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Seminars in Nuclear Medicine Nov 2023This article discusses the current clinical role and scope of functional radionuclide imaging using testicular perfusion scintigraphy with Tc-pertechnetate in patients... (Review)
Review
This article discusses the current clinical role and scope of functional radionuclide imaging using testicular perfusion scintigraphy with Tc-pertechnetate in patients presenting with an acute hemiscrotum for an early and reliable diagnosis of testicular torsion. The technique of testicular perfusion scintigraphy is described, and the characteristic findings are detailed with examples. The imaging characteristics of the various phases of testicular torsion and its differentiation from epididymitis and/or epididymo-orchitis and the other related conditions presenting as an acute hemiscrotum are detailed. In some cases, further evaluation by SPECT imaging increases the clarity and accuracy of diagnosis and, on occasion, hybrid SPECT/CT in selected complicated cases improves the diagnostic yield of the perfusion scintigraphy. Ultrasonographic and color Doppler findings are described concurrently with the scintigraphic findings. The several case examples presented demonstrate the additional clinical benefit of complementing functional and structural imaging for improving the sensitivity, specificity and accuracy of testicular imaging in the diagnosis.
Topics: Male; Humans; Spermatic Cord Torsion; Diagnosis, Differential; Orchitis; Epididymitis; Radionuclide Imaging
PubMed: 37210316
DOI: 10.1053/j.semnuclmed.2023.04.005 -
Abdominal Radiology (New York) Dec 2023Molecular imaging plays a vital role in the management of neuroendocrine neoplasms (NENs). Somatostatin receptor (SSTR) PET is critical for evaluating NENs, ascertaining... (Review)
Review
Molecular imaging plays a vital role in the management of neuroendocrine neoplasms (NENs). Somatostatin receptor (SSTR) PET is critical for evaluating NENs, ascertaining peptide receptor radionuclide therapy (PRRT) eligibility, and treatment response. SSTR-PET/MRI can provide a one-stop-shop multiparametric evaluation of NENs. The acquisition of complementary imaging information in PET/MRI has distinct advantages over PET/CT and MR imaging acquisitions. The purpose of this manuscript is to provide a comprehensive overview of PET/MRI and a current review of recent PET/MRI advances in the diagnosis, staging, treatment, and surveillance of NENs.
Topics: Humans; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Receptors, Somatostatin; Magnetic Resonance Imaging; Neuroendocrine Tumors
PubMed: 36525051
DOI: 10.1007/s00261-022-03757-1 -
PET Clinics Jul 2024Neuroendocrine neoplasms (NEN) are rare tumors arising from neuroendocrine cells. NEN are ideally suited for a theragnostic approach due to their specific expression of... (Review)
Review
Neuroendocrine neoplasms (NEN) are rare tumors arising from neuroendocrine cells. NEN are ideally suited for a theragnostic approach due to their specific expression of somatostatin receptors (SSTR). SSTR imaging of NEN dates back to the 1980s, but has evolved recently due to the introduction of more sensitive SSTR PET radiotracers. SSTR PET is a primary imaging modality for identifying NEN and characterizing SSTR expression. SSTR PET is complementary to anatomic imaging for assessing tumor response to treatment. SSTR PET is mandated to determine eligibility for peptide receptor radionuclide therapy. Here, the role of imaging to aid management of NEN is reviewed.
Topics: Humans; Neuroendocrine Tumors; Receptors, Somatostatin; Positron-Emission Tomography; Radiopharmaceuticals; Positron Emission Tomography Computed Tomography
PubMed: 38714399
DOI: 10.1016/j.cpet.2024.03.008 -
Seminars in Nuclear Medicine Nov 2023Imaging of gastrointestinal bleeding crucial in the diagnosis of occult gastrointestinal bleeding. Gastrointestinal bleeding scintigraphy is a well-established study to... (Review)
Review
Imaging of gastrointestinal bleeding crucial in the diagnosis of occult gastrointestinal bleeding. Gastrointestinal bleeding scintigraphy is a well-established study to aid localisation of gastrointestinal bleeding site. This article discusses about the use of gastrointestinal bleeding scintigraphy in its current practice with emphasis on radiopharmaceutical, imaging techniques, interpretation and pitfalls. There is also discussion on the use of Single Photon Emission Computed Tomography-Computed Tomography (SPECT-CT) within this method of scintigraphy. Meckel's diverticulum is known to be a frequent source of bleeding, mainly in children. It is also know that nuclear medicine imaging can help with Meckel's diverticulum identification. This article also discusses about the technique, imaging, interpretation and SPECT-CT usage for Meckel's diverticulum imaging.
