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In positron emission tomography (PET), measurements of depth-of-interaction (DOI) information and time-of-flight (TOF) information are important. DOI information reduces the parallax error, and TOF information reduces noise by measuring the arrival time difference of the annihilation photons. Historically, these have been studied independently, and there has been less implementation of both DOI and TOF capabilities because previous DOI detectors did not have good TOF resolution. However, recent improvements in PET detector performance have resulted in commercial PET scanners achieving a coincidence resolving time of around 200 ps, which result in an effect even for small objects. This means that TOF information can now be utilized even for a brain PET scanner, which also requires DOI information. Therefore, various methods have been proposed to obtain better DOI and TOF information. In addition, the cost of PET detectors is also an important factor to consider, since several hundred detectors are used per PET scanner. In this paper, we review the latest DOI–TOF detectors including the history of detector development. When put into practical use, these DOI–TOF detectors are expected to contribute to the improvement of imaging performance in brain PET scanners. [ABSTRACT FROM AUTHOR]

Personalised dosimetry based on molecular imaging is a field that has grown exponentially in the last decade due to the increasing success of Radioligand Therapy (RLT). Despite advances in imaging-based 3D dose estimation, the administered dose of a therapeutic radiopharmaceutical for RLT is often nonpersonalised, with standardised dose regimens administered every 4–6 weeks. Biodosimetry markers, such as chromosomal aberrations, could be used alongside image-based dosimetry as a tool for individualised dose estimation to further understand normal tissue toxicity and refine the administered dose. In this review we give an overview of biodosimetry markers that are used for blood dose estimation, followed by an overview of their current results when applied in RLT patients. Finally, an in-depth discussion will provide a perspective on the potential for the use of biodosimetry in the nuclear medicine clinic. [ABSTRACT FROM AUTHOR]

It has been a big challenge to distinguish synchronous multiple primary lung cancer (sMPLC) from primary lung cancer with intrapulmonary metastases (IPM). We aimed to assess the clinical application of dynamic 18F-FDG PET/CT in patients with multiple lung cancer nodules. We enrolled patients with multiple pulmonary nodules who had undergone dynamic 18F-FDG PET/CT and divided them into sMPLC and IPM groups based on comprehensive features. The SUVmax, fitted K i value based on dynamic scanning, and corresponding maximum diameter ( D max ) from the two largest tumors were determined in each patient. We determined the absolute between-tumor difference of SU V max / D max and K i / D max (Δ SU V max / D max ; Δ K i / D max ) and assessed the between-group differences. Further, the diagnostic accuracy was evaluated by ROC analysis and the correlation between Δ SU V max / D max and Δ K i / D max from all groups was determined. There was no significant difference for Δ SU V max / D max between the IPM and sMPLC groups, while the IPM group had a significantly higher Δ K i / D max than the sMPLC group. The AUC of Δ K i / D max for differentiating sMPLC from IPM was 0.80 (cut-off value of K i = 0.0059 , sensitivity 79%, specificity 75%, p < 0.001). There was a good correlation (Pearson r = 0.91 , 95% CI: 0.79-0.96, p < 0.0001) between Δ SU V max / D max and Δ K i / D max in the IPM group but not in the sMPLC group (Pearson r = 0.45 , p > 0.05). Dynamic 18F-FDG PET/CT could be a useful tool for distinguishing sMPLC from IPM. K i calculation based on Patlak graphic analysis could be more sensitive than SUVmax in discriminating IPM from sMPLC in patients with multiple lung cancer nodules. [ABSTRACT FROM AUTHOR]

This work reports on a model that describes patient-specific absorbed dose-dependent DNA damage response in peripheral blood mononuclear cells of thyroid cancer patients during radioiodine therapy and compares the results with the ex vivo DNA damage response in these patients. Blood samples of 18 patients (nine time points up to 168 h post-administration) were analyzed for radiation-induced γ-H2AX + 53BP1 DNA double-strand break foci (RIF). A linear one-compartment model described the absorbed dose-dependent time course of RIF (Parameters: c characterizes DSB damage induction; k1 and k2 are rate constants describing fast and slow repair). The rate constants were compared to ex vivo repair rates. A total of 14 patient datasets could be analyzed; c ranged from 0.012 to 0.109 mGy−1, k2 from 0 to 0.04 h−1. On average, 96% of the damage is repaired quickly with k1 (range: 0.19–3.03 h−1). Two patient subgroups were distinguished by k1-values (n = 6, k1 > 1.1 h−1; n = 8, k1 < 0.6 h−1). A weak correlation with patient age was observed. While induction of RIF was similar among ex vivo and in vivo, the respective repair rates failed to correlate. The lack of correlation between in vivo and ex vivo repair rates and the applicability of the model to other therapies will be addressed in further studies. [ABSTRACT FROM AUTHOR]

