1、Site ScanningInstructions for Useof the MR Phantomfor the ACRMRI AccreditationProgramThe American College of Radiology1891 Preston White DrReston, VA 20191-4397www.acr.org12/021891 Preston White DriveReston, Virginia 20191(703) 648-8900(800) 227-5463fax: (703) 648-9176e-mail: infoacr.orgACR MRI Accr
2、editation Program PhantomVersion 2Please note: The image on the other side of this page, is a sample image of version 2 ofthe ACR MRI Accreditation Program Phantom. If you have purchased a phantom, and havereceived version 2 with serial numbers: 2001-2113, and 2401 and higher, your images maylook si
3、milar to those in the image sample on the other side of this page. If your sitepurchased version 1 of the ACR phantom, then please disregard this insert, and you mayuse your current phantom for accreditation testing, or for quality control purposes. For sitesthat have version 2, you may notice some
4、minor differences in the images you obtain ofyour phantom in comparison to those in the site scanning instruction booklet. See thearrows and corresponding captions on the sample image for information regarding thisissue. Although there are slight differences between version 1 and 2, there is no chan
5、ge inthe actual dimensions of the phantom analyzed during the image review process by theACR. Both versions can be used for accreditation testing and quality control. Sites can stilluse all the documents, and information contained in both the Site Scanning InstructionBooklet, as well as the Phantom
6、Test Guidance Booklet enclosed in the testing package toprepare their image submission.If you have any questions about the information above, please contact the MRIAccreditation department at (800) 770-0145.4 MRI Accreditation Program Site Scanning Instructions (12/02)MRI Accreditation Program Site
7、Scanning Instructions (12/02) 5Site Scanning Instructions for Use of the MR Phantom for the ACR MRI Accreditation ProgramINTRODUCTIONThe intent of the MRI Accreditation Program is to use theinformation obtained from the review of both clinical andphantom images to assess overall image quality. Yourf
8、acility will need to perform two specified phantom scansusing ACR protocols as well as two phantom scans usingyour sites routine clinical head protocol as outlined inSection 2 of this instruction book.It has come to our attention that some manufacturers ofMRI systems have sent “sample” or “recommend
9、ed”phantom site scanning protocols to their users. Please beaware that the requirement for MRI accreditation isthat in the second set of scans mentioned above,facilities use the same protocol for the phantom thatthe facility uses for head imaging. Failure to complywith this requirement could result
10、in failure to achieveaccreditation.Please review the following site scanning instructions andfollow them carefully before obtaining images forsubmission to the accreditation program. If you have anyquestions about the site scanning instructions pleasecontact the ACR.1. PHANTOM SET-UP AND ALIGNMENT F
11、ORSCANNINGThe MRI Accreditation Phantom should be scanned in thehead coil with the cylindrical phantom aligned as a headwould be in the coil. Transaxial slices should result incircular crosssections of the phantom. The phantomshould be positioned so that the word “Nose” is where thenose would be for
12、 a standard head study and the word“Chin” is where the chin would be located in a standardhead study. The center of the phantom (the dark notch onthe side of the phantom) should be placed in the center ofthe head coil and aligned with the positioning indicatorlight so that it will be in the isocente
13、r of the scanner. Oncegrossly positioned, it is then necessary to “fine tune” theposition of the phantom along all three axes. For this, youwill need to use the non-metallic bubble level enclosed.Place the level along the top of the phantom running inand out of the scanner (along the z-axis) to ensu
14、re that thephantom is horizontal. Place a gauze pad under either endof the phantom to level the phantom horizontally. Next,place the level on top of the plastic bar at the chin surface,rotating the phantom so that the plastic bar is horizontal.With the phantom then clamped or wedged inside the headc
15、oil, check to see that the sagittal laser alignment light isparallel to the line running along the “nose” surface of thephantom. (To see the laser light reflection, it may benecessary to place a piece of white paper on top of thephantom.) After each position adjustment, recheck that thetop of the ph
16、antom and the chin bar are still horizontal.After the phantom has been moved into the center of themagnet, verify its positioning by performing sagittal and,if desired, coronal plane localizer scans, until correct.(Please note, some systems require that a weight beentered in order to scan the phanto
