Lung Scintigraphy in Pulmonary Embolism

Abstract

As recently reviewed [1–4], lung scintigraphy has long been the mainstay for diagnosing acute pulmonary embolism (PE), whether based on the ventilation/perfusion study, as in the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) approach [5, 6], or on perfusion only as in the Prospective Investigative Study of Acute Pulmonary Embolism Diagnosis (PISA-PED) approach [7]. Nevertheless, advanced imaging technologies, most notably, multidetector-row CT pulmonary angiography (MDCT-PA), are now challenging the concept of lung scintigraphy as the first-line approach when diagnosing acute PE (APE) [8–11]. On the other hand, the issue is especially relevant considering the fact that APE is a relatively common cardiovascular emergency that, if not timely diagnosed and adequately treated, may cause sudden death or acute life-threatening right-ventricular failure [12, 13]. In the long term, untreated PE can also be a common cause of chronic pulmonary hypertension, a complication that can be avoided with efficient therapies readily and widely available, such as heparin or thrombolytic agents in the acute phase and oral anticoagulants for long-term secondary prevention [14–17]. The clinical problem is even more complicated because of the stringent requirement of employing an adequate diagnostic approach when APE is suspected on clinical ground [18] and because this condition often occurs with nonspecific or atypical presentations and thus remains a serious underlying challenge in the diagnostic pathway of any cardiovascular emergency.