Modalities Including Positron Emission Tomography Research Articles

Role of amide proton transfer imaging in maximizing tumor resection in malignant glioma: a possibility to take the place of 11C-methionine positron emission tomography.

Amide proton transfer (APT) imaging has been proposed as a technique to assess tumor metabolism. However, the relationship between APT imaging and other quantitative modalities including positron emission tomography (PET) has not been investigated in detail. This study aimed to evaluate the clinical usefulness of APT imaging in determining the metabolic status of malignant glioma and to compare findings with those from 11C-methionine (Met)-PET. This research analyzed APT imaging data from 20 consecutive patients with malignant glioma treated between January 2022 and July 2023. Patients underwent tumor resection and correlations between tumor activity and intensity of APT signal were investigated. We also compared 11C-Met-PET and APT imaging for the same regions of the perifocal tumor invasion area. Clear, diagnostic APT images were obtained from all 20 cases. Mean APT intensity (APTmean) was significantly higher in the glioblastoma (GBM), IDH wild type group (27.2 ± 12.8%) than in other gliomas (6.0 ± 4.7%; p < 0.001). The cut-off APTmean to optimally distinguish between GBM and other malignant gliomas was 12.8%, offering 100% sensitivity and 83.3% specificity. These values for APTmean broadly matched the tumor-to-contralateral normal brain tissue ratio from 11C-Met-PET analysis (r = 0.66). The APT signal was also observed in the gadolinium non-contrast region on T1-weighted imaging, appearing to reflect the surrounding tumor-infiltrated area. APT imaging can be used to evaluate the area of tumor invasion, similar to 11C-Met-PET. APT imaging revealed low invasiveness in patients and was useful in preoperative planning for tumor resection, facilitating maximum tumor resection including the tumor invasive area.

Modeling of Whale Optimization with Deep Learning based Brain Disorder Detection and Classification

Brain disorders are a significant source of economic strain and unfathomable suffering in modern society. Imaging techniques help diagnose, monitor and treat mental health, neurological, and developmental disorders. To aid in the Computer-Aided Diagnosis of brain diseases, deep learning (DL) was used for the analysis of neuroimages from modalities including Positron Emission Tomography (PET), Structural Magnetic Resonance Imaging (SMRI), and functional MRI. In this study, a Whale Optimization Algorithm is used with Deep Learning to analyse MRI scans for signs of neurological disease. WOADL-BDDC may detect and label abnormalities in the brain based on an MRI scan. It uses a two-step pre-processing procedure, first using guided filtering to get rid of background noise and then using U-Net segmentation to get rid of the top of the head. QuickNAT, along with RMSProp, is used to segment the brain. When analysing data, WOADL-BDDC uses radionics to collect information from every layer. When used in a convolutional recurrent neural network model, the Whale Optimization Algorithm may accurately categorize mental illness. WOADL-BDDC is put through its paces using ADNI 3D. Compared to state-of-the-art classification results from Vgg16, Graph CNN, Modified ResNet18, Non-linear SVM, ResNet50-SVM, ResNet50-RF, the suggested technique achieved the greatest accuracy. It was demonstrated that the suggested model is superior to other models for classification from MRI images. In simulations, the proposed approach is shown to be effective in optimizing hyperparameters with an accuracy of 94.38 % on TR set and 94.87% on TS set, Precision of 96.43% on TR set and 97.62% on TS set, and an F1-Score of 89.35 % and 92.10% on TR and TS set, respectively.

Acute Autoimmune Encephalitis With Features of Bickerstaff Brainstem Encephalitis (BBE) and Two Abnormal Autoantibodies Presenting With Prominent Cerebellar Abnormality on MRI–A Case Report

