scholarly journals Wykorzystanie obrazowania rezonansem magnetycznym w radioterapii (planowanie leczenia i procedury IGRT) oraz związana z tym rola elektroradiologa

2017 ◽  
Vol 14 (3) ◽  
pp. 69-74
Author(s):  
Elżbieta Czajka
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

Wykorzystanie rezonansu magnetycznego (ang. magnetic resonance imaging, MRI) w radioterapii jest często poruszanym zagadnieniem w ostatnich latach. Osobny blok wystąpień poświęcony temu tematowi pojawił się również w części programu dedykowanej elektroradiologom na 3rd ESTRO FORUM. Podczas wystąpień omówiono trzy obszary, w których możliwe jest wykorzystanie rezonansu magnetycznego w radioterapii, tj. 1) akwizycja obrazów niezbędnych do planowania leczenia 2) planowanie leczenia w systemie komputerowym w oparciu o obrazowanie rezonansem magnetycznym oraz 3) realizacja leczenia na aparacie terapeutycznym. Zastąpienie w łańcuchu terapeutycznym przede wszystkim tomografii komputerowej (ang. computed tomography, CT) ale również w dalszym etapie innych metod obrazowania, wykorzystujących promieniowanie rentgenowskie np. CBCT (ang. cone beam CT), MVCT (ang. mega voltage CT) lub kVCT (ang. kilo voltage CT) rezonansem magnetycznym, wprowadza do radioterapii tzw. „full-MR workflow”, czyli koncepcję radioterapii opartej wyłącznie o obrazowanie rezonansem magnetycznym. Analiza wybranych doniesień ma na celu przybliżenie czytelnikowi tego zagadnienia, omówienie jego zalet i potencjalnych ograniczeń, ale również umiejscowienie elektroradiologia w całym procesie radioterapeutycznym opartym o rezonans magnetyczny.

scholarly journals Clinically Delivered Treatment for Glioma Patients on a Hybrid Magnetic Resonance Imaging (MRI)-Linear Accelerator (MR-Linac) and a Cone Beam CT (CBCT)-Guided Linac: Dosimetric Comparisons with In Vivo Skin Dose Correlation

2021 ◽  
Author(s):  
Michael H. Wang ◽  
Anthony Kim ◽  
Mark Ruschin ◽  
Hendrick Tan ◽  
Hany Soliman ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Monte Carlo ◽  
Magnetic Resonance ◽  
Linear Accelerator ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Skin Dose ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

Abstract Background Magnetic Resonance Imaging (MRI)-Linear Accelerator (MR-Linac) radiotherapy requires special consideration for secondary electron interactions within the magnetic field, which can alter dose deposition at air-tissue interfaces. Methods Thirty-seven consecutive glioma patients treated during their radiotherapy course with at least one fraction delivered on MR-Linac or Cone Beam CT (CBCT)-guided Linac, were analyzed. Treatment planning for both systems were completed prior to radiotherapy initiation and approved for clinical delivery using commercial treatment planning systems (TPS): a Monte Carlo calculation-based or convolution calculation-based TPS for MR-Linac or CBCT-Linac, respectively. Dosimetric parameters for planning target volume (PTV), organs-at-risk (OARs), and air-tissue interface were compared. In vivo skin dose during a single fraction of MR-Linac and CBCT-Linac treatment was measured using an Optically Stimulated Luminescent Dosimeter (OSLD) and correlated with TPS skin dose. Results Monte Carlo-based MR-Linac plans and convolution-based CBCT-Linac plans exhibited minimal differences in PTV and OAR parameters. However, MR-Linac plans had greater doses within tissues surrounding air cavities (1.52 Gy higher mean Dmean, p < 0.0001) and skin (1.10 Gy higher mean Dmean, p < 0.0001). In vivo OSLD skin readings were 14.5% greater for MR-Linac treatments (p = 0.0027), and were more accurately predicted by Monte Carlo-based calculation (ρ = 0.95, p < 0.0001) vs. convolution-based (ρ = 0.80, p = 0.0096). Conclusions The magnetic field’s dosimetric impact was minimal for PTV and OARs in glioma as compared to standard CBCT-Linac treatment plans. However, skin doses were significantly greater with the MR-Linac and correlated with in vivo measurements. Future MR-Linac planning processes are being designed to account for skin dosimetry and treatment delivery.

