Diffusion weighted MRI in head-and-neck cancer: Geometrical accuracy

Schäkel, T.; Hoogduin, Johannes M.; Terhaard, Chris H.J.; Philippens, M.E.P.

doi:10.1016/j.radonc.2013.10.004

Cited by 41 publications

(30 citation statements)

References 21 publications

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“…The acquired B0 field maps were processed using in-house developed software. 5,25 First, phase unwrapping was performed to account for phase wraps in the data. The unwrapped field map was converted to a pixel-shift map using the sequence parameters that dictate the effective spectral width per pixel.…”

Section: C Image Evaluationmentioning

confidence: 99%

“…3 Due to the high contrast on a DW image between a tumor and its surrounding tissue, DW-MRI shows great potential to facilitate target definition. 4 The main reason why DW-MRI is not more widely used for target definition in radiotherapy treatment planning of primary tumors is the poor geometrical accuracy of the technique, 5 especially around air cavities. Air-tissue interfaces give rise to strong susceptibility variations which cause large local magnetic field inhomogeneities.…”

Section: Introductionmentioning

confidence: 99%

“…However, using this EPI technique in the presence of local magnetic field inhomogeneities can lead to image distortions up to centimeters. 5 To address these susceptibility-induced image distortions, DW-MRI can also be acquired using Turbo Spin Echo (TSE) type imaging sequences. Here, the EPI acquisition module is replaced by a single-shot TSE module, which improves the geometrical accuracy.…”

Section: Introductionmentioning

confidence: 99%

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Technical Note: Diffusion‐weighted MRI with minimal distortion in head‐and‐neck radiotherapy using a turbo spin echo acquisition method

et al. 2017

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Purpose: Diffusion-weighted (DW) MRI, showing high contrast between tumor and background tissue, is a promising technique in radiotherapy for tumor delineation. However, its use for head-and-neck patients is hampered by poor geometric accuracy in conventional echo planar imaging (EPI) DW-MRI. An alternative turbo spin echo sequence, DW-SPLICE, is implemented and demonstrated in patients. Methods: The DW-SPLICE sequence was implemented on a 3.0 T system and evaluated in 10 patients. The patients were scanned in treatment position, using a customized head support and immobilization mask. Image distortions were quantified at the gross tumor volume (GTV) using field map analysis. The apparent diffusion coefficient (ADC) was evaluated using an ice water phantom. Results: The DW images acquired by DW-SPLICE showed no image distortions. Field map analysis at the gross tumor volumes resulted in a median distortion of 0.2 mm for DW-SPLICE, whereas for the conventional method this was 7.2 mm. ADC values, measured using an ice water phantom were in accordance with literature values. Conclusions: The implementation of DW-SPLICE allows for diffusion-weighted imaging of patients in treatment position with excellent geometrical accuracy. The images can be used to facilitate target volume delineation in RT treatment planning.

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Section: C Image Evaluationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Technical Note: Diffusion‐weighted MRI with minimal distortion in head‐and‐neck radiotherapy using a turbo spin echo acquisition method

et al. 2017

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“…Studies have found that substantial geometric distortions can occur in DW MR images, even on the order of centimeters (39). Such distortions, both global and local, can also occur for other imaging sequences, including sequences used for perfusion MRI.…”

