection fraction and longitudinal deformation measurements using two analysis systems.^[ref] This is an experimental acquisition comparison: the view changes while the patient's chamber is not assumed to have become anatomically shorter.

An original geometric example shows why a constant scale error and a phase-dependent distortion have different consequences. Let a modeled chamber length change from $L_d=10$ to $L_s=8$ cm. Its fractional shortening isMultiplying both lengths by 0.9 leaves the ratio unchanged. If instead the measured lengths become 9 and 7 cm because the same 1 cm terminal segment is missed in each phase, the apparent fractional shortening is $-2/9\approx -0.222$. Neither model is a complete echocardiography reconstruction; they demonstrate why the error mechanism matters even in a normalized measurement.

The primary study found that deliberately foreshortened views changed measured deformation, with the effect differing by myocardial layer and analysis system.^[ref] Ünlü's documented contribution is to test that dependence experimentally. Repeatable software output does not establish that the acquired image represents the intended anatomical view.