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This article discusses a rare case of iatrogenic renal pelvis injury following ureteric cannulation with a 5-F catheter. The patient, who was undergoing surgery for a retroperitoneal sarcoma, experienced acute kidney injury and worsening renal function postoperatively. Due to the patient's renal impairment, a CT urogram was not possible, so alternative imaging techniques, including MAG3 and single-photon emission CT (SPECT)/CT, were used to diagnose the injury. The patient underwent a successful stent insertion and experienced rapid improvement in renal function. The article highlights the importance of considering alternative imaging modalities in cases where intravenous contrast is contraindicated. [Extracted from the article]

Background and Purpose: Frontotemporal dementia (FTD) is the second most common cause of presenile dementia. The clinical distinction between FTD, Alzheimer's disease (AD), and other dementias is a clinical challenge. Brain perfusion SPECT may contribute to the diagnosis of FTD, but its value is unclear. Methods: We performed a systematic review to investigate the diagnostic accuracy of the brain SPECT in (1) distinguishing FTD from AD and other dementias and (2) differentiating FTD variants. Results: Overall, 391 studies were retrieved on the initial search and 35 studies composed the final selection, comprising a total number of 3142 participants of which 1029 had FTD. The sensitivity and the specificity for the differential diagnosis of FTD versus AD ranged from 56% to 88% and from 51% to 93%, respectively. SPECT is not superior to the clinical method of diagnosis, but the combination of SPECT with clinical data seems to improve the diagnostic accuracy. Conclusion: Brain perfusion SPECT has a limited value in the diagnostic framework of FTD. SPECT can be performed when FDG‐PET is not available. SPECT is recommended only for selected cases when the diagnosis is challenging using conventional methods. [ABSTRACT FROM AUTHOR]

The diagnosis and understanding of pain is challenging in clinical practice. Assessing pain relies heavily on self-reporting by patients, rendering it inherently subjective. Traditional clinical imaging methods such as computed tomography and magnetic resonance imaging can only detect anatomical abnormalities, offering limited sensitivity and specificity in identifying pain-causing conditions. Radiotracers play a vital role in molecular imaging that aims to identify abnormal biological processes at the cellular level, even in apparently normal anatomical structures. Therefore, molecular imaging is an important area of research as a prospective diagnostic modality for pain-causing pathophysiology. We present a mini review of the current knowledge base regarding radiotracers for identification of pain in vivo. We also describe radiocaine, a novel positron emission tomography imaging agent for sodium channels that has shown great potential for identifying/labeling pain-producing nerves and producing an objectively measurable pain intensity signal. [ABSTRACT FROM AUTHOR]

Purpose: Orbital [99mTc]TcDTPA orbital single-photon emission computed tomography (SPECT)/CT is an important method for assessing inflammatory activity in patients with Graves' orbitopathy (GO). However, interpreting the results requires substantial physician workload. We aim to propose an automated method called GO-Net to detect inflammatory activity in patients with GO. Materials and methods: GO-Net had two stages: (1) a semantic V-Net segmentation network (SV-Net) that extracts extraocular muscles (EOMs) in orbital CT images and (2) a convolutional neural network (CNN) that uses SPECT/CT images and the segmentation results to classify inflammatory activity. A total of 956 eyes from 478 patients with GO (active: 475; inactive: 481) at Xiangya Hospital of Central South University were investigated. For the segmentation task, five-fold cross-validation with 194 eyes was used for training and internal validation. For the classification task, 80% of the eye data were used for training and internal fivefold cross-validation, and the remaining 20% of the eye data were used for testing. The EOM regions of interest (ROIs) were manually drawn by two readers and reviewed by an experienced physician as ground truth for segmentation GO activity was diagnosed according to clinical activity scores (CASs) and the SPECT/CT images. Furthermore, results are interpreted and visualized using gradient-weighted class activation mapping (Grad-CAM). Results: The GO-Net model combining CT, SPECT, and EOM masks achieved a sensitivity of 84.63%, a specificity of 83.87%, and an area under the receiver operating curve (AUC) of 0.89 (p < 0.01) on the test set for distinguishing active and inactive GO. Compared with the CT-only model, the GO-Net model showed superior diagnostic performance. Moreover, Grad-CAM demonstrated that the GO-Net model placed focus on the GO-active regions. For EOM segmentation, our segmentation model achieved a mean intersection over union (IOU) of 0.82. Conclusion: The proposed Go-Net model accurately detected GO activity and has great potential in the diagnosis of GO. [ABSTRACT FROM AUTHOR]

