MRI FORMULA
Calculate the pixel area for a fast spin echo sequence with the following parameters: FOV 36cm, TR 600, TE 10, 512 x 512 matrix, 4 NEX, 5 mm slice thickness, 3 ETL.
0.49 mm2
Calculate the pixel area for a fast spin echo sequence with the following parameters: FOV 20cm, TR 3000, TE 120, 224 x 256 matrix, 3 NEX, 5 mm slice thickness, 12 ETL.
0.69 mm2 FOV ÷ phase matrix = phase dimension pixel FOV ÷ frequency matrix = frequency pixel Multiply phase pixel size x frequency pixel size = Pixel area (answer squared) Convert 20cm to 200 mm before calculating. 200 ÷ 224 = 0.89mm (phase dimension) 200 ÷ 256 = 0.78mm (frequency dimension) 0.89mm x 0.78mm = 0.69mm2
Calculate the pixel area for a fast spin echo sequence with the following parameters: FOV 30cm, TR 600, TE 10, 320 x 320 matrix, 4 NEX, 3 mm slice thickness, 3 ETL.
0.88 mm2 FOV ÷ phase matrix = phase dimension pixel FOV ÷ frequency matrix = frequency pixel Multiply phase pixel size x frequency pixel size = Pixel area (answer squared2) Convert 30cm to 300 mm before calculating. 300 ÷ 320 = 0.94mm (phase dimension) 300 ÷ 320 = 0.94mm (frequency dimension) 0.94 x 0.94 = 0.88 mm2
Calculate the pixel size for a fast spin echo sequence with the following parameters: FOV 20cm, TR 3000, TE 120, 224 x 256 matrix, 3 NEX, 5 mm slice thickness, 12 ETL.
0.89 mm x 0.78 mm FOV ÷ Matrix = pixel size FOV ÷ phase matrix = phase dimension pixel FOV ÷ frequency matrix = frequency pixel Convert 20cm to 200 mm before calculating. 200 ÷ 224 = 0.89mm (phase dimension) 200 ÷ 256 = 0.78mm (frequency dimension)
Calculate the pixel size for a fast spin echo sequence with the following parameters: FOV 30cm, TR 600, TE 10, 320 x 320 matrix, 4 NEX, 3 mm slice thickness, 3 ETL.
0.94 mm x 0.94 mm FOV ÷ Matrix = pixel size FOV ÷ phase matrix = phase dimension pixel FOV ÷ frequency matrix = frequency pixel Convert 30cm to 300 mm before calculating. 300 ÷ 320 = 0.94mm (phase dimension) 300 ÷ 320 = 0.94mm (frequency dimension)
Calculate the pixel area for a fast spin echo sequence with the following parameters: FOV 28cm, TR 2000, TE 30, 256 x 320 matrix, 2 NEX, 4 mm slice thickness, 8 ETL.
0.96 mm2 FOV ÷ phase matrix = phase dimension pixel FOV ÷ frequency matrix = frequency pixel Convert 28cm to 280 mm before calculating. 280 ÷ 256 = 1.09mm (phase dimension) 280 ÷ 320 = 0.88mm (frequency dimension) 1.09 x 0.88 = 0.96 mm2
Calculate the pixel size for a fast spin echo sequence with the following parameters: FOV 28cm, TR 2000, TE 30, 256 x 320 matrix, 2 NEX, 4 mm slice thickness, 8 ETL.
1.09 mm x 0.88 mm FOV ÷ Matrix = pixel size FOV ÷ phase matrix = phase dimension pixel FOV ÷ frequency matrix = frequency pixel Convert 28cm to 280 mm before calculating. 280 ÷ 256 = 1.09mm (phase dimension) 280 ÷ 320 = 0.88mm (frequency dimension)
Calculate the scan time for a spin echo sequence with the following parameters: TR 400, TE 25, 192 x 256 matrix, 2 NSA, 3mm slice thickness.
2 min 34 sec TR x Phase Matrix x NSA/NEX = Scan Time in a Spin Echo sequence, Divide by 1000 to convert ms (milliseconds) into seconds. 400 x 192 (phase matrix) x 2 ÷ 1000 = 153.6 seconds
Calculate the scan time for a spin echo sequence with the following parameters: TR 400, TE 24, 208 x 256 matrix, 2 NSA, Flip angle 90, 3.5 mm slice thickness.
