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F18-FET PET/MRI scan of 60-year-old male patient with glioblastoma multiforme (see text for further details). Axial MR (PET/MR, phased array head/neck coil): FLAIR with TR/TE: 9,000/ 94 ms; T1 with TR/TE: 1,900/2.44 ms; ASL with TR/TE: 9,000/

F18-FET PET/MRI scan of 60-year-old male patient with glioblastoma multiforme (see text for further details). Axial MR (PET/MR, phased array head/neck coil): FLAIR with TR/TE: 9,000/ 94 ms; T1 with TR/TE: 1,900/2.44 ms; ASL with TR/TE: 9,000/

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Combined PET/MRI systems are now commercially available and are expected to change the medical imaging field by providing combined anato-metabolic image information. We believe this will be of particular relevance in imaging of cancer patients. At the Department of Clinical Physiology, Nuclear Medicine & PET at Rigshospitalet in Copenhagen we insta...

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... studies in this area with a focus on MR spectroscopy and diffusion tensor imaging have been reported [20][21][22][23]. Figure 1 shows a 60-year-old male patient investigated preoperatively with simultaneous FET PET/MRI acquisi- tion including tissue perfusion measures using ASL. The bulk of the tumor is located in the left temporal region (red arrow, solid). ...

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... MRI has allowed the characterization and diagnosis of human brain cancers in spatial and volumetric analysis [285], as a substitute for biopsies [286], in glioma genotyping [287], brain cancer classification [288,289], as a non-invasive tool for simultaneous and automated tumor segmentation [290], and to investigate the early stages of slow-growing invasive tumors [291][292][293][294]. MRI is used before treatment and at the end of treatment or disease progression [295,296] and to assess neurological complications of cancer treatment [297]. PET/MRI is used in brain tumor grading and staging [298,299] as a diagnostic and therapeutic strategy for glioma [300] and for improved diagnostic and therapeutic assessment in pediatric, teenage, and young adult brain tumors [301]. 11 C-methyl-L-methionine (C-11-MET) PET/MRI was found to improve the diagnostic accuracy to differentiate treatment-related changes from true progression in recurrent glioma [302] and was useful for the assessment of isocitrate dehydrogenase (IDH) status [303]. ...
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Humans are exposed to a complex mix of man-made electric and magnetic fields (MFs) at many different frequencies, at home and at work. Epidemiological studies indicate that there is a positive relationship between residential/domestic and occupational exposure to extremely low frequency electromagnetic fields and some types of cancer, although some other studies indicate no relationship. In this review, after an introduction on the MF definition and a description of natural/anthropogenic sources, the epidemiology of residential/domestic and occupational exposure to MFs and cancer is reviewed, with reference to leukemia, brain, and breast cancer. The in vivo and in vitro effects of MFs on cancer are reviewed considering both human and animal cells, with particular reference to the involvement of reactive oxygen species (ROS). MF application on cancer diagnostic and therapy (theranostic) are also reviewed by describing the use of different magnetic resonance imaging (MRI) applications for the detection of several cancers. Finally, the use of magnetic nanoparticles is described in terms of treatment of cancer by nanomedical applications for the precise delivery of anticancer drugs, nanosurgery by magnetomechanic methods, and selective killing of cancer cells by magnetic hyperthermia. The supplementary tables provide quantitative data and methodologies in epidemiological and cell biology studies. Although scientists do not generally agree that there is a cause-effect relationship between exposure to MF and cancer, MFs might not be the direct cause of cancer but may contribute to produce ROS and generate oxidative stress, which could trigger or enhance the expression of oncogenes.
... Kjaer., et al. (2012) conducted a PET/MRI examination on a female patient with cervical cancer for restaging following radiotherapy and compared the results with PET/CT[27]. They found that PET/MRI was better than PET/CT imaging regarding the precise definitionof the primary tumor. ...
