Distortion Inherent to Magnetic Resonance Imaging (MRI) Can Lead to Geometric Miss in Radiosurgery Planning

Seibert, Tyler M.; White, Nate; Kim, G.; McDonald, Carrie R.; Farid, Nikdokht; Moiseenko, Vitali; Bartsch, Hauke; Kuperman, Joshua; Holland, Diane T.; Mundt, Arno J.; Dale, Anders M.; Hattangadi‐Gluth, Jona A.

doi:10.1016/j.ijrobp.2014.05.500

Cited by 4 publications

(4 citation statements)

References 23 publications

(50 reference statements)

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“…These margins accommodate the uncertainties from microscopic disease, interobserver variation during target delineation, organ motion, and patient setup. Unlike CT images, MRI images have a considerable magnitude of geometrical distortion due to the scanner‐related inhomogeneities of magnet fields and the signal processing–dependent artifacts of MRI scanners 2–4 . Image distortion means that a position showed on an MRI image with the coordinate of

( {x,\;y,\;z} )

is indeed different from what it really locates.…”

Section: Introductionmentioning

confidence: 99%

“…Unlike CT images, MRI images have a considerable magnitude of geometrical distortion due to the scannerrelated inhomogeneities of magnet fields and the signal processing-dependent artifacts of MRI scanners. [2][3][4] Image distortion means that a position showed on an MRI image with the coordinate of (x, y, z) is indeed different from what it really locates. In other word, there is a deviation between what one sees on the MRI image and what is its real location, and the actual coordinate should be (x + Δx, y + Δy, z + Δz).…”

Section: Introductionmentioning

confidence: 99%

“…(Δx) 2 + (Δy) 2 + (Δz) 2 , could be up to several mms or even worse. [5][6][7][8] This deviation leads to inaccurate delineations of targets and OARs as well as the margin determination in a treatment plan,and for some challenging scenarios utilizing small targets such as trigeminal neuralgia, tremors, obsessive compulsive disorder (OCD) in Gamma Knife radiosurgery or other SBRT/SRS treatments where a high dose is being delivered; this deviation may result in missing the treatment target or causing unexcepted damage to OARs.…”

mentioning

confidence: 99%

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Assessment of MRI image distortion based on 6 consecutive years of annual QAs and measurements on 14 MRI scanners used for radiation therapy

Yang

Raterman

et al. 2022

J Applied Clin Med Phys

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Purpose To determine the magnitude of MRI image distortion based on 6 consecutive years of annual quality assurances/measurements on 14 MRI scanners used for radiation therapy and to provide evidence for the inclusion of additional margin for treatment planning. Methods and materials We used commercial MRI image phantoms to quantitatively study the MRI image distortion over period of 6 years for up to 14 1.5 and 3 T MRI scanners that could potentially be used to provide MRI images for treatment planning. With the phantom images collected from 2016 to 2022, we investigated the MRI image distortion, the dependence of distortion on the distance from the imaging isocenter, and the possible causes of large distortion discovered. Results MRI image distortion increases with the distance from the imaging isocenter. For a region of interest (ROI) with a radius of 100 mm centered at the isocenter, the mean magnitude of distortion for all MRI scanners is , and the maximum distortion varies from depending on MRI scanners. For an ROI with a radius of 200 mm centered at the isocenter, the mean magnitude of distortion increases to , and the range of the maximum distortion increases to depending on MRI scanners. The distortion could reach 2 mm at 150 mm from the isocenter. Conclusion An additional margin to accommodate image distortion should be considered for treatment planning. Imaging with proper patient alignment to the isocenter is vital to reducing image distortion. We recommend performing image distortion checks annually and after major upgrade on MRI scanners.