scholarly journals Clinically Delivered Treatment for Glioma Patients on Hybrid Magnetic Resonance Imaging (MRI)-Linear Accelerator (MR-Linac) versus Cone Beam CT (CBCT)-Guided Linac

2021 ◽  
Author(s):  
Michael H. Wang ◽  
Anthony Kim ◽  
Mark Ruschin ◽  
Hendrick Tan ◽  
Hany Soliman ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Monte Carlo ◽  
Magnetic Resonance ◽  
Linear Accelerator ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Skin Dose ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

Abstract Magnetic Resonance Imaging (MRI)-Linear Accelerator (MR-Linac) radiotherapy is an innovative technology that requires special consideration for secondary electron interactions within the magnetic field, which can alter dose deposition at air-tissue interfaces. Thirty-seven consecutive glioma patients had treatment planning completed and approved prior to radiotherapy initiation using commercial treatment planning systems (TPS): a Monte Carlo-based or convolution-based TPS for MR-Linac or Cone Beam CT (CBCT)-guided Linac, respectively. In vivo skin dose was measured using an Optically Stimulated Luminescent Dosimeter (OSLD) and correlated with TPS skin dose. We found that Monte Carlo-based MR-Linac plans and convolution-based CBCT-Linac plans had similar dosimetric parameters for target volumes and organs-at-risk. However, MR-Linac plans had 1.52 Gy higher mean dose to air cavities (p<0.0001) and 1.10 Gy higher mean dose to skin (p<0.0001). In vivo skin dose was 14.5% greater for MR-Linac (p=0.0027), and were more accurately predicted by Monte Carlo-based calculation (ρ=0.95, p<0.0001) vs. convolution-based (ρ=0.80, p=0.0096). This is the first prospective dosimetric comparison of glioma patients clinically treated on both MR-Linac and CBCT-guided Linac. Skin doses were significantly greater with MR-Linac and correlated with in vivo measurements. Future MR-Linac planning processes are being designed to account for skin dosimetry and treatment delivery.

scholarly journals Initial experience of using an iron-containing fiducial marker for radiotherapy of prostate cancer: Advantages in the visualization of markers in Computed Tomography and Magnetic Resonance Imaging

2016 ◽  
Vol 22 (4) ◽  
pp. 93-96 ◽  
Author(s):  
Osamu Tanaka ◽  
Takayoshi Iida ◽  
Hisao Komeda ◽  
Masayoshi Tamaki ◽  
Kensaku Seike ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Cone Beam Ct ◽  
Intensity Modulated Radiotherapy ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Planning Ct

Abstract Visualization of markers is critical for imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). However, the size of the marker varies according to the imaging technique. While a large-sized marker is more useful for visualization in MRI, it results in artifacts on CT and causes substantial pain on administration. In contrast, a small-sized marker reduces the artifacts on CT but hampers MRI detection. Herein, we report a new ironcontaining marker and compare its utility with that of non-iron-containing markers. Five patients underwent CT/MRI fusion-based intensity-modulated radiotherapy, and the markers were placed by urologists. A Gold Anchor™ (GA; diameter, 0.28 mm; length, 10 mm) was placed using a 22G needle on the right side of the prostate. A VISICOIL™ (VIS; diameter, 0.35 mm; length, 10 mm) was placed using a 19G needle on the left side. MRI was performed using T2*-weighted imaging. Three observers evaluated and scored the visual qualities of the acquired images. The mean score of visualization was almost identical between the GA and VIS in radiography and cone-beam CT (Novalis Tx). The artifacts in planning CT were slightly larger using the GA than using the VIS. The visualization of the marker on MRI using the GA was superior to that using the VIS. In conclusion, the visualization quality of radiography, conebeam CT, and planning CT was roughly equal between the GA and VIS. However, the GA was more strongly visualized than was the VIS on MRI due to iron containing.