Introduction: Parkinson's disease (PD) is a neurodegenerative movement disorder that is typically diagnosed clinically. DaT-SPECT scanning (DaT Scan) can be used when there is diagnostic difficulty differentiating from non-neurodegenerative Parkinsonism. This study assessed the effect of DaT Scan imaging on diagnosis and subsequent clinical management of these disorders. Methods: This single-trust retrospective study involved 455 patients who had undergone DaT scans for investigation for Parkinsonism, between 01/01/2014 and 31/12/2021. Data collected included patient demographics, date of clinical assessment, scan report, pre-scan and post-scan diagnosis, and clinical management. Results: The mean age at scan was 70.5 years and 57% were male. The percentage of patients who had an abnormal scan result was 40% (n = 184), whilst 53% (n = 239) had a normal scan result, and 7% (n = 32) had an equivocal scan. Pre-scan diagnosis was consistent with scan results in 71% of cases of neurodegenerative Parkinsonism, whereas this figure was 64% for cases of non-neurodegenerative Parkinsonism. For all DaT scans, the diagnosis was changed in 37% of patients (n = 168), whilst the clinical management was changed in 42% of patients (n = 190). Change in management involved 63% starting dopaminergic medication, 5% stopping dopaminergic medications, and 31% undergoing other changes in management. Conclusion: DaT imaging is useful for confirming the correct diagnosis and clinical management for patients with clinically indeterminate Parkinsonism. Pre-scan diagnoses were generally consistent with scan results. [ABSTRACT FROM AUTHOR]

Background: Insulinomas are the most common neuroendocrine neoplasms of the pancreas. Diagnosis is made through patient clinical presentation with hypoglycemia symptoms and imaging, such as EUS, CT, MRI, and functional imaging. Exendin-4 PET/CT (and SPECT/CT) is a new prominent radiotracer developed to image insulinomas. The aim of the study is to evaluate whether exendin-4 imaging is a useful tool in imaging for insulinoma patients when other imaging methods do not reach them. Methods: MEDLINE research conducted on PubMed, Scopus, and Web of Science gathered a total of 501 papers. Studies that evaluated exendin-4 SPECT and PET in insulinoma patients were screened and assessed through QUADAS-2 for risk of bias and applicability concerns' assessment. Sensitivity, specificity, and accuracy were reported when available. Results: A total of 13 studies were deemed eligible for a QUADAS 2 review. Studies included ranged from 2009 to 2022. The most-used tracer was 68Ga-DOTA-exendin-4 in PET and 111In-DTPA-exendin-4 in SPECT. Exendin-4 labeled with 99mTc was also reported. The QUADAS-2 risk of bias assessment was overall low, with some unclear reports in the reference and index domains. Only two domains were at high risk of bias because of an explicated non-blind imaging review. Applicability concerns for bias were low in all domains. Reported sensitivities ranged from 95% to 100% and specificities from 20% to 100%. Conclusions: exendin-4 imaging is a sensitive functional imaging tracer in both SPECT and PET applications, especially in suspicion of benign insulinomas located where endoscopic ultrasound cannot reach, being more sensitive than morfostructural imaging. [ABSTRACT FROM AUTHOR]