17、m. The ACRrecommends that your site enter a weight of 200 lbs.)Once correctly aligned, the phantom should be kept in thesame position during the entire series of scans.2. SCANNING THE PHANTOMA sagittal locator sequence should be acquired with theacquisition parameters listed on the Site Scanning Dat
18、aForm. Use exactly these pulse sequence parameters, ifpossible, placing a check mark under each prescribedparameter to indicate that it has been used. If alternativeparameters must be used because of machine or softwarelimitations, enter the alternative scan parameters actuallyused below the ACR pre
19、scribed scan parameters. Fill inalternative parameters only for those parameters that differFigure 1: Sagittal localizer view of ACR MRI Phantom withseveral inclusions of the phantom labeled.6 MRI Accreditation Program Site Scanning Instructions (12/02)from the ACR prescribed parameters. Deviations
20、from thespecified imaging parameters will often require a differentoverall study time. List the actual scan time required onthe data form.The sagittal locator scan should result in an image similarto Figure 1. If the pairs of 45 crossed wedges are notvisible in the scan, the phantom must be repositi
21、oned andrescanned. A horizontal line used for slice prescription(see Figure 2) should be parallel to the low contrast diskslocated at the top of Figure 1 or Figure 2. If not, thephantom must be repositioned.The next two scan acquisitions are transaxial pulsesequences acquired with identical spatial
22、parameters: 5mm slice thickness, 5 mm gap, 25 cm FOV, 256 x 256matrix. At least 11 slices should be obtained, aligned usinggraphic prescription from the sagittal locator as shown inFigure 2 (Note: This is the preferred method for slicepositioning). The center of slice #1 should be aligned withthe ve
23、rtex of the crossed wedges (visible on the lower leftin Figures 1 and 2) and through the center of the darkchemical shift and resolution insert (visible on the lowerright). Slice #1 should result in a transaxial image thatlooks like Figure 3. The centers of slices #811 shouldalign with the four low-
24、contrast discs shown toward thetop in Figures 1 and 2. (Record this sagittal locator image,using a 12 on 1 format, showing the locations of theprescribed transaxial slices.) If your scanner cannot obtainenough slices in a single scan, then perform multiple scanswith the specified TR/TE and with the
25、maximum numberof slices allowed by the system. Repeat the scans, eachwith the specified scan time, until all 11 transaxial imageshave been obtained in the proper locations.Figure 2: Sagittal locator image with slice locations for transaxial scans indicated.Figure 3: Slice #1 of the SE 500/20 transax
26、ial scan.MRI Accreditation Program Site Scanning Instructions (12/02) 7Figure 4: The sagittal localizer and all 11 slices of the SE 500/20 transaxial scan filmed in 12 on 1 format.8 MRI Accreditation Program Site Scanning Instructions (12/02)If your scanner is not capable of obtaining 5 mm sliceswit
27、h 5 mm gaps, then use the closest slice thickness to 5mm for the specified TR and TE. Set the slice gap so thatslice thickness plus slice gap equals 10 mm and be carefulthat the images are positioned as specified in Figure 2. Ifnecessary, perform multiple scans, each with thespecified scan parameter
28、s, to get these 11 images in asclose to the proper locations as possible. Record each ofthese 11 transaxial images on the same sheet of film asthe sagittal localizer image. The full sheet should looklike the 11 images in Figure 4 in terms of window settingsand image positions on the film. Please not
29、e: Your axialslices must be positioned as shown in Figure 2 in orderfor your images to be acceptable for evaluation. If yourMRI system is unable to prescribe a 5-mm slice gap thenyou should try the following alternative slice positioningmethod: Either perform an interleaved multisliceacquisition or
30、perform 11 single slice acquisitions. Pleasemake sure that each slice is positioned as shown in Figure2. If you are unable to perform the axial slice positioningas indicated in this manual, then stop and contact theACR before proceeding any further.The conventional spin-echo (SE) 500/20 scan should
31、beacquired with one acquisition per phase encoding step(one signal average acquisition or NEX) and thebandwidth used routinely for brain studies. This shouldtake a total scan time of approximately two minutes.Enter the exact scan time required, along with thebandwidth (in kHz) on the Site Scanning D
32、ata Form.Remember to place check marks below the scanparameters that are used exactly as they appear on thetable of Pulse Sequence Acquisition Parameters or enterthe alternative parameters in each blank.Acquire the SE 2000/20, 80 double-echo scan with oneacquisition per phase encoding step at the sa
33、me 11 slicelocations as used for the previous scan. If a double echoat TEs of 20 and 80 ms cannot be obtained, then use theclosest multiecho TEs to 20 and 80 ms (e.g., 40 and 80ms). This scan should take approximately 8.5 minutes.(Record the sagittal localizer and each of the 11 SE2000/80 images onl