... Kjaer., et al. (2012) conducted a PET/MRI examination on a female patient with cervical cancer for restaging following radiotherapy and compared the results with PET/CT[27]. They found that PET/MRI was better than PET/CT imaging regarding the precise definitionof the primary tumor. ...
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Although the term "nuclear medicine" sounds contemporary, its exact history and study of uses date to the late 19 th century. Nuclear medicine is a noninvasive, multidisciplinary technique involving radiopharmaceuticals and instrumentation to examine physiological functions and diagnose, stage, and treat diseases. The World Health Organization designates nuclear medicine as a medical specialty that employs radioactive materials to diagnose or treat a patient's condition. Nuclear medicine is also used in medical research. The application of nuclear medicine is typically conducted as an outpatient procedure for assessing or treating functional disorders. Nuclear medicine comprises molecular imaging, such as molecular magnetic resonance spectroscopy, magnetic resonance imaging , targeted ultrasound, optical bioluminescence, optical fluorescence, positron emission tomography, and single-photon emission computerized tomography. Radiopharmaceuticals are radioactive agents used in therapeutic and diagnostic procedures-and are organized into four categories: radiopharmaceutical preparations (a ready-to-use formulation suitable for human consumption), radionuclide generator ("off-spring" radionuclide separated from the parent radionuclide in developing radiopharmaceutical preparations), radiopharmaceutical precursor (a radionuclide designed for radio-labeling procedures using a radiopharmaceutical preparation), and a radiopharmaceu-tical preparation kit (a multidose vial that may need further processing, such as heating, boiling, filtering, and buffering to create a radiopharmaceutical preparation, and must be used within 12h). Nuclear medicine techniques include PET, PET-CT, SPECT, micro-PET, and micro-CAT. Nearly 10,000 hospitals worldwide use radionuclides (about 90% of their use is for diagnostic purposes). The most frequently used radionucleotide in diagnostics is 99m Tc, comprising about 40 million examinations per year and accounting for 80% of all examinations in nuclear medicine worldwide. The application of nuclear medicine has upgraded patient care and medical research in numerous ways. Nuclear imaging allows physicians to cost-effectively obtain medical data that would be otherwise unobtainable or need more invasive and costly procedures. Nuclear medicine in telediagnosis is currently well-regarded concerning the digitization of images, image compression, the transmission of images, and data interpretation. Teleradiology systems are widely accepted in clinical practice. Nuclear medicine plays an essential role in specific medical specialties, including oncology, cardiology, neurology, and psychiatry. Training for nuclear medicine includes a radiation medicine diploma program, a 1-year diploma course in medical physics and techniques, a diplomate program in medical radioisotope techniques; more expanded specialty programs are being developed and introduced. Nuclear medicine and radiopharmaceutical procedures are vital to medicine and specific medical procedures.
... Furthermore, deviations caused by physiological changes during the time interval between PET and MR imaging are avoided (7). Previous studies have revealed that integrated PET/MR provides comprehensive information and excellent image quality in the diagnosis and staging of different types of cancers, and is superior to PET alone (14)(15)(16). ...