Unilateral condylar hyperplasia (UCH) is an uncommon disease involving progressive facial asymmetry. The aim of this research was to perform an analysis of the diagnosis and treatment of patients with UCH in a clinical series. An observational retrospective study was performed on subjects with progressive facial asymmetry in the lower third of the face; all the subjects were under treatment with condylectomy and orthodontics to improve occlusion and face balance. Variables such as age, sex, clinical type, SPECT (single photon emission computed tomography) intensity and a requirement for secondary surgery were included; the Shapiro Wilk test was performed to analyze the normality of the data and nonparametric analysis and the Kruskal-Wallis or Mann-Whitney tests were used to assess the association between the SPECT difference and the variables, where 2-tailed p values < 0.05 were considered to be statistically significant. Forty-nine patients between 10 and 45 y.o. (average age: 19.1 ± 7.4 y.o.) were included in the study. There were 41 female (83.6%) and 8 male (16.4%) subjects. The SPECT analysis comparing the right and left condyles with more than 10% in caption of the isotope was present in 46 subjects; the results obtained using SPECT were not statistically related to the age or sex of the sample (p = 0.277). The patients were classified into clinical types I, II and III, and no correlations could be confirmed between the clinical type and other variables. High condylectomy was conducted on all patients, among which 14 patients underwent a secondary surgery for orthognathic or cosmetic treatment, and was not related to the initial variables used in diagnosis (p = 0.98); interestingly, the second surgical treatment was more present in the clinical type I and in subjects under 16 years old with no statistical differences. Clinical analysis, medical records, 3D imaging and SPECT should be used as a complementary analysis in assessing the diagnosis of UCH and progressive facial asymmetry. [ABSTRACT FROM AUTHOR]

During the last decades, the utilization of imaging modalities such as single photon emission computed tomography (SPECT), positron emission tomography (PET), and magnetic resonance imaging (MRI) in every day clinical practice has enabled clinicians to diagnose diseases accurately at early stages. Radiolabeled iron oxide nanoparticles (RIONs) combine their intrinsic magnetic behavior with the extrinsic character of the radionuclide additive, so that they constitute a platform of multifaceted physical properties. Thus, at a practical level, RIONs serve as the physical parent of the so-called dual-modality contrast agents (DMCAs) utilized in SPECT/MRI and PET/MRI applications due to their ability to combine, at real time, the high sensitivity of SPECT or PET together with the high spatial resolution of MRI. This review focuses on the synthesis and in vivo investigation of both biodistribution and imaging efficacy of RIONs as potential SPECT/MRI or PET/MRI DMCAs. [ABSTRACT FROM AUTHOR]

Early diagnosis of the neurodegenerative disorder Parkinson's disease (PD) and Scan without Evidence of Dopaminergic Deficit (SWEDD) is essential for effective patient management in neurodisorders, as both have the same clinical characteristics. The present work intends to propose an efficient method for analyzing volume rendering Single-Photon Emission Computed Tomography (SPECT) image slices, using Alpha stable distribution-based intensity normalization techniques for discriminating early PD from Healthy Control (HC) and SWEDD. The Volume rendering image (VRI) slices of early PD, HC and SWEDD are chosen from the database called Parkinson's Progression Markers Initiative (PPMI). The alpha stable distribution technique is adapted to normalize the intensity values outside the striatum of the VRI in order to keep up the uniform intensity values throughout the database images. The shape features and image surface-related features are taken out from the VRI slices of the three different groups. The most optimized feature set is computed based on its consistency by Genetic Algorithm (GA). The computed optimized features of VRI slices show a remarkable performance in detecting the early stage of PD. The Extreme learning machine (ELM) classifier with Radial Basis Function (RBF) kernel shows a better performance accuracy of 99.12% than Support vector machine (SVM). Performance measures of the classifiers have ensured the validity of the experiments. Thus, the proposed method is advantageous to the neurologist in the early diagnosis of PD. [ABSTRACT FROM AUTHOR]

