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Prostate Cancer: Prostate-specific Membrane Antigen Positron-emission Tomography/Computed Tomography or Positron-emission Tomography/Magnetic Resonance Imaging for Staging. Top Magn Reson Imaging 2020; 29:59-66. [PMID: 32015295 DOI: 10.1097/rmr.0000000000000229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Positron-emission tomography (PET) with prostate-specific membrane antigen (PSMA) has been increasingly used to image prostate cancer in the last decade. In the staging setting several studies have already been published suggesting PSMA PET can be a valuable tool. They, however, did not translate into recommendations by guidelines. Both PSMA PET/computed tomography (CT) and PET/magnetic resonance imaging have been investigated in the staging setting, showing higher detection rate of prostate cancer lesions over the conventional imaging work-up and some studies already showed an impact on disease management. The aim of this review is to provide an overview of the existing published data regarding PSMA PET for staging prostate cancer, with emphasis on PET/magnetic resonance imaging. Despite the fact that PSMA is a relatively new tool and not officially recommended for staging yet, there are >50 original studies in the literature assessing PSMA PET performance in the staging setting of prostate cancer, and some meta-analyses.
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Mendes C, Serpa J. Revisiting lactate dynamics in cancer—a metabolic expertise or an alternative attempt to survive? J Mol Med (Berl) 2020; 98:1397-1414. [DOI: 10.1007/s00109-020-01965-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 07/14/2020] [Accepted: 08/14/2020] [Indexed: 12/15/2022]
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Abstract
In academic centers, PET/MR has taken the road to clinical nuclear medicine in the past 6 years since the last review on its applications in head and neck cancer patients in this journal. Meanwhile, older sequential PET + MR machines have largely vanished from clinical sites, being replaced by integrated simultaneous PET/MR scanners. Evidence from several studies suggests that PET/MR overall performs equally well as PET/CT in the staging and restaging of head and neck cancer and in radiation therapy planning. PET/MR appears to offer advantages in the characterization and prognostication of head and neck malignancies through multiparametric imaging, which demands an exact preparation and validation of imaging modalities, however. The majority of available clinical PET/MR studies today covers FDG imaging of squamous cell carcinoma arising from a broad spectrum of locations in the upper aerodigestive tract. In the future, specific PET/MR studies are desired that address specific histopathological tumor entities, nonepithelial malignancies, such as major salivary gland tumors, squamous cell carcinomas arising in specific locations, and malignancies imaged with non-FDG radiotracers. With the advent of digital PET/CT scanners, PET/MR is expected to partake in future technical developments, such as novel iterative reconstruction techniques and deviceless motion correction for respiration and gross movement in the head and neck region. Owing to the still comparably high costs of PET/MR scanners and facility requirements on the one hand, and the concentration of multidisciplinary head and neck cancer treatment mainly at academic centers on the other hand, a more widespread use of this imaging modality outside major hospitals is currently limited.
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Duffy IR, Boyle AJ, Vasdev N. Improving PET Imaging Acquisition and Analysis With Machine Learning: A Narrative Review With Focus on Alzheimer's Disease and Oncology. Mol Imaging 2020; 18:1536012119869070. [PMID: 31429375 PMCID: PMC6702769 DOI: 10.1177/1536012119869070] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Machine learning (ML) algorithms have found increasing utility in the medical imaging field and numerous applications in the analysis of digital biomarkers within positron emission tomography (PET) imaging have emerged. Interest in the use of artificial intelligence in PET imaging for the study of neurodegenerative diseases and oncology stems from the potential for such techniques to streamline decision support for physicians providing early and accurate diagnosis and allowing personalized treatment regimens. In this review, the use of ML to improve PET image acquisition and reconstruction is presented, along with an overview of its applications in the analysis of PET images for the study of Alzheimer's disease and oncology.
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Affiliation(s)
- Ian R Duffy
- 1 Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Amanda J Boyle
- 1 Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Neil Vasdev
- 1 Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,2 Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
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Park J, Pak K, Yun TJ, Lee EK, Ryoo I, Lee JY, Hwang I, Yoo RE, Kang KM, Choi SH, Sohn CH, Cheon GJ, Kim JH. Diagnostic Accuracy and Confidence of [18F] FDG PET/MRI in comparison with PET or MRI alone in Head and Neck Cancer. Sci Rep 2020; 10:9490. [PMID: 32528161 PMCID: PMC7289810 DOI: 10.1038/s41598-020-66506-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 05/18/2020] [Indexed: 12/22/2022] Open
Abstract
The usefulness of PET/MRI in head and neck malignancy has not been fully elucidated. The purpose of our study was to evaluate the diagnostic accuracy and confidence of PET/MRI in comparison with PET or MRI alone. This study included 73 consecutive patients who underwent [18F] FDG PET/MRI in head and neck under the suspicion of malignancy. A neuroradiologist and a nuclear medicine specialist reviewed MRI and PET images, respectively and independently, followed by a consensus review of PET/MRI one month later. For 134 lesions, accuracy and confidence were compared among PET, MRI, and PET/MRI. For lesion base, PET/MRI had a sensitivity of 85.7%, a specificity of 89.1%, a PPV of 89.6%, a negative predictive value of 85.1%, and an accuracy of 87.3%. AUCs of PET/MRI per lesion (0.926) and per patient (0.934) for diagnosing malignancy were higher than PET (0.847 and 0.747, respectively) or MRI (0.836 and 0.798, respectively) alone (P < 0.05). More than 80% of the cases (111/134) showed diagnostic concordance between PET and MRI. PPV of PET/MRI was higher in malignant concordant cases (93.2%, 55/59) than in discordant cases (62.5%, 5/8) (p = 0.040). Confident scoring rate in malignant concordant cases was higher on PET/MRI (96.6%, 57/59) than on MRI (76.3%, 45/59) (p = 0.003). In conclusion, compared with PET or MRI alone, PET/MRI presents better diagnostic performance in accuracy and confidence for diagnosis of malignancy. PET/MRI is useful in patients with head and neck cancer.
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Affiliation(s)
- Jisang Park
- Department of Radiology, Konkuk University Chungju Hospital, 82, Gukwondae-ro, Chunju, Chungcheongbuk-do, 27376, Republic of Korea
| | - Kyoungjune Pak
- Department of Nuclear medicine, Pusan National University Hospital, 179, Guduk-ro, seo-gu, Pusan, 49241, Republic of Korea
| | - Tae Jin Yun
- Department of Radiology, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Eun Kyoung Lee
- Department of Radiology, Seoul National University Hospital Healthcare System Gangnam Center, Gangnam Finance Center 152, Teheran-ro, Gangnam-gu, Seoul, 06236, Republic of Korea
| | - Inseon Ryoo
- Department of Radiology, Korea University Guro Hospital, 148, Gurodong-ro, Guro-gu, Seoul, 08308, Republic of Korea
| | - Ji Ye Lee
- Department of Radiology, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Inpyeong Hwang
- Department of Radiology, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Roh-Eul Yoo
- Department of Radiology, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Koung Mi Kang
- Department of Radiology, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Seung Hong Choi
- Department of Radiology, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Chul-Ho Sohn
- Department of Radiology, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Gi Jeong Cheon
- Department of Nuclear medicine, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Ji-Hoon Kim
- Department of Radiology, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
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Diagnostic performance of zero-TE lung MR imaging in FDG PET/MRI for pulmonary malignancies. Eur Radiol 2020; 30:4995-5003. [PMID: 32300969 PMCID: PMC7431435 DOI: 10.1007/s00330-020-06848-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/10/2020] [Accepted: 03/30/2020] [Indexed: 10/27/2022]
Abstract
OBJECTIVES This study aimed to evaluate the diagnostic performance of the lung zero-echo time (ZTE) sequence in FDG PET/MRI for detection and differentiation of lung lesions in oncologic patients in comparison with conventional two-point Dixon-based MR imaging. METHODS In this single-institution retrospective study approved by the institutional review board, 209 patients with malignancies (97 men and 112 women; age range, 17-89 years; mean age, 66.5 ± 12.9 years) underwent 18F-FDG PET/MRI between August 2017 and August 2018, with diagnostic Dixon and ZTE under respiratory gating acquired simultaneously with PET. Image analysis was performed for PET/Dixon and PET/ZTE fused images by two readers to assess the detectability and differentiation of lung lesions. The reference standard was pathological findings and/or the data from a chest CT. The detection and differentiation abilities were evaluated for all lesions and subgroups divided by lesion size and maximum standardized uptake value (SUVmax). RESULTS Based on the reference standard, 227 lung lesions were identified in 113 patients. The detectability of PET/ZTE was significantly better than that of PET/Dixon for overall lesions, lesions with a SUVmax less than 3.0 and lesions smaller than 4 mm (p < 0.01). The diagnostic performance of PET/ZTE was significantly better than that of PET/Dixon for overall lesions and lesions smaller than 4 mm (p < 0.01). CONCLUSIONS ZTE can improve diagnostic performance in the detection and differentiation of both FDG-avid and non-FDG-avid lung lesions smaller than 4 mm in size, yielding a promising tool to enhance the utility of FDG PET/MRI in oncology patients with lung lesions. KEY POINTS • The detection rate of PET/ZTE for lesions with a SUVmax of less than 1.0 was significantly better than that of PET/Dixon. • The performance for differentiation of PET/ZTE for lesions that were even smaller than 4 mm in size were significantly better than that of PET/Dixon. • Inter-rater agreement of PET/ZTE for the differentiation of lesions less than 4 mm in size was substantial and better than that of PET/Dixon.
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Kreuzaler P, Panina Y, Segal J, Yuneva M. Adapt and conquer: Metabolic flexibility in cancer growth, invasion and evasion. Mol Metab 2020; 33:83-101. [PMID: 31668988 PMCID: PMC7056924 DOI: 10.1016/j.molmet.2019.08.021] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/05/2019] [Accepted: 08/14/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND It has been known for close to a century that, on average, tumors have a metabolism that is different from those found in healthy tissues. Typically, tumors show a biosynthetic metabolism that distinguishes itself by engaging in large scale aerobic glycolysis, heightened flux through the pentose phosphate pathway, and increased glutaminolysis among other means. However, it is becoming equally clear that non tumorous tissues at times can engage in similar metabolism, while tumors show a high degree of metabolic flexibility reacting to cues, and stresses in their local environment. SCOPE OF THE REVIEW In this review, we want to scrutinize historic and recent research on metabolism, comparing and contrasting oncogenic and physiological metabolic states. This will allow us to better define states of bona fide tumor metabolism. We will further contextualize the stress response and the metabolic evolutionary trajectory seen in tumors, and how these contribute to tumor progression. Lastly, we will analyze the implications of these characteristics with respect to therapy response. MAJOR CONCLUSIONS In our review, we argue that there is not one single oncogenic state, but rather a diverse set of oncogenic states. These are grounded on a physiological proliferative/wound healing program but distinguish themselves due to their large scale of proliferation, mutations, and transcriptional changes in key metabolic pathways, and the adaptations to widespread stress signals within tumors. We find evidence for the necessity of metabolic flexibility and stress responses in tumor progression and how these responses in turn shape oncogenic progression. Lastly, we find evidence for the notion that the metabolic adaptability of tumors frequently frustrates therapeutic interventions.
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Oh G, O'Mahoney E, Jeavons S, Law P, Ngai S, McGill G, Yu C, Miles KA. Discrepancies between positron emission tomography/magnetic resonance imaging and positron emission tomography/computed tomography in a cohort of oncological patients. J Med Imaging Radiat Oncol 2020; 64:204-210. [PMID: 32037655 DOI: 10.1111/1754-9485.13000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 01/09/2020] [Indexed: 12/12/2022]
Abstract
INTRODUCTION This study aims to evaluate discrepant findings between positron emission tomography/magnetic resonance imaging (PET/MRI) and positron emission tomography/computed tomography (PET/CT) in a cohort of oncological patients and to undertake a phantom study to assess the potential for extended PET acquisitions to lead to false-positive findings on PET/MRI. METHODS Discrepant findings from a series of 106 patients undergoing same-day 18 F-fluorodeoxyglucose (FDG)-PET/CT and PET/MRI were reviewed. Phantom studies explored the potential for PET acquisition time to contribute to discrepancy. RESULTS There were 14 discrepant cases, 5 (35.7%) of which related to PET/MRI acquisitions that had been extended to 10 min. Three of these five cases proved to be falsely positive. Phantom studies showed greater contrast recovery and signal to noise ratio for 10-min PET/MRI acquisitions compared to 2-min acquisitions using PET/CT. There were no discrepancies when PET/CT showed disseminated disease (P = 0.036). CONCLUSIONS Extended PET/MRI acquisitions used to accommodate multiple MRI sequences may be associated with false-positive findings compared to PET/CT. PET/MRI is more likely to have incremental value when the prior probability for disseminated disease is low.
