Katherine L Wright^1,2, Nicole Seiberlich^2,3, John A Jesberger², Raymond F Muzic^1,3, Mark A Griswold^1,3, and Vikas Gulani^2,3
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States, ²Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio, United States, ³Department of Radiology, University Hospitals, Cleveland, Ohio, United States

Complete evaluation of both large and small vessel status would typically require two separate contrast enhanced acquisitions: MR angiography and dynamic contrast enhanced (DCE) perfusion. Both the MRA and quantitative DCE perfusion could be obtained simultaneously if a 3D time-resolved contrast enhanced data set could be acquired in a manner that the contrast and spatial/temporal resolution requirements for both exams could be met. This study demonstrates feasibility and repeatability of simultaneous MRA and perfusion (MRAP) with a time resolved MRA acquisition, and initial application for leg angiography and quantitative skeletal muscle perfusion at rest and following a physiological stimulus (exercise).

Benjamin Landgraf¹, Alex Frydrychowicz¹, Kevin Johnson², Alejandro Roldan¹, Chris Francois¹, Scott Reeder^1,2, and Oliver Wieben^2
1Radiology, University of Wisconsin - Madison, Madison, WI, United States, ²Medical Physics, University of Wisconsin - Madison, Madison, WI, United States

This study aims to determine the effects of intravascular contrast agent on radially encoded velocity mapping MRI on the quality of visualization of the portal venous vasculature. While imaging without a contrast agent provides good image quality, examination of vessel signal and diagnostic quality of vasculature in derived angiograms from human volunteer after contrast administration shows greatly improved image quality and visualization of distal branches of the portal vasculature.

Phillip Young¹, James F Glockner¹, Terri R Vrtiska², Thanila Macedo², Petrice Mostardi², and Stephen J Riederer^2
1Radiology, Mayo Clinic, Rochester, MN, United States, ²Mayo Clinic

We describe initial results of a comparison of radiologist confidence in evaluating CAPR MRA and CTA for below the knee runoff in clinical patients. CAPR MRA demonstrates significantly higher radiologist confidence for distal vessels than CTA

Moritz Wagner^1,2, Yutaka Natsuaki^2,3, Bernd Hamm¹, Gerhard Laub^2,3, and Paul Finn^2
1Radiology, Charite - University Hospital, Berlin, Germany, ²Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, United States, ³Siemens Healthcare, United States

Our study presents a novel ECG gated first-pass CEMRA sequence which reads out central k-space data during the cardiac resting phase while the overall center of k-space was made to coincide with peak arterial enhancement. The improved data acquisition efficiency of the ECG-gated first-pass CEMRA allowed for high resolution imaging of the entire thorax. We report initial data of ECG-gated first-pass CEMRA in healthy volunteers and patients.

Dariusch Reza Hadizadeh¹, Guido M Kukuk¹, Ute L Fahlenkamp¹, Jürgen Gieseke^1,2, Frank Träber¹, Josephine Pressacco³, Christian Schäfer⁴, Eberhard Rabe⁵, Arne Koscielny⁶, Frauke Verrel⁶, Hans H Schild¹, and Winfried A Willinek^1
1Radiology, University of Bonn, Bonn, NRW, Germany, ²Philips Healthcare, Best, Netherlands, ³Radiology, Montreal Heart Institute, Montreal, Quebec, Canada, ⁴Internal Medicine II, Division of Cardiology, Pneumology, and Angiology, University of Bonn, Bonn, NRW, Germany, ⁵Dermatology, Division of Phlebology, University of Bonn, Bonn, NRW, Germany, ⁶Vascular Surgery, University of Bonn, Bonn, NRW, Germany

Synopsis: High-spatial resolution contrast-enhanced-MRA of the run-off vessels during the equilibrium phase of blood-pool contrast agents (SSMRA) has been shown to increase sensitivity and specificity in stenosis grading of the arterial vasculature. The simultaneous visualization of veins allows for diagnosis of important additional venous findings that may affect therapeutic regimen. Acute and chronic deep venous thrombosis was diagnosed in 26 of 245 patients of patients with peripheral arterial occlusive disease and was confirmed by duplex ultrasound.

Andew Nicholas Priest¹, Martin J Graves¹, and David J Lomas^1
1Department of Radiology, Addenbrookes Hospital and University of Cambridge, Cambridge, United Kingdom

Recently demonstrated methods for non-contrast enhanced MR angiography use velocity-sensitised preparation to suppress the signal from flowing blood. Arterial images are generated by subtraction of bright- and dark-blood images, acquired with and without flow suppression. However, discrimination between arteries and veins is inadequate to allow reliable depiction of arteries without venous contamination. An alternative approach, using acceleration-dependent flow suppression, has been implemented, taking advantage of the pulsatility of arterial flow. It is demonstrated to give good arterial depiction with no venous contamination over a wide range of motion suppression gradient amplitudes, without substantial background signals, fluid contamination and other artifacts.

Ioannis Koktzoglou^1,2, NavYash Gupta³, and Robert R Edelman^1
1Radiology, NorthShore University HealthSystem, Evanston, IL, United States, ²Radiology, The University of Chicago, Chicago, IL, United States, ³Vascular Surgery, NorthShore University HealthSystem, Evanston, IL, United States

Compared with alternate nonenhanced approaches of time-of-flight magnetic resonance angiography (MRA), new nonenhanced techniques such as pulsed arterial spin labeling (PASL) may offer potential benefits. A more recent labeling approach, pseudocontinuous arterial spin labeling (PCASL), has been reported to improve the signal-to-noise ratio (SNR) of cerebral perfusion imaging compared with PASL. The purpose of this study was to investigate whether PCASL can improve the SNR of nonenhanced carotid MRA compared with pulsed methods.

Huimin Wu¹, Walter F Block², Patrick A Turski³, Charles A Mistretta¹, and Kevin M Johnson^1
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, ²Biomedical engineering, University of Wisconsin-Madison, Madison, WI, United States,³Radiology, University of Wisconsin-Madison, Madison, WI, United States

3D angiography with pseudo continuous Arterial Spin Labeling (PCASL) tagging scheme and accelerated radial sampling pattern has been implemented. Feasibility studies on intracranial vasculature have been done on healthy volunteer and images show large coverage, transparent background, isotropic resolution, high contrast and SNR. Comparison with standard 3D TOF demonstrate the advantage of 3D PCASL angiography on substantially improved visualization of vessels with slow filling.

Ricardo Otazo¹, Pippa Storey¹, Daniel Kim¹, Daniel K Sodickson¹, and Vivian S Lee^1
1Department of Radiology, NYU School of Medicine, New York, NY, United States

Non-gadolinium MRA with varying flow sensitivities can be performed by acquiring sets of FSE images in systole and diastole with different refocusing flip angles, so that the subtraction of systolic and diastolic images provides angiograms that resemble “time-resolved” MRA. In order to achieve feasible acquisition times and reduce sensitivity to subject motion, accelerated imaging is required. The inherent sparsity of the angiograms and the presence of correlations among the images acquired with different flip angles make the technique a good candidate for compressed sensing. We demonstrate feasibility of 16-fold accelerated dynamic non-contrast MRA using compressed sensing and parallel imaging.