scholarly journals Geometric Reproducibility of Three-Dimensional Oral Implant Planning Based on Magnetic Resonance Imaging and Cone-Beam Computed Tomography

2021 ◽  
Vol 10 (23) ◽  
pp. 5546
Author(s):  
Franz Schwindling ◽  
Sophia Boehm ◽  
Christopher Herpel ◽  
Dorothea Kronsteiner ◽  
Lorenz Vogel ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Cone Beam Computed Tomography ◽  
Three Dimensional ◽  
Cone Beam ◽  
Resonance Imaging ◽  
Mean Values ◽  
Entry Level ◽  
Magnetic Resonance Imaging Mri

This study aimed to investigate the geometric reproducibility of three-dimensional (3D) implant planning based on magnetic resonance imaging (MRI) and cone-beam computed tomography (CBCT). Four raters used a backward-planning approach based on CBCT imaging and standard software to position 41 implants in 27 patients. Implant planning was repeated, and the first and second plans were analyzed for geometric differences regarding implant tip, entry-level, and axis. The procedure was then repeated for MRI data of the same patients. Thus, 656 implant plans were available for analysis of intra-rater reproducibility. For both imaging modalities, the second-round 3D implant plans were re-evaluated regarding inter-rater reproducibility. Differences between the modalities were analyzed using paired t-tests. Intra- and inter-rater reproducibility were higher for CBCT than for MRI. Regarding intra-rater deviations, mean values for MRI were 1.7 ± 1.1 mm/1.5 ± 1.1 mm/5.5 ± 4.2° at implant tip/entry-level/axis. For CBCT, corresponding values were 1.3 ± 0.8 mm/1 ± 0.6 mm/4.5 ± 3.1°. Inter-rater comparisons revealed mean values of 2.2 ± 1.3 mm/1.7 ± 1 mm/7.5 ± 4.9° for MRI, and 1.7 ± 1 mm/1.2 ± 0.7 mm/6 ± 3.7° for CBCT. CBCT-based implant planning was more reproducible than MRI. Nevertheless, more research is needed to increase planning reproducibility—for both modalities—thereby standardizing 3D implant planning.

scholarly journals A243 A RETROSPECTIVE REVIEW OF THE RADIOGRAPHIC DIAGNOSIS AND SURGICAL RESECTION RATES OF PANCREATIC SEROUS CYSTS

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 300-301
Author(s):  
M Monachese ◽  
S Li ◽  
M Salim ◽  
L Guimaraes ◽  
P D James
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Surgical Resection ◽  
Predictive Value ◽  
Resected Specimen ◽  
Cystic Lesions ◽  
Resonance Imaging ◽  
Guided Biopsy ◽  
Magnetic Resonance Imaging Mri