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Affiliation(s)
- Geon Oh
- Department of Diagnostic Radiology, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Eoin O'Mahoney
- Biomedical Technology Services, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Susanne Jeavons
- Department of Diagnostic Radiology, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Phillip Law
- Department of Diagnostic Radiology, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Stanley Ngai
- Department of Diagnostic Radiology, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - George McGill
- Biomedical Technology Services, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Chris Yu
- Department of Diagnostic Radiology, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Kenneth A Miles
- Department of Diagnostic Radiology, Princess Alexandra Hospital, Brisbane, Queensland, Australia.,Institute of Nuclear Medicine, University College London, London, UK
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Performing clinical 18F-FDG-PET/MRI of the mediastinum optimising a dedicated, patient-friendly protocol. Nucl Med Commun 2019; 40:815-826. [PMID: 31169592 DOI: 10.1097/mnm.0000000000001035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To construct a mediastinal-specific fluorine-18-fluorodeoxyglucose (F-FDG)-PET/MR protocol with high-quality MRI of minimal acquisition-time and comparable diagnostic value to F-FDG-PET/computed tomography (CT). MATERIALS AND METHODS Fifteen healthy participants received PET/MRI and 10 patients with mediastinal tumours (eight non-small-cell lung, two oesophageal cancer) received F-FDG-PET/MRI immediately after F-FDG-PET/CT. Sequences volume interpolated breath-hold examination (T1-VIBE) and Half-Fourier acquisition single-shot turbo spin echo (T2-HASTE) were optimised by varying the parameters: breath-hold (BH, end-expiration), fat suppression (spectral adiabatic inversion recovery), and ECG-triggering (ECG, end-diastole). Image quality (IQ) of each sequence-variation was qualitatively scored by medical experts and quantitatively assessed by calculating signal-to-noise ratios, contrast relative to muscle, standardized-uptake-value, and tumour-to-blood ratios. Patient comfort was evaluated on patients' experience. Diagnostic accuracy of F-FDG-PET/MRI was compared to F-FDG-PET/CT, in reference to histopathology/cytopathology. RESULTS ECG-triggered T1-VIBE images showed the highest signal-to-noise ratio (P < 0.01) and the largest contrast between mediastinal soft-tissues, regardless of BH or free-breathing acquisition. IQ of ECG-triggered T1-VIBE scans in BH were scored qualitatively highest with good reader agreement (κ = 0.62). IQ of T2-HASTE was not significantly affected by BH acquisition (P > 0.9). Qualitative IQ of T1-VIBE and T2-HASTE declined after spectral adiabatic inversion recovery fat-suppression. All patients could maintain BH at end-expiration and reported no discomfort. Diagnostic performance of F-FDG-PET/MR was not significantly different from F-FDG-PET/CT with comparable staging, standardized-uptake-values, and tumour-to-blood ratios. However, T-status was more often over-staged on F-FDG-PET/CT, while N-status was more frequently under-staged on F-FDG-PET/MR. CONCLUSION ECG-triggered T1-VIBE sequences acquired during short, multiple BHs are recommended for mediastinal imaging using F-FDG-PET/MR. With dedicated protocols, F-FDG-PET/MRI will be useful in thoracic oncology and aid in diagnostic evaluation and tailored treatment decision-making.
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Martin O, Schaarschmidt BM, Kirchner J, Suntharalingam S, Grueneisen J, Demircioglu A, Heusch P, Quick HH, Forsting M, Antoch G, Herrmann K, Umutlu L. PET/MRI Versus PET/CT for Whole-Body Staging: Results from a Single-Center Observational Study on 1,003 Sequential Examinations. J Nucl Med 2019; 61:1131-1136. [DOI: 10.2967/jnumed.119.233940] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 12/02/2019] [Indexed: 12/31/2022] Open
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Abstract
Purpose: We proposed and developed a new microstrip transmission line radiofrequency (RF) coil for a positron emission tomography (PET) insert for MRI, which has low electrical interactions with PET shield boxes. We performed imaging experiments using a single-channel and a four-channel proposed RF coils for proof-of-concept. Methods: A conventional microstrip coil consists of a microstrip conductor, a ground conductor, and a dielectric between the two conductors. We proposed a microstrip coil for the PET insert that replaced the conventional single-layer ground conductor with the RF shield of the PET insert. A dielectric material, which could otherwise attenuate gamma photons radiated from the PET imaging tracer, was not used. As proof-of-concept, we compared conventional and the proposed single-channel coils. To study multichannel performance, we further developed a four-channel proposed RF coil. Since the MRI system had a single-channel transmission port, an interfacing four-way RF power division circuit was designed. The coils were implemented as both RF transmitters and receivers in a cylindrical frame of diameter 150 mm. Coil bench performances were tested with a network analyzer (Rohde & Schwarz, Germany), and a homogeneous phantom study was conducted for gradient echo imaging and RF field (B1) mapping in a 3T clinical MRI system (Verio, Siemens, Erlangen, Germany). Results: For all coils, the power reflection coefficient was below −30 dB, and the transmission coefficients in the four-channel configuration were near or below −20 dB. The comparative single-channel coil study showed good similarity between the conventional and proposed coils. The gradient echo image of the four-channel coil showed expected flashing image intensity near the coils and no phase distortion was visible. Transmit B1 field map resembled the image performance. Conclusion: The proposed PET-microstrip coil performed similarly to the conventional microstrip transmission line coil and is promising for the development of a compact coil-PET system capable of simultaneous PET/MRI analysis with an existing MRI system.
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Affiliation(s)
- Md Shahadat Hossain Akram
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology
| | - Takayuki Obata
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology
| | - Taiga Yamaya
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology
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Sequential PET/diffusion-weighted imaging in the evaluation of myocardial perfusion and viability in coronary artery disease: a preliminary study. Nucl Med Commun 2019; 41:40-47. [PMID: 31764594 DOI: 10.1097/mnm.0000000000001109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To evaluate the utility of sequential F-18 fluorodeoxyglucose PET/diffusion-weighted imaging in assessing myocardial perfusion and viability in coronary artery disease. METHODS Fourteen coronary artery disease patients and five non-coronary artery disease subjects underwent sequential cardiac F-18 fluorodeoxyglucose PET/diffusion-weighted imaging using a trimodality PET/computed tomography-MRI system. The perfusion data were acquired by measuring low b-values apparent diffusion coefficient using diffusion-weighted imaging. Regional myocardial viability was determined by perfusion/metabolism patterns. The perfusion/metabolism patterns obtained by low b-values apparent diffusion coefficient/fluorodeoxyglucose uptake were analyzed and compared with the results from the combination of rest methoxyisobutylisonitrile (Tc-MIBI) myocardial perfusion single-photon emission computed tomography with F-18 fluorodeoxyglucose PET/computed tomography. RESULTS Ten coronary artery disease patients and five non-coronary artery disease subjects were included in the final analysis. Low b-values apparent diffusion coefficient defects involved with 25 myocardial regions were demonstrated in nine coronary artery disease patients, while Tc-MIBI defects involved with 21 myocardial regions were shown in the same patients. The agreement between low b-values apparent diffusion coefficient and MIBI uptake was good in coronary artery disease patients (κ = 0.627, P < 0.001) and was better still in the whole subjects (κ = 0.733, P < 0.001). Low b-values apparent diffusion coefficient/fluorodeoxyglucose uptake demonstrated mismatch patterns in six coronary artery disease patients and MIBI/fluorodeoxyglucose uptake revealed mismatch patterns in seven coronary artery disease patients. Agreement in the evaluation of regional myocardial viability between low b-values apparent diffusion coefficient/fluorodeoxyglucose uptake and MIBI/fluorodeoxyglucose uptake was high in coronary artery disease patients (κ = 0.627, P < 0.001) and all subjects (κ = 0.728, P < 0.001). CONCLUSIONS Low b-values apparent diffusion coefficient/fluorodeoxyglucose uptake is comparable to MIBI/fluorodeoxyglucose uptake in assessing perfusion/metabolism patterns, indicating that microperfusion might dominate the diffusion signal at low b-values and sequential PET/diffusion-weighted imaging might be useful to evaluate myocardial viability in coronary artery disease patients.
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Cheng Y, Bai L, Shang J, Tang Y, Ling X, Guo B, Gong J, Wang L, Xu H. Preliminary clinical results for PET/MR compared with PET/CT in patients with nasopharyngeal carcinoma. Oncol Rep 2019; 43:177-187. [PMID: 31746412 PMCID: PMC6908933 DOI: 10.3892/or.2019.7392] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 09/09/2019] [Indexed: 12/23/2022] Open
Abstract
The present study aimed to assess the performance of positron emission tomography-magnetic resonance imaging (PET/MR) for the visualization and characterization of lesions. In addition, the present study investigated whether the apparent diffusion coefficient (ADC) and intravoxel incoherent motion parameters exhibited any significant correlation with standardized uptake values (SUV) in patients with nasopharyngeal carcinoma (NPC). A total of 35 patients with NPC underwent whole body PET-computed tomography (CT) and head and neck MR imaging (MRI) scans using the PET/CT-MRI system. Image quality, lesion conspicuity and the diagnostic confidence of PET/CT, T1 weighted (T1w) PET/MR and T2w PET/MR imaging were assessed. The true diffusion coefficient (D), the pseudo-diffusion coefficient or diffusion within the microcirculation (D*), and the perfusion fraction or the contribution of water moving in the capillaries (f), and ADC, were calculated. The correlation between the ADC, D*, D and f values and the SUV were analyzed using Pearson's correlation analysis. Similar image quality was obtained using PET/CT, T1w PET/MR and T2w PET/MR imaging. However, the T1w PET/MR and T2w PET/MR imaging were more effective than PET/CT in analyzing the lesion conspicuity of the primary tumors and lymph nodes. In addition, T2w PET/MR imaging was more efficient than T1w PET/MR imaging in analyzing primary tumors and lymph nodes. Pearson's correlation analysis showed no significant correlation between the SUV and ADC, and D*, D and f values in NPC. The present results suggested that the application of PET/MR is feasible and could serve as a reliable alternative to PET/CT, while SUV and ADC, D*, D and f values were identified as independent biomarkers in NPC.
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Affiliation(s)
- Yong Cheng
- Department of Nuclear Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, P.R. China
| | - Le Bai
- Department of Radiology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, P.R. China
| | - Jingjie Shang
- Department of Nuclear Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, P.R. China
| | - Yongjin Tang
- Department of Nuclear Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, P.R. China
| | - Xueying Ling
- Department of Nuclear Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, P.R. China
| | - Bin Guo
- Department of Nuclear Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, P.R. China
| | - Jian Gong
- Department of Nuclear Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, P.R. China
| | - Lu Wang
- Department of Nuclear Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, P.R. China
| | - Hao Xu
- Department of Nuclear Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, P.R. China
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Comparison of 18F-FDG PET/MRI, MRI, and 18F-FDG PET/CT for the detection of synchronous cancers and distant metastases in patients with oropharyngeal and hypopharyngeal squamous cell carcinoma. Eur J Nucl Med Mol Imaging 2019; 47:94-104. [PMID: 31606831 DOI: 10.1007/s00259-019-04510-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/23/2019] [Indexed: 12/17/2022]
Abstract
PURPOSE In this prospective study, we sought to compare the clinical utility of fluorodeoxyglucose PET/MRI, MRI, and PET/CT in the detection of synchronous cancers and distant metastases in patients with oropharyngeal and hypopharyngeal squamous cell carcinoma (OHSCC). METHODS We examined 198 consecutive patients with biopsy-proven OHSCC who agreed to receive chemoradiation. All patients underwent pretreatment PET/MRI and PET/CT on the same day. Patients were followed-up for a minimum of 12 months or until death. The McNemar's test and receiver-operating characteristic (ROC) curves were used to compare sensitivity/specificity and the diagnostic capabilities of PET/MRI, MRI, and PET/CT, respectively. RESULTS We identified 55 patients (27.7%) who had synchronous cancers and/or distant metastases (number of involved sites: 83). The results of site-based analysis revealed that the sensitivity of PET/MRI was 15.7% higher than that of MRI (73.5% versus 57.8%, p < 0.001) and 3.6% higher compared with PET/CT (73.5% versus 69.9%, p = 0.083), whereas the sensitivity of PET/CT was 12.1% higher than that of MRI (69.9% versus 57.8%, p = 0.012). On a patient-basis, ROC curve analysis demonstrated that PET/MRI yielded a greater area under curve than MRI (0.930 versus 0.905, p = 0.023). There were no significant differences in terms of diagnostic capability between MRI and PET/CT (0.905 versus 0.917, p = 0.469) and between PET/MRI and PET/CT (0.930 versus 0.917, p = 0.062). CONCLUSIONS In our cohort, PET/MRI showed a significantly higher diagnostic capability than MRI and no significant difference compared with PET/CT for the detection of synchronous cancers or distant metastases in patients with OHSCC.
