Figure 1
Multidetector Spiral CTA of the peripheral vessels
A very large volume acquired (120 cm) with 3d recontruction shows the peripheral arterial tree from the celiac trunk to the distal arteries of the legs
Clinical History
A 56 years old man with history of hypertension recent, “claudicatio” intermittens and continuos pain on the right leg, underwent CT angiography.
Imaging Findings
A 56 years old man smoking 20 cigarettes per day since his 16th birthday with history of hypertension (170/97), presented with a right leg “claudicatio” intermittens started a few months before. He went to the vascular surgeon for continuos pain on the right leg and he decided for a minimally-invasive angiographic study: a multislice spiral CT Angiography was performed.
A large volume was acquired by means of this technique: from the celiac trunk to distal arteries of both lower limbs. No contrast filling in the right femoral artery was observed on axial images.
Volume data were transferred to a free-standing workstation using a Volume Rendering algorythm in order to generate a “panoramic” 3D angiography.
Discussion
Peripheral arteries obstructive disease frequently occurs on elderly patients, particularly if high atherosclerosis risk factors are present. Diffuse and mono-pluri segmental lesions distribution represent two patterns of this disease.
In order to evaluate stenosis, obstructions and vascular supplyings, US (Doppler and Power Doppler),DSA (Digital Subtraction Angiography) and MRA are actually performed. Nowadays multidetector spiral CT angiography allows acquisition of large volumes displaying the whole abdominal aorta and inferior limbs arterial tree. Moreover, 3D imaging, particularly Volume Rendering, provides further information on spatial arrangement of vascular structures.
Volume Rendering technique, despite MIP (a projective method which may entayl problems if calcifications or bony structures are included in the volume of interest), Surface Shaded Display (in which each voxel within a data set is included or excluded whether its density reaches a selected treshold value), uses the entire data set with no information loss as happens on both projectional and surface algorithms. A selective visualization of different structures is obtained by modulating relative opacities and transparencies, using dedicated curves. In order to visualise vascular structures only, bones can be excluded from CT acquisitions by means of sculpture tools.
Differential Diagnosis List
Peripheral arteries obstructive disease
Final Diagnosis
Peripheral arteries obstructive disease
References
[1] Hayashi H, Kobayashi H, Takagi R, Kawamata H, Ichikawa T, Kumazaki T. Three-dimensional CT angiographic assessment of vascular diseases using various postprocessing techniques: the voxel transmission and cruising eye view methods and their respective merits. Int Angiol 1999 Jun;18(2):113-21. (PMID: 10424366)
[2] Calhoun PS, Kuszyk BS, Heath DG, Carley JC, Fishman EK. Three-dimensional volume rendering of spiral CT data: theory and method. Radiographics 1999 May-Jun;19(3):745-64. (PMID: 10336201)
[3] Ishikawa M, Morimoto N, Sasajima T, Kubo Y. Three-dimensional computed tomographic angiography in lower extremity revascularization. Surg Today 1999;29(3):243-7. (PMID: 10192735)
[4] Smith PA, Fishman EK. Three-dimensional CT angiography: renal applications. Semin Ultrasound CT MR 1998 Oct;19(5):413-24. (PMID: 9800251)
[5] Smith PA, Klein AS, Heath DG, Chavin K, Fishman EK. Dual-phase spiral CT angiography with volumetric 3D rendering for preoperative liver transplant evaluation:preliminary observations. J Comput Assist Tomogr 1998 Nov-Dec;22(6):868-74. (PMID: 9843223)
Case information
| URL: | https://eurorad.org/case/424 |
| DOI: | 10.1594/EURORAD/CASE.424 |
| ISSN: | 1563-4086 |
Figure 2
Multidetector Spiral CTA: 3D evaluation
Post-processing bone segmentation allows to better visualize the obstruction of the right superficial femoral artery with recanalization due to collateral circles from the right deep femoral artery.
Multidetector Spiral CTA of the peripheral vessels
A very large volume acquired (120 cm) with 3d recontruction shows the peripheral arterial tree from the celiac trunk to the distal arteries of the legs
Multidetector Spiral CTA: 3D evaluation
Post-processing bone segmentation allows to better visualize the obstruction of the right superficial femoral artery with recanalization due to collateral circles from the right deep femoral artery.