Topics: Child; Humans; Meckel Diverticulum; Diagnostic Imaging; Radionuclide Imaging; Gastrointestinal Hemorrhage; Nuclear Medicine
PubMed: 37451934
DOI: 10.1053/j.semnuclmed.2023.06.002 -
Seminars in Nuclear Medicine Sep 2023Prostate cancer remains a major cause of mortality and morbidity, affecting millions of men, with a large percentage expected to develop the disease as they reach... (Review)
Review
Prostate cancer remains a major cause of mortality and morbidity, affecting millions of men, with a large percentage expected to develop the disease as they reach advanced ages. Treatment and management advances have been dramatic over the past 50 years or so, and one aspect of these improvements is reflected in the multiple advances in diagnostic imaging techniques. Much attention has been focused on molecular imaging techniques that offer high sensitivity and specificity and can now more accurately assess disease status and detect recurrence earlier. During development of molecular imaging probes, single-photon emission computed tomography (SPECT) and positron emission tomography (PET) must be evaluated in preclinical models of the disease. If such agents are to be translated to the clinic, where patients undergoing these imaging modalities are injected with a molecular imaging probe, these agents must first be approved by the FDA and other regulatory agencies prior to their adoption in clinical practice. Scientists have worked assiduously to develop preclinical models of prostate cancer that are relevant to the human disease to enable testing of these probes and related targeted drugs. Challenges in developing reproducible and robust models of human disease in animals are beset with practical issues such as the lack of natural occurrence of prostate cancer in mature male animals, the difficulty of initiating disease in immune-competent animals and the sheer size differences between humans and conveniently smaller animals such as rodents. Thus, compromises in what is ideal and what can be achieved have had to be made. The workhorse of preclinical animal models has been, and remains, the investigation of human xenograft tumor models in athymic immunocompromised mice. Later models have used other immunocompromised models as they have been found and developed, including the use of directly derived patient tumor tissues, completely immunocompromised mice, orthotopic methods for inducing prostate cancer within the mouse prostate itself and metastatic models of advanced disease. These models have been developed in close parallel with advances in imaging agent chemistries, radionuclide developments, computer electronics advances, radiometric dosimetry, biotechnologies, organoid technologies, advances in in vitro diagnostics, and overall deeper understandings of disease initiation, development, immunology, and genetics. The combination of molecular models of prostatic disease with radiometric-based studies in small animals will always remain spatially limited due to the inherent resolution sensitivity limits of PET and SPECT decay processes, fundamentally set at around a 0.5 cm resolution limit. Nevertheless, it is central to researcher's efforts and to successful clinical translation that the best animal models are adopted, accepted, and scientifically verified as part of this truly interdisciplinary approach to addressing this important disease.
Topics: Humans; Male; Mice; Animals; Prostatic Neoplasms; Positron-Emission Tomography; Tomography, Emission-Computed, Single-Photon; Radioisotopes
PubMed: 36882335
DOI: 10.1053/j.semnuclmed.2023.02.002 -
Cancer Imaging : the Official... Aug 2023F18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) plays a crucial role in tumour diagnosis, staging, and therapy response evaluation... (Review)
Review
F18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) plays a crucial role in tumour diagnosis, staging, and therapy response evaluation of various cancer types and has been a standard imaging modality used in clinical oncology practice for many years. However, it has certain limitations in evaluating some particular gastrointestinal cancer types due to low FDG-avidity or interphering physiological background activity. Fibroblast activation protein (FAP), a protein of the tumour microenvironment, is overexpressed in a wide range of cancers which makes it an attractive target for both tumour imaging and therapy. Recently, FAP-targeted radiopharmaceuticals are widely used in clinical research and achieved great results in tumour imaging. Considering the limitations of FDG PET/CT and the lack of physiological FAP-targeted tracer uptake in liver and intestinal loops, gastrointestinal cancers are among the most promising indications of FAP-targeted imaging. Herein, we present a comprehensive review of FAP-targeted imaging in gastrointestinal cancers in order to clarify the current and potential future role of this class of molecules in gastrointestinal oncology.