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Das SK, McGurk R, Miften M, Mutic S, Bowsher J, Bayouth J, Erdi Y, Mawlawi O, Boellaard R, Bowen SR, Xing L, Bradley J, Schoder H, Yin FF, Sullivan DC, Kinahan P. Task Group 174 Report: Utilization of [ 18 F]Fluorodeoxyglucose Positron Emission Tomography ([ 18 F]FDG-PET) in Radiation Therapy. Med Phys 2019; 46:e706-e725. [PMID: 31230358 DOI: 10.1002/mp.13676] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 04/30/2019] [Accepted: 06/06/2019] [Indexed: 02/03/2023] Open
Abstract
The use of positron emission tomography (PET) in radiation therapy (RT) is rapidly increasing in the areas of staging, segmentation, treatment planning, and response assessment. The most common radiotracer is 18 F-fluorodeoxyglucose ([18 F]FDG), a glucose analog with demonstrated efficacy in cancer diagnosis and staging. However, diagnosis and RT planning are different endeavors with unique requirements, and very little literature is available for guiding physicists and clinicians in the utilization of [18 F]FDG-PET in RT. The two goals of this report are to educate and provide recommendations. The report provides background and education on current PET imaging systems, PET tracers, intensity quantification, and current utilization in RT (staging, segmentation, image registration, treatment planning, and therapy response assessment). Recommendations are provided on acceptance testing, annual and monthly quality assurance, scanning protocols to ensure consistency between interpatient scans and intrapatient longitudinal scans, reporting of patient and scan parameters in literature, requirements for incorporation of [18 F]FDG-PET in treatment planning systems, and image registration. The recommendations provided here are minimum requirements and are not meant to cover all aspects of the use of [18 F]FDG-PET for RT.
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Affiliation(s)
- Shiva K Das
- Department of Radiation Oncology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Ross McGurk
- Department of Radiation Oncology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Moyed Miften
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Sasa Mutic
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA
| | - James Bowsher
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - John Bayouth
- Human Oncology, University of Wisconsin, Madison, WI, USA
| | - Yusuf Erdi
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Osama Mawlawi
- Department of Imaging Physics, University of Texas, M D Anderson Cancer Center, Houston, TX, USA
| | - Ronald Boellaard
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Stephen R Bowen
- Department of Radiation Oncology, University of Washington, Seattle, WA, USA
| | - Lei Xing
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Jeffrey Bradley
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA
| | - Heiko Schoder
- Molecular Imaging and Therapy Service, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Fang-Fang Yin
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - Daniel C Sullivan
- Department of Radiology, Duke University School of Medicine, Durham, NC, USA
| | - Paul Kinahan
- Department of Radiology, University of Washington, Seattle, WA, USA
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Derlin T, Grünwald V, Steinbach J, Wester HJ, Ross TL. Molecular Imaging in Oncology Using Positron Emission Tomography. DEUTSCHES ARZTEBLATT INTERNATIONAL 2019; 115:175-181. [PMID: 29607803 DOI: 10.3238/arztebl.2018.0175] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 07/04/2017] [Accepted: 11/22/2017] [Indexed: 12/22/2022]
Abstract
BACKGROUND Anatomical and molecular data can be acquired simultaneously through the use of positron emission tomography (PET) in combination with computed tomography (CT) or magnetic resonance imaging (MRI) as a hybrid technique. A variety of radiopharmaceuticals can be used to characterize various metabolic processes or to visualize the expression of receptors, enzymes, and other molecular target structures. METHODS This review is based on pertinent publications retrieved by a selective search in PubMed, as well as on guidelines from Germany and abroad and on systematic reviews and meta-analyses. RESULTS Established radiopharmaceuticals for PET, such as 2-[18F]fluoro-2- deoxyglucose ([18F]FDG), enable the visualization of physiological processes on the molecular level and can provide vital information for clinical decision-making. For example, PET can be used to evaluate pulmonary nodules for malignancy with 95% sensitivity and 82% specificity. It can be used both for initial staging and for the guidance of further treatment. Alongside the PET radiopharmaceuticals that have already been well studied and evaluated, newer ones are increasingly becoming available for the noninvasive phenotyping of tumor diseases, e.g., for analyzing the expression of prostate-specific membrane antigen (PSMA), of somatostatin receptors, or of chemokine receptors on tumor cells. CONCLUSION PET is an important component of diagnostic algorithms in oncology. It can help make diagnosis more precise and treatment more individualized. An increasing number of PET radiopharmaceuticals are now expanding the available options for imaging. Many radiopharmaceuticals can be used not only for noninvasive analysis of the expression of therapeutically relevant target structures, but also for the ensuing, target-directed treatment with radionuclides.
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Affiliation(s)
- Thorsten Derlin
- Department of Nuclear Medicine, Hannover Medical School; Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School; Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden; Department of Pharmaceutical Radiochemistry, Technical University of Munich, Garching
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69
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Metser U, Chua S, Ho B, Punwani S, Johnston E, Pouliot F, Tau N, Hawsawy A, Anconina R, Bauman G, Hicks RJ, Weickhardt A, Davis ID, Pond G, Scott AM, Tunariu N, Sidhu H, Emmett L. The Contribution of Multiparametric Pelvic and Whole-Body MRI to Interpretation of 18F-Fluoromethylcholine or 68Ga-HBED-CC PSMA-11 PET/CT in Patients with Biochemical Failure After Radical Prostatectomy. J Nucl Med 2019; 60:1253-1258. [PMID: 30902875 DOI: 10.2967/jnumed.118.225185] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 01/30/2019] [Indexed: 12/24/2022] Open
Abstract
Our purpose was to assess whether the addition of data from multiparametric pelvic MRI (mpMR) and whole-body MRI (wbMR) to the interpretation of 18F-fluoromethylcholine (18F-FCH) or 68Ga-HBED-CC PSMA-11 (68Ga-PSMA) PET/CT (=PET) improves the detection of local tumor recurrence or of nodal and distant metastases in patients after radical prostatectomy with biochemical failure. Methods: The current analysis was performed as part of a prospective, multicenter trial on 18F-FCH or 68Ga-PSMA PET, mpMR, and wbMR. Eligible men had an elevated level of prostate-specific antigen (PSA) (>0.2 ng/mL) and high-risk features (Gleason score > 7, PSA doubling time < 10 mo, or PSA > 1.0 ng/mL) with negative or equivocal conventional imaging results. PET was interpreted with mpMR and wbMR in consensus by 2 radiologists and compared with prospective interpretation of PET or MRI alone. Performance measures of each modality (PET, MRI, and PET/mpMR-wbMR) were compared for each radiotracer and each individual patient (for 18F-FCH, or 68Ga-PSMA for patients who had 68Ga-PSMA PET) and to a composite reference standard. Results: There were 86 patients with PET (18F-FCH [n = 76] and/or 68Ga-PSMA [n = 26]) who had mpMR and wbMR. Local tumor recurrence was detected in 20 of 76 (26.3%) on 18F-FCH PET/mpMR, versus 11 of 76 (14.5%) on 18F-FCH PET (P = 0.039), and in 11 of 26 (42.3%) on 68Ga-PSMA PET/mpMR, versus 6 of 26 (23.1%) on 68Ga-PSMA PET (P = 0.074). Per patient, PET/mpMR was more often positive for local tumor recurrence than PET (P = 0.039) or mpMR (P = 0.019). There were 20 of 86 patients (23.3%) with regional nodal metastases on both PET/wbMR and PET (P = 1.0) but only 12 of 86 (14%) on wbMR (P = 0.061). Similarly, there were more nonregional metastases detected on PET/wbMR than on PET (P = 0.683) or wbMR (P = 0.074), but these differences did not reach significance. Compared with the composite reference standard for the detection of disease beyond the prostatic fossa, PET/wbMR, PET, and wbMR had sensitivity of 50%, 50%, and 8.3%, respectively, and specificity of 97.1%, 97.1%, and 94.1%, respectively. Conclusion: Interpretation of PET/mpMR resulted in a higher detection rate for local tumor recurrence in the prostatic bed in men with biochemical failure after radical prostatectomy. However, the addition of wbMR to 18F-FCH or 68Ga-PSMA PET did not improve detection of regional or distant metastases.
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Affiliation(s)
- Ur Metser
- University of Toronto, Toronto, Canada
| | - Sue Chua
- Royal Marsden Hospital, London, United Kingdom
| | - Bao Ho
- St. Vincent's Hospital, Sydney, Australia
| | | | | | | | - Noam Tau
- University of Toronto, Toronto, Canada
| | | | | | | | | | | | - Ian D Davis
- Eastern Health Clinical School, Monash University, Box Hill, Victoria, Australia; and
| | - Greg Pond
- McMaster University, Hamilton, Ontario Canada
| | | | | | - Harbir Sidhu
- University College London, London, United Kingdom
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70
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Witoszynskyj S, Andrzejewski P, Georg D, Hacker M, Nyholm T, Rausch I, Knäusl B. Attenuation correction of a flat table top for radiation therapy in hybrid PET/MR using CT- and 68Ge/ 68Ga transmission scan-based μ-maps. Phys Med 2019; 65:76-83. [PMID: 31437602 DOI: 10.1016/j.ejmp.2019.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 08/01/2019] [Accepted: 08/02/2019] [Indexed: 12/28/2022] Open
Abstract
Hybrid PET/MR offers new opportunities in radiation oncology for tissue/tumour characterisation and response assessment. Attenuation correction (AC) is an important issue especially in the presence of immobilization devices and flat table tops (FTT). The goal of this study was to compare two methods of AC using CT- and 68Ge/68Ga transmission scan-based attenuation maps (μ-maps) for a custom-designed FTT. Measurements were performed in the mMR PET/MR and TrueV PET/CT Biograph Siemens scanners with three different phantoms, namely the Siemens MR-QA, a cubic canister and the NEMA IEC body phantom. The study revealed that the MR image quality is not hampered by the presence of the FTT. For cubic canister applying the scanner's inherent AC alone resulted in inaccuracies in PET images, with up to -4.0% underestimation of the activity. The mean NEMA sphere activity measurements without FTT, agreed within 3.5% with the respective inserted activity. Placing the FTT in the PET/MR scanner resulted in a difference to the injected activity of 4.5% when the table was not corrected for. By introducing the μ-maps the discrepancy between the used activity and the measurements decreased down to 2.6%. To improve the AC of the FTT the creation of a dedicated μ-map was necessary while the CT-based μ-map performed equally good as the source transmission scan-based one.