Abstract Background Pancreatic cystic lesions are increasingly identified in persons undergoing abdominal imaging. Serous cystic neoplasms (SCNs) have a very low risk of malignant transformation. Resection of SCNs is not recommended in the absence of related symptoms. The accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) to identify SCNs is not known and may impact clinical care. Aims To evaluate the accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) for the diagnosis of SCN. To see how this can impact the decision to resect suspected SCNs. Methods Retrospective cohort study of patients from the University Health Network with suspected SCNs from 2017–2020 who underwent either a CT or MRI of the abdomen. Reports noting pancreatic cystic lesions were identified and reviewed. Only cases with suspected SCNs were included. Clinical (age, sex, symptoms, treatment) and radiographic (type of imaging, reported cyst characteristics) data was collected. Pathology was reviewed for all cases where the cysts was biopsied or resected during follow-up. The gold standard for the diagnosis for SCN was pathology of resected specimen or EUS-guided biopsy cytopathology showing no evidence of a mucinous lesion, CEA level below 10ug per L and amylase level below 50 U/L. Results 163 patients were included in the study. 99 (61%) were female and 98 (60%) underwent CT scan. EUS-guided biopsy was performed in 24 (15%) of patients and 8 (5%) had surgical resection. Multidisciplinary review was performed in 6 of the 8 cases that went to surgery. Of the resected specimens, 5 (63%) were SCN, 1 was a mucinous cystic lesion, 1 was a neuroendocrine tumor and 1 was a carcinoma. Two patients underwent EUS evaluation prior to surgical resection. In one case SCN was resected when EUS reported an undetermined cyst type. Reasons for surgical resection were: the diagnosis of serous cyst was not definitive (n=5), symptoms (n=2), and high-risk mucinous cystic neoplasm identified on EUS (n=1). Of 30 patients with pathology available, 15 (50%) were confirmed to have a SCN. CT and MRI had a sensitivity, specificity, positive predictive value and negative predictive value of 93%, 25%, 52% and 80%, respectively. Conclusions Surgical resection for SCN lesions is driven by diagnostic uncertainty after cross-sectional imaging. Multidisciplinary review and EUS evaluation may improve diagnostic accuracy and should be considered prior to surgical resection of possible SCN lesions. Funding Agencies None

scholarly journals Imaging of larynx: Diagnostic value of computed tomography and magnetic resonance imaging

2009 ◽  
Vol 56 (3) ◽  
pp. 39-44
Author(s):  
R.M. Maksimovic ◽  
B.A. Banko ◽  
J.P. Milovanovic
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Regional Lymph Node ◽  
Diagnostic Value ◽  
Resonance Imaging ◽  
Precise Diagnosis ◽  
Node Metastases ◽  
Magnetic Resonance Imaging Mri

Computed tomography (CT) and magnetic resonance imaging (MRI) are enabling more precise diagnosis and treatment planning in patients with diseases of the larynx. The aim of this article is to describe the role of these methods in assessment of the laringeal diseases and key local anatomic characteristics important for spread of the disease. CT and MRI have a valuable contribution to the staging of the tumors due to the possibility to show the relationship to the ventricular complex, involvement of the subumucosal spaces, defining craniocaudal and anterposterior extension, laringeal cartilage invasion, as well as regional lymph node metastases.

Hypercementosis: Diagnostic imaging by radiograph, cone-beam computed tomography, and magnetic resonance imaging

2017 ◽  
Vol 5 (3) ◽  
pp. 90 ◽  
Author(s):  
AntonioneSantos Bezerra Pinto ◽  
MatheusSantos Carvalho ◽  
AlanLeandro Carvalho de Farias ◽  
Brunna da Silva Firmino ◽  
LuisPaulo da Silva Dias ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Diagnostic Imaging ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Resonance Imaging

Neurogenic Stuttering: Further Corroboration of Site of Lesion

1996 ◽  
Vol 75 (3) ◽  
pp. 161-168 ◽  
Author(s):  
Reinhardt J. Heuer ◽  
Robert Thayer Sataloff ◽  
Steven Mandel ◽  
Nancy Travers
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Past Century ◽  
Unilateral Lesion ◽  
Resonance Imaging ◽  
The Past ◽  
Magnetic Resonance Imaging Mri

Cases of neurogenic stuttering have been reported in the literature throughout the past century. Site(s) of lesion(s) have been documented usually by association of symptoms, EEG studies and occasionally by computed tomography (CT). The authors present three cases in which the site(s) of lesion(s) are documented by CT, magnetic resonance imaging (MRI) and SPECT. This study supports previous findings of neurogenic stuttering following either bilateral diffuse lesions or a unilateral lesion. In at least one case, the actual site of the lesion would have been missed without the use of SPECT testing. EEG studies were not helpful in identifying the site of the lesion.

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