Objective To present an unusual cerebellar imaging finding of a patient with clinical features of BBE Background BBE is characterized by progressive ataxia, ophthalmoplegia and impaired consciousness. Magnetic resonance imaging (MRI) of the brain is usually normal. However, rare T2 Flair changes have been reported. Scarcity of cerebellar findings on imaging led to the controversy of peripheral vs central etiology for the ataxia. Despite other modalities including positron emission tomography, magnetic resonance spectroscopy and molecular level evidence pointing towards involvement of the cerebellum, MRI is usually unrevealing. Design/Methods A 62-year-old woman presented with acute onset ataxia with multiple falls, dysarthria, diplopia, and blurred vision that started 3 days prior to presentation. She had left face angioedema couple days after her flu inoculation 6 weeks prior to presentation. Her exam revealed normal mental status, scanning speech, bilateral dysmetria and ataxia as well as left-sided facial palsy, square wave jerks and hyperreflexia. CSF showed 30 RBC, 17 WBC, normal glucose, and elevated protein of 68 mg/dl. No infectious etiologies were identified. MRI brain showed infratentorial leptomeningeal enhancement with T2 hyperintensities in the both cerebellar hemispheres. Anti-GQ1b antibodies were 51 IV (negative &lt; 30 IV) and anti-GAD65 antibodies were also weakly positive only in serum, 0.12 nmol/L (negative &lt; 0.02 nmol/L). Results She was diagnosed with autoimmune encephalitis and treated with IV methylprednisolone and IVIG. She rapidly improved clinically, and her imaging findings resolved. Conclusions We demonstrated prominent cerebellar imaging findings and good recovery in a patient with anti-GQ1b and mild anti-GAD65 seropositive autoimmune encephalitis. Our case is the first reported double positive autoimmune encephalitis with features of BBE and direct cerebellar involvement

Current and novel radiopharmaceuticals for imaging cardiovascular inflammation.

Cardiovascular disease (CVD) remains the leading cause of death worldwide despite advances in diagnostic technologies and treatment strategies. The underlying cause of most CVD is atherosclerosis, a chronic disease driven by inflammatory reactions. Atherosclerotic plaque rupture could cause arterial occlusion leading to ischemic tissue injuries such as myocardial infarction (MI) and stroke. Clinically, most imaging modalities are based on anatomy and provide limited information about the on-going molecular activities affecting the vulnerability of atherosclerotic lesion for risk stratification of patients. Thus, the ability to differentiate stable plaques from those that are vulnerable is an unmet clinical need. Of various imaging techniques, the radionuclide-based molecular imaging modalities including positron emission tomography and single-photon emission computerized tomography provide superior ability to noninvasively visualize molecular activities in vivo and may serve as a useful tool in tackling this challenge. Moreover, the well-established translational pathway of radiopharmaceuticals may also facilitate the translation of discoveries from benchtop to clinical investigation in contrast to other imaging modalities to fulfill the goal of precision medicine. The relationship between inflammation occurring within the plaque and its proneness to rupture has been well documented. Therefore, an active effort has been significantly devoted to develop radiopharmaceuticals specifically to measure CVD inflammatory status, and potentially elucidate those plaques which are prone to rupture. In the following review, molecular imaging of inflammatory biomarkers will be briefly discussed.

Fluciclovine positron emission tomography in the setting of biochemical recurrence following local therapy of prostate cancer.

Approximately one in five men will demonstrate biochemical recurrence (BCR) following local therapy for prostate cancer (PCa). Advanced imaging modalities including positron emission tomography (PET) imaging of various radiotracers have become more commonplace to visualize foci of disease recurrence. We performed a systematic review of the literature to describe current evidence in support of 18F-fluciclovine (Axumin) PET imaging in this clinical setting. An English literature search was conducted on PubMed/Medline for original investigations on 18F-fluciclovine PET for PCa. Boolean criteria included the terms: prostate, fluciclovine, FACBC and Axumin. Published articles meeting these criteria and their respective bibliographies and diagnostic modalities were included after review, when appropriate. Our literature review identified 93 articles. Among these, 18 met our inclusion criteria. Evidence suggests 18F-fluciclovine PET imaging is safe, well-tolerated and offers acceptable sensitivity and specificity for the detection of localized intraglandular and extraprostatic PCa foci in the setting of persistence or recurrence after primary treatment. Compared to other available PET radiotracers available, evidence suggests that 18F-fluciclovine may outperform ProstaScint and 11C-choline in this clinical setting. Furthermore, 18F-fluciclovine PET may aid guiding decision-making in regards to salvage therapy planning. Further investigation is warranted to validate these early findings and to further compare this agent to other available radiotracers in this setting.