Allergic reactions are the most frequent adverse events in blood transfusion, and anaphylactic shock, although less frequent, is systemic and serious. The cause of allergic reactions to blood transfusions are largely unknown, but deficiencies in serum proteins such as haptoglobin (Hp) can lead to anaphylactic shock. A complete deletion of the haptoglobin gene (HPdel) was first identified in families with anomalous inheritance and then verified as a genetic variant that can cause anaphylactic shock because homozygotes for HPdel have complete Hp deficiency. Thereby, they may produce antibodies against Hp from blood transfusions. HPdel is found in East and Southeast Asian populations, with a frequency of approximately 0.9% to 4%, but not in other populations. Diagnosis of Hp deficiency due to HPdel prior to transfusion is advisable because severe adverse reactions can be prevented by washing the red blood cells and/or platelets with saline or by administering plasma products obtained from an Hp-deficient donor pool. This review outlines the background of the identification of HPdel and several genetic and immunological methods developed for diagnosing Hp deficiency caused by HPdel. [ABSTRACT FROM AUTHOR]

Understanding the consistency of pituitary macroadenomas is crucial for neurosurgeons planning surgery. This retrospective study aimed to evaluate the utility of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) as non-invasive imaging modalities for predicting the consistency of pituitary macroadenomas. This could contribute to appropriate surgical planning and therefore reduce the likelihood of incomplete resections. The study included 45 patients with pathologically confirmed pituitary macroadenomas. Conventional MRI sequences, DWIs, ADC maps, and pre- and post-contrast MRIs were performed. Two neuroradiologists assessed all of the images. Neurosurgeons assessed the consistency of the tumor macroscopically, and histopathologists examined it microscopically. The MRI findings were compared with postoperative data. According to the operative data, macroadenomas were divided into the two following categories based on their consistency: aspirable (n = 27) and non-aspirable tumors (n = 18). A statistically significant difference in DWI findings was found when comparing macroadenomas of different consistencies (p < 0.001). Most aspirable macroadenomas (66.7%) were hyperintense according to DWI and hypointense on ADC maps, whereas most non-aspirable macroadenomas (83.3%) were hypointense for DWI and hyperintense on ADC maps. At a cut-off value of 0.63 × 10−3 mm2/s, the ADC showed a sensitivity of 85.7% and a specificity of 75% for the detection of non-aspirable macroadenomas (AUC, 0.946). The study concluded that DWI should be routinely performed in conjunction with ADC measurements in the preoperative evaluation of pituitary macroadenomas. This approach may aid in surgical planning, ensure that appropriate techniques are utilized, and reduce the risk of incomplete resection. [ABSTRACT FROM AUTHOR]

Purpose: We investigated the value of magnetic resonance imaging (MRI) histogram features, a non-invasive method, in assessing the changes in chemoresistance of colorectal cancer xenografts in rats. Methods: A total of 50 tumor-bearing mice with colorectal cancer were randomly divided into two groups: control group and 5-fluorouracil (5-FU) group. The MRI histogram characteristics and the expression levels of p53 protein and MRP1 were obtained at 24 h, 48 h, 72 h, 120 h, and 168 h after treatment. Results: Sixty highly repeatable MRI histogram features were obtained. There were 16 MRI histogram parameters and MRP1 resistance protein differences between groups. At 24 h after treatment, the MRI histogram texture parameters of T2-weighted imaging (T2WI) images (10%, 90%, median, energy, and RootMeanSquared) and D images (10% and Range) were positively correlated with MRP1 (r = 0.925, p = 0.005). At 48 h after treatment, histogram texture parameters of apparent diffusion coefficient (ADC) images (Energy) were positively correlated with the presence of MRP1 resistance protein (r = 0.900, p = 0.037). There was no statistically significant difference between MRI histogram features and p53 protein expression level. Conclusions: MRI histogram texture parameters based on T2WI, D, and ADC maps can help to predict the change of 5-FU resistance in colorectal cancer in the early stage and provide important reference significance for clinical treatment. [ABSTRACT FROM AUTHOR]