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The current study aimed to evaluate the correlation between maximum standardized uptake value (SUVmax) and minimum apparent diffusion coefficient (ADCmin) of cervical cancer using an integrated 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance (PET/MR) imaging system, and to determine the association with pathological prognostic factors. A total of 46 patients were pathologically diagnosed with cervical cancer and underwent PET/MR prior to surgery, including total hysterectomy, bilateral pelvic lymph node dissection or paraaortic lymph node dissection. The imaging biomarkers included the SUVmax and ADCmin. The pathological prognostic factors were as follows: Tumor size, histological grade, International Federation of Gynecology and Obstetrics (FIGO) stage and lymph node metastasis. Pearson's correlation analysis was used to evaluate the correlation between imaging biomarkers and the tumor size and the Mann-Whitney U test analysis was used to evaluate the association between imaging biomarkers and pathological factors. The mean SUVmax was 11.1±8.7 (range, 3.16-51.6) and the mean ADCmin was 0.76±0.15×10-3 mm2/s (range, 0.47-1.04×10-3 mm2/s). The SUVmax had a significant negative correlation with the ADCmin (r=-0.700; P<0.001). The SUVmax was significantly increased in patients with poorly differentiated tumors (P=0.001), patients with FIGO stage IIB (P=0.005) and the patients with lymph node metastasis (P=0.040). The ADCmin was significantly decreased in patients with poorly differentiated tumors (P<0.001) and patients with FIGO stage IIB (P=0.017). Statistical analysis revealed no significant correlation between the tumor size and the SUVmax (r=0.286;P=0.054), or between the tumor size and the ADCmin (r=-0.231; P=0.122). Area under the curve (AUC) analysis revealed that SUVmax had a higher diagnostic value for lymph node metastasis (AUC=0.681) and FIGO staging (AUC=0.837) compared with ADCmin, whereas ADCmin had a higher diagnostic value for the grade of pathological differentiation (AUC=0.816) compared with SUVmax (AUC=0.788). The results of the current study demonstrated that there was a significant negative correlation between SUVmax and ADCmin, which were associated with prognostic factors.
... The vast majority of the published work concerning response evaluation has been performed with 18 F-FDG PET and/or CT. However, the new modality PET/Magnetic Resonance Imaging (MRI) which combines simultaneous MRI with superior soft tissue contrast and PET with metabolic information could probably improve the response assessment of patients with AEG [7][8][9][10] despite the fact that clinical application of MRI in esophageal surgical oncology is not widespread. No available data regarding response evaluation with PET/MRI based on histopathological/clinical response in patients with AEG receiving NT currently exist. ...
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Study design and purpose Positron emission tomography (PET)/magnetic resonance imaging (MRI) is a new modality that has showed promising results for various clinical indications. Currently, evaluation of neoadjuvant therapy (NT) among patients with adenocarcinoma of the esophagogastric junction has primarily been reserved for PET/computed tomography. Our aim was to evaluate if early response evaluation by PET/MRI is a feasible method to predict resectability. Methods and materials Patients with untreated adenocarcinoma of the esophagogastric junction (Siewert types I/II) and fit for NT with no contraindications for PET/MRI were considered eligible. A baseline scan was performed prior to NT induction and an evaluation scan 3 weeks later. For histopathological response evaluation, the Mandard tumor regression grade score was applied. Response on PET/MRI was evaluated with Response Evaluation Criteria in Solid Tumors (RECIST 1.1), and change in ADC and SUVmax values. Results Twenty-eight patients were enrolled, and 22 completed both scans and proceeded to final analyses. Seventeen patients were found resectable versus five who were found unresectable. PET/MRI response evaluation had a sensitivity 94%, specificity 80%, and AUC = 0.95 when predicting resectability in patients with adenocarcinoma of the esophagogastric junction. No association with histopathological response (tumor regression grade) was found nor was RECIST correlated with resectability. Conclusion Response evaluation using PET/MRI was a feasible method to predict resectability in patients with adenocarcinoma of the esophagogastric junction in this pilot study. However, larger studies are warranted to justify the use of the modality for this indication.
... This is integrated in the hybrid PET/MR imaging. A PET/MRI system is installed at Rigshospitalet with numerous clinical investigations of clinical use [114]. This modality is believed to be of use to guide cancer treatment and monitor response especially were MRI is considered a preferred modality to CT. ...