34、y on one sheet of film. The PDweighted images do not need to be filmed.) Enter thebandwidth for the scan in the space provided on the SiteScanning Data Form; enter the exact scan time requiredin the blank below scan time on the Data Form if it differsfrom the scan time specified on the form. Place c
35、heckmarks or enter the revised scan parameter in each blockof the Data Form. The ACR protocols do not specify any scan options, suchas autoshim or image filtering, and you are not requiredto use any. If you wish, you may use the scan options younormally use for clinical head imaging, provided thoseo
36、ptions do not interfere with attaining the scanparameters and slice prescriptions specified for the ACRprotocols. Record all scan options used in the spaceprovided on the Data Form. For the ACR protocols, on scanners that have a range ofimage filter settings available, we recommend againststrong fil
37、ter settings because they are often detrimental tohigh-contrast resolution.Next, scan the phantom using your sites T1- and T2-weighted scan protocols. It is important to acquire imageswith 5 m slice thickness, if possible, or as close to 5 mmslice thickness as possible, and to acquire slices withcen
38、ter-to-center spacing of 10 mm for both T1- and T2-weighted images. Please try to adapt your normal scanprotocols to obtain the 5 mm slice thickness and thespecified 11 slice locations for both T1- and T2-weightedimages. Enter the precise scan parameters used for T1-and T2-weighted scans (adapted to
39、 5-mm slice thicknessand the 11 prescribed slice locations) in the Site ScanningData Form. When adapting your sites sequences, only change slicethickness and slice spacing. Do not change other scanparameters. Many sites normally use a reduced field ofview in the right-left dimension on their axial h
40、eadimages. This leads to wrap-around (aliasing) artifactwhen scanning the ACR phantom. Do not change thefield of view of your sequences to avoid this artifact. Thisartifact does not interfere with our assessment of theimages, and you will not be penalized for it.Please film the sagittal localizer an
41、d each of the 11 slicesfor both T1- and T2-weighted scan protocols used byyour site. This should result in a total of four sheets offilm acquired in 12 on 1 format. Next, transfer the sagittallocator scan and the four sets of transaxial scans to aDICOM formatted CD-ROM. For more information onthis,
42、please refer to the instructions for digital datasubmission provided elsewhere in your accreditationpackage. Use a separate CD-ROM for each magnet. Donot store any clinical exams on the CD-ROM.Submit data forms, films, and images on CD-ROM to theAmerican College of Radiology.If you have any suggesti
43、ons or comments about thephantom image Site Scanning Instructions, please includethose on the back of the Site Scanning Data Form.Pulse Sequence Acquisition ParametersIn the box below each parameter:Record actual values if they differ from the prescribed protocol parameters or Place a check mark to
44、indicate use of prescribed parameter.Fill in all parameters for “Your Sites Axial T1- and T2-weighted Brain Scan.”ab c d e f ghIj k INumber Slice Slice Routine ScanPulse TR TE FOV of Thickness Gap NEX Matrix Receive TimeStudy Sequence (ms) (ms) (cm) Slices (mm) (mm) Band- (min:sec)Width(kHz)ACR Spin
45、 200 20 25 1 20 N/A 1 256 256 0:568. Sagittal Echolocator N/AACR Spin 500 20 25 11 5 5 1 256 256 2:169. Axial EchoT1ACR Spin 2000 20/80 25 11 5 5 1 256 256 8:5610. Axial T2 EchoDouble-echo /Your Sites11. Axial T1weightedBrain ScanYour Sites12. Axial T2weightedBrain ScanMRI Phantom Site Scanning Data
46、 FormPlease complete one copy of these data for each MR Magnet being evaluated. Photocopy this blank form for additional magnets. Detailedinstructions for scanning the MRI phantom are attached.All information on this data sheet must be accurately specified. Please print or type.Please place your Pha
47、ntom Data Form Label in the space above. Return completed form with phantom images.1. MR Manufacturer: check oneELS EIscint HI Health Images OTS Otsuka RES Resonex TCH TechnicareFON Fonar HIT Hitachi PIC Picker SIE Siemens TOS ToshibaGE GE IN Instrumentarium PHI Philips SHI Shimadzu OTH Otherspecify
48、 _2. Model Name: _ 3. Serial Number:_4. Software Version: _ 5. Year Manufactured: _6. Magnetic Field Strength: check one10.06420.2 T3 0.3 T 40.35 T50.5 T 61.0 T 71.5 T99Other specify7. Operating Location: check one6Fixed2Fixed Trailer 3Mobile Trailer9Other specifyAmerican College of RadiologyMRI Accreditation Program1891 Preston White DriveReston VA 20191-4397Phantom Data Form Label here13. Scan Options Used on the ACR Spin-echo T1- and T2-weighted Axial Scans: _14. Scan Options Used on “Your Sites Axial T1- and T2-weighted Brain Scans:” _15. Serial number of phantom used for testing _