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Affiliation(s)
- Stephan Witoszynskyj
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Währingergürtel 18-20, 1090 Vienna, Austria
| | - Piotr Andrzejewski
- Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Währingergürtel 18-20, 1090 Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Währingergürtel 18-20, 1090 Vienna, Austria
| | - Dietmar Georg
- Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Währingergürtel 18-20, 1090 Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Währingergürtel 18-20, 1090 Vienna, Austria
| | - Marcus Hacker
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Währingergürtel 18-20, 1090 Vienna, Austria
| | - Tufve Nyholm
- Department of Radiation Sciences, Umeå University, SE-90187 Umeå, Sweden
| | - Ivo Rausch
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währingergürtel 18-20, 1090 Vienna, Austria
| | - Barbara Knäusl
- Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna, Währingergürtel 18-20, 1090 Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Währingergürtel 18-20, 1090 Vienna, Austria.
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71
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Basson L, Jarraya H, Escande A, Cordoba A, Daghistani R, Pasquier D, Lacornerie T, Lartigau E, Mirabel X. Chest Magnetic Resonance Imaging Decreases Inter-observer Variability of Gross Target Volume for Lung Tumors. Front Oncol 2019; 9:690. [PMID: 31456936 PMCID: PMC6700272 DOI: 10.3389/fonc.2019.00690] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 07/12/2019] [Indexed: 12/14/2022] Open
Abstract
Purpose: PET/CT is a standard medical imaging used in the delineation of gross tumor volume (GTV) in case of radiation therapy for lung tumors. However, PET/CT could present some limitations such as resolution and standardized uptake value threshold. Moreover, chest MRI has shown good potential in diagnosis for thoracic oncology. Therefore, we investigated the influence of chest MRI on inter-observer variability of GTV delineation. Methods and Materials: Five observers contoured the GTV on CT for 14 poorly defined lung tumors during three contouring phases based on true daily clinical routine and acquisition: CT phase, with only CT images; PET phase, with PET/CT; and MRI phase, with both PET/CT and MRI. Observers waited at least 1 week between each phases to decrease memory bias. Contours were compared using descriptive statistics of volume, coefficient of variation (COV), and Dice similarity coefficient (DSC). Results: MRI phase volumes (median 4.8 cm3) were significantly smaller than PET phase volumes (median 6.4 cm3, p = 0.015), but not different from CT phase volumes (median 5.7 cm3, p = 0.30). The mean COV was improved for the MRI phase (0.38) compared to the CT (0.58, p = 0.024) and PET (0.53, p = 0.060) phases. The mean DSC of the MRI phase (0.67) was superior to those of the CT and PET phases (0.56 and 0.60, respectively; p < 0.001 for both). Conclusions: The addition of chest MRI seems to decrease inter-observer variability of GTV delineation for poorly defined lung tumors compared to PET/CT alone and should be explored in further prospective studies.
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Affiliation(s)
- Laurent Basson
- Universitary Radiation Oncology Department, Oscar Lambret Comprehensive Cancer Center, Lille, France.,University of Lille, Lille, France
| | - Hajer Jarraya
- Medical Imaging Department, Oscar Lambret Comprehensive Cancer Center, Lille, France
| | - Alexandre Escande
- Universitary Radiation Oncology Department, Oscar Lambret Comprehensive Cancer Center, Lille, France.,University of Lille, Lille, France
| | - Abel Cordoba
- Universitary Radiation Oncology Department, Oscar Lambret Comprehensive Cancer Center, Lille, France
| | - Rayyan Daghistani
- University of Lille, Lille, France.,Medical Imaging Department, Oscar Lambret Comprehensive Cancer Center, Lille, France
| | - David Pasquier
- Universitary Radiation Oncology Department, Oscar Lambret Comprehensive Cancer Center, Lille, France.,University of Lille, Lille, France
| | - Thomas Lacornerie
- Department of Medical Physics, Oscar Lambret Comprehensive Cancer Center, Lille, France
| | - Eric Lartigau
- Universitary Radiation Oncology Department, Oscar Lambret Comprehensive Cancer Center, Lille, France.,University of Lille, Lille, France
| | - Xavier Mirabel
- Universitary Radiation Oncology Department, Oscar Lambret Comprehensive Cancer Center, Lille, France
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Øen SK, Aasheim LB, Eikenes L, Karlberg AM. Image quality and detectability in Siemens Biograph PET/MRI and PET/CT systems-a phantom study. EJNMMI Phys 2019; 6:16. [PMID: 31385052 PMCID: PMC6682841 DOI: 10.1186/s40658-019-0251-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 07/23/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The technology of modern positron emission tomography (PET) systems continuously improving, and with it the possibility to detect smaller lesions. Since first introduced in 2010, the number of hybrid PET/magnetic resonance imaging (MRI) systems worldwide is constantly increasing. It is therefore important to assess and compare the image quality, in terms of detectability, between the PET/MRI and the well-established PET/computed tomography (CT) systems. For this purpose, a PET image quality phantom (Esser) with hot spheres, ranging from 4 to 20 mm in diameter, was prepared with fluorodeoxyglucose and sphere-to-background activity concentrations of 8:1 and 4:1, to mimic clinical conditions. The phantom was scanned on a PET/MRI and a PET/CT system for both concentrations to obtain contrast recovery coefficients (CRCs) and contrast-to-noise ratios (CNRs), for a range of reconstruction settings. The detectability of the spheres was scored by three human observers for both systems and concentrations and all reconstructions. Furthermore, the impact of acquisition time on CNR and observer detectability was investigated. RESULTS Reconstructions applying point-spread-function modeling (and time-of-flight for the PET/CT) yielded the highest CRC and CNR in general, and PET/CT demonstrated slightly higher values than PET/MRI for most sphere sizes. CNR was dependent on reconstruction settings and was maximized for 2 iterations, a pixel size of less than 2 mm and a 4 mm Gaussian filter. Acquisition times of 97 s (PET/MRI) and 150 s (PET/CT) resulted in similar total net true counts. For these acquisition times, the smallest detected spheres by the human observers in the 8:1 activity concentration was the 6-mm sphere with PET/MRI (CNR = 5.6) and the 5-mm sphere with PET/CT (CNR = 5.5). With an acquisition time of 180 s, the 5-mm sphere was also detected with PET/MRI (CNR = 5.8). The 8-mm sphere was the smallest detected sphere in the 4:1 activity concentration for both systems. CONCLUSION In this experimental study, similar detectability was found for the PET/MRI and the PET/CT, although for an increased acquisition time for the PET/MRI.
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Affiliation(s)
- Silje Kjærnes Øen
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Postbox 8905, N-7491, Trondheim, Norway.
| | - Lars Birger Aasheim
- Department of Radiology and Nuclear Medicine, St. Olavs University Hospital, Olav Kyrres gt 17, N-7006, Trondheim, Norway
| | - Live Eikenes
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Postbox 8905, N-7491, Trondheim, Norway
| | - Anna Maria Karlberg
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Postbox 8905, N-7491, Trondheim, Norway.,Department of Radiology and Nuclear Medicine, St. Olavs University Hospital, Olav Kyrres gt 17, N-7006, Trondheim, Norway
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73
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Soret M, Piekarski E, Yeni N, Giron A, Maisonobe JA, Khalifé M, Zaslavsky C, Bertaux M, Habert MO, Kas A. Dose Reduction in Brain [18F]FDG PET/MRI: Give It Half a Chance. Mol Imaging Biol 2019; 22:695-702. [DOI: 10.1007/s11307-019-01398-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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74
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Kaggie JD, Deen S, Kessler DA, McLean MA, Buonincontri G, Schulte RF, Addley H, Sala E, Brenton J, Graves MJ, Gallagher FA. Feasibility of Quantitative Magnetic Resonance Fingerprinting in Ovarian Tumors for T 1 and T 2 Mapping in a PET/MR Setting. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2019; 3:509-515. [PMID: 32066996 PMCID: PMC7025887 DOI: 10.1109/trpms.2019.2905366] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Multiparametric magnetic resonance imaging (MRI) can be used to characterize many cancer subtypes including ovarian cancer. Quantitative mapping of MRI relaxation values, such as T 1 and T 2 mapping, is promising for improving tumor assessment beyond conventional qualitative T 1- and T 2-weighted images. However, quantitative MRI relaxation mapping methods often involve long scan times due to sequentially measuring many parameters. Magnetic resonance fingerprinting (MRF) is a new method that enables fast quantitative MRI by exploiting the transient signals caused by the variation of pseudorandom sequence parameters. These transient signals are then matched to a simulated dictionary of T 1 and T 2 values to create quantitative maps. The ability of MRF to simultaneously measure multiple parameters, could represent a new approach to characterizing cancer and assessing treatment response. This feasibility study investigates MRF for simultaneous T 1, T 2, and relative proton density (rPD) mapping using ovarian cancer as a model system.
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Affiliation(s)
- Joshua D. Kaggie
- Department of Radiology, University of Cambridge, Cambridge CB2 0QQ, U.K.; Cambridge University Hospitals, NHS Foundation Trust, Addenbrooke’s Hospital, Cambridge, U.K
| | - Surrin Deen
- Department of Radiology, University of Cambridge, Cambridge CB2 0QQ, U.K.; Cambridge University Hospitals, NHS Foundation Trust, Addenbrooke’s Hospital, Cambridge, U.K
| | - Dimitri A. Kessler
- Department of Radiology, University of Cambridge, Cambridge CB2 0QQ, U.K.; Cambridge University Hospitals, NHS Foundation Trust, Addenbrooke’s Hospital, Cambridge, U.K
| | - Mary A. McLean
- Cancer Research U.K. Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, U.K
| | | | | | - Helen Addley
- Department of Radiology, University of Cambridge, Cambridge CB2 0QQ, U.K.; Cambridge University Hospitals, NHS Foundation Trust, Addenbrooke’s Hospital, Cambridge, U.K
| | - Evis Sala
- Department of Radiology, University of Cambridge, Cambridge CB2 0QQ, U.K.; Cambridge University Hospitals, NHS Foundation Trust, Addenbrooke’s Hospital, Cambridge, U.K.; Cancer Research U.K. Cambridge Institute, Cambridge CB2 0RE, U.K
| | - James Brenton
- Cancer Research U.K. Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, U.K
| | - Martin J. Graves
- Department of Radiology, University of Cambridge, Cambridge CB2 0QQ, U.K.; Cambridge University Hospitals, NHS Foundation Trust, Addenbrooke’s Hospital, Cambridge, U.K
| | - Ferdia A. Gallagher
- Department of Radiology, University of Cambridge, Cambridge CB2 0QQ, U.K.; Cambridge University Hospitals, NHS Foundation Trust, Addenbrooke’s Hospital, Cambridge, U.K
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Vuong D, Tanadini-Lang S, Huellner MW, Veit-Haibach P, Unkelbach J, Andratschke N, Kraft J, Guckenberger M, Bogowicz M. Interchangeability of radiomic features between [18F]-FDG PET/CT and [18F]-FDG PET/MR. Med Phys 2019; 46:1677-1685. [PMID: 30714158 DOI: 10.1002/mp.13422] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 01/13/2019] [Accepted: 01/14/2019] [Indexed: 12/22/2022] Open
Abstract
PURPOSE Radiomics is a promising tool for identification of new prognostic biomarkers. However, image reconstruction settings and test-retest variability may influence the absolute values of radiomic features. Unstable radiomic features cannot be used as reliable biomarkers. PET/MR is becoming increasingly available and often replaces PET/CT for different indications. The aim of this study was to quantify to what extend [18F]-FDG PET/CT radiomics models can be transferred to [18F]-FDG PET/MR and thereby to investigate the feasibility of combined PET/CT-PET/MR models. For this purpose, we compared PET radiomic features calculated on PET/MR and PET/CT and on a 4D-gated PET/MR dataset to select radiomic features that are robust to attenuation correction differences and test-retest variability, respectively. METHODS Two cohorts of patients with lung lesions were studied. In the first cohort (n = 10), inhale and exhale phases of a 4D [18F]-FDG PET/MR (4DPETMR) scan were used as a surrogate for a test-retest dataset. In the second cohort (n = 9), patients underwent first an [18F]-FDG PET/MR scan (SIGNA PET/MR, GE Healthcare, Waukesha) followed by an [18F]-FDG PET/CT scan (Discovery 690, GE Healthcare) with a delay of 33 ± 5 min (PETCT-PETMR). Lesions were segmented on inhale and exhale 4D-PET phases and on the individual PET scans from PET/CT and PET/MR with two semi-automated methods (gradient-based and threshold-based). The scan resolution was 2.73 × 2.73 × 3.27 mm and 2.34 × 2.34 × 2.78 mm for the PET/CT and PET/MR, respectively. In total, 1355 radiomic features were calculated, i.e., shape (n = 18), intensity (n = 17), texture (n = 136), and wavelet (n = 1184). The intraclass correlation coefficient (ICC) was calculated to compare the radiomic features of the 4DPETMR (ICC(1,1)) and PETCT-PETMR (ICC(3,1)) datasets. An ICC > 0.9 was considered stable among both types of PET scans. RESULTS AND CONCLUSION The 4DPETMR showed highest stability for shape, intensity, and texture (>80%) and lower stability for wavelet features (40%). Gradient-based method showed higher stability compared to threshold-based method except from shape features. In PETCT-PETMR, more than 61% of shape and intensity features were stable for both segmentation methods. However, a reduced stability was observed for texture (50%) and wavelet (<30%) features. More wavelet features were robust in the smoothed images (low-pass filtering) compared to images with emphasized heterogeneity (high-pass filtering). Comparing stable features of both investigations, highest agreement was found for intensity and lower agreement for shape, texture, and wavelet features. Only 53.6% of stable texture features in 4DPETMR were also stable in PETCT-PETMR, and even less in case of wavelet features (40.4%). Approximately 16.9% (texture) and 43.2% (wavelet) of stable PETCT-PETMR features are unstable in 4DPETMR. To conclude, shape and intensity features were robust when comparing two types of [18F]-FDG PET scans (PET/CT and PET/MR). Reduced stability was observed for texture and wavelet features. We identified multiple origins of instability of radiomic features, such as attenuation correction differences, different uptake times, and spatial resolution. This needs to be considered when models based on PET/CT are transferred PET/MR models or when combined models are used.
