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Validation of high temporal resolution spiral phase velocity mapping of temporal patterns of left and right coronary artery blood flow against Doppler guidewire.

Keegan J, Raphael CE, Parker K, Simpson RM, Strain S, de Silva R, Di Mario C, Collinson J, Stables RH, Wage R, Drivas P, Sugathapala M, Prasad SK, Firmin DN - J Cardiovasc Magn Reson (2015)

Bottom Line: A non-invasive alternative would be beneficial as it would allow study of a wider patient population and serial scanning.Cardiovascular magnetic resonance (CMR) velocity-time curves were processed semi-automatically and compared with corresponding invasive Doppler data.In individual vessels, plots of CMR velocities at all cardiac phases against corresponding Doppler velocities showed a consistent linear relationship between the two with high R(2) values (mean +/-SD: 0.79 +/-.13).

View Article: PubMed Central - PubMed

Affiliation: Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK. j.keegan@rbht.nhs.uk.

ABSTRACT

Background: Temporal patterns of coronary blood flow velocity can provide important information on disease state and are currently assessed invasively using a Doppler guidewire. A non-invasive alternative would be beneficial as it would allow study of a wider patient population and serial scanning.

Methods: A retrospectively-gated breath-hold spiral phase velocity mapping sequence (TR 19 ms) was developed at 3 Tesla. Velocity maps were acquired in 8 proximal right and 15 proximal left coronary arteries of 18 subjects who had previously had a Doppler guidewire study at the time of coronary angiography. Cardiovascular magnetic resonance (CMR) velocity-time curves were processed semi-automatically and compared with corresponding invasive Doppler data.

Results: When corrected for differences in heart rate between the two studies, CMR mean velocity through the cardiac cycle, peak systolic velocity (PSV) and peak diastolic velocity (PDV) were approximately 40 % of the peak Doppler values with a moderate - good linear relationship between the two techniques (R(2): 0.57, 0.64 and 0.79 respectively). CMR values of PDV/PSV showed a strong linear relationship with Doppler values with a slope close to unity (0.89 and 0.90 for right and left arteries respectively). In individual vessels, plots of CMR velocities at all cardiac phases against corresponding Doppler velocities showed a consistent linear relationship between the two with high R(2) values (mean +/-SD: 0.79 +/-.13).

Conclusions: High temporal resolution breath-hold spiral phase velocity mapping underestimates absolute values of coronary flow velocity but allows accurate assessment of the temporal patterns of blood flow.

No MeSH data available.


Related in: MedlinePlus

a Segmented gradient echo scout images showing in-plane (left) and proximal through-plane (right) right coronary artery (arrows). b Single early diastolic frame from the corresponding high temporal resolution spiral phase velocity mapping study acquired with water-excitation (WE) (magnitude image on left, velocity map on right) together with corresponding fat-excitation (FE) images. c CMR velocity-time curve before (top) and after (middle) correction for through-plane velocity of the vessel and corresponding Doppler guide wire trace (bottom). On the Doppler guidewire trace, the peak pixel velocity within the sample volume is highlighted in blue
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Fig3: a Segmented gradient echo scout images showing in-plane (left) and proximal through-plane (right) right coronary artery (arrows). b Single early diastolic frame from the corresponding high temporal resolution spiral phase velocity mapping study acquired with water-excitation (WE) (magnitude image on left, velocity map on right) together with corresponding fat-excitation (FE) images. c CMR velocity-time curve before (top) and after (middle) correction for through-plane velocity of the vessel and corresponding Doppler guide wire trace (bottom). On the Doppler guidewire trace, the peak pixel velocity within the sample volume is highlighted in blue

Mentions: Example LAD and RCA studies analysed with the semi-automatic technique are shown in Figs. 2 and 3 respectively. Figure 4 shows plots of CMR measured mean velocity (a), PDV (b) and PSV (c) against Doppler measured values, after normalising the CMR data to the same heart rate as the corresponding Doppler data. The negative PSV values in (c) reflect early systolic reverse coronary flow which is an expected feature in patients with HCM [31]. There is an approximately linear relationship between the two techniques for all three parameters with coefficients of determination ranging from moderate for MV (R2 = 0.57) to good for PDV (R2 = 0.64) to very good for PSV (R2 = 0.79). The heart rate normalised CMR velocities are typically ~40 % of the Doppler values (MV: 93 +/−35 mm/s vs 251 +/−143 mm/s, p < .0001, PDV: 199 +/−94 mm/s vs 468 +/−275 mm/s, p < .0001; PSV: 95 +/−41 mm/s vs 229 +/−174 mm/s, p < .0001).Fig. 2


Validation of high temporal resolution spiral phase velocity mapping of temporal patterns of left and right coronary artery blood flow against Doppler guidewire.