Spectrum of Chronic Complications Related to Silicone Leakage and Migration

BackgroundMedical silicone is widely used as implants and free injections, but the spectrum of complications related to migration or embolization of silicone remains unclear. MethodsWe retrospectively reviewed 79 patients with silicone migration as confirmed on pathology between January 1, 2001, and December 31, 2016. The presenting clinical and imaging features, diagnostic testing, treatment, and outcome were assessed. ResultsNearly all patients were women, and 43% had a history of breast cancer. Sixty-three cases (80%) consisted of localized silicone granulomas, including 1 patient who developed severe hypercalcemia related to the granulomatous reaction. The remaining 16 cases (20%) involved migration of silicone to regional lymph nodes or distant tissue and included 1 case of chronic silicone pneumonitis. These complications were detected many years (median, 22 years; range, 1-40 years) after initial silicone placement. Only magnetic resonance imaging, dual-energy computed tomography (CT), and ultrasonography demonstrated specificity for detection of silicone in lymph nodes and soft tissues. Other modalities including positron emission tomography, single-energy CT, and mammography detected only nonspecific abnormalities. Excisional biopsy of symptomatic lymphadenopathy or masses usually led to resolution of symptoms. The patient with silicone pneumonitis improved with corticosteroid therapy. ConclusionsChronic complications related to silicone extravasation and migration can present with local or distant manifestations, typically encountered many years after the original silicone placement. Magnetic resonance imaging, dual-energy CT, and ultrasonography are helpful for noninvasive diagnosis.

Molecular and Functional Imaging of Internet Addiction

Maladaptive use of the Internet results in Internet addiction (IA), which is associated with various negative consequences. Molecular and functional imaging techniques have been increasingly used for analysis of neurobiological changes and neurochemical correlates of IA. This review summarizes molecular and functional imaging findings on neurobiological mechanisms of IA, focusing on magnetic resonance imaging (MRI) and nuclear imaging modalities including positron emission tomography (PET) and single photon emission computed tomography (SPECT). MRI studies demonstrate that structural changes in frontal cortex are associated with functional abnormalities in Internet addicted subjects. Nuclear imaging findings indicate that IA is associated with dysfunction of the brain dopaminergic systems. Abnormal dopamine regulation of the prefrontal cortex (PFC) could underlie the enhanced motivational value and uncontrolled behavior over Internet overuse in addicted subjects. Further investigations are needed to determine specific changes in the Internet addictive brain, as well as their implications for behavior and cognition.

New SPECT and PET radiopharmaceuticals for imaging cardiovascular disease.

Nuclear cardiology has experienced exponential growth within the past four decades with converging capacity to diagnose and influence management of a variety of cardiovascular diseases. Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) with technetium-99m radiotracers or thallium-201 has dominated the field; however new hardware and software designs that optimize image quality with reduced radiation exposure are fuelling a resurgence of interest at the preclinical and clinical levels to expand beyond MPI. Other imaging modalities including positron emission tomography (PET) and magnetic resonance imaging (MRI) continue to emerge as powerful players with an expanded capacity to diagnose a variety of cardiac conditions. At the forefront of this resurgence is the development of novel target vectors based on an enhanced understanding of the underlying pathophysiological process in the subcellular domain. Molecular imaging with novel radiopharmaceuticals engineered to target a specific subcellular process has the capacity to improve diagnostic accuracy and deliver enhanced prognostic information to alter management. This paper, while not comprehensive, will review the recent advancements in radiotracer development for SPECT and PET MPI, autonomic dysfunction, apoptosis, atherosclerotic plaques, metabolism, and viability. The relevant radiochemistry and preclinical and clinical development in addition to molecular imaging with emerging modalities such as cardiac MRI and PET-MR will be discussed.