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Affiliation(s)
- Diem Vuong
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, 8091, Switzerland
| | - Stephanie Tanadini-Lang
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, 8091, Switzerland
| | - Martin W Huellner
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, 8091, Switzerland
| | - Patrick Veit-Haibach
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, 8091, Switzerland
| | - Jan Unkelbach
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, 8091, Switzerland
| | - Nicolaus Andratschke
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, 8091, Switzerland
| | - Johannes Kraft
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, 8091, Switzerland
| | - Matthias Guckenberger
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, 8091, Switzerland
| | - Marta Bogowicz
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, 8091, Switzerland
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Sun H, Xin J, Zhou J, Lu Z, Guo Q. Applying Amide Proton Transfer MR Imaging to Hybrid Brain PET/MR: Concordance with Gadolinium Enhancement and Added Value to [ 18F]FDG PET. Mol Imaging Biol 2019; 20:473-481. [PMID: 29063304 DOI: 10.1007/s11307-017-1136-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE The purpose of this study is to evaluate the diagnostic concordance and metric correlations of amide proton transfer (APT) imaging with gadolinium-enhanced magnetic resonance imaging (MRI) and 2-deoxy-2-[18F-]fluoro-D-glucose ([18F]FDG) positron emission tomography (PET), using hybrid brain PET/MRI. PROCEDURES Twenty-one subjects underwent brain gadolinium-enhanced [18F]FDG PET/MRI prospectively. Imaging accuracy was compared between unenhanced MRI, MRI with enhancement, APT-weighted (APTW) images, and PET based on six diagnostic criteria. Among tumors, the McNemar test was further used for concordance assessment between gadolinium-enhanced imaging, APT imaging, and [18F]FDG PET. As well, the relation of metrics between APT imaging and PET was analyzed by the Pearson correlation analysis. RESULTS APT imaging and gadolinium-enhanced MRI showed superior and similar diagnostic accuracy. APTW signal intensity and gadolinium enhancement were concordant in 19 tumors (100 %), while high [18F]FDG avidity was shown in only 12 (63.2 %). For the metrics from APT imaging and PET, there was significant correlation for 13 hypermetabolic tumors (P < 0.05) and no correlation for the remaining six [18F]FDG-avid tumors. CONCLUSIONS APT imaging can be used to increase diagnostic accuracy with no need to administer gadolinium chelates. APT imaging may provide an added value to [18F]FDG PET in the evaluation of tumor metabolic activity during brain PET/MR studies.
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Affiliation(s)
- Hongzan Sun
- Department of Radiology, Shengjing Hospital of China Medical University, Sanhao Street No. 36, Heping District, Shenyang, 110004, Liaoning, People's Republic of China
| | - Jun Xin
- Department of Radiology, Shengjing Hospital of China Medical University, Sanhao Street No. 36, Heping District, Shenyang, 110004, Liaoning, People's Republic of China.
| | - Jinyuan Zhou
- Division of MR Research, Department of Radiology, Johns Hopkins University, 600 N. Wolfe Street, Park 336, Baltimore, MD, 21287, USA
| | - Zaiming Lu
- Department of Radiology, Shengjing Hospital of China Medical University, Sanhao Street No. 36, Heping District, Shenyang, 110004, Liaoning, People's Republic of China
| | - Qiyong Guo
- Department of Radiology, Shengjing Hospital of China Medical University, Sanhao Street No. 36, Heping District, Shenyang, 110004, Liaoning, People's Republic of China
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Ladefoged CN, Marner L, Hindsholm A, Law I, Højgaard L, Andersen FL. Deep Learning Based Attenuation Correction of PET/MRI in Pediatric Brain Tumor Patients: Evaluation in a Clinical Setting. Front Neurosci 2019; 12:1005. [PMID: 30666184 PMCID: PMC6330282 DOI: 10.3389/fnins.2018.01005] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/13/2018] [Indexed: 11/13/2022] Open
Abstract
Aim: Positron emission tomography (PET) imaging is a useful tool for assisting in correct differentiation of tumor progression from reactive changes. O-(2-18F-fluoroethyl)-L-tyrosine (FET)-PET in combination with MRI can add valuable information for clinical decision making. Acquiring FET-PET/MRI simultaneously allows for a one-stop-shop that limits the need for a second sedation or anesthesia as with PET and MRI in sequence. PET/MRI is challenged by lack of a direct measure of photon attenuation. Accepted solutions for attenuation correction (AC) might not be applicable to pediatrics. The aim of this study was to evaluate the use of the subject-specific MR-derived AC method RESOLUTE, modified to a pediatric cohort, against the performance of an MR-AC technique based on deep learning in a pediatric brain tumor cohort. Methods: The modifications to RESOLUTE and the implementation of a deep learning method were performed using 79 pediatric patient examinations. We analyzed the 36 of these with active brain tumor area above 1 mL. We measured background (B), tumor mean and maximal activity (TMEAN, TMAX), biological tumor volume (BTV), and calculated the clinical metrics TMEAN/B and TMAX/B. Results: Overall, we found both RESOLUTE and our DeepUTE methodologies to accurately reproduce the CT-AC clinical metrics. Regardless of age, both methods were able to obtain AC maps similar to the CT-AC, albeit with DeepUTE producing the most similar based on both quantitative metrics and visual inspection. In the patient-by-patient analysis DeepUTE was the only technique with all patients inside the predefined acceptable clinical limits. It also had a higher precision with relative %-difference to the reference CT-AC (TMAX/B mean: -0.1%, CI: [-0.8%, 0.5%], p = 0.54) compared to RESOLUTE (TMAX/B mean: 0.3%, CI: [-0.6%, 1.2%], p = 0.67) and DIXON-AC (TMAX/B mean: 5.9%, CI: [4.5%, 7.4%], p < 0.0001). Conclusion: Overall, we found DeepUTE to be the AC method that most robustly reproduced the CT-AC clinical metrics per se, closely followed by RESOLUTE modified to pediatric cohorts. The added accuracy due to better noise handling of DeepUTE, ease of use, as well as the improved runtime makes DeepUTE the method of choice for PET/MRI attenuation correction.
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Affiliation(s)
- Claes Nøhr Ladefoged
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Lisbeth Marner
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Amalie Hindsholm
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Ian Law
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Liselotte Højgaard
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
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Oldan JD, Khandani AH, Fielding JR, Jones EL, Gehrig PA, Sills TM, Roy P, Lin W. Quantitative accuracy of positron emission tomography/magnetic resonance and positron emission tomography/computed tomography for cervical cancer. World J Nucl Med 2018; 17:213-218. [PMID: 30505216 PMCID: PMC6216731 DOI: 10.4103/wjnm.wjnm_56_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
With the spread of positron emission tomography/magnetic resonance (PET/MR), the question of comparability of studies becomes important. We aim to determine whether PET/MR and PET/computed tomography (PET/CT) are comparable for the case of cervical cancer. Fifteen cervical cancer patients identified by either a radiation oncologist or an oncologic surgeon had both PET/MR and PET/CT performed for initial staging within 3 weeks. We then compared the results both quantitatively (measuring standardized uptake values [SUVs] on visible lesions) as well as qualitatively (having radiologists and nuclear medicine physicians interprets the results). While interpretations between PET/MR and PET/CT varied in many cases, SUVs of primary lesions were similar to within 25% in all but one case, and correlation coefficient was 0.92. Maximum SUV ranged between 4.9 and 25.2 for PET-MR and between 5.8 and 30.4 for PET-CT for primary tumors and between 1.5 and 18.8 for PET-MR and between 1.8 and 20.8 for PET-CT for nodes. However, clinical reads often varied significantly between PET/MR and PET/CT. This suggests that SUV is similar on PET/MR and PET/CT although the differing anatomic modalities available for correlation may make the difference in terms of qualitative interpretation.
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Affiliation(s)
- Jorge Daniel Oldan
- Department of Radiology, Division of Nuclear Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Amir Hossein Khandani
- Department of Radiology, Division of Nuclear Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Julia R Fielding
- Department of Radiology, Division of Abdominal Radiology, University of Texas-Southwestern, Dallas, Texas, USA
| | - Ellen Louise Jones
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC, USA
| | - Paola Alvarez Gehrig
- Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, University of North Carolina, Chapel Hill, NC, USA
| | | | - Pinakpani Roy
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Weili Lin
- Biomedical Research Imaging Center, Chapel Hill, NC, USA
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Sollini M, Berchiolli R, Kirienko M, Rossi A, Glaudemans AWJM, Slart R, Erba PA. PET/MRI in Infection and Inflammation. Semin Nucl Med 2018; 48:225-241. [PMID: 29626940 DOI: 10.1053/j.semnuclmed.2018.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hybrid positron emission tomography/magnetic resonance imaging (PET/MR) systems are now more and more available for clinical use. PET/MR combines the unique features of MR including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most of the evidence of the potential clinical utility of PET/MRI is available for neuroimaging. Other areas, where PET/MR can play a larger role include head and neck, upper abdominal, and pelvic tumours. Although the role of PET/MR in infection and inflammation of the cardiovascular system and in musculoskeletal applications are promising, these areas of clinical investigation are still in the early phase and it may be a little longer before these areas reach their full potential in clinical practice. In this review, we outline the potential of hybrid PET/MR for imaging infection and inflammation. A background to the main radiopharmaceuticals and some technical considerations are also included.
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Affiliation(s)
- Martina Sollini
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - Raffaella Berchiolli
- Vascular Surgery Unit Department of Translational Research and Advanced Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Margarita Kirienko
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - Alexia Rossi
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - A W J M Glaudemans
- University of Groningen, University Medical Center Groningen, Medical Imaging Center, Groningen, The Netherlands
| | - Riemer Slart
- University of Groningen, University Medical Center Groningen, Medical Imaging Center, Groningen, The Netherlands.; University of Twente, Faculty of Science and Technology, Biomedical Photonic Imaging, Enschede, The Netherlands
| | - Paola Anna Erba
- Regional Center of Nuclear Medicine, Department of Translational Research and Advanced, Technologies in Medicine, University of Pisa, Pisa, Italy..
