Radiologic mimics of pulmonary embolism

The Harms of Unnecessary CT Pulmonary Angiography: A Case Report and Literature Review

Pulmonary embolism (PE) poses a significant health risk in the United States, with high mortality rates. Clinicians maintain a low threshold for suspecting PE, potentially leading to deviation from guideline-recommended algorithms and unnecessary computed tomography pulmonary angiography (CTPA). This case discusses a 46-year-old woman who presented with symptoms suggestive of PE following a prolonged road trip. Despite a low Wells score and negative D-dimer results, she underwent CTPA, resulting in an unnecessary and harmful interventional radiology-guided thrombectomy. This highlights the importance of adhering to guidelines in PE diagnosis to mitigate potential harms associated with the overuse of available medical tools.

Slow flow mimicking pulmonary embolism

A man in his 70s in a rehabilitation hospital, post cerebral infarct, became acutely short of breath with reduced oxygen saturations and an elevated d-dimer.Non-occlusive filling defects were noted on the CT pulmonary angiogram in the proximal left pulmonary arteries. There was associated hypoplasia of the distal pulmonary arterial tree in the left hemithorax with left pulmonary vein stenosis. Review of previous imaging suggested this oligaemia was longstanding.Although filling defects in the pulmonary arteries usually correspond to embolic material, in our patient they were too dense to represent thrombus and probably represented flow-related artefacts in the setting of chronic air trapping.Given the associated volume loss, bronchiectasis and bronchial wall thickening in the left hemithorax Swyer-James-McLeod syndrome was thought to be the most likely underlying cause.

False-Positive for Pulmonary Emboli on Ventilation/Perfusion Scan Due to Improper Patient Positioning During Tracer Administration

ABSTRACT

A 67-year-old woman presented with shortness of breath and a ventilation/perfusion scan was performed. Initial images demonstrated mismatched bilateral apical defects that would be classified as high probability for pulmonary emboli. However, it was unusual that the defects were only in the bilateral apices. Investigation discovered that 99m Tc-MAA was administered while the patient was in a seated position. Repeat scan the following day with the patient in the correct, supine, position during 99m Tc-MAA administration demonstrated no defects. In this case, incorrect patient positioning could have resulted in an incorrect diagnosis of pulmonary emboli and inappropriate treatment of the patient.