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( {x,\;y,\;z} )

is indeed different from what it really locates.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

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Assessment of MRI image distortion based on 6 consecutive years of annual QAs and measurements on 14 MRI scanners used for radiation therapy

Yang

Raterman

et al. 2022

J Applied Clin Med Phys

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“…While the dosimetric impact of these distortions has yet to be fully characterized, it can be postulated that the largest dosimetric consequences would occur when a lesion was incorrectly identified, resulting in a geometric miss. The impact of using vendor provided system‐level distortion corrections was recently explored at 3.0T and revealed that displacements of up to

~ 4 mm

were observed when vendor corrections were disabled (54) . For a single‐fraction SRS treatment, six out of 18 displaced lesions studied had

> 20 %

of the target volume outside of the 90% isodose line.…”

Section: Discussionmentioning

confidence: 99%

Initial clinical experience with a radiation oncology dedicated open 1.0T MR‐simulation

Glide-Hurst

Hearshen

Kim

et al. 2015

J Applied Clin Med Phys

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The purpose of this study was to describe our experience with 1.0T MR‐SIM including characterization, quality assurance (QA) program, and features necessary for treatment planning. Staffing, safety, and patient screening procedures were developed. Utilization of an external laser positioning system (ELPS) and MR‐compatible couchtop were illustrated. Spatial and volumetric analyses were conducted between CT‐SIM and MR‐SIM using a stereotactic QA phantom with known landmarks and volumes. Magnetic field inhomogeneity was determined using phase difference analysis. System‐related, in‐plane distortion was evaluated and temporal changes were assessed. 3D distortion was characterized for regions of interest (ROIs) 5–20 cm away from isocenter. American College of Radiology (ACR) recommended tests and impact of ELPS on image quality were analyzed. Combined ultrashort echotime Dixon (UTE/Dixon) sequence was evaluated. Amplitude‐triggered 4D MRI was implemented using a motion phantom (2–10 phases, ~2 cm excursion, 3–5 s periods) and a liver cancer patient. Duty cycle, acquisition time, and excursion were evaluated between maximum intensity projection (MIP) datasets. Less than 2% difference from expected was obtained between CT‐SIM and MR‐SIM volumes, with a mean distance of <0.2 mm between landmarks. Magnetic field inhomogeneity was <2 ppm. 2D distortion was <2 mm over 28.6–33.6 mm of isocenter. Within 5 cm radius of isocenter, mean 3D geometric distortion was 0.59±0.32 mm (maximum=1.65 mm) and increased 10–15 cm from isocenter (mean=1.57±1.06 mm, maximum=6.26 mm). ELPS interference was within the operating frequency of the scanner and was characterized by line patterns and a reduction in signal‐to‐noise ratio (4.6–12.6% for TE=50−150 ms). Image quality checks were within ACR recommendations. UTE/Dixon sequences yielded detectability between bone and air. For 4D MRI, faster breathing periods had higher duty cycles than slow (50.4% (3 s) and 39.4% (5 s), p<0.001) and ~ fourfold acquisition time increase was measured for ten‐phase versus two‐phase. Superior–inferior object extent was underestimated 8% (6 mm) for two‐phase as compared to ten‐phase MIPs, although <2% difference was obtained for ≥4 phases. 4D MRI for a patient demonstrated acceptable image quality in ~7 min. MR‐SIM was integrated into our workflow and QA procedures were developed. Clinical applicability was demonstrated for 4D MRI and UTE imaging to support MR‐SIM for single modality treatment planning.PACS numbers: 87.56.Fc, 87.61.‐c, 87.57.cp

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Characterization of hardware-related spatial distortions for IR-PETRA pulse sequence using a brain specific phantom

Ahmadian

Jabbari

BagheriMofidi

et al. 2020

Magn Reson Mater Phy

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Distortion Inherent to Magnetic Resonance Imaging (MRI) Can Lead to Geometric Miss in Radiosurgery Planning

Cited by 4 publications

References 23 publications

Assessment of MRI image distortion based on 6 consecutive years of annual QAs and measurements on 14 MRI scanners used for radiation therapy

Assessment of MRI image distortion based on 6 consecutive years of annual QAs and measurements on 14 MRI scanners used for radiation therapy

Initial clinical experience with a radiation oncology dedicated open 1.0T MR‐simulation

Characterization of hardware-related spatial distortions for IR-PETRA pulse sequence using a brain specific phantom

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