Total Body PET/CT: A Role in Musculoskeletal Diseases.

Recent advancements in PET technology have culminated in the development of total-body PET (TB-PET) systems, which overcome many limitations of traditional scanners. These TB-PET scanners, while still becoming widely available, represent the forefront of clinical imaging across numerous medical institutions worldwide. Early clinical applications have demonstrated their enhanced image quality, precise lesion quantification, and overall superior performance relative to conventional scanners. The capabilities of TB-PET technology, including extended scan range, ultrahigh sensitivity, exceptional temporal resolution, and dynamic imaging, offer significant potential to tackle unresolved clinical challenges in medical imaging. In this discussion, we aim to explore the emerging applications, opportunities, and future perspectives of TB-PET/CT in musculoskeletal disorders (MSDs). Clinical applications for both oncologic and non-oncologic musculoskeletal diseases are discussed, including inflammatory arthritis, infections, osteoarthritis, osteoporosis, and skeletal muscle disorders. From the ability to visualize small musculoskeletal structures and the entire axial and appendicular skeleton, TB-PET shows significant potential in the diagnosis and management of MSD conditions as it becomes more widely available.

PET Molecular Imaging in Breast Cancer: Current Applications and Future Perspectives.

Positron emission tomography (PET) plays a crucial role in breast cancer management. This review addresses the role of PET imaging in breast cancer care. We focus primarily on the utility of 18F-fluorodeoxyglucose (FDG) PET in staging, recurrence detection, and treatment response evaluation. Furthermore, we delve into the growing interest in precision therapy and the development of novel radiopharmaceuticals targeting tumor biology. This includes discussing the potential of PET/MRI and artificial intelligence in breast cancer imaging, offering insights into improved diagnostic accuracy and personalized treatment approaches.

Imaging of lower extremity infections: predisposing conditions, atypical infections, mimics, and differentiating features.

Imaging evaluation for lower extremity infections can be complicated, especially in the setting of underlying conditions and with atypical infections. Predisposing conditions are discussed, including diabetes mellitus, peripheral arterial disease, neuropathic arthropathy, and intravenous drug abuse, as well as differentiating features of infectious versus non-infectious disease. Atypical infections such as viral, mycobacterial, fungal, and parasitic infections and their imaging features are also reviewed. Potential mimics of lower extremity infection including chronic nonbacterial osteomyelitis, foreign body granuloma, gout, inflammatory arthropathies, lymphedema, and Morel-Lavallée lesions, and their differentiating features are also explored.

Update on Positron Emission Tomography/Magnetic Resonance Imaging: Cancer and Inflammation Imaging in the Clinic.

Hybrid PET/MRI is highly valuable, having made significant strides in overcoming technical challenges and offering unique advantages such as reduced radiation, precise data coregistration, and motion correction. Growing evidence highlights the value of PET/MRI in broad clinical aspects, including inflammatory and oncological imaging in adults, pregnant women, and pediatrics, potentially surpassing PET/CT. This newly integrated solution may be preferred over PET/CT in many clinical conditions. However, further technological advancements are required to facilitate its broader adoption as a routine diagnostic modality.

Clinical Applications of PET in Evaluating the Aging Spine.

Back pain is a common health complaint that contributes globally to medical burden and costs, particularly in elderly populations. Nuclear medicine techniques using PET tracers offer diagnostic information about various spine disorders, including malignant, degenerative, inflammatory, and infectious diseases. Herein, the authors briefly review applications of PET in the evaluation of spine disorders in elderly patients.

Advantages and Applications of Total-Body PET Scanning.

Recent studies have focused on the development of total-body PET scanning in a variety of fields such as clinical oncology, cardiology, personalized medicine, drug development and toxicology, and inflammatory/infectious disease. Given its ultrahigh detection sensitivity, enhanced temporal resolution, and long scan range (1940 mm), total-body PET scanning can not only image faster than traditional techniques with less administered radioactivity but also perform total-body dynamic acquisition at a longer delayed time point. These unique characteristics create several opportunities to improve image quality and can provide a deeper understanding regarding disease detection, diagnosis, staging/restaging, response to treatment, and prognostication. By reviewing the advantages of total-body PET scanning and discussing the potential clinical applications for this innovative technology, we can address specific issues encountered in routine clinical practice and ultimately improve patient care.

Theranostic Agents in Musculoskeletal Disorders.

Theranostic-based strategies, combining therapeutic and diagnostic properties of a single agent, have gained enormous attention in the past few years. Today, various multifunctional theranostic modalities have been examined, using different bioactive targeting, for the detection, quantifying, and monitoring of therapy response in different pathologies. Herein we review the newly emerging approaches in theranostic nanomedicine for the detection and therapy for musculoskeletal disorders to provide valuable insights for developing more efficient agents for clinical use. Some potential preclinical applications of radionuclide nanotheranostic agents are described in rheumatoid arthritis, osteoarthrosis, multiple myeloma, and neoplastic diseases.

SARS-CoV-2 reinfection: "New baseline" imaging concept in the era of COVID-19.

Recent reports have suggested COVID-19 relapse or reinfection may lead to readmission, which may cause a diagnostic challenge between recently infected patients and reinfections. Compounding this problem is the post-viral lung sequela that may be expected after COVID-19 pneumonia, similar to both SARS and MERS. Although chest imaging may play a role in the diagnosis of primary SARS-CoV-2 infection, reinfection or relapse of COVID-19 will have similar imaging findings. A "new-baseline" imaging can be obtained from COVID-19 patients at the time of hospital discharge or clinical recovery. This new reference can not only determine if readmissions are from relapse or reinfection of COVID-19, resolving COVID-19 or potentially a different viral infection (influenza), but also for long term sequela of COVID-19 lung infection. Strategic use of imaging before discharge may be helpful in the subset of the population at the highest risk of a secondary viral infection such as influenza. Determining the residual abnormalities in post-discharge imaging can guide us in the long-term management of patients for many years to come.