2 min 46 sec TR x Phase Matrix x NSA/NEX = Scan Time in a Spin Echo sequence, Divide by 1000 to convert ms (milliseconds) into seconds. 400 x 208 x 2 ÷ 1000 = 166
Calculate the scan time for a fast spin echo sequence with the following parameters: FOV 20cm, TR 3000, TE 120, 224 x 256 matrix, 3 NEX, 5 mm slice thickness, 12 ETL.
2 min 48 sec Scan Time in a Fast Spin Echo Sequence : TR x Phase Matrix x NEX ÷ ETL, ÷ 1000 to convert to seconds. 3000 x 224 x 3 ÷ 12 ÷ 1000 = 168 seconds (2 min 48 sec)
Calculate the scan time for a fast spin echo sequence with the following parameters: TR 3000, TE 100, 512 x 512 matrix, 2 NEX, 5 mm slice thickness, 18 ETL.
2 min 51 sec 3000 x 512 x 2 ÷ 18 ÷ 1000 = 171 seconds
Calculate the scan time for a fast spin echo sequence with the following parameters: FOV 16cm, TR 2500, TE 90, 208 x 256 matrix, 6 NEX, 5 mm slice thickness, 18 ETL.
2 min 53 sec Scan Time in a Fast Spin Echo Sequence : TR x Phase Matrix x NEX ÷ ETL, ÷ 1000 to convert to seconds. 2500 x 208 x 6 ÷ 18 ÷ 1000 = 173 seconds (2 min 53 sec)
Calculate the scan time for a spin echo sequence with the following parameters: TR 350, TE 10, 256 x 256 matrix, 2 NEX, 5 mm slice thickness.
2 min 59 sec TR x Phase Matrix x NSA/NEX = Scan Time in a Spin Echo sequence, Divide by 1000 to convert ms (milliseconds) into seconds. 350 x 256 x 2 ÷ 1000 = 179 seconds.
Calculate the voxel volume for a fast spin echo sequence with the following parameters: FOV 34cm, TR 3000, TE 120, 512 x 512 matrix, 3 NEX, 6 mm slice thickness, 12 ETL.
2.64 mm3 340 ÷ 512 = 0.66 0.66 x 0.66 = 0.44mm2 (pixel area) 0.44 x 6 = 2.64mm3 (voxel volume)
Calculate the voxel volume for a fast spin echo sequence with the following parameters: FOV 30cm, TR 600, TE 10, 320 x 320 matrix, 4 NEX, 3 mm slice thickness, 3 ET
2.64 mm3 FOV ÷ phase matrix = phase dimension pixel FOV ÷ frequency matrix = frequency pixel Multiply phase pixel size x frequency pixel size = Pixel area (answer squared2) Pixel area x slice thickness = Voxel volume (answer cubic3) Convert 30cm to 300 mm before calculating. 300 ÷ 320 = 0.94mm (phase dimension) 300 ÷ 320 = 0.94mm (frequency dimension) 0.94 x 0.94 = 0.88 mm2 (pixel area) 0.88 x 3mm (thickness) = 2.64mm3
Calculate the scan time for a fast spin echo sequence with the following parameters: TR 2000, TE 30, 192 x 224 matrix, 3 NEX, 4 mm slice thickness, 6 ETL.
3 min 12 sec Scan Time in a Fast Spin Echo Sequence : TR x Phase Matrix x NEX ÷ ETL, ÷ 1000 to convert to seconds. 2000 x 192 x 3 ÷ 6 ÷ 1000 = 192 seconds (3 min 12 sec)
Calculate the scan time for a 3D gradient echo sequence with the following parameters: FOV 20cm, TR 24, TE 10, 224 x 256 matrix, 1 NEX, 3.5 mm slice thickness, 40 slices.
3 min 35 sec 3D sequence scan time : TR x Phase Matrix x NSA/NEX x # Slices = 3D Scan Time, ÷ 1000 to convert to seconds. 24 x 224 x 1 x 40 ÷ 1000 = 215 seconds (3 min 35sec)
Calculate the scan time for a 3D gradient echo sequence with the following parameters: FOV 16cm, TR 25, TE 12, 208 x 256 matrix, 1 NEX, 4 mm slice thickness, 36 slices.