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Bradshaw TJ, Zhao G, Jang H, Liu F, McMillan AB. Feasibility of Deep Learning-Based PET/MR Attenuation Correction in the Pelvis Using Only Diagnostic MR Images. Tomography 2018; 4:138-147. [PMID: 30320213 PMCID: PMC6173790 DOI: 10.18383/j.tom.2018.00016] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This study evaluated the feasibility of using only diagnostically relevant magnetic resonance (MR) images together with deep learning for positron emission tomography (PET)/MR attenuation correction (deepMRAC) in the pelvis. Such an approach could eliminate dedicated MRAC sequences that have limited diagnostic utility but can substantially lengthen acquisition times for multibed position scans. We used axial T2 and T1 LAVA Flex magnetic resonance imaging images that were acquired for diagnostic purposes as inputs to a 3D deep convolutional neural network. The network was trained to produce a discretized (air, water, fat, and bone) substitute computed tomography (CT) (CTsub). Discretized (CTref-discrete) and continuously valued (CTref) reference CT images were created to serve as ground truth for network training and attenuation correction, respectively. Training was performed with data from 12 subjects. CTsub, CTref, and the system MRAC were used for PET/MR attenuation correction, and quantitative PET values of the resulting images were compared in 6 test subjects. Overall, the network produced CTsub with Dice coefficients of 0.79 ± 0.03 for cortical bone, 0.98 ± 0.01 for soft tissue (fat: 0.94 ± 0.0; water: 0.88 ± 0.02), and 0.49 ± 0.17 for bowel gas when compared with CTref-discrete. The root mean square error of the whole PET image was 4.9% by using deepMRAC and 11.6% by using the system MRAC. In evaluating 16 soft tissue lesions, the distribution of errors for maximum standardized uptake value was significantly narrower using deepMRAC (-1.0% ± 1.3%) than using system MRAC method (0.0% ± 6.4%) according to the Brown-Forsy the test (P < .05). These results indicate that improved PET/MR attenuation correction can be achieved in the pelvis using only diagnostically relevant MR images.
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Affiliation(s)
| | - Gengyan Zhao
- Medical Physics, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI; and
| | - Hyungseok Jang
- Department of Radiology, University of California, San Diego, San Diego, CA
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Akram MSH, Levin CS, Obata T, Hirumi G, Yamaya T. Geometry optimization of electrically floating PET inserts for improved RF penetration for a 3 T MRI system. Med Phys 2018; 45:4627-4641. [PMID: 30118140 DOI: 10.1002/mp.13132] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 08/08/2018] [Accepted: 08/08/2018] [Indexed: 12/30/2022] Open
Abstract
PURPOSE An electrically floating radio frequency (RF) shielded PET insert with individual PET detectors shielded by separate Faraday cages enables the MRI built-in body RF coil to be used at least as an RF transmitter, in which the RF field penetrates the imaging region inside the PET ring through the narrow gaps between the shielded PET detector modules. Because the shielded PET ring blocks more than 90% of the imaging region for the transmit field from the body RF coil, it is very challenging to obtain the required RF field inside a full-ring floating PET insert. In this study, experiments were performed on the dependence of RF penetrability on different geometric aspects of the shielded PET modules and PET rings to optimize the design parameters to obtain the required RF field inside the PET ring. METHODS We developed several prototype cylindrical full-ring PET inserts using completely enclosed empty RF shield boxes (considered as dummy PET modules). Considering the RF shield box, we conducted studies for different axial lengths (240 and 120 mm) and heights (30 and 45 mm) of the shield boxes. On the other hand, considering the PET ring geometry, we also performed studies on three different categories of PET rings: a long-ring insert (longer than the MRI phantom), a short-ring insert (shorter than the MRI phantom), and a two-ring insert that combined two short-rings. In each ring category, two different inter-shield box gaps (1 and 3 mm) were considered. In the case of the two-ring insert, three different ring-gaps (5, 10, and 20 mm) were studied. In total, 21 PET inserts were studied with an inner diameter (i.d.) of 210 mm. To study the effect of ring diameter, another long-ring insert was studied for the 270 mm i.d. Experiments were conducted for the transmit RF (B1 ) fields and signal-to-noise ratios of spin-echo and gradient-echo images using a homogeneous phantom in a 700 mm bore-diameter 3 T clinical MRI system. RF pulse amplitudes generated automatically by the MRI system were recorded for comparison. RESULTS A PET insert with a 3 mm inter-box gap was found to perform the best, at a level which is acceptable for PET imaging. In the case of an insert of multiple short-rings instead of one long-ring insert, the 5 and 10 mm ring-gaps provided higher RF field penetration. Increasing the inter-box gap improved the RF field penetration, whereas a ring-gap that was too wide concentrated the field near the ring-gap region. Relatively reduced RF power was required for wider inter-box gap or ring-gap or larger shield box height. Moreover, the rectangular shield box outperformed the trapezoidal shield box. On the other hand, when we changed the inner or outer diameter of the PET ring by keeping the same transaxial width of the shield boxes, we did not see any noticeable variation. CONCLUSIONS Our study results provide comprehensive guidance on the geometrical design aspects of RF-penetrable PET inserts for efficient RF penetration inside the PET ring. By choosing proper geometric design parameters, we could get the RF field that was similar to the MRI-only case.
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Affiliation(s)
- Md Shahadat Hossain Akram
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Craig S Levin
- Department of Radiology, School of Medicine, Stanford University, Stanford, CA, 94305-5128, USA
| | - Takayuki Obata
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Genki Hirumi
- Artificial System Science, Graduate School of Engineering, Chiba University, Chiba, 263-8522, Japan
| | - Taiga Yamaya
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
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Kirchner J, Sawicki LM, Nensa F, Schaarschmidt BM, Reis H, Ingenwerth M, Bogner S, Aigner C, Buchbender C, Umutlu L, Antoch G, Herrmann K, Heusch P. Prospective comparison of 18F-FDG PET/MRI and 18F-FDG PET/CT for thoracic staging of non-small cell lung cancer. Eur J Nucl Med Mol Imaging 2018; 46:437-445. [PMID: 30074073 DOI: 10.1007/s00259-018-4109-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 07/23/2018] [Indexed: 12/20/2022]
Abstract
OBJECTIVES To compare the diagnostic performance of 18F-FDG PET/MRI and 18F-FDG PET/CT for primary and locoregional lymph node staging in non-small cell lung cancer (NSCLC). METHODS In this prospective study, a total of 84 patients (51 men, 33 women, mean age 62.5 ± 9.1 years) with histopathologically confirmed NSCLC underwent 18F-FDG PET/CT followed by 18F-FDG PET/MRI in a single injection protocol. Two readers independently assessed T and N staging in separate sessions according to the seventh edition of the American Joint Committee on Cancer staging manual for 18F-FDG PET/CT and 18F-FDG PET/MRI, respectively. Histopathology as a reference standard was available for N staging in all 84 patients and for T staging in 39 patients. Differences in staging accuracy were assessed by McNemars chi2 test. The maximum standardized uptake value (SUVmax) and longitudinal diameters of primary tumors were correlated using Pearson's coefficients. RESULTS T stage was categorized concordantly in 18F-FDG PET/MRI and 18F-FDG PET/CT in 38 of 39 (97.4%) patients. Herein, 18F-FDG PET/CT and 18F-FDG PET/MRI correctly determined the T stage in 92.3 and 89.7% of patients, respectively. N stage was categorized concordantly in 83 of 84 patients (98.8%). 18F-FDG PET/CT correctly determined the N stage in 78 of 84 patients (92.9%), while 18F-FDG PET/MRI correctly determined the N stage in 77 of 84 patients (91.7%). Differences between 18F-FDG PET/CT and 18F-FDG PET/MRI in T and N staging accuracy were not statistically significant (p > 0.5, each). Tumor size and SUVmax measurements derived from both imaging modalities exhibited excellent correlation (r = 0.963 and r = 0.901, respectively). CONCLUSION 18F-FDG PET/MRI and 18F-FDG PET/CT show an equivalently high diagnostic performance for T and N staging in patients suffering from NSCLC.
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Affiliation(s)
- Julian Kirchner
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Moorenstrasse 5, D-40225, Dusseldorf, Germany.
| | - Lino M Sawicki
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Moorenstrasse 5, D-40225, Dusseldorf, Germany
| | - Felix Nensa
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, D-45147, Essen, Germany
| | - Benedikt M Schaarschmidt
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Moorenstrasse 5, D-40225, Dusseldorf, Germany
| | - Henning Reis
- Institute of Pathology, University Hospital Essen, West German Cancer Center, University Duisburg-Essen and the German Cancer Consortium (DKTK) Essen, D-45147, Essen, Germany
| | - Marc Ingenwerth
- Institute of Pathology, University Hospital Essen, West German Cancer Center, University Duisburg-Essen and the German Cancer Consortium (DKTK) Essen, D-45147, Essen, Germany
| | - Simon Bogner
- Department of Medical Oncology, University Hospital Essen, West German Cancer Center, University of Duisburg-Essen, D-45122, Essen, Germany
| | - Clemens Aigner
- Department of Thoracic Surgery and Surgical Endoscopy, University Hospital Essen, Ruhrlandklinik, University of Duisburg-Essen, D-45147, Essen, Germany
| | - Christian Buchbender
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Moorenstrasse 5, D-40225, Dusseldorf, Germany
| | - Lale Umutlu
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, D-45147, Essen, Germany
| | - Gerald Antoch
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Moorenstrasse 5, D-40225, Dusseldorf, Germany
| | - Ken Herrmann
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, D-45147, Essen, Germany
| | - Philipp Heusch
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Moorenstrasse 5, D-40225, Dusseldorf, Germany
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Early Response Assessment in Pancreatic Ductal Adenocarcinoma Through Integrated PET/MRI. AJR Am J Roentgenol 2018; 211:1010-1019. [PMID: 30063366 DOI: 10.2214/ajr.18.19602] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE The purpose of this study is to investigate early changes in 18F-FDG PET/MRI metrics after treatment in patients with advanced pancreatic ductal adenocarcinoma (PDAC) and to correlate those changes with eventual tumor response at standard-of-care CT. SUBJECTS AND METHODS Thirteen patients with advanced PDAC underwent integrated FDG PET/MRI before and 4 weeks after treatment initiation. Patients were classified as responders or nonresponders according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 at subsequent CT performed 8-12 weeks after treatment initiation. Changes in the primary tumor's maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) determined at PET and apparent diffusion coefficient (ADC) determined at DWI at 4 weeks were compared between responders and nonresponders. RESULTS Seven patients had a partial response according to RECIST, and six did not. Responders displayed significantly greater decreases in MTV (p = 0.003) and TLG (p = 0.006) in the primary pancreatic tumor at 4 weeks. Responders also displayed a greater increase in the mean (p = 0.004) and minimum (p = 0.024) ADC of the primary tumors. Tumor size change at 4 weeks was not significantly different between responders and nonresponders (p = 0.11). PET responders enjoyed longer progression-free survival (PFS) (p = 0.0004) and overall survival (OS) (p = 0.013) than did nonresponders, using either a 60% reduction in MTV or 65% reduction in TLG as a threshold. MRI responders had significantly longer PFS (p = 0.0002) and OS (p = 0.027) than did nonresponders, using a 20% increase in either mean or minimum ADC as a threshold. CONCLUSION Integrated PET/MRI can provide early response assessment in patients with advanced PDAC, thus potentially allowing early treatment adaptation in nonresponders.
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Abstract
OBJECTIVE The purpose of this article is to provide an update on clinical PET/MRI, including current and developing clinical indications and technical developments. CONCLUSION PET/MRI is evolving rapidly, transitioning from a predominant research focus to exciting clinical practice. Key technical obstacles have been overcome, and further technical advances promise to herald significant advancements in image quality. Further optimization of protocols to address challenges posed by this hybrid modality will ensure the long-term success of PET/MRI.
