Contrast-to-Noise Ratio Optimization in Coronary Computed Tomography Angiography: Validation in a Swine Model

Hubbard, Logan; Malkasian, Shant; Zhao, Yixiao; Abbona, Pablo; Molloi, Sabee

doi:10.1016/j.acra.2018.06.026

Cited by 11 publications

(17 citation statements)

References 26 publications

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“…The variable time delays between V1 and V2 for the low-dose acquisitions were also estimated from the reference standard acquisitions, which is clinically unrealistic. Consequently, each time delay can be determined with a diluted test bolus and single slice CINE scanning [ 36 ], with only slight increases in contrast and radiation dose. The proper time delay may also be estimated as a function of the contrast injection time plus a fixed dispersion time [ 37 ], where the accuracy of perfusion measurement is maintained as long as the V2 volume scan is acquired within approximately ± 2 cardiac cycles of the true peak of the aortic enhancement [ 37 ].…”

Section: Discussionmentioning

confidence: 99%

“…That said, the low-dose technique derives perfusion using the integrated change in HU within the entire myocardium over time; thus, the impact of motion on the accuracy of perfusion measurement was not significant. Still, despite optimal CTA acquisition at the peak of the aortic enhancement [ 36 , 37 ], the impact of motion combined with metal artifacts from the angioplasty balloons and wires significantly reduced coronary image quality, preventing morphological cross-sectional assessment of the stenoses. However, such motion and metal artifacts were not significant enough to prevent coronary centerline extraction; hence, the accuracy of minimum-cost-path myocardial assignment was unaffected.…”

Section: Discussionmentioning

confidence: 99%

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Combining perfusion and angiography with a low-dose cardiac CT technique: a preliminary investigation in a swine model

Hubbard

Malkasian

Zhao

et al. 2021

Int J Cardiovasc Imaging

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Morphological and physiological assessment of coronary artery disease (CAD) is necessary for proper stratification of CAD risk. The objective was to evaluate a low-dose cardiac CT technique that combines morphological and physiological assessment of CAD. The low-dose technique was evaluated in twelve swine, where three of the twelve had coronary balloon stenosis. The technique consisted of rest perfusion measurement combined with angiography followed by stress perfusion measurement, where the ratio of stress to rest was used to derive coronary flow reserve (CFR). The technique only required two volume scans for perfusion measurement in mL/min/g; hence, four volume scans were acquired in total; two for rest with angiography and two for stress. All rest, stress, and CFR measurements were compared to a previously validated reference technique that employed 20 consecutive volume scans for rest perfusion measurement combined with angiography, and stress perfusion measurement, respectively. The 32 cm diameter volumetric CT dose index ($${\text{CTDI}}_{\text{vol}}^{32}$$ CTDI vol 32 ) and size-specific dose estimate (SSDE) of the low-dose technique were also recorded. All low-dose perfusion measurements (PLOW) in mL/min/g were related to reference perfusion measurements (PREF) through regression by PLOW = 1.04 PREF − 0.08 (r = 0.94, RMSE = 0.32 mL/min/g). The $${\text{CTDI}}_{\text{vol}}^{32}$$ CTDI vol 32 and SSDE of the low-dose cardiac CT technique were 8.05 mGy and 12.80 mGy respectively, corresponding to an estimated effective dose and size-specific effective dose of 1.8 and 2.87 mSv, respectively. Combined morphological and physiological assessment of coronary artery disease is feasible using a low-dose cardiac CT technique.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Combining perfusion and angiography with a low-dose cardiac CT technique: a preliminary investigation in a swine model

Hubbard

Malkasian

Zhao

et al. 2021

Int J Cardiovasc Imaging

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“…A previous report has shown that accurate perfusion measurements can be made using the FPA technique for different timing protocols of the first (V1) and second (V2) volume scans [34]. Furthermore, a diluted test-bolus technique [35] was also reported to prospectively determine the timing for the two-volume scans, however, with slightly increased contrast and radiation dose. By injecting the same amount of diluted contrast as the actual contrast bolus, Dynamic pulmonary CT perfusion using first-pass analysis technique with only two volume scans the contrast arrival timing (V1) and maximal enhancement timing (V2) can be monitored and used for the prospective FPA volume scans [35].…”

Section: Discussionmentioning

confidence: 99%

Dynamic pulmonary CT perfusion using first-pass analysis technique with only two volume scans: Validation in a swine model

