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

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.

Background: One can assess cortical defects on the early images of [99mTc]Tc-MAG3 renography. We aimed to assess interobserver and intraobserver reproducibility for detecting renal cortical defects using [99mTc]Tc-MAG3 for adults and children; identify causes for poor inter- and intraobserver reproducibility and to assess the effect of the kidney to background ratio (KTBR) on reproducibility.

Methods: One hundred adult and 200 pediatric renograms were included. The observers reviewed the summed 1-minute posterior images for the first four minutes to detect cortical defects. Interobserver reproducibility between three observers and intra-observer reproducibility for two observers were determined. Agreement was tested using percentage agreement, Krippendorff's reliability coefficient alpha and Cohen's kappa statistic. The association between KTBR and agreement was evaluated.

Results: Interobserver agreement on the 1-2 minutes images was 78 (95% CI: 74.8-82.7%) and 79.7 (95% CI: 75.9-83.5%) for left and right kidneys respectively. Intraobserver percentage was 89.7% (95% CI: 86.2-93.1%) for the senior and 80.7% (95% CI: 76.2-85.2%) for the junior observer. In 13.5% (27) of the adult and 4.5% (19) of the pediatric kidneys the difference in image interpretation between the observers would have had a clinical impact. If the KTBR is ≤2, the percentage agreement was between 61.5% and 64.8%. In cases with a KTBR >2, the percentage agreement was between 83.6% and 87.1%.

Conclusions: The percentage interobserver agreement was moderate. Disagreement between normal and abnormal cases were infrequent. The interobserver reproducibility was decreased when the KTBR was ≤2.

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.

Hepatobiliary scintigraphy with single-photon emission computed tomography (SPECT) is an essential Nuclear Medicine exam for assessing hepatobiliary abnormalities and planning therapy. We aim to offer a thorough and all-encompassing analysis of hepatobiliary imaging with SPECT to emphasize the practicality, precision in diagnosis, surgical or transplant planning, and advanced uses of SPECT/CT in assessing hepatobiliary disease. Readers can anticipate acquiring a comprehensive understanding of the subsequent facets. The manuscript will explore in detail the diverse clinical uses of SPECT/CT imaging in hepatobiliary system, recent technological breakthroughs in SPECT/CT imaging techniques, specifically addressing quantitative analysis methodologies, and the integration of SPECT/CT with other imaging modalities. This article will provide readers with information on current research trends and future prospects in SPECT/CT imaging for hepatobiliary applications, such as strategies for monitoring therapy, the use of artificial intelligence and machine learning for quantitative imaging biomarkers, how these advanced techniques influence patient care, treatment choices, and prognostic predictions. The goal of the review is to help the readers acquire useful knowledge about the latest hepatobiliary SPECT/CT imaging, their clinical applications, and their prospective contribution to the advancement.

Background: Arterial spin labeling (ASL) MRI has been anecdotally used to assess brain perfusion in autoimmune encephalitis (AE) and its relationship with [¹⁸F]FDG-PET dysmetabolism has been scarcely investigated.Considering the physiological coupling of metabolism and perfusion, we aimed to evaluate the degree of correspondence between ASL-MRI and [¹⁸F]FDG-PET in AE.

Methods: A retrospective cohort of five patients underwent ASL-MRI and [¹⁸F]FDG-PET during the acute stage and at follow-up. We assessed the presence of regions with hypermetabolism on [¹⁸F]FDG-PET and hyperperfusion on ASL-MRI and evaluated concordance and spatial overlap of these metrics. Clinical assessment scale in AE and modified Rankin Scale were obtained at baseline and follow-up.

Results: In two patients [¹⁸F]FDG-PET and ASL-MRI were unremarkable; in three patients there were anatomically overlapping areas of hypermetabolism and hyperperfusion (average DICE similarity coefficient 0.358). Following immunotherapy, metabolic and perfusion changes consistently demonstrated a progressive normalization, aligning with clinical improvement.

Conclusions: We identified suboptimal anatomical correspondence of abnormalities assessed with [¹⁸F]FDG-PET and ASL-MRI. Hyperperfusion and hypermetabolism might reflect differently AE-related pathophysiological correlates, but they both demonstrate ability to monitor disease activity. ASL-MRI is a promising marker of disease activity in AE and a favorable alternative to [¹⁸F]FDG-PET due to its cost-effectiveness, safety, and wide availability.

Background: The diagnostic utility of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) compared to bone marrow biopsy (BMB) in patients with non-Hodgkin lymphoma (NHL) remained to be confirmed. This study aimed to compare BMB and PET/CT for bone marrow infiltration (BMI) in patients with NHL.

Methods: PubMed, Embase, and the Cochrane library were searched for papers published up to October 2021. The outcomes were the true positive and negative and false positive and negative rates for BMB and PET/CT. The summarized sensitivity, specificity, positive likelihood ratios (PLR), negative likelihood ratios (NLR), and diagnostic odds ratios (DOR) were calculated.

Results: Thirteen studies with a total of 2396 patients were included. Significant differences are observed between BMB and PET/CT for sensitivity (relative ratio: 0.749; 95% CI: 0.586-0.956; P=0.020) and NLR (relative ratio: 1.839; 95% CI: 1.106-3.058; P=0.019), but not for specificity (P=0.819), PLR (P=0.802), and DOR (P=0.150). The summary area under the receiver operating characteristic curves for BMB is 0.692 (SE: 0.170) and 0.977 (SE: 0.021) for PET/CT.

Conclusions: PET/CT presents a better sensitivity and NLR for the detection of BMI in patients with NHL, whereas no differences are found regarding specificity, PLR, and DOR compared with BMB.