Mohamed Marwan, MD
Department of Radiology, University Hospital Erlangen, Erlangen, Germany
History
A 56-year-old female
patient, complaining of exertional dyspnea, was referred for an outpatient
coronary CT angiography. Her medical history was unremarkable, apart from a
positive treadmill stress ECG test. She had neither known risk factors, nor
family history of coronary artery disease (CAD). A coronary CT angiography (cCTA)
was performed for evaluation.
Diagnosis
cCTA images revealed a severe
stenosis at the ostium of the left circumflex artery (LCX) with no evidence of
any atherosclerotic plaque. No stenoses were found in the rest of the coronary arteries
and their branches. The patient underwent invasive coronary angiography (ICA),
which confirmed the diagnosis. However, due to the difficult anatomy which was
not suitable for interventional treatment, the patient was referred for bypass
surgery.
Courtesy of Department of Radiology, University Hospital Erlangen, Erlangen, Germany
Fig. 1:
MPR (Fig. 1a), MIP (Fig. 1b) and cVRT (Figs. 1c and 1d) images show a severe stenosis (arrows) at proximal LCX, without any evidence of plaque.Comments
cCTA is an established
non-invasive imaging modality that provides robust assessment of CAD, owing to
the continuous evolution of CT technologies, especially since the introduction
of dual source CT (DSCT). This technology uses two X-ray tubes and two
detectors arranged at 90° angles, allowing reconstruction of cross-sectional
images at one quarter of the gantry rotation time, thus significantly improving
the temporal resolution. This case was acquired with the very first dual source
CT scanner clinically available – SOMATOM Definition. A severe stenosis at the
ostium of the LCX was clearly depicted and freely demonstrated in three
dimensions. While in ICA, it could have been challenging to project this lesion
and potentially miss it especially if prior knowledge from CT was not
available. Coronary stenosis is normally associated with the presence of
plaques – either calcified or non-calcified. Coronary stenosis without evidence
of plaques, such as this case, is rarely seen. The underlying cause of such a
stenosis is unknown and yet to be investigated.
Courtesy of Department of Radiology, University Hospital Erlangen, Erlangen, Germany
Fig. 2:
Angiographic images show a severe stenosis (arrows) at the ostium of the LCX, which is challenging to project and could potentially be missed without the prior knowledge from CT.