Imaging Pearls ❯ Vascular ❯ Technical
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- “Through a marriage of spiral computed tomography (CT) and graphical volumetric image processing, CT angiography was born 20 years ago. Fueled by a series of technical innovations in CT and image processing, over the next 5-15 years, CT angiography toppled conventional angiography, the undisputed diagnostic reference standard for vascular disease for the prior 70 years, as the preferred modality for the diagnosis and characterization of most cardiovascular abnormalities.”
CT angiography after 20 years: a transformation in cardiovascular disease characterization continues to advance.
Rubin GD et al
Radiology. 2014 Jun;271(3):633-52 - “Lower extremity CT angiography is an accurate imaging modality in patients with intermittent claudication, with a sensitivity of 95% (95% confidence interval: 92%, 97%) and a specificity of 96% (95% confidence interval: 93%, 97%) for detecting more than 50% stenosis or occlusions reported in a recent meta-analysis .”
CT angiography after 20 years: a transformation in cardiovascular disease characterization continues to advance.
Rubin GD et al
Radiology. 2014 Jun;271(3):633-52 - “One important concern regarding the performance of coronary CT angiography is that its positive predictive value is not nearly as robust as its negative predictive value. Given the high prevalence of clinical symptoms where CAD is within the differential diagnosis, there remain concerns that false-positive results from the routine use of coronary CT angiography will increase downstream costs.”
CT angiography after 20 years: a transformation in cardiovascular disease characterization continues to advance.
Rubin GD et al
Radiology. 2014 Jun;271(3):633-52 - “Over a short 20-year span, CT angiography has evolved from a fledgling imaging modality, incapable of encompassing most vascular territories, to a critical clinical tool that plays a dominant role in the diagnosis and management of disease within virtually every arterial bed in the body. While technological developments in CT acquisition and image processing techniques have enabled great innovation and important discovery, there is no sign of this trend slowing.”
CT angiography after 20 years: a transformation in cardiovascular disease characterization continues to advance.
Rubin GD et al
Radiology. 2014 Jun;271(3):633-52
- “ The use of an advanced imaging software for measurement of ascending aortic aneurysm reduces interobservor variability.”
MDCT interpretation of the ascending aorta with semiautomated measurement software: Improved reproducibility compared with manual techniques
Ahmed S, Zimmerman SL, Johnson PT, Lai H, Kawamoto S, Horton KM, Fishman EK
J Cardiovasc Comput Tomogr
8 (2014)108-114 - “ A semiautomated measurement system can decrease measurement variability when assessing the maximal diameter of an ascending aortic aneurysm. The interobserver variability was reduced substantially with this software.”
MDCT interpretation of the ascending aorta with semiautomated measurement software: Improved reproducibility compared with manual techniques
Ahmed S, Zimmerman SL, Johnson PT, Lai H, Kawamoto S, Horton KM, Fishman EK
J Cardiovasc Comput Tomogr
8 (2014)108-114 - “ The historically inflated risk of CIN reflects logistic and intellectual pitfalls that continue to confound the study of this disease. Recent advances have clarified that the incidence of CIN is much lower than previously thought, but there are lingering questions. We suggest that CIN is likely real but is rare and offer directions for future study.”
The Challenges in Assessing Contrast-Induced Nephropathy: Where Are We Now-
Davenport MS et al.
AJR 2014;202:784-789 - “ In conclusion it is an exciting time for the study of CIN. Although most recent investigations agree that CIN is an overdiagnosed illness confounded by countless alternative nephrotoxic events and physiologic variation, there are data indicating that for at least patients with severe renal insufficiency, IV LOCM and IOCM are potential nephrotoxins that merit continued scrutiny.”
The Challenges in Assessing Contrast-Induced Nephropathy: Where Are We Now-
Davenport MS et al.
AJR 2014;202:784-789
- Aneurysm Measurement
- Axial measurements prone to error
- Current scanners with sub-millimeter detector thickness yield isotropic CT volumes
- Multiplanar interpretation is standard of care for aneurysm analysis
- Measurements orthogonal to aortic centerline
- "Whereas editing with IWT is an efficient method of improving the diagnostic capacity of 3D-rendered imaging,errors can still arise when vessels are located in close proximity to bone."
Automated Multidetector Row CT Dataset Segmentation with an Interactive Watershed Transform (IWT) Algorithm:Part 2-Body CT Angiographic and Orthopedic Applications
Heath DP, Hahn HK, Johnson PT, Fishman EK
J Digital Imaging (in press)
- "The purpose of this paper is to demonstrate the utility of a fast, automated editing tool, an Interactive Watershed Transform (IWT) technique, for segmenting body multidetector row computed tomography (MDCT) volumes."
Automated Multidetector Row CT Dataset Segmentation with an Interactive Watershed Transform (IWT) Algorithm:Part 2-Body CT Angiographic and Orthopedic Applications
Heath DP, Hahn HK, Johnson PT, Fishman EK
J Digital Imaging (in press)
- "The use of power injectors through 18- to 24-guage angiocatheters in children is safe when meticulous technique is used and personnel are appropriately trained. Our study showed a similar rate of extravasation as has been reported in other studies."
Safety of Power Injector Use in Children as Measured by Incidence of Extravasation
Amaral JG et al.
AJR 2006; 187:580-583
- "The use of power injectors through 18- to 24-guage angiocatheters in children is safe when meticulous technique is used and personnel are appropriately trained."
Safety of Power Injector Use in Children as Measured by Incidence of Extravasation
Amaral JG et al.
AJR 2006; 187:580-583
- Scanning Parameters
Scanner type 16 slice MDCT 64 slice MDCT
kVp 120 120
mAs 150-180 130-180
Scan collimati on .75 mm .6
Slice thickness .75 mm .75
Interscan spacing .5 mm .5