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Abstract
PURPOSE PET/computed tomography (CT) has been shown to detect lesions in patients with pulmonary tuberculosis (PTB) and may be useful for assessing PTB disease in clinical research studies. However, radiation dose is of concern for clinical research in individuals with an underlying curable disease. This study aimed to determine whether PET/MR is equivalent to PET/CT in PTB. MATERIALS AND METHODS Ten patients with microbiologically confirmed PTB were recruited. Patients received 129.0±4.1 MBq of fluorine-18-fluorodeoxyglucose. Five of the 10 patients underwent a PET/MR scan, followed by PET/CT. The remaining five were first imaged on the PET/CT, followed by the PET/MRI. PET acquisition began at 66.7±14.4 min (mean±SD) after injection when performing PET/MR first (PET/CT: 117.2±5.6 min) and 92.4±7.6 min when patients were imaged on PET/MR second (PET/CT: 61.1±3.9 min). PET data were reconstructed iteratively with Ordinary-Poisson Ordered-Subset Expectation-Maximization and reconstruction parameters were matched across the two scanners. A visual lesion detection task and a standardized uptake value (SUV) analysis were carried out. The CT Hounsfield unit values of PTB lesions were also compared with MR-based attenuation correction mu-map tissue classes. RESULTS A total of 108 PTB lesions were detected on PET/MR and 112 on PET/CT. SUV analysis was carried out on 50 of these lesions that were observed with both modalities. Mean standardized uptake value (SUVmean) and maximum standardized uptake value (SUVmax) were significantly lower on PET/MR (SUVmean: 2.6±1.4; SUVmax: 4.3±2.5) than PET/CT (SUVmean: 3.5±1.5; SUVmax: 5.3±2.4). CONCLUSION PET/MR visual performance was shown to be comparable to PET/CT in terms of the number of PTB lesions detected. SUVs were significantly lower on PET/MR. Dixon-based attenuation correction underestimates the linear attenuation coefficient of PTB lesions, resulting in lower SUVs compared with PET/CT. However, the use of PET/MR to measure the response of lung lesions to assess response to treatment in research studies is unlikely to be affected by these differences in quantification.
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Miles KA, Voo SA, Groves AM. Additional Clinical Value for PET/MRI in Oncology: Moving Beyond Simple Diagnosis. J Nucl Med 2018; 59:1028-1032. [DOI: 10.2967/jnumed.117.203612] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 03/06/2018] [Indexed: 12/13/2022] Open
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Chan SC, Yeh CH, Yen TC, Ng SH, Chang JTC, Lin CY, Yen-Ming T, Fan KH, Huang BS, Hsu CL, Chang KP, Wang HM, Liao CT. Clinical utility of simultaneous whole-body 18F-FDG PET/MRI as a single-step imaging modality in the staging of primary nasopharyngeal carcinoma. Eur J Nucl Med Mol Imaging 2018; 45:1297-1308. [PMID: 29502310 DOI: 10.1007/s00259-018-3986-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/19/2018] [Indexed: 12/19/2022]
Abstract
PURPOSE Both head and neck magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) play a crucial role in the staging of primary nasopharyngeal carcinoma (NPC). In this study, we sought to prospectively investigate the clinical utility of simultaneous whole-body 18F-FDG PET/MRI for primary staging of NPC patients. METHODS We examined 113 patients with histologically confirmed NPC who underwent pretreatment, simultaneous whole-body PET/MRI and PET/CT for primary tumor staging. The images obtained with the different imaging modalities were interpreted independently and compared with each other. RESULTS PET/MRI increased the accuracy of head and neck MRI for assessment of primary tumor extent in four patients via addition of FDG uptake information to increase the conspicuity of morphologically subtle lesions. PET/MR images were more discernible than PET/CT images for mapping tumor extension, especially intracranial invasion. Regarding the N staging assessment, the sensitivity of PET/MRI (99.5%) was higher than that of head and neck MRI (94.2%) and PET/CT (90.9%). PET/MRI was particularly useful for distinguishing retropharyngeal nodal metastasis from adjacent nasopharyngeal tumors. For distant metastasis evaluation, PET/MRI exhibited a similar sensitivity (90% vs. 86.7% vs. 83.3%), but higher positive predictive value (93.1% vs. 78.8% vs. 83.3%) than whole-body MRI and PET/CT, respectively. CONCLUSIONS For tumor staging of NPC, simultaneous whole-body PET/MRI was more accurate than head and neck MRI and PET/CT, and may serve as a single-step staging modality.
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Affiliation(s)
- Sheng-Chieh Chan
- Department of Nuclear Medicine, Linkou Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Chih-Hua Yeh
- Department of Diagnostic Radiology, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Tzu-Chen Yen
- Department of Nuclear Medicine, Linkou Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Shu-Hang Ng
- Department of Diagnostic Radiology, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
| | - Joseph Tung-Chieh Chang
- Department of Radiation Oncology, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Chien-Yu Lin
- Department of Radiation Oncology, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Tsang Yen-Ming
- Department of Radiation Oncology, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Kang-Hsing Fan
- Department of Radiation Oncology, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Bing-Shen Huang
- Department of Radiation Oncology, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Cheng-Lung Hsu
- Division of Medical Oncology, Department of Internal Medicine, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Kai-Ping Chang
- Department of Otorhinolaryngology, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Hung-Ming Wang
- Division of Medical Oncology, Department of Internal Medicine, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Chun-Ta Liao
- Department of Otorhinolaryngology, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
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88
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Pareek A, Muehe AM, Theruvath AJ, Gulaka PK, Spunt SL, Daldrup-Link HE. Whole-body PET/MRI of Pediatric Patients: The Details That Matter. J Vis Exp 2017. [PMID: 29286486 DOI: 10.3791/57128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Integrated PET/MRI is a hybrid imaging technique enabling clinicians to acquire diagnostic images for tumor assessment and treatment monitoring with both high soft tissue contrast and added metabolic information. Integrated PET/MRI has shown to be valuable in the clinical setting and has many promising future applications. The protocol presented here will provide step-by-step instructions for the acquisition of whole-body 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) PET/MRI data in children with cancer. It also provides instructions on how to combine a whole-body staging scan with a local tumor scan for evaluation of the primary tumor. The focus of this protocol is to be both comprehensive and time-efficient, which are two ubiquitous needs for clinical applications. This protocol was originally developed for children above 6 years, or old enough to comply with breath-hold instructions, but can also be applied to patients under general anesthesia. Similarly, this protocol can be modified to fit institutional preferences in terms of choice of MRI pulse sequences for both the whole-body scan and local tumor assessment.
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Affiliation(s)
- Anuj Pareek
- Department of Radiology, Pediatric Molecular Imaging Program at Stanford (PEDS-MIPS), Stanford University
| | - Anne M Muehe
- Department of Radiology, Pediatric Molecular Imaging Program at Stanford (PEDS-MIPS), Stanford University
| | - Ashok J Theruvath
- Department of Radiology, Pediatric Molecular Imaging Program at Stanford (PEDS-MIPS), Stanford University
| | - Praveen K Gulaka
- Department of Radiology, Pediatric Molecular Imaging Program at Stanford (PEDS-MIPS), Stanford University
| | | | - Heike E Daldrup-Link
- Department of Radiology, Pediatric Molecular Imaging Program at Stanford (PEDS-MIPS), Stanford University;
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89
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Sawicki LM, Kirchner J, Grueneisen J, Ruhlmann V, Aktas B, Schaarschmidt BM, Forsting M, Herrmann K, Antoch G, Umutlu L. Comparison of 18F–FDG PET/MRI and MRI alone for whole-body staging and potential impact on therapeutic management of women with suspected recurrent pelvic cancer: a follow-up study. Eur J Nucl Med Mol Imaging 2017; 45:622-629. [DOI: 10.1007/s00259-017-3881-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/07/2017] [Indexed: 01/18/2023]
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90
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Zhu T, Das S, Wong TZ. Integration of PET/MR Hybrid Imaging into Radiation Therapy Treatment. Magn Reson Imaging Clin N Am 2017; 25:377-430. [PMID: 28390536 DOI: 10.1016/j.mric.2017.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Hybrid PET/MR imaging is in early development for treatment planning. This article briefly reviews research and clinical applications of PET/MR imaging in radiation oncology. With improvements in workflow, more specific tracers, and fast and robust acquisition protocols, PET/MR imaging will play an increasingly important role in better target delineation for treatment planning and have clear advantages in the evaluation of tumor response and in a better understanding of tumor heterogeneity. With advances in treatment delivery and the potential of integrating PET/MR imaging with research on radiomics for radiation oncology, quantitative and physiologic information could lead to more precise and personalized RT.
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Affiliation(s)
- Tong Zhu
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, 101 Manning Drive, Chapel Hill, NC 27599, USA
| | - Shiva Das
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, 101 Manning Drive, Chapel Hill, NC 27599, USA
| | - Terence Z Wong
- Department of Radiology, University of North Carolina at Chapel Hill, 101 Manning Drive, Chapel Hill, NC 27599, USA.
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91
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Fowler AM, Mankoff DA, Joe BN. Imaging Neoadjuvant Therapy Response in Breast Cancer. Radiology 2017; 285:358-375. [DOI: 10.1148/radiol.2017170180] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Amy M. Fowler
- From the Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792-3252 (A.M.F.); Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pa (D.A.M.); and Department of Radiology and Biomedical Imaging, University of California–San Francisco School of Medicine, San Francisco, Calif (B.N.J.)
| | - David A. Mankoff
- From the Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792-3252 (A.M.F.); Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pa (D.A.M.); and Department of Radiology and Biomedical Imaging, University of California–San Francisco School of Medicine, San Francisco, Calif (B.N.J.)
| | - Bonnie N. Joe
- From the Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792-3252 (A.M.F.); Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pa (D.A.M.); and Department of Radiology and Biomedical Imaging, University of California–San Francisco School of Medicine, San Francisco, Calif (B.N.J.)
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92
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Quantification accuracy of neuro-oncology PET data as a function of emission scan duration in PET/MR compared to PET/CT. Eur J Radiol 2017; 95:257-264. [PMID: 28987677 DOI: 10.1016/j.ejrad.2017.08.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 08/23/2017] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To evaluate and compare the effect of reduced acquisition time, as a surrogate of injected activity, on the PET quantification accuracy in PET/CT and PET/MR imaging. METHODS Twenty min 18F-FDG phantom measurements and 10min 18F-FET brain scans were acquired in a Biograph-True-Point-True-View PET/CT (n=8) and a Biograph mMR PET/MR (n=16). Listmode data were repeatedly split into frames of 1min to 10min length and reconstructed using two different reconstruction settings of a 3D-OSEM algorithm: with post-filtering ("OSEM"), and without post-filtering but with resolution recovery ("PSF"). Recovery coefficients (RCmax, RCA50) and standard uptake values (SUVmax, SUVA50) were evaluated. RESULTS RCmax (phantom) and SUVmax (patients) increased significantly when reducing the frame duration. Significantly lower deviations were observed for RCA50 and SUVA50, respectively, making them more appropriate to compare PET studies at different number of counts. No statistical significant differences were observed when using post-filtering and reducing the frame time to 4min (RCA50, reference 20min, phantom) and to 3min (SUVA50, reference 10min, patients). CONCLUSIONS For hybrid aminoacid brain imaging, frame duration (or injected activity) can potentially be reduced to 30% of the standard used in clinical routine without significant changes on the quantification accuracy of the PET images if adequate reconstruction settings and quantitative measures are used. Frame times below 4min in the NEMA phantom are not advisable to obtain quantitative and reproducible measures.
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93
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Abstract
Positron emission tomography (PET)/computerised tomography is now established in clinical practice for oncologic and non-oncological applications. Improvement and development of scanner hardware has allowed faster acquisitions and wider application. PET/magnetic resonance imaging offers potential improvements in diagnostic accuracy and patient acceptability but clinical applications are still being developed. A range of new radiotracers and non-radioactive contrast agents is likely to lead to a growth in hybrid molecular imaging applications that will allow better characterisation of disease processes.
