Screening CT angiography in patients with suspected fibromuscular dysplasia: improved patient care with single-session skull vertex to pelvis coverage

Abstract

Background: Imaging plays a key role in the workup of patients with clinically suspected fibromuscular dysplasia (FMD), and research has highlighted the potential of computed tomography angiography (CTA) in screening for thoracic, abdominal, and pelvic arterial abnormalities in these patients. We sought to evaluate imaging findings from patients with suspected or diagnosed FMD who underwent screening CTA at our institution with a novel single-acquisition protocol that offers increased anatomic coverage, with images obtained from the skull vertex to the pelvis.

Methods: Images from 80 consecutive patients scanned with the novel single-session CTA protocol covering the skull vertex to the pelvis were compared with images from 20 additional consecutive patients who underwent CTA for the head and neck separate from CTA of the chest, abdomen, and pelvis.

Results: Compared with CTA performed in separate sessions, the single-session CTA protocol decreased the radiation dose by 38% (P<0.001) and decreased the contrast dose by 39% (P<0.001), with satisfactory image quality noted in all instances. Additionally, higher mean contrast attenuation was noted in the aortic arch with use of the novel protocol (409±76 HU) versus with use of the dual-acquisition protocol (260±38 HU; P<0.001).

Conclusions: These results suggest that use of a novel single-session CTA protocol extending from the skull vertex to the pelvis provides effective screening imaging in patients with suspected or diagnosed FMD as compared with multisession, standard-pitch CTA.

Keywords: Computed tomography angiography (CTA); fibromuscular dysplasia (FMD); screening.

Figure 1

Images obtained from the skull vertex to the ischial tuberosities in a single session using the novel technique. Volume-rendered images demonstrate the range of body coverage (A) and the thoracoabdominal aorta after bone removal (B).

Figure 2

Images of arterial beading obtained using the novel technique. Fibromuscular dysplasia (arrows) demonstrated on coronal multiplanar images involving the bilateral carotid arteries (A) and axial images of the right renal artery (B) in 2 different patients.

Figure 3

Dissections (arrows) in 3 different patients with fibromuscular dysplasia. Axial images obtained using the novel technique demonstrate dissection of the right common carotid artery (A), left vertebral artery (B), and right external iliac artery (C).

Figure 4

Multiplanar reformatted images obtained using the novel imaging technique. (A) Diffuse ectasia and tortuosity of the vessel (arrows) demonstrated on a coronal reformatted image of the left vertebral artery; (B) ectasia and tortuosity of the left common carotid and left vertebral arteries (arrows) demonstrated on a sagittal maximum intensity projection image.

Figure 5

High-quality images obtained using the novel technique. Right renal beading demonstrated on a coronal maximum intensity projection image (A); right carotid dissection/pseudoaneurysm (arrow) demonstrated on an axial image (B); on an axial image, the level of the aortic root is demonstrated (C).

Figure 6

Medium-quality images obtained using the novel technique. Right renal (A) and left renal (B) beading demonstrated on coronal maximum intensity projection images. On axial images, the level of the aortic root (C) and a left carotid dissection (D) from different patients can be seen.