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Metastatic spinal cord compression is caused by the progression of metastatic lesions within the vicinity of the spinal cord. The consequences are very severe with loss of neurological function and severe pain. The standard treatment is surgical intervention followed by radiotherapy or radiotherapy alone. However, the majority of patients are treated with radiotherapy only due to contraindications to surgery and technical inoperability. Stereotactic body radiotherapy is a technology to deliver higher radiation dose to the radiotherapy target with the use of spatial coordinates. This modality has shown positive results in treating lesions in brain and lungs. Hence, it could prove beneficial in metastatic spinal cord compression. We designed and planned a trial to investigate this method in patients with metastatic spinal cord compression. The method was usable but the trial was stopped prematurely due to low accrual that made comparison with surgery impossible. Low accrual is a known problem for trials evaluating new approaches in radiotherapy. Target definition in radiotherapy of metastatic spinal cord compression is defined by patient history, examination and imaging. Functional imaging could provide information to guide target definition with the sparring of normal tissue e.g. spinal cord and hematopoietic tissue of the bone marrow. In future trials this may be used for dose escalation of spinal metastases. The trial showed that PET/MRI was feasible in this group of patients but did not change the radiotherapy target in the included patients. Neurological outcome is similar irrespective of course length and therefore single fraction radiotherapy is recommended for the majority of patients. In-field recurrence is a risk factor of both short and long fractionation schemes and re-irradiation have the potential risk of radiation-induced myelopathy. In a retrospective study of re-irradiation, we investigated the incidence of radiation-induced myelopathy. In our study population, we found a higher number of patients experiencing vertebral fractures than the number of patient developing myelopathy. Patients with diabetes had an increased risk of toxicity compared to the remaining patients. Stereotactic body radiotherapy is effective in treating metastatic spinal cord compression but the efficacy cannot be determined due low accrual. The use of PET/MRI did not spare normal tissue in radiotherapy planning of spinal metastases. The incidence of toxicity after re-irradiation of the spine and spinal cord was low. For patients with in-field recurrence, re-irradiation is safe and has a low incidence of toxicity.
... Hybrid positron emission tomography/magnetic resonance (PET/MR) has emerged as a promising modality in various applications. For example, PET/MR was demonstrated to be superior to PET/CT in the characterization of malignancies in the central nervous system [13,14] and body [15][16][17]. The benefits of PET/MR over PET/CT derive from PET/MR's capability to synchronously acquire PET and MR data, from excellent soft tissue signal-to-noise and contrast-to-noise ratios of MR, and from additional functional imaging capabilities (e.g., diffusion-weighted imaging) [14,18]. ...
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This study investigates the performance of PET/MR versus each sub-modality alone in the assessment of active inflammation in patients with Crohn disease, when compared to surgery as standard of reference. Sensitivity for detecting active inflammation was 91.5% for PET, 80% for MR, and 88% for PET/MR. Specificity for active inflammation was 74% for PET, 87% for MR, and 93% for PET/MR. Diagnostic accuracy was 84% for PET, 83% for MR, and 91% for PET/MR. In conclusion, PET/MR is significantly more accurate than either sub-modality alone and more specific than PET alone in the detection of active inflammation in patients with Crohn disease.
... for example, it improves staging of central nervous system cancers, detection of satellite brain lesions, residual disease, and evaluation of intra-tumoral heterogeneity. [64][65][66][67][68] in oncologic body imaging PeT/Mr has been demonstrated to be superior to PeT/cT and also to Mr in several respects, including evaluation of liver, peritoneal, bone, and lymph node metastases, and whole body staging of different primary cancers; moreover, it can also provide insights into the tumor biology, as in the case of breast cancer. [69][70][71][72][73][74][75][76][77][78] PeT/Mr has enormous potentialities also in the evaluation of cd. ...
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Crohn's disease is a chronic relapsing disease characterized by mucosal inflammation, lymphocytes infiltration and fibrotic strictures. Usually, the assessment of location, extension, inflammatory activity and severity of intestinal lesions is complex and invasive with endoscopic methods or histological and biochemical investigations. Thus, the diagnosis remains a challenge for the management of patients. Nuclear medicine techniques, in particular hybrid and molecular imaging, might offer a valid option for the evaluation and determination of the prognosis of the disease. Indeed, imaging methods provide a noninvasive, reproducible and quantitative analysis. An overview of the currently available multimodality imaging techniques in Crohn's disease are reviewed, with particular regard to PET/MR and the choice of the best evaluation score, explaining advantages and disadvantages of each one, with particular regard to their potential role for the assessment of disease activity and extent of inflammation in order to improve the diagnosis. We propose new interpretation criteria for PET/MR images.
