the Quarterly Journal of Nuclear Medicine and Molecular Imaging最新文献

Diagnosis of spondylodiscitis remains a challenge for clinicians. It results from various causative agents and conditions that can be challenging to identify. Prompt and appropriate treatment are necessary to prevent long-term irreversible complications and sequelae. The diagnosis of spondylodiscitis often constitutes a major challenge for the clinicians, and relies on the combination of clinical, laboratory and imaging findings. Various imaging techniques can be used for the workup of spondylodiscitis, with magnetic resonance imaging and 18-fluoro-deoxy-glucose positron emission tomography, combined with a CT being the most commonly used in daily practice. The aim of this review is to provide general information about indications and protocols for [¹⁸F]FDG PET/CT imaging in spinal infections, focusing on spondylodiscitis, in adults.

¹⁸F fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) has established itself as a critical diagnostic tool in the evaluation of patients with bacteremia and fever of unknown origin (FUO), particularly following futile conventional investigations. These conditions are often challenging due to diverse underlying etiologies, including infections, inflammatory conditions and malignancies. PET/CT has the advantage of being a whole-body imaging technique with high sensitivity for detecting areas of increased metabolism often associated with infection or inflammation. In bacteremia, [¹⁸F]FDG PET/CT can help identify metastatic infections, endocarditis, or abscesses which may be clinically silent and missed on conventional imaging. In FUO, it helps to identify underlying etiologies, directing treatment and management strategies. This review aims to describe the role of PET/CT imaging in these diverse clinical scenarios. Perspectives in the field, including novel equipment and tracers, will be briefly discussed.

Cardiovascular infections have a high mortality rate requiring prompt diagnosis and timely management. [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) has emerged as a valuable diagnostic imaging modality for various cardiovascular infections, including infective endocarditis (IE) and cardiac implantable electronic device (CIED) infections, particularly when the diagnosis remains challenging. In this article, we provide an overview of the epidemiology and clinical presentation of IE and CIED-related infections, the indications for ¹⁸F-FDG-PET/CT and its incremental role in establishing diagnosis as well as illustrate a variety of clinical cases and discuss interpretation criteria.

Vascular graft infections (VGI) are rare but severe complications following vascular surgery, with significant morbidity and mortality. Diagnosing VGI requires a multidisciplinary approach combining clinical, laboratory, and imaging findings. While CTA remains the first-line imaging modality, its limitations in detecting chronic or low-grade infections highlight the value of advanced nuclear medicine techniques, particularly [¹⁸F]FDG PET/CT. In this review, we discuss the role of [¹⁸F]FDG PET/CT in diagnosing VGI, emphasizing its high sensitivity and negative predictive value, which are critical for ruling out infection. Nevertheless, there are currently no universally accepted criteria for analyzing PET/CT findings in VGI, which poses challenges for consistent interpretation and clinical decision-making. This review aims to provide a comprehensive understanding of FDG PET/CT imaging in the context of VGI by exploring visual grading scales, uptake patterns, and semi-quantitative parameters while highlighting potential pitfalls such as post-surgical inflammation and false-positive results due to graft materials or surgical adhesives. Through a series of illustrative cases, we outline characteristic imaging patterns of infected and non-infected grafts, offering practical guidance for accurate interpretation. Additionally, we discuss the evolving role of FDG PET/CT in assessing treatment response and guiding follow-up in VGI management. This pictorial review seeks to enhance diagnostic accuracy and bridge the gap in standardized PET/CT interpretation criteria, ultimately contributing to improved patient care.

Osteomyelitis in infections encompasses heterogeneous group of condition that frequently have high morbidity and comes at a huge cost to healthcare system. Accurate and early diagnosis is important for the proper management of the condition. FDG PET/CT has been found useful in the osteomyelitis of complicated bones, including prosthetic joint infections, fracture related infections and sternal wound infections. The altered anatomy and the replacement of marrow in some cases of metallic implant makes the use of anatomic-based methods less optimal. FDG PET/CT has been found to be useful under these circumstances, however, it also has its own limitation of lack of specificity especially due to inflammation. Recent meta-analysis of the role of FDG PET/CT in complicated osteomyelitis have result in the validation defined the indications for its use. This has led to the publication of best use criteria and recommendations of by joint committees of major nuclear medicine societies.