Keegan J, Raphael CE, Parker K, Simpson RM, Strain S, de Silva R, Di Mario C, Collinson J, Stables RH, Wage R, Drivas P, Sugathapala M, Prasad SK, Firmin DN - J Cardiovasc Magn Reson (2015)

a Segmented gradient echo scout images showing in-plane (left) and proximal through-plane (right) right coronary artery (arrows). b Single early diastolic frame from the corresponding high temporal resolution spiral phase velocity mapping study acquired with water-excitation (WE) (magnitude image on left, velocity map on right) together with corresponding fat-excitation (FE) images. c CMR velocity-time curve before (top) and after (middle) correction for through-plane velocity of the vessel and corresponding Doppler guide wire trace (bottom). On the Doppler guidewire trace, the peak pixel velocity within the sample volume is highlighted in blue
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4591589&req=5

Fig3: a Segmented gradient echo scout images showing in-plane (left) and proximal through-plane (right) right coronary artery (arrows). b Single early diastolic frame from the corresponding high temporal resolution spiral phase velocity mapping study acquired with water-excitation (WE) (magnitude image on left, velocity map on right) together with corresponding fat-excitation (FE) images. c CMR velocity-time curve before (top) and after (middle) correction for through-plane velocity of the vessel and corresponding Doppler guide wire trace (bottom). On the Doppler guidewire trace, the peak pixel velocity within the sample volume is highlighted in blue
Mentions: Example LAD and RCA studies analysed with the semi-automatic technique are shown in Figs. 2 and 3 respectively. Figure 4 shows plots of CMR measured mean velocity (a), PDV (b) and PSV (c) against Doppler measured values, after normalising the CMR data to the same heart rate as the corresponding Doppler data. The negative PSV values in (c) reflect early systolic reverse coronary flow which is an expected feature in patients with HCM [31]. There is an approximately linear relationship between the two techniques for all three parameters with coefficients of determination ranging from moderate for MV (R2 = 0.57) to good for PDV (R2 = 0.64) to very good for PSV (R2 = 0.79). The heart rate normalised CMR velocities are typically ~40 % of the Doppler values (MV: 93 +/−35 mm/s vs 251 +/−143 mm/s, p < .0001, PDV: 199 +/−94 mm/s vs 468 +/−275 mm/s, p < .0001; PSV: 95 +/−41 mm/s vs 229 +/−174 mm/s, p < .0001).Fig. 2

Bottom Line: A non-invasive alternative would be beneficial as it would allow study of a wider patient population and serial scanning.Cardiovascular magnetic resonance (CMR) velocity-time curves were processed semi-automatically and compared with corresponding invasive Doppler data.In individual vessels, plots of CMR velocities at all cardiac phases against corresponding Doppler velocities showed a consistent linear relationship between the two with high R(2) values (mean +/-SD: 0.79 +/-.13).

View Article: PubMed Central - PubMed

Affiliation: Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK. j.keegan@rbht.nhs.uk.

ABSTRACT

Background: Temporal patterns of coronary blood flow velocity can provide important information on disease state and are currently assessed invasively using a Doppler guidewire. A non-invasive alternative would be beneficial as it would allow study of a wider patient population and serial scanning.

Methods: A retrospectively-gated breath-hold spiral phase velocity mapping sequence (TR 19 ms) was developed at 3 Tesla. Velocity maps were acquired in 8 proximal right and 15 proximal left coronary arteries of 18 subjects who had previously had a Doppler guidewire study at the time of coronary angiography. Cardiovascular magnetic resonance (CMR) velocity-time curves were processed semi-automatically and compared with corresponding invasive Doppler data.

Results: When corrected for differences in heart rate between the two studies, CMR mean velocity through the cardiac cycle, peak systolic velocity (PSV) and peak diastolic velocity (PDV) were approximately 40 % of the peak Doppler values with a moderate - good linear relationship between the two techniques (R(2): 0.57, 0.64 and 0.79 respectively). CMR values of PDV/PSV showed a strong linear relationship with Doppler values with a slope close to unity (0.89 and 0.90 for right and left arteries respectively). In individual vessels, plots of CMR velocities at all cardiac phases against corresponding Doppler velocities showed a consistent linear relationship between the two with high R(2) values (mean +/-SD: 0.79 +/-.13).

Conclusions: High temporal resolution breath-hold spiral phase velocity mapping underestimates absolute values of coronary flow velocity but allows accurate assessment of the temporal patterns of blood flow.

No MeSH data available.


Related in: MedlinePlus