Otolaryngology Research: A New frontier in Head and Neck Cancer Genomics

Current research on diseases of the ear, nose, throat and related structures of the head and neck has experienced significant strides in areas including cancer, otology, rhinology and laryngology. Molecular diagnostics and advanced imaging modalities including positron emission tomography have facilitated diagnosis and patient outcomes. Collaborations between physicians and laboratory researchers working to identify key clinical issues and translating the biological insights into novel therapeutic approaches are crucial to significant progress in the field. Tumors of the head and neck are the 6th most common cancer worldwide with high 5-year mortality rates. The most common type of head and neck cancer is squamous cell carcinoma (SCC). Although the incidence of the disease has been reducing possibly due to an increased awareness of the carcinogenic effects of tobacco, there has been a steady rise in human papilloma virus (HPV) associated oropharyngeal carcinoma. Mutations in the tumor suppressor gene p53 is observed in the majority of head and neck SCC patients [1]. Recently, two reports by independent teams comprising of an amalgamation of clinicians and basic scientists elucidated the whole-exome (protein coding genes) mutational profile of head and neck tumor-normal pairs [2,3]. In addition to p53 mutations, both groups reported mutations in genes involved in the differentiation pathway involving NOTCH 1. Interestingly, tobacco exposure increased the number mutations compared to tumors with no tobacco exposure [3]. In addition, HPV expressing tumors had fewer mutations than HPV positive tumors. Further determinations of the function of these mutations in tumor growth and dissemination are necessary. These studies set the stage for further work in the areas of target identification and therapeutics pertaining to personalized medicine.

Prospective evaluation of whole-body cancer screening with multiple modalities including FDG-PET: Results from annual screening for 5 years in 1,197 healthy volunteers.

1517 Background: We started a prospective cohort study in August 2003 to evaluate the utility of whole- body cancer screening with multiple modalities including positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) in a healthy population. Methods: A total of 1,197 healthy volunteers age 35 or older (46.7 ± 7.7 y.o.) were enrolled between August 2003 and July 2004 and offered annual cancer screening for 5 years (screening phase) with subsequent long-term follow-up. Screening modalities included were whole-body FDG-PET, abdominal and chest computed tomography, brain and pelvic magnetic resonance imaging, several tumor markers, and fecal occult blood testing. Results: The screening phase ended in June 2009. Of the 1,197 subjects, 1,025 completed the screening five times, while 53, 46, 38, and 35 completed four, three, two, and one screenings, respectively. As of the end of December 2009, a total of 35 cancers (2.9% of 1197) were confirmed. Twenty-seven of the 35 (77.1%) were detected by screening. FDG-PET was positive in 15 (42.9%). Twenty of the 27 showed positive findings in the initial screening. Fifteen incident cancers were observed. Of the 15, seven were detected by the subsequent annual screening (1, 0, 5, and 1 in the second, third, fourth, and fifth screening, respectively), but eight were not detected by screening and were diagnosed after developing symptoms (2, 1, 3, and 2 before the second, third, forth, and fifth screening, respectively). Four of the 8 were progressive diseases and 3 of the 4 died of cancer. One of the 7 with incident cancers detected by the screening also died of cancer. Others live well without recurrence. Positive predictive values were 7.5% (20/267) and 1.9% (7/363) for the initial and subsequent screening, respectively. Conclusions: While whole-body cancer screening has initial performance supporting possible utility, the results do not support annual screening; screening every three years would not affect outcome in this working-age population. Stages of cancers I II III IV N.A. Total Initial screening 12 2 4 0 2 20 Subsequent screening 3 3 0 1* 7 Not detected 3 1 1 2* 1* 8 * Patient died. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Hamamatsu Photonics KK Hamamatsu Photonics KK

Posture-dependent Human 3He Lung Imaging in an Open-access MRI System : Initial Results

The human lung and its functions are extremely sensitive to orientation and posture, and debate continues as to the role of gravity and the surrounding anatomy in determining lung function and heterogeneity of perfusion and ventilation. However, study of these effects is difficult. The conventional high-field magnets used for most hyperpolarized (3)He magnetic resonance imaging (MRI) of the human lung, and most other common radiologic imaging modalities including positron emission tomography and computed tomography, restrict subjects to lying horizontally, minimizing most gravitational effects. In this article, we review the motivation for posture-dependent studies of human lung function and present initial imaging results of human lungs in the supine and vertical body orientations using inhaled hyperpolarized (3)He gas and an open-access MRI instrument. The open geometry of this MRI system features a "walk-in" capability that permits subjects to be imaged in vertical and horizontal positions and potentially allows for complete rotation of the orientation of the imaging subject in a two-dimensional plane. Initial results include two-dimensional lung images acquired with approximately 4 x 8 mm in-plane resolution and three-dimensional images with approximately 2-cm slice thickness. Effects of posture variation are observed, including posture-related effects of the diaphragm and distension of the lungs while vertical.