Coronavirus Disease 2019 (COVID-19) in Molecular Imaging: A Systematic Review of Incidental Detection of SARS-CoV-2 Pneumonia on PET Studies.

There have been several reports of the incidental detection of severe acute respiratory syndrome coronavirus 2 pneumonia on positron emission tomography/computed tomography (PET/CT) studies, which represent the potential role of molecular imaging in the detection and management of coronavirus disease 2019. Here, we systematically review the value of PET/CT in this setting. We conducted a systematic search on June 23, 2020, for PET studies with findings suggestive of coronavirus disease 2019. Web of Science, PubMed, Scopus, EMBASE, and Google Scholar databases were used. Patients with at least one PET/CT imaging evaluation were included in the study. Fifty-two patients in 30 publications with a mean age of 60 ± 12.74 (age range; 27-87) were included in this study, of which 28 (53.8%) were male, and 19 (36.5%) were female. In 5 (9.7%) patients, gender was not reported. PET/CT was performed with 18F-fluorodeoxyglucose for 48 (92.3%), 18F-choline for 3 (5.8%), and 68Ga-PSMA for 1 (1.9%) patients. The mean SUV max of pulmonary lesions with 18F-fluorodeoxyglucose uptake was 4.9 ± 2.3. Moreover, 39 (75%) cases had an underlying malignancy, including 18 different type of primary cancers and 6 (11.5%) patients with metastatic disease. The most common pulmonary findings in PET/CT were bilateral hypermetabolic ground-glass opacities in 39 (75%), consolidation in 18 (34.6%), and interlobular thickening in 4 (7.6%). In addition, mediastinal 14 (27%) and hilar 10 (19.2%) lymph node involvement with increased metabolic activity was frequently identified. Early diagnosis of severe acute respiratory syndrome coronavirus 2 pneumonia is not only crucial for both appropriate patient management but also helps to ensure appropriate postexposure precautions are implemented for the department and hospital staff and those who have been in contact with the patient.

Chest-CT findings of COVID-19 in patients with pre-existing malignancies; a pictorial review.

As of April 17th, 2020, more than 2,190,010 COVID-19 cases with 147,010 deaths have been recorded worldwide. It has been suggested that a high mortality rate occurs in patients with severe disease and is associated with advanced age and underlying comorbidities, such as malignancies. To the best of our knowledge, no study has been conducted to evaluate chest CT features in patients with malignancy and concomitant COVID-19 infection. In fact, the imaging findings can be challenging and have not yet been fully understood in this setting. In this manuscript, we go over imaging findings in chest CT of patients with COVID-19 and known cancer. With the ongoing COVID-19 pandemic and exponentially increasing incidence throughout the world, in at-risk and vulnerable populations such as patients with known malignancies, infection with SARS-CoV-2 should be included in the differential considerations even with atypical image pictures. Detection of superimposed infection in patients with cancers who present with pulmonary infiltrations warrant correlation with clinical picture, contact history, and RT-PCR confirmatory testing.

PET in the Diagnostic Management of Soft Tissue Sarcomas of Musculoskeletal Origin.

Soft tissue sarcomas (STSs) account for less than 1% of adult solid tumors and about 7% of pediatric malignancies, causing 2% of cancer-related deaths. With the advent of PET-computed tomography (CT), the value of (18) fluorine-2-fluoro-2-deoxy-d-glucose (FDG) PET imaging to improve the management of STSs has been explored. FDG PET imaging has been found useful in restaging and treatment response assessment. This article reviews current knowledge and application of FDG PET-CT in initial diagnosis, staging, restaging, treatment response monitoring, and prognosis, with a brief overview of the most common histologic subtypes of STS.

The value of (18) F-fluorodeoxyglucose positron emission tomography for prediction of treatment response in gastrointestinal stromal tumors: a systematic review and meta-analysis.

BACKGROUND: Early detection of response to treatment is critically important in gastrointestinal stromal tumors (GIST). Therefore, the present systematic review and meta-analysis assessed the value of (18) f-fluorodeoxyglucose positron emission tomography ((18) FDG-PET) on prediction of therapeutic response of GIST patients to systemic treatments. METHODS: The literature search was conducted using PubMed, SCOPUS, Cochrane, and Google Scholar databases, and review article references. Eligible articles were defined as studies included confirmed GIST patients who underwent (18) FDG-PET as well as assessing the screening role of it. RESULTS: Finally, 21 relevant articles were included. The analysis showed the pooled sensitivity and specificity of 18FDG-PET in evaluation of response to treatment of GIST patient were 0.90 (95% CI: 0.85-0.94; I(2) = 52.59, P = 0.001) and 0.62 (95% CI: 0.49-0.75; I(2) = 69.7, P = 0.001), respectively. In addition, the pooled prognostic odds ratio of (18) FDG-PET for was 14.99 (95% CI, 6.42-34.99; I(2) = 100.0, P < 0.001). The Meta regression showed that sensitivity of (18) FDG-PET was higher if the sample size of study was equal or more than 30 cases (sensitivity = 0.93; 95% CI: 0.89-0.97), when using PET/CT (sensitivity = 0.92; 95% CI: 0.89-0.97), and self-design criteria (sensitivity = 0.93; 95% CI: 0.87-1.0). CONCLUSION: The present meta-analysis showed (18) FDG-PET has a significant value in predicting treatment response in GIST patients.