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Affiliation(s)
- Sally Barrington
- King's College London and Guy's & St Thomas' PET Centre, London, UK
| | | | - Gary Cook
- Department of Cancer Imaging and Guy's & St Thomas' PET Centre, King's College London, London, UK
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94
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Freitag MT, Fenchel M, Bäumer P, Heußer T, Rank CM, Kachelrieß M, Paech D, Kopka K, Bickelhaupt S, Dimitrakopoulou-Strauss A, Maier-Hein K, Floca R, Ladd ME, Schlemmer HP, Maier F. Improved clinical workflow for simultaneous whole-body PET/MRI using high-resolution CAIPIRINHA-accelerated MR-based attenuation correction. Eur J Radiol 2017; 96:12-20. [PMID: 29103469 DOI: 10.1016/j.ejrad.2017.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 08/17/2017] [Accepted: 09/12/2017] [Indexed: 10/18/2022]
Abstract
PURPOSE To explore the value and reproducibility of a novel magnetic resonance based attenuation correction (MRAC) using a CAIPIRINHA-accelerated T1-weighted Dixon 3D-VIBE sequence for whole-body PET/MRI compared to the clinical standard. METHODS The PET raw data of 19 patients from clinical routine were reconstructed with standard MRAC (MRACstd) and the novel MRAC (MRACcaipi), a prototype CAIPIRINHA accelerated Dixon 3D-VIBE sequence, both acquired in 19 s/bed position. Volume of interests (VOIs) for liver, lung and all voxels of the total image stack were created to calculate standardized uptake values (SUVmean) followed by inter-method agreement (Passing-Bablok regression, Bland-Altman analysis). A voxel-wise SUV comparison per patient was performed for intra-individual correlation between MRACstd and MRACcaipi. Difference images (MRACstd-MRACcaipi) of attenuation maps and SUV images were calculated. The image quality of in/opposed-phase water and fat images obtained from MRACcaipi was assessed by two readers on a 5-point Likert-scale including intra-class coefficients for inter-reader agreement. RESULTS SUVmean correlations of VOIs demonstrated high linearity (0.95<Spearman's rho<1, p<0.0001, respectively), substantiated by voxel-wise SUV scatter-plots (1.79×108 pixels). Outliers could be explained by different physiological conditions between the scans such as different segmentation of air-containing tissue, lungs, kidneys, metal implants, diaphragm edge or small air bubbles in the gastrointestinal tracts that moved between MRAC acquisitions. Nasal sinuses and the trachea were better segmented in MRACcaipi. High-resolution T1w Dixon 3D VIBE images were acquired in all cases and could be used for PET/MRI fusion. MRACcaipi images were of high diagnostic quality (4.2±0.8) with 0.92-0.96 intra-class correlation. CONCLUSIONS The novel prototype MRACcaipi extends the value for attenuation correction by providing a high spatial resolution DIXON-based dataset suited for diagnostic assessment towards time-efficient whole-body PET/MRI.
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Affiliation(s)
- Martin T Freitag
- Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | | | - Philipp Bäumer
- Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Thorsten Heußer
- Department of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christopher M Rank
- Department of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Marc Kachelrieß
- Department of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Daniel Paech
- Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Klaus Kopka
- Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | | | - Klaus Maier-Hein
- Junior Group Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ralf Floca
- Junior Group Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Mark E Ladd
- Department of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
| | | | - Florian Maier
- Department of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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95
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Vitor T, Martins KM, Ionescu TM, Cunha MLD, Baroni RH, Garcia MRT, Wagner J, Campos GDC, Nogueira SA, Guerra EG, Amaro E. PET/MRI: a novel hybrid imaging technique. Major clinical indications and preliminary experience in Brazil. EINSTEIN-SAO PAULO 2017; 15:115-118. [PMID: 28444102 PMCID: PMC5433320 DOI: 10.1590/s1679-45082017md3793] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 10/30/2016] [Indexed: 11/22/2022] Open
Abstract
In recent years, medical imaging with hybrid techniques has widely accepted and employed in clinical routine. PET/MRI offers significant advantages, including excellent contrast and resolution and reduced ionizing radiation, as compared to well-established PET/CT. Therefore, PET/MRI is a promising modality for oncologic imaging of some regions, such as brain, head and neck, liver and pelvis. This article set out to analyze clinical conditions that could benefit from PET/MRI imaging based on our caseload. The potential of PET/MRI to become the imaging modality of choice for assessment of neurologic and oncologic conditions associated with soft tissues is highlighted. Clinical aspects of PET/MRI and its application to clinical cases are illustrated with examples extracted from the authors’ preliminary experience.
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Affiliation(s)
- Taise Vitor
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil
| | | | | | | | | | | | - Jairo Wagner
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil
| | | | | | | | - Edson Amaro
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil
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96
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Beyer T, Hacker M, Goh V. PET/MRI-knocking on the doors of the rich and famous. Br J Radiol 2017; 90:20170347. [PMID: 28707543 DOI: 10.1259/bjr.20170347] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Since 2010 the portfolio of positron emission tomography (PET)-based imaging has been expanded by industry with the introduction of combined whole-body PET/MRI systems with the intent of merging PET-based molecular imaging with the strengths of MRI. PET/MRI has created a lot of hype in the scientific community but comparatively little traction in the clinic. The first years of whole-body PET/MRI were used to address inherent technical challenges; however, it is now time to make use of the full potential of this integrated imaging modality. This opinion piece highlights the continuing challenges for the clinical adoption of PET/MRI and cautions against putting too much emphasis on comparisons with clinical PET/CT. In order for PET/MRI to enter clinical practice, cross-specialty co-operation must be pursued with rigour and use-case scenarios must be propagated, following long-awaited expansion of reimbursement strategies and protocol standardization.
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Affiliation(s)
- Thomas Beyer
- Center for Medical Physics and Biomedical Engineering, QIMP Group , Vienna , Austria
| | - Marcus Hacker
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna , Vienna , Austria
| | - Vicky Goh
- Department of Cancer Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College London , London , UK
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97
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CD44v6-Targeted Imaging of Head and Neck Squamous Cell Carcinoma: Antibody-Based Approaches. CONTRAST MEDIA & MOLECULAR IMAGING 2017; 2017:2709547. [PMID: 29097914 PMCID: PMC5612744 DOI: 10.1155/2017/2709547] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/23/2017] [Accepted: 05/21/2017] [Indexed: 12/11/2022]
Abstract
Head and neck squamous cell carcinoma (HNSCC) is a common and severe cancer with low survival rate in advanced stages. Noninvasive imaging of prognostic and therapeutic biomarkers could provide valuable information for planning and monitoring of the different therapy options. Thus, there is a major interest in development of new tracers towards cancer-specific molecular targets to improve diagnostic imaging and treatment. CD44v6, an oncogenic variant of the cell surface molecule CD44, is a promising molecular target since it exhibits a unique expression pattern in HNSCC and is associated with drug- and radio-resistance. In this review we summarize results from preclinical and clinical investigations of radiolabeled anti-CD44v6 antibody-based tracers: full-length antibodies, Fab, F(ab′)2 fragments, and scFvs with particular focus on the engineering of various antibody formats and choice of radiolabel for the use as molecular imaging agents in HNSCC. We conclude that the current evidence points to CD44v6 imaging being a promising approach for providing more specific and sensitive diagnostic tools, leading to customized treatment decisions and functional diagnosis. Improved imaging tools hold promise to enable more effective treatment for head and neck cancer patients.
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98
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Chaput A, Robin P, Podeur F, Ollivier M, Keromnes N, Tissot V, Nonent M, Salaün PY, Rousset J, Abgral R. Diagnostic performance of 18
fluorodesoxyglucose positron emission/computed tomography and magnetic resonance imaging in detecting T1-T2 head and neck squamous cell carcinoma. Laryngoscope 2017; 128:378-385. [DOI: 10.1002/lary.26729] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 04/26/2017] [Accepted: 05/09/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Anne Chaput
- Department of Nuclear Medicine; University Hospital of Brest; Brest France
| | - Philippe Robin
- Department of Nuclear Medicine; University Hospital of Brest; Brest France
- Thrombosis Study Group in Western Brittany; Research's Federative Institute 148, European University of Brittany; Brest France
| | - Fabien Podeur
- Department of Radiology; University Hospital of Brest; Brest France
| | - Morgan Ollivier
- Department of Radiology; University Hospital of Brest; Brest France
| | - Nathalie Keromnes
- Department of Nuclear Medicine; University Hospital of Brest; Brest France
| | - Valentin Tissot
- Department of Radiology; University Hospital of Brest; Brest France
| | - Michel Nonent
- Department of Radiology; University Hospital of Brest; Brest France
| | - Pierre-Yves Salaün
- Department of Nuclear Medicine; University Hospital of Brest; Brest France
- Thrombosis Study Group in Western Brittany; Research's Federative Institute 148, European University of Brittany; Brest France
| | - Jean Rousset
- Department of Radiology; University Hospital of Brest; Brest France
- Department of Radiology; Military Hospital of Brest; Brest France
| | - Ronan Abgral
- Department of Nuclear Medicine; University Hospital of Brest; Brest France
- Thrombosis Study Group in Western Brittany; Research's Federative Institute 148, European University of Brittany; Brest France
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99
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Brady SL, Shulkin BL. Dose optimization: a review of CT imaging for PET attenuation correction. Clin Transl Imaging 2017. [DOI: 10.1007/s40336-017-0232-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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100
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Seith F, Schmidt H, Gatidis S, Bezrukov I, Schraml C, Pfannenberg C, la Fougère C, Nikolaou K, Schwenzer N. SUV-quantification of physiological lung tissue in an integrated PET/MR-system: Impact of lung density and bone tissue. PLoS One 2017; 12:e0177856. [PMID: 28562622 PMCID: PMC5451041 DOI: 10.1371/journal.pone.0177856] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/04/2017] [Indexed: 11/18/2022] Open
Abstract
Purpose The aim of the study was to investigate the influence of lung density changes as well as bone proximity on the attenuation correction of lung standardized uptake values (SUVs). Methods and materials 15 patients with mostly oncologic diseases were examined in 18F-FDG-PET/CT and subsequently in a fully integrated PET/MR scanner. From each PET dataset acquired in PET/MR, four different PET reconstructions were computed using different attenuation maps (μ-maps): i) CT-based μ-map (gold standard); ii) CT-based μ-map in which the linear attenuation coefficients (LAC) of the lung tissue was replaced by the lung LAC from the MR-based segmentation method; iii) based on reconstruction ii), the LAC of bone structures was additionally replaced with the LAC from the MR-based segmentation method; iv) the vendor-provided MR-based μ-map (segmentation-based method). Those steps were performed using MATLAB. CT Hounsfield units (HU) and SUVmean was acquired in different levels and regions of the lung. Relative differences between the differently corrected PETs were computed. Results Compared to the gold standard, reconstruction ii), iii) and iv) led to a relative underestimation of SUV in the posterior regions of -9.0%, -13.4% and -14.0%, respectively. Anterior and middle regions were less affected with an overestimation of about 6–8% in reconstructions ii)–iv). Conclusion It could be shown that both, differences in lung density and the vicinity of bone tissue in the μ-map may have an influence on SUV, mostly affecting the posterior lung regions.
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Affiliation(s)
- Ferdinand Seith
- Diagnostic and Interventional Radiology, Department of Radiology, Eberhard Karls University, Hoppe-Seyler-Straße 3, Tuebingen, Germany
| | - Holger Schmidt
- Diagnostic and Interventional Radiology, Department of Radiology, Eberhard Karls University, Hoppe-Seyler-Straße 3, Tuebingen, Germany
- * E-mail:
| | - Sergios Gatidis
- Diagnostic and Interventional Radiology, Department of Radiology, Eberhard Karls University, Hoppe-Seyler-Straße 3, Tuebingen, Germany
| | - Ilja Bezrukov
- Preclinical Imaging and Radiopharmacy, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens Foundation, Department of Radiology, Eberhard Karls University, Hoppe-Seyler-Straße 3, Tuebingen, Germany
- Max Planck Institute for Intelligent Systems, Spemannstr. 38, Tuebingen, Germany
| | - Christina Schraml
- Diagnostic and Interventional Radiology, Department of Radiology, Eberhard Karls University, Hoppe-Seyler-Straße 3, Tuebingen, Germany
| | - Christina Pfannenberg
- Diagnostic and Interventional Radiology, Department of Radiology, Eberhard Karls University, Hoppe-Seyler-Straße 3, Tuebingen, Germany
| | - Christian la Fougère
- Nuclear Medicine, Department of Radiology, Eberhard Karls University, Hoppe-Seyler-Straße 3, Tuebingen, Germany
| | - Konstantin Nikolaou
- Diagnostic and Interventional Radiology, Department of Radiology, Eberhard Karls University, Hoppe-Seyler-Straße 3, Tuebingen, Germany
| | - Nina Schwenzer
- Diagnostic and Interventional Radiology, Department of Radiology, Eberhard Karls University, Hoppe-Seyler-Straße 3, Tuebingen, Germany
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