3 min 7 sec 3D sequence scan time : TR x Phase Matrix x NSA/NEX x # Slices = 3D Scan Time, ÷ 1000 to convert to seconds. 25 x 208 x 1 x 36 ÷ 1000 = 187 seconds (3 min 7 sec)
Calculate the scan time for a fast spin echo sequence with the following parameters: TR 1800, TE 25, 208 x 224 matrix, 4 NEX, 3 mm slice thickness, 8 ETL.
3 min 7 sec Scan Time in a Fast Spin Echo Sequence : TR x Phase Matrix x NEX ÷ ETL, ÷ 1000 to convert to seconds. 1800 x 208 x 4 ÷ 8 ÷ 1000 = 187 seconds (3 min 7 sec)
Calculate the voxel volume for a fast spin echo sequence with the following parameters: FOV 20cm, TR 3000, TE 120, 224 x 256 matrix, 3 NEX, 5 mm slice thickness, 12 ETL.
3.45 mm3 FOV ÷ phase matrix = phase dimension pixel FOV ÷ frequency matrix = frequency pixel Multiply phase pixel size x frequency pixel size = Pixel area (answer squared2) Pixel area x slice thickness = Voxel volume (answer cubic3) Convert 20cm to 200 mm before calculating. 200 ÷ 224 = 0.89mm (phase dimension) 200 ÷ 256 = 0.78mm (frequency dimension) 0.89 x 0.78 = 0.69mm2 (pixel area) 0.69 x 5mm(slice thickness) = 3.45mm3
Calculate the voxel volume for a fast spin echo sequence with the following parameters: FOV 28cm, TR 2000, TE 30, 256 x 320 matrix, 2 NEX, 4 mm slice thickness, 8 ETL.
3.84 mm3 FOV ÷ phase matrix = phase dimension pixel FOV ÷ frequency matrix = frequency pixel Multiply phase pixel size x frequency pixel size = Pixel area (answer squared2) Pixel area x slice thickness = Voxel volume (answer cubic3) Convert 28cm to 280 mm before calculating. 280 ÷ 256 = 1.09mm (phase dimension) 280 ÷ 320 = 0.88mm (frequency dimension) 1.09 x 0.88 = 0.96mm2 (pixel area) 0.96mm x 4 (sl thickness) = 3.84mm3 (voxel volume)
Calculate the scan time for a fast spin echo sequence with the following parameters: TR 3500, TE 100, 256 x 256 matrix, 4 NEX, 5 mm slice thickness, 14 ETL.
4 min 16 sec Scan Time in a Fast Spin Echo Sequence : TR x Phase Matrix x NEX ÷ ETL, ÷ 1000 to convert to seconds. 3500 x 256 x 4 ÷ 14 ÷ 1000 = 256 seconds (4 min 16 sec)
Calculate the scan time for a spin echo sequence with the following parameters: TR 450, TE 20, 224 x 256 matrix, 3 NSA, 4mm slice thickness.
5 min 2 sec TR x Phase Matrix x NSA/NEX = Scan Time in a Spin Echo sequence, Divide by 1000 to convert ms (milliseconds) into seconds. 450 x 224 x 3 ÷ 1000 = 302 seconds.
Calculate the scan time for a spin echo sequence with the following parameters: TR 500, TE 24, 224 x 256 matrix, 3 NEX, 4 mm slice thickness.
5 min 36 sec TR x Phase Matrix x NSA/NEX = Scan Time in a Spin Echo sequence, Divide by 1000 to convert ms (milliseconds) into seconds. 500 x 224 x 3 ÷ 1000 = 336 seconds.
Calculate the scan time for a 3D gradient echo sequence with the following parameters: FOV 16cm, TR 20, TE 9, 192 x 256 matrix, 2 NEX, 5 mm slice thickness, 40 slices.
5 min 7 sec 3D sequence scan time : TR x Phase Matrix x NSA/NEX x # Slices = 3D Scan Time, ÷ 1000 to convert to seconds. 20 x 192 x 2 x 40 ÷ 1000 = 307 seconds (5 min 7sec)