Transcription factor 21 (TCF21) and estrogen receptor beta (ERβ, encoded by ESR2) are highly expressed in endometriotic stromal cells (ESCs) and contribute to the pathogenesis of endometriosis. However, the exploration of TCF21 and ERβ expression regulation at the molecular level remains limited. Here, by using bioinformatics analysis and experimental verification, we identified PES1, also known as Pescadillo, as a negative regulator in the development of endometriosis that downregulates TCF21 and ERβ expression in ESCs. PES1 overexpression regulated critical biological processes involved in endometriosis development, such as invasion and apoptosis. A coimmunoprecipitation assay showed that PES1 could form a complex with Forkhead box M1 (FOXM1). Further analyses elucidated that siPES1 in ectopic lesions decreased the stability of FOXM1 protein and reduced the binding activities of FOXM1 to TCF21 and ESR2 promoters, thus weakening the transcriptional inhibition of TCF21 and ERβ by FOXM1. Moreover, in an endometriosis mouse model, overexpressing PES1 effectively reduced the growth of ectopic lesions and suppressed TCF21 and ERβ expression, which suggests a promising therapeutic strategy for endometriosis. Collectively, our results indicate that the loss of PES1 in ectopic lesions contributes to endometriosis progression by upregulating ERβ and TCF21 expression through heterodimer formation with FOXM1. Moreover, targeting PES1 could serve as a treatment method for endometriosis. [ABSTRACT FROM AUTHOR]

Peroxidases, like horseradish peroxidase (HRP), are heme metalloenzymes that are powerful biocatalysts for various oxidation reactions. By using simple grafting-from approach, ring-opening polymerization (ROP), and manganese porphyrins, star-shaped polypeptides analogues of HRP capable of catalyzing oxidation reactions with H 2 O 2 is successfully prepared. Like their protein model, these simplified analogues show interesting Michaelis-Menten constant (K M ) in the mM range for the oxidant. Interestingly, the polymer structures are more resistant to denaturation (heat, proteolysis and oxidant concentration) than HRP, opening up interesting prospects for their use in catalysis or in biosensing devices., (© 2024 The Author(s). Macromolecular Bioscience published by Wiley‐VCH GmbH.)