The Influence of CA 125 and CEA Levels on the Results of 18F-Deoxyglucose Positron Emission Tomography in Suspected Recurrence of Epithelial Ovarian Cancer

The follow-up of epithelial ovarian cancer (OCA) consists of clinical investigation, sonography, and tumor markers (TMs), especially CA 125. If tumor recurrence is suspected, other imaging modalities including positron emission tomography (PET) with (18)F-deoxyglucose (FDG) are often used. While there is still no consensus about the method of choice and the timing of its application, this study aims to find a TM threshold at which a PET would be appropriate. A total of 90 PET studies and the associated CA 125 values (normal value < 35 U/ml) were available in 71 patients during the follow-up after primary therapy for OCA. In 48 studies a CEA value (normal value < 3 ng/ml) was also available. The results of PET imaging were related to the level of TM increase. In 23/90 studies the PET scan was normal. These patients had a median CA 125 of 13.3 U/ml (range 4.2-168 U/ml). In 67/90 studies the PET indicated a potential recurrence of OCA and the median CA 125 was 166.7 U/ml (range 13.3-4,060 U/ml). The TM levels were significantly different (p < 0.001, U-test). With one exception, there were no normal PET scans above CA 125 levels of 30 U/ml; between 20 and 30 U/ml PET was positive in 4/7 studies. In suspected recurrence of OCA, if imaging modalities are to be used, an FDG PET may be considered. Since the costs of this investigation are high, it should be restricted to clinical situations where it is likely to be most effective. In this study a PET indication is worthwhile at CA 125 levels of approximately 30 U/ml.

Cardiac metabolism: a technical spectrum of modalities including positron emission tomography, single-photon emission computed tomography, and magnetic resonance spectroscopy.

Noninvasive techniques for the assessment of cardiac metabolism are important for the detection of potentially salvageable tissue in jeopardized areas of the myocardium. The correct identification of hibernating and stunned myocardium in patients with severely depressed cardiac function can have vital therapeutic consequences for the patient. Changes in myocardial fatty acid and glucose metabolism during acute and prolonged ischemia can be traced by positron-emitting or gamma-emitting radiopharmaceuticals. Alternatively, 31P-labeled magnetic resonance spectroscopy can be used for the assessment of high-energy phosphate metabolism. It is not yet clear which modality will emerge as the most useful in the clinical setting. Positron emission tomography (PET) that uses combinations of flow tracers and metabolic tracers offers unique opportunities for quantification and high-resolution static and rapid dynamic studies. Currently, assessment of glucose metabolism with 18F-fluorodeoxyglucose is regarded as the gold standard for myocardial viability and prediction of improvement of impaired contractile function after revascularization. However, preserved oxidative metabolism may be required for potential functional improvement, and therefore assessment of residual oxidative metabolism by 11C-labeled acetate PET may prove to be more accurate than 18F-fluorodeoxyglucose PET, which reflects both anaerobic and oxidative metabolism. Moreover, because fatty acids are metabolized only aerobically, they are excellent candidates for the clinical assessment of myocardial viability and prediction of functional improvement after revascularization. Especially derivatives of fatty acids that are not metabolized but accumulate in the myocyte are attractive for myocardial imaging. Examples are 123I-beta-methyl-p-iodophenyl pentadecanoic acid and 15-(o-123I-phenyl)-pentadecanoic acid. These tracers can be detected by planar scintigraphy and single-photon emission computed tomography, which are more economical and widely available than PET. In addition, 511 keV collimators have been developed recently, making the detection of positron emitters by planar scintigraphy and single-photon emission computed tomography feasible. The experience with 31P-labeled magnetic resonance spectroscopy in humans is still limited. With current magnetic resonance spectroscopic techniques, insufficient spatial resolution is achieved for clinical purposes, but the possibility of serial measurements to monitor rapid changes of phosphate-containing molecules in time makes magnetic resonance spectroscopy very valuable for the research of myocardial metabolism.