This is an on-going trial prospective study. Our aim is to include 50 subjects in this project. Subjects will be scanned with the “Quiet” T2 PROPELLER and  “Quiet” T2 FLAIR PROPELLER technique in addition to conventional T2 PROPELLER and T2 FLAIR PROPELLER on a 1.5T MR.

To date, 8 subjects have been included. 2 healthy volunteers (two men, age range 26-45) and 6 patients (three women, three men, age range 79-34) diagnosed with stroke (n=2), headache (n=1), multiple sclerosis (n=1), metastatic disease (n=1) and first episode of psychosis (n=1) were imaged after obtaining Institutional Review Board approval and informed consent. All exams were performed on a clinical 1.5 T magnetic resonance system (Optima 450W; GE Healthcare, Waukesha, WI) with a 32-channel head coil (24 elements are activated). Subjects were imaged with a clinical standard T2 PROPELLER and T2 FLAIR PROPELLER scan and with “Quiet” FSE PROPELLER techniques.

The standard T2 PROPELLER scan was acquired with the following parameters: TR/TE 3066ms/99ms; field of view 22 x 22 cm; matrix 320x320; slice thickness 5 mm and slice spacing of 0 mm; Number of slice 30; Refocus flip angle 160º; bandwidth 50 kHz; Echo Train Length 28; Number of excitation 1.7; Acceleration factor 2; Scan time 1.26 minutes.

The standard T2 FLAIR PROPELLER scan was acquired with the following parameters: TR/TE 9500ms/109ms; TI 2250ms; field of view 23 x 23 cm; matrix 288 x 288, slice thickness 5 mm and slice spacing of 0 mm; Number of slice 30; Refocus flip angle 160º; bandwidth 62.5 kHz; Echo Train Length 32; Number of excitation 1.7; Acceleration factor 2; Scan time 3.10 minutes.

For the “Quiet” T2 PROPELLER scan, the protocol set was: TR/TE 6380ms/98ms; FOV = 22 x 22 cm; matrix of 320 X 320; 5mm slice thickness and slice spacing of 0 mm; Number of slice 30; bandwidth = 41KHz; refocus flip angle = 160º; Echo Train Length 16; Number of excitation 1.5; Acceleration factor 2; Scan time 2.16 minutes.

The “Quiet” T2 FLAIR PROPELLER protocol set was: TR/TE 9500ms/105ms; TI 2250ms; FOV = 23 x 23 cm, matrix of 288 X 288; 5mm slice thickness and slice spacing of 0 mm; Number of slice 30; bandwidth = 41KHz; refocus flip angle = 160º; Echo Train Length 18; Number of excitation 1.5; Acceleration factor 2; Scan time 5.20 minutes.

Images from both “Quiet” T2 PROPELLER and “Quiet” T2 FLAIR PROPELLER, together with conventional PROPELLER sequences were presented, on a radiology workstation, to an experienced neuroradiologist, who assessed the images quantitatively and qualitatively. The reader was blinded to the exams.

To assess the four different sequences quantitatively, a region of interest (ROI), measuring 10 mm², was placed on the periventricular white matter at the level of left lateral ventricle avoiding lesions and artifacts. ROI was placed on one MRI sequence and then automatically propagated to the other three.

“Quiet” T2 PROPELLER, “Quiet” T2 FLAIR PROPELLER and conventional T2 and FLAIR PROPELLER MR images were evaluated qualitatively using 3 criteria: overall quality, differentiation between grey and white matter and blurring perception (Table 1).

Additionally, the observer was asked to rank the images (“Quiet” T2 PROPELLER and “Quiet” T2 FLAIR PROPELLER and conventional T2 and FLAIR PROPELLER MR images) in order of preference and declare images as either better, worse, or equal to each other (overall preference).

A non-parametric paired Wilcoxon test was used to compare the quantitative and qualitative parameters. The results were express in mean standard deviation (mean SD). Statistical analysis was performed using commercially available software (SPSS version 20). A p < 0.05 indicated a statistically significant difference.