et al. 2020

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PurposeTo evaluate the accuracy of a low-dose first-pass analysis (FPA) CT pulmonary perfusion technique in comparison to fluorescent microsphere measurement as the reference standard. MethodThe first-pass analysis CT perfusion technique was validated in six swine (41.7 ± 10.2 kg) for a total of 39 successful perfusion measurements. Different perfusion conditions were generated in each animal using serial balloon occlusions in the pulmonary artery. For each occlusion, over 20 contrast-enhanced CT images were acquired within one breath (320 x 0.5mm collimation, 100kVp, 200mA or 400mA, 350ms gantry rotation time). All volume scans were used for maximum slope model (MSM) perfusion measurement, but only two volume scans were used for the FPA measurement. Both MSM and FPA perfusion measurements were then compared to the reference fluorescent microsphere measurements. ResultsThe mean lung perfusion of MSM, FPA, and microsphere measurements were 6.21 ± 3.08 (p = 0.008), 6.59 ± 3.41 (p = 0.44) and 6.68 ± 3.89 ml/min/g, respectively. The MSM (P MSM ) and FPA (P FPA ) perfusion measurements were related to the corresponding reference microsphere measurement (P MIC ) by P MSM = 0.51P MIC + 2.78 (r = 0.64) and P FPA = 0.79P MIC + 1.32 (r = 0.90). The root-mean-square-error for the MSM and FPA techniques were 3.09 and 1.72 ml/min/g, respectively. The root-mean-square-deviation for the MSM and FPA techniques were 2.38 and 1.50 ml/min/g, respectively. The CT dose index for MSM and FPA techniques were 138.7 and 8.4mGy, respectively. ConclusionsThe first-pass analysis technique can accurately measure regional pulmonary perfusion and has the potential to reduce the radiation dose associated with dynamic CT perfusion for assessment of pulmonary disease. Citation: Zhao Y, Hubbard L, Malkasian S, Abbona P, Molloi S (2020) Dynamic pulmonary CT perfusion using first-pass analysis technique with only two volume scans: Validation in a swine model. PLoS ONE 15(2): e0228110. https://doi.

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“…A minimum delay of 10 minutes was again employed during each acquisition delay. Of note, during each delay, the time (Δt) between V1 and V2 was estimated from the prior reference acquisition using automatic time-density-curve analysis (Acquilion One; Canon Medical Systems, Tustin, CA) and was used, in place of a diluted test bolus 25 or an empirically derived time delay, 26 for proper timing of the subsequent prospective 2-volume FPA perfusion acquisition. After each delay, contrast material and a saline chaser were injected as described previously, and low-dose, 2-mm slab, dynamic bolus tracking at 100 kVp and 50 mA (SureStart; Aquilion One, Canon Medical Systems, Tustin, CA) was performed, where V1 was acquired after the aortic enhancement exceeded 140 HU above the baseline blood pool intensity while V2 was acquired after V1 using the previously estimated time delay, Δt.…”

Section: Prospective Fpa Perfusion Protocolmentioning

confidence: 99%

“…29 Another limitation was proper prospective acquisition of V2 at approximately the peak of the aortic enhancement. 22,23,25 For the purposes of this study, the optimal time delay (Δt) between V1 and V2 to capture V2 at the peak was estimated from the reference standard retrospective acquisition before each subsequent prospective acquisition. Although such a scheme is clinically unrealistic, fortunately, the optimal time delay can also be derived through the preemptive use of a low-dose diluted test bolus acquisition, as previously validated.…”

Section: Limitationsmentioning

confidence: 99%

Low-Radiation-Dose Stress Myocardial Perfusion Measurement Using First-Pass Analysis Dynamic Computed Tomography

et al. 2019

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Objectives: The aim of this study was to assess the feasibility of a prospective first-pass analysis (FPA) dynamic computed tomography (CT) perfusion technique for accurate low-radiation-dose global stress perfusion measurement. Materials and Methods: The prospective FPA technique was evaluated in 10 swine (42 ± 12 kg) by direct comparison to a previously validated retrospective FPA technique. Of the 10 swine, 3 had intermediate stenoses with fractional flow reserve severities of 0.70 to 0.90. In each swine, contrast and saline were injected peripherally followed by dynamic volume scanning with a 320-slice CT scanner. Specifically, for the reference standard retrospective FPA technique, volume scans were acquired continuously at 100 kVp and 200 mA over 15 to 20 seconds, followed by systematic selection of only 2 volume scans for global perfusion measurement. For the prospective FPA technique, only 2 volume scans were acquired at 100 kVp and 50 mA for global perfusion measurement. All prospective global stress perfusion measurements were then compared with the corresponding reference standard retrospective global stress perfusion measurements through regression analysis. The CTDI 32 vol and size-specific dose estimate of the prospective FPA technique were also determined. Results: All prospective global stress perfusion measurements (P PRO ) at 50 mA were in good agreement with the reference standard retrospective global stress perfusion measurements (P REF ) at 200 mA (P PRO = 1.07 P REF −0.09, r = 0.94; root-mean-square error = 0.30 mL/min per gram). The CTDI 32 vol and size-specific dose estimate of the prospective FPA technique were 2.3 and 3.7 mGy, respectively. Conclusions: Accurate low-radiation-dose global stress perfusion measurement is feasible using a prospective FPA dynamic CT perfusion technique.

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Contrast-to-Noise Ratio Optimization in Coronary Computed Tomography Angiography: Validation in a Swine Model

Abstract: A new combined diluted test bolus and CT angiography protocol was shown to improve coronary enhancement and CNR as compared to an existing standard CT angiography protocol.

Cited by 11 publications

References 26 publications

Combining perfusion and angiography with a low-dose cardiac CT technique: a preliminary investigation in a swine model

Combining perfusion and angiography with a low-dose cardiac CT technique: a preliminary investigation in a swine model

Dynamic pulmonary CT perfusion using first-pass analysis technique with only two volume scans: Validation in a swine model

Low-Radiation-Dose Stress Myocardial Perfusion Measurement Using First-Pass Analysis Dynamic Computed Tomography

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