Philip Anthony Hodnett1,2, Ioannis
Kokztzoglou3, Timothy Scanlon, Jeremy Collins4, John
Sheehan, Eugene Dunkle, James C. Carr, Robert Edelman
1Northwestern University, Chicago, IL,
United States; 2Northshore University Healthcare System, Chicago,
IL, United States; 3Northshore University Healthcare System,
United States; 4Northwestern University, United States
Imtroduction:The
purpose of this study was to test the hypothesis that a hybrid technique
employing a new unenhanced MRA technique, quiescent interval single shot
(QISS) in combination with a low-dose time resolved (TWIST)of the calf
provides comparable diagnostic accuracy to the standard hybrid approach using
low-dose TWIST of the calf and high-dose stepping table CE-MRA. Materials and
Methods:20 prospective patients referred for evaluation of peripheral
arterial disease underwent unenhanced and combined low-dose time-resolved
(TWIST)evaluation followed by standard hybrid stepping table bolus chase MRA.
Results:The combined unenhanced QISS technique and low-dose time resolved
(TWIST ) calf study resulted in an overall sensitivity of 97.4%, specificity
of 98.3%, a negative predictive value of 98.7% and a positive predictive
value of 96.7% using CE-MRA as the reference standard. Cohen kappa analysis
for inter-rater indicates almost perfect agreement (= 0.86) between the
hybrid approach of unenhanced QISS and TWIST and standard hybrid CE-MRA.
Conclusion: This hybrid strategy
permits a dramatic reduction in contrast agent dosage with no loss of
diagnostic accuracy.