Section: Manual Tumor Segmentationmentioning

confidence: 99%

Molecular Imaging to Plan Radiotherapy and Evaluate Its Efficacy

2015

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Learning Objectives: On successful completion of this activity, participants should be able to describe (1) how to acquire high-quality molecular images for use in radiation therapy; (2) how molecular imaging can be used to plan radiotherapy and evaluate treatment efficacy; and (3) the limitations and challenges to widespread use of molecular imaging in radiation oncology.Financial Disclosure: The authors of this article have indicated no relevant relationships that could be perceived as a real or apparent conflict of interest. CME Credit: SNMMI is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing education for physicians. SNMMI designates each JNM continuing education article for a maximum of 2.0 AMA PRA Category 1 Credits. Physicians should claim only credit commensurate with the extent of their participation in the activity. For CE credit, SAM, and other credit types, participants can access this activity through the SNMMI website (http://www.snmmilearningcenter.org) through November 2018.Molecular imaging plays a central role in the management of radiation oncology patients. Specific uses of imaging, particularly to plan radiotherapy and assess its efficacy, require an additional level of reproducibility and image quality beyond what is required for diagnostic imaging. Specific requirements include proper patient preparation, adequate technologist training, careful imaging protocol design, reliable scanner technology, reproducible software algorithms, and reliable data analysis methods. As uncertainty in target definition is arguably the greatest challenge facing radiation oncology, the greatest impact that molecular imaging can have may be in the reduction of interobserver variability in target volume delineation and in providing greater conformity between target volume boundaries and true tumor boundaries. Several automatic and semiautomatic contouring methods based on molecular imaging are available but still need sufficient validation to be widely adopted. Biologically conformal radiotherapy (dose painting) based on molecular imaging-assessed tumor heterogeneity is being investigated, but many challenges remain to fully exploring its potential. Molecular imaging also plays increasingly important roles in both early (during treatment) and late (after treatment) response assessment as both a predictive and a prognostic tool. Because of potentially confounding effects of radiation-induced inflammation, treatment response assessment requires careful interpretation. Although molecular imaging is already strongly embedded in radiotherapy, the path to widespread and all-inclusive use is still long. The lack of solid clinical evidence is the main impediment to broader use. Recommendations for practicing physicians are still rather scarce. 18 F-FDG PET/CT remains the main molecular imaging modality in radiation oncology applications. Although other molecular imaging options (e.g., proliferation imaging) are becoming more common, their widespread use is limited ...

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“…[5] Furthermore, some reports showed the application of DWI with calculation of apparent diffusion coefficient (ADC) in the differentiation between malignant and benign diseases in head and neck. [6][7][8][9][10] Studies regarding absolute ADC values in the normal human brain and the effect of aging on diffusion are scarce, and only a few reports involving small numbers of subjects have been published. [11] Moreover, age is an important factor for spinal cord injury and repair.…”

Section: Introductionmentioning

confidence: 99%

Changes of cerebrospinal fluid in the upper neck area with age using diffusion weighted MR imaging

Ogura¹,

Oda²,

Sue³

et al. 2018

IJDI

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Purpose: Few studies have concerned the absolute apparent diffusion coefficient (ADC) values in the normal cerebrospinal fluid in the upper neck area and the effect of aging on diffusion. The purpose of this study was to evaluate changes of cerebrospinal fluid in the upper neck area with age using diffusion weighted MR imaging (DWI). Methods and methods: Our study included 160 patients who underwent MR imaging for oral and maxillofacial diseases. All patients were examined by DWI with 2 b values (0 and 800 sec/mm 2 ) at 1.5 Tesla and ADC maps. The cerebrospinal fluid and spinal cord in the upper neck area were analyzed using the ADC values and age.Results: ADC value of cerebrospinal fluid was significantly correlated to ADC value of spinal cord (R 2 = 0.141, p = .000). ADC value of spinal cord had no relation to age (R 2 = 0.015, p = .125). ADC value of cerebrospinal fluid had significant relation to age (R 2 = 0.026, p = .042). Conclusions:We indicated the changes of cerebrospinal fluid in the upper neck area with age using DWI. The data reported herein are representative, and the ADC values can be used for reference in future studies and in clinical settings.

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Diffusion weighted MRI in head-and-neck cancer: Geometrical accuracy

Cited by 41 publications

References 21 publications

Technical Note: Diffusion‐weighted MRI with minimal distortion in head‐and‐neck radiotherapy using a turbo spin echo acquisition method

Technical Note: Diffusion‐weighted MRI with minimal distortion in head‐and‐neck radiotherapy using a turbo spin echo acquisition method

Molecular Imaging to Plan Radiotherapy and Evaluate Its Efficacy

Changes of cerebrospinal fluid in the upper neck area with age using diffusion weighted MR imaging

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