Cerebral Venography Using Fluid-Suppressed STARFIRE Robert R Edelman, 1,2 * Ioannis Koktzoglou, 1,2 William J. Ankenbrandt, 1,2 and Eugene E. Dunkle 1 Fluid-suppressed STARFIRE (Signal Targeting Alternative Radio- frequency and Flow-Independent Relaxation Enhancement) is a noncontrast method for flow-independent MR venography (MRV). It uses magnitude subtraction of two inversion recovery-prepared segmented three-dimensional (3D) balanced steady-state free precession acquisitions to obtain isotropic cerebral venograms in which both fat and cerebrospinal fluid signals are suppressed. Unlike two-dimensional time-of-flight (2D TOF) MRV, it is insensi- tive to the flow velocity of the cerebral veins. The method provided excellent depiction of the dural venous sinuses and cortical veins on maximum intensity projection images. Fluid-suppressed STARFIRE and 2D TOF were compared with contrast-enhanced 3D MRV as the reference standard in seven healthy subjects at 1.5 Tesla. Fluid-suppressed STARFIRE compared favorably to 2D TOF on both quantitative and qualitative analyses. Contrast-enhanced MRV provided the highest vein-background relative contrast and best demonstrated the straight sinus, whereas STARFIRE de- picted the most venous branches. Further investigation will be required to determine the accuracy for cerebral venous thrombosis. Magn Reson Med 62:538 –543, 2009. © 2009 Wiley- Liss, Inc. Key words: cerebral veins; dural sinuses; angiography; noncon- trast; STARFIRE MR venography (MRV) is the most sensitive approach for cerebral venous thrombosis (1,2). Two-dimensional time- of-flight (2D TOF) MRV is widely used, relying on the inflow of fresh spins to produce high signal in the veins (3). However, diagnosis with 2D TOF MRV can be chal- lenging, given the existence of several normal variations to cerebral venous anatomy, as well as limited spatial reso- lution and saturation of flow signal relating to vessel ori- entation and flow velocity (4). Another limitation of 2D TOF MRV is the possibility of a false-negative examination due to T1-hyperintense thrombus simulating flowing blood (5). Contrast-enhanced 3D MRV provides excellent depiction of the cerebral veins and dural sinuses (6). How- ever, the administration of contrast media may not be desirable in some cases, for instance if the patient has severely impaired renal function because of concerns about nephrogenic systemic fibrosis. The goal of this pilot study is to demonstrate the feasi- bility of performing flow-independent cerebral MRV using a technique, called fluid-suppressed STARFIRE (Signal Targeting using Alternative Radiofrequency and Flow-In- dependent Relaxation Enhancement), that displays the du- ral venous sinuses and cortical veins while eliminating the signal from cerebrospinal fluid (CSF). SUBJECTS AND METHODS The study was approved by the hospital Institutional Re- view Board. Seven healthy subjects (6 male, ages 18 – 43 years) were studied. Imaging was performed on a 32-chan- nel 1.5 Tesla (T) MR system (Avanto, Siemens Medical, Erlangen, Germany) using a 12-channel head phased array coil with the body coil as RF transmitter. Pulse sequence parameters for both noncontrast and contrast-enhanced MR venography are summarized in Table 1. Pulse Sequence Description Fluid-suppressed STARFIRE is a subtraction technique that takes the difference of two inversion recovery-pre- pared segmented 3D balanced steady-state free precession (SSFP) acquisitions. The inversion is spatially nonselec- tive and uses a 10-ms adiabatic pulse. The first acquisition uses a segment repetition time (TR) of 4 s and inversion time (TI) of 1900 ms to suppress CSF signal and accentuate vascular signal. The second acquisition, which is acquired immediately upon completion of the first acquisition, uses a segment TR of 2 s and TI of 700 ms to suppress both CSF and vascular signal. Phase-encode order was linear. Al- though the process of image subtraction reduces fat signal, a further reduction in fat signal was obtained by the ap- plication of chemical shift-selective fat suppression on both acquisitions. Magnitude subtraction of the two image sets produces an angiogram in which the CSF and fat signals are substantially eliminated, whereas blood vessels appear bright. Whole-brain imaging is performed with the use of a spatially nonselective radiofrequency excitation, with the acquisition oriented in a sagittal or oblique sag- ittal plane. Arterial signal is suppressed by the repeated application of 150-mm-thick 90-degree saturation pulses placed inferior to the brain during quiescent portions of the scan. This pulse sequence is shown in Figure 1. Contrast-enhanced MRV was acquired following the ad- ministration of 0.1 mmol/kg gadopentetate dimeglumine (Bayer Healthcare, Berlin) administered at 2 cc/s. Spatial resolution was equal to that of the STARFIRE acquisition. Data were acquired at approximately 30 s and 80 s after the start of contrast infusion. A precontrast image set was subtracted from the best postcontrast image set to elimi- nate the signal from background tissues. The 2D TOF MRV was acquired in an oblique sagittal plane using 3-mm slice thickness because of constraints imposed by the signal-to- noise ratio (SNR) and image acquisition time. Data Analysis For the quantitative analysis, only source images through the superior sagittal sinus were evaluated. The images 1 Department of Radiology, NorthShore University Health System, Evanston, Illinois. 2 Feinberg School of Medicine, Northwestern University, Chicago, Illinois. *Correspondence to: Robert R. Edelman, Evanston Northwestern Healthcare, Walgreen Jr. Building, G547, 2650 Ridge Avenue, Evanston, IL 60201. E-mail: redelman@enh.org Received 18 July 2008; revised 13 February 2009; accepted 25 February 2009. DOI 10.1002/mrm.22026 Published online 13 April 2009 in Wiley InterScience (www.interscience. wiley.com). Magnetic Resonance in Medicine 62:538 –543 (2009) © 2009 Wiley-Liss, Inc. 538