Infected foot ulcers are common complications in diabetic patients and frequently progress to osteomyelitis. [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) has emerged as a practical and accurate imaging modality to differentiate between soft tissue infection and diabetic foot osteomyelitis (DFO). This study describes [¹⁸F]FDG PET/CT indications, diagnostic accuracy, imaging protocols, interpretation criteria and pitfalls for the work-up of DFO.

Hepatocellular carcinoma (HCC) and biliary tract cancers (BTC) pose significant diagnostic and therapeutic challenges. Magnetic resonance imaging (MRI) and multiphase computed tomography (CT) have been the preferred imaging modalities for diagnosis, staging, and surveillance of patients with these malignancies. The best clinical outcomes depend on the appropriate selection of treatment options from the tools available in neo-adjuvant therapy, surgical resection, locoregional therapy, liver transplantation, and adjuvant therapy. While not a part of the routine diagnostic work-up or follow-up, F-18 fluorodeoxyglucose positron emission tomography (FDG PET/CT) can inform therapeutic decision making and help avoid futile surgeries by detecting unsuspected distant metastases. Additionally, metabolic information obtained with FDG PET/CT has prognostic value, predicting treatment response and survival. In patients with HCC metabolic parameters obtained by FDG PET/CT have been shown to correlate with microvascular invasion and predict recurrence in orthotopic transplant recipients. This article will highlight studies that have evaluated the role of FDG PET/CT in diagnosis, staging and therapeutic response assessment in patients with hepatobiliary cancers.

Transarterial radioembolization (TARE), also called Selective Internal Radiation Therapy (SIRT), has emerged as an effective locoregional therapy for primary and secondary hepatic tumors, utilizing yttrium-90 (Y90) microspheres and other agents such as holmium-166 and rhenium-188. TARE has various applications in the management of HCC across different BCLC stages. Radiation segmentectomy, which involves administering high doses of Y90 (>190 Gy), can be both curative and ablative, achieving complete necrosis of the tumor. In contrast, radiation lobectomy involves administering a lower dose of Y90 (80-120 Gy) as a neoadjuvant treatment modality to improve local control and induce future liver remnant (FLR) hypertrophy in patients who are planned to undergo surgery but have insufficient FLR. Modified radiation lobectomy combines both techniques and offers several advantages over portal vein embolization (PVE). Y90 is also used in downstaging HCC patients outside liver transplantation criteria, as well as bridging those awaiting liver transplantation (LT). Multiple studies and combined analyses were described to highlight the outcomes of TARE and compare it with other treatment modalities, including TACE and sorafenib. Additionally, the review delves into the efficacy and safety of radioembolization in managing metastatic colorectal cancer and other metastatic tumors to the liver. Recent studies have emphasized the role of personalized dosimetry for improved outcomes, and thus we described the different methods used for this purpose. Pretherapy imaging, estimating lung shunt, selection of therapeutic radionuclides, adverse effects, and cost-effectiveness were all discussed as well.

Positron-emission tomography magnetic resonance imaging (PET/MRI) has emerged as a powerful hybrid molecular imaging technique in clinical practice, overcoming initial technical challenges to provide comprehensive anatomic and metabolic information. This advanced modality combines the superior soft tissue contrast of MRI with the metabolic insights of PET, offering advantages in hepatobiliary imaging, including improved detection of small liver metastases and reduced radiation exposure. The evolution of PET/MRI technology has been marked by significant advancements, such as the development of MRI-compatible PET detectors and sophisticated motion compensation techniques. These innovations have enhanced image quality and co-registration accuracy, crucial for hepatobiliary imaging. The integration of time-of-flight capability and silicon photomultipliers has further improved spatial resolution and sensitivity. PET/MRI protocols for liver imaging typically involve a whole-body scan followed by a targeted liver examination, utilizing radiotracers like FDG and DOTATATE. This approach allows for comprehensive staging and detailed liver assessment in a single session, potentially altering management decisions in up to 30% of patients with intrahepatic cholangiocarcinoma. While PET/MRI excels in characterizing various hepatobiliary lesions, including hepatocellular carcinoma and cholangiocarcinoma, challenges remain in differentiating certain benign entities like small hemangiomas from metastases. Ongoing research and clinical experience continue to refine the role of PET/MRI in hepatobiliary imaging, promising improved diagnostic accuracy and patient care.