... Pediatrik hastalarda yağ dokusu daha az olduğundan yumuşak doku lezyonlarının normal dokulardan ayırt edilebilirliği PET/BT sistemlerinde zor olabilir. MR görüntülemenin sahip olduğu yüksek yumuşak doku kontrastı nedeniyle bu durum pediatrik yaş grubunda PET/MR görüntülemenin tercih edilmesi için başka bir gerekçe oluşturur (5,6,8,9,33,34,35,36). Özellikle pediatrik yaş grubunda sık olarak gözlenen yumuşak doku ve santral sinir sistemi tümörlerinin ve kemik iliği tutulumlarının değerlendirilmesi bakımından PET/MR sistemi PET/ BT'ye üstünlük sağlayabilir. ...
... Pediatrik hastalarda yağ dokusu daha az olduğundan yumuşak doku lezyonlarının normal dokulardan ayırt edilebilirliği PET/BT sistemlerinde zor olabilir. MR görüntülemenin sahip olduğu yüksek yumuşak doku kontrastı nedeniyle bu durum pediatrik yaş grubunda PET/MR görüntülemenin tercih edilmesi için başka bir gerekçe oluşturur (5,6,8,9,33,34,35,36). Özellikle pediatrik yaş grubunda sık olarak gözlenen yumuşak doku ve santral sinir sistemi tümörlerinin ve kemik iliği tutulumlarının değerlendirilmesi bakımından PET/MR sistemi PET/ BT'ye üstünlük sağlayabilir. ...
... Combined PET (positron emission tomography) and MRI (magnetic resonance imaging) shows promise as a powerful tool for multi-parameter disease characterization, beyond what is currently possible with either modality individually. 1,2 While PET offers excellent molecular sensitivity, it is fundamentally a functional imaging modality and cannot effectively visualize structure. MRI excels at soft tissue contrast and structural imaging, while also being capable of functional imaging techniques such as diffusion weighted imaging. ...
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Purpose: A brain sized radio frequency (RF)-penetrable PET insert has been designed for simultaneous operation with MRI systems. This system takes advantage of electro-optical coupling and battery power to electrically float the PET insert relative to the MRI ground, permitting RF signals to be transmitted through small gaps between the modules that form the PET ring. This design facilitates the use of the built-in body coil for RF transmission and thus could be inserted into any existing MR site wishing to achieve simultaneous PET/MR imaging. The PET detectors employ nonmagnetic silicon photomultipliers in conjunction with a compressed sensing signal multiplexing scheme, and optical fibers to transmit analog PET detector signals out of the MRI room for decoding, processing, and image reconstruction. Methods: The PET insert was first constructed and tested in a laboratory benchtop setting, where tomographic images of a custom resolution phantom were successfully acquired. The PET insert was then placed within a 3T body MRI system, and tomographic resolution/contrast phantom images were acquired both with only the B0 field present, and under continuous pulsing from different MR imaging sequences. Results: The resulting PET images have comparable contrast-to-noise ratios (CNR) under all MR pulsing conditions: The maximum percent CNR relative difference for each rod type among all four PET images acquired in the MRI system has a mean of 14.0 ± 7.7%. MR images were successfully acquired through the RF-penetrable PET shielding using only the built-in MR body coil, suggesting that simultaneous imaging is possible without significant mutual interference. Conclusions: These results show promise for this technology as an alternative to costly integrated PET/MR scanners; a PET insert that is compatible with any existing clinical MRI system could greatly increase the availability, accessibility, and dissemination of PET/MR.