Topics: Humans; Positron Emission Tomography Computed Tomography; Fluorodeoxyglucose F18; Gastrointestinal Neoplasms; Positron-Emission Tomography; Liver; Tumor Microenvironment
PubMed: 37608378
DOI: 10.1186/s40644-023-00598-z -
Rheumatic Diseases Clinics of North... Aug 2023Technological advances and increased recognition of the prevalence and implications of large vessel vasculitis have led to robust research into various imaging... (Review)
Review
Technological advances and increased recognition of the prevalence and implications of large vessel vasculitis have led to robust research into various imaging techniques. Although there is still debate about which modality to choose in specific clinical scenarios, Ultrasound, PET/CT, MRI/A, and CT/A offer complementary information regarding diagnosis, disease activity, and vascular complication monitoring. Recognition of the strengths and limitations of each technique is important for appropriate application in clinical practice.
Topics: Humans; Positron Emission Tomography Computed Tomography; Fluorodeoxyglucose F18; Takayasu Arteritis; Giant Cell Arteritis; Positron-Emission Tomography
PubMed: 37331729
DOI: 10.1016/j.rdc.2023.03.001 -
Neuroimaging Clinics of North America Aug 2023Spinal extradural tumors, although uncommon, have high morbidity and mortality rates. Radiographs and computed tomography scans are typically used to assess and... (Review)
Review
Spinal extradural tumors, although uncommon, have high morbidity and mortality rates. Radiographs and computed tomography scans are typically used to assess and determine the characteristics of these tumors. However, MR imaging is the preferred method for the evaluation of complications that can increase morbidity, such as spinal cord and nerve compression. Imaging features, such as type of matrix, cortical involvement, and margins, aid in determining the diagnosis. This article discusses common and infrequent extradural spinal tumors, their imaging characteristics, and how age, location, and clinical presentation help in diagnosing these neoplasms.
Topics: Humans; Spinal Neoplasms; Spinal Cord; Tomography, X-Ray Computed; Magnetic Resonance Imaging; Radionuclide Imaging
PubMed: 37356861
DOI: 10.1016/j.nic.2023.03.004 -
Molecular Imaging 2023Amyotrophic lateral sclerosis (ALS) is a disease leading to progressive motor degeneration and ultimately death. It is a complex disease that can take a significantly... (Review)
Review
Amyotrophic lateral sclerosis (ALS) is a disease leading to progressive motor degeneration and ultimately death. It is a complex disease that can take a significantly long time to be diagnosed, as other similar pathological conditions must be ruled out for a definite diagnosis of ALS. Noninvasive imaging of ALS has shed light on disease pathology and altered biochemistry in the ALS brain. Other than magnetic resonance imaging (MRI), two types of functional imaging, positron emission tomography (PET) and single photon emission computed tomography (SPECT), have provided valuable data about what happens in the brain of ALS patients compared to healthy controls. PET imaging has revealed a specific pattern of brain metabolism through [F]FDG, while other radiotracers have uncovered neuroinflammation, changes in neuronal density, and protein aggregation. SPECT imaging has shown a general decrease in regional cerebral blood flow (rCBF) in ALS patients. This educational review summarizes the current state of ALS imaging with various PET and SPECT radiopharmaceuticals to better understand the pathophysiology of ALS.
Topics: Humans; Amyotrophic Lateral Sclerosis; Positron-Emission Tomography; Tomography, Emission-Computed, Single-Photon; Brain; Fluorodeoxyglucose F18
PubMed: 37636591
DOI: 10.1155/2023/5864391 -
Magnetic Resonance Imaging Clinics of... Nov 2023Head and neck squamous cell carcinoma (HNSCC) can either be examined with hybrid PET/MR imaging systems or sequentially, using PET/CT and MR imaging. Regardless of the... (Review)
Review
Head and neck squamous cell carcinoma (HNSCC) can either be examined with hybrid PET/MR imaging systems or sequentially, using PET/CT and MR imaging. Regardless of the acquisition technique, the superiority of MR imaging compared to CT lies in its potential to interrogate tumor and surrounding tissues with different sequences, including perfusion and diffusion. For this reason, PET/MR imaging is preferable for the detection and assessment of locoregional residual/recurrent HNSCC after therapy. In addition, MR imaging interpretation is facilitated when combined with PET. Nevertheless, distant metastases and distant second primary tumors are detected equally well with PET/MR imaging and PET/CT.
Topics: Humans; Positron Emission Tomography Computed Tomography; Squamous Cell Carcinoma of Head and Neck; Magnetic Resonance Imaging; Head and Neck Neoplasms; Positron-Emission Tomography
PubMed: 37741640
DOI: 10.1016/j.mric.2023.08.001