Background: Fibrous dysplasia (FD) is a benign developmental disorder of the bone that causes normal skeletal tissue to be replaced by excess fibrous tissue and poorly differentiated osteoblasts. Intraosseous xanthomas are benign intraosseous tumor growths characterized microscopically by the presence of lipid-laden foamy histiocytes, often with cortical expansion or disruption. Although FD commonly occurs in craniofacial bones, primary intraosseous xanthomas of the skull or facial skeleton are extremely rare. Although 2 distinct conditions, each may be difficult to differentiate on CT imaging when occurring in the facial skeleton., Methods: We report a case of an incidental finding on craniofacial CT of a frontal bone lesion originally thought to be FD. The finding was in a 55-year-old transgender woman who was assigned male at birth before receiving multiprocedural facial feminization surgery., Results: The clinical features, radiological findings, and treatment are discussed. Postoperatively, the patient had no sequelae secondary to facial feminization surgery or to the orbital lesion biopsy procedure. Bone graft appeared stable on CT imaging, although FD did not appear to resolve completely., Conclusions: Diagnosis of such lesions is challenging and may require both radiographic and histopathologic assessment. As in the case of this patient, intraosseous xanthomas may also be misdiagnosed as other benign lesions such as FD. In most known cases, surgical intervention leads to complete resolution without recurrence of the lesion., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Non-traumatic orbital hemorrhage without underlying vascular malformations or predisposing conditions is uncommon, and particularly rare in the context of maternal labor. This study combines a novel case report and retrospective review to analyze reported cases and propose insights., Methods: This study is both a unique case report and literature review examining PubMed publications with articles traced back to original sources through citations for inclusion. Analysis included clinical presentation, visual examination, hematoma characteristics, neuroimaging, management strategies, and outcomes., Results: We present a 37-year-old multigravida woman at 40 weeks gestation who developed acute right-sided proptosis, diplopia, retrobulbar pain, and periorbital edema during the second stage of labor. Computed tomography (CT) revealed a subperiosteal hemorrhage, with subsequent magnetic resonance imaging (MRI) excluding vascular anomalies. Symptoms resolved within two months. Only 14 cases of maternal orbital hematoma associated with labor have been reported. The average age was 28 with 42% (6/14) being primigravid. Including our case, forty percent (6/15) developed symptoms during the second stage of labor, 40% (6/15) immediately postpartum, and 20% (3/15) over 24 hours postpartum. Overall, 33% (5/15) had potentially contributing conditions including coagulopathies, delivery complications, or vascular malformations. Unilateral orbital hemorrhage occurred in 87% (13/15). Surgical intervention was necessary in 13% (2/15). Most (87%, 13/15) underwent observation or medical management with full recovery of symptoms., Conclusions: Non-traumatic orbital hematomas associated with maternal labor are rare and likely related to increased valsalva during delivery and heightened blood volume in pregnancy. Neuro-imaging and systemic workup are recommended to assess for vascular anomalies or underlying coagulopathies. The overall prognosis is favorable with most having full recovery., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The purpose of this study is to compare the subjective and objective quality and confidence between conventional angiography with cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI) for the preoperative evaluation of potential donors for living donor liver transplant. Seventeen patients undergoing preoperative donor evaluation for living donor liver transplantation that underwent angiography with CBCT and contrast-enhanced MRI for evaluation of hepatic vascular anatomy were included in the study. Four attending radiologists interpreted anonymized, randomized angiography with CBCT images and MRIs, rating the diagnostic quality and confidence of their interpretation (on a 3-point scale) for each element, as well as clinically relevant measurements. Overall, the readers rated the quality of angiography with CBCT to be higher than that of MRI (median [interquartile range] = 3 (2, 3) vs. 2 (1-3), p < 0.001) across all patients. Readers of angiography with CBCT had more confidence in their interpretations as an average of all elements evaluated than the MRI readers (3 (3) vs. 3 (2, 3), p < 0.001). When the same reader interpreted both MRI and CBCT, the right hepatic artery diameter (3.8 mm ± 0.72 mm vs. 4.5 mm ± 1.2 mm, p < 0.005) and proper hepatic artery diameter (4.43 mm ± 0.98 mm vs. 5.4 mm ± 1.05 mm, p < 0.003) were significantly different between MRI and CBCT. There was poor interrater reliability for determining segment IV arterial supply for both modalities (κ < 0.2). Angiography with CBCT provides higher subjective diagnostic quality and greater radiologist confidence than MRI. The difference in measurements between CBCT and MRI when the same reader reads both studies suggests CBCT adds additional information over MRI evaluation alone., (© 2023 American Association of Clinical Anatomists and British Association of Clinical Anatomists.)

Purpose: This meta-analysis evaluated the diagnostic accuracy and diagnostic value of [ 18 F]FDG PET/MRI for mediastinal lymph node staging of NSCLC., Methods: Relevant articles in PubMed, Embase, Web of Science, and the Cochrane Library were searched until January 2023. Research evaluating [ 18 F]FDG PET/MRI for mediastinal lymph node staging of NSCLC was included. Pooled estimates of sensitivity, specificity, PLR, and NLR were calculated by the "Stata" software., Results: Nine researches were included, containing 618 patients. The pooled sensitivity of [ 18 F]FDG PET/MRI for detecting mediastinal lymph node staging of NSCLC was 0.82 (0.70-0.90), and the pooled specificity was 0.88 (0.82-0.93). PLR and NLR were 7.38 (4.73-11.52) and 0.20 (0.11-0.36), respectively. The AUC value of this imaging modality was 0.92 (0.90-0.94). The post-test probability for [ 18 F]FDG PET/MRI might rise to 88% when the pre-test probability was set at 50%., Conclusions: We considered [ 18 F]FDG PET/MRI as an effective imaging tool with relatively high specificity and sensitivity. It has great potential to be used in the clinical management of patients in NSCLC who are amenable to early surgery. More studies with large sample sizes in the same direction are needed in future to obtain more reliable evidence-based support., (© 2023. The Author(s) under exclusive licence to Japan Radiological Society.)