The diagnosis of pulmonary embolism (PE) employs a combination of clinical assessment, D-dimer assay and imaging with pulmonary ventilation-perfusion (V/P) scintigraphy and/or computed tomography pulmonary angiography (CTPA). It is generally accepted that V/P SPECT and CTPA have high diagnostic accuracy. Nonetheless, there are only limited data directly comparing these two modalities. This prospective cross-sectional study included 184 hospitalized patients with clinically suspected PE. Clinical assessment, electrocardiography (ECG), vein ultrasound, echocardiography, arterial blood gas test, D-dimer assay, perfusion single photon-emission computed tomography/computed tomography (P-SPECT/CT) and CTPA were carried out. PE was diagnosed in 109 of 146 patients (74.66%) by P-SPECT/CT and 47 of 89 patients (52.81%) by CTPA. The sensitivity and specificity of P-SPECT/CT were 82.9%, respectively, 64.7%. The positive predictive value of SPECT/CT was 94.7%, the negative predictive value was 33.3% and the validity was 80.8%. For CTPA the sensitivity was 58.2% and specificity 90%. The positive predictive value of CTPA was 97.9%, the negative predictive value 21.4% and the accuracy (performance) 61.8%. There was no significant difference between the two methods regarding the diagnosis of PE at sub-segmental and segmental level. The sensitivity of P-SPECT/CT was significantly higher compared with CTPA, whereas the specificity was significantly higher at CTPA for diagnosis of PE. The P-SPECT/CT showed excellent diagnostic performance with high sensitivity and a very high positive predictive value. Thus, it could serve as first-line imaging for PE in the number of prevalent cases. [ABSTRACT FROM AUTHOR]

A summary of the fundamental lines of medical equipment for Cuban public health developed by the Center for Technological Applications and Nuclear Development (CEADEN) is made. These lines are grouped in two fundamental directions: optical instrumentation and nuclear instrumentation for medical diagnosis, quality control and dosimetry. The main developments and impacts achieved in these two directions in the National Health System are exposed, as well as their perspectives for present and future developments. [ABSTRACT FROM AUTHOR]

Radioiodine remnant ablation (RRA) was previously demonstrated to be a safe and effective alternative to completion thyroidectomy for patients with differentiated thyroid cancer (DTC). However, its side effects have not been fully investigated, particularly in patients with lobectomy. We reported a young euthyroidal female who underwent RRA post lobectomy and lymph node dissection for papillary thyroid cancer, whose post-ablation 131I-whole-body scan accidentally showed diffuse radioiodine distribution on chest-mimicking pulmonary metastases. Immediately-added single-photon emission computed tomography/computed tomography (SPECT/CT), nevertheless, revealed a 131I-accumulating swollen left thyroid lobe and emerging pleural effusion, which relieved after short-term treatment with prednisone. In summary, acute pleural effusion ascribed to RRA-induced thoracic duct compression was reported for the first time. 131I-lobectomy-induced pleural effusion could be precisely diagnosed by SPECT/CT and efficiently manipulated via treating radiation thyroiditis with the short-term administration of corticosteroid. [ABSTRACT FROM AUTHOR]

Background: Osteochondral lesions of the talus (OLTs) are a common orthopedic condition. The image presentation is very similar to that of ischemic necrosis of the talus complicated by a talar neck fracture, but the two are very different lesions. When abnormalities in bone density (or signal) of the talar body (apex of the fornix) with concomitant bone defects and cystic changes are found on X-ray, computed tomography (CT), or magnetic resonance imaging, it is important to accurately determine the nature of the lesion and make a correct diagnosis for the treatment and prognosis of the patient. The purpose of this study was to explore the imaging features of three-phase single-photon emission computed tomography (SPECT)/CT images of cystic lesions of the talus. Methods: A total of 189 patients with chronic pain in the ankle joint suspected to be caused by cystic degeneration of the talus were enrolled. All patients underwent 99mTc-methyl diphosphonate (99mTc-MDP) three-phase SPECT/CT bone imaging and delayed scans in our hospital. The location, range of involvement, classification, CT value, and radioactivity uptake of the sclerotic areas of cystic lesions on the talus, and the continuity of the articular surface, were recorded. All recorded parameters were analyzed in comparison with pathological results. Results: Eighty-three percent (157/189) of the talar cysts were located on the medial fornix, largely involving the anterior middle part (43.27%), with larger cysts involving the posterior part (9.6%). Sixty-three percent (119/189) of the patients had type I lesions and 37% (70/189) had type II lesions. The articular surface of the medial dome of the talus was intact in all patients, but the subchondral bony articular surface was rough in 88% (166/189) of patients. The coincidence rate for the location, type, and range of involvement of cystic lesions with the pathological results was 87.83% (166/189). The mean CT value of the cystic lesions was 45 ± 15 HU (30–60 HU). The percentages of pathological chondrogenesis in high CT value ≥ 50 HU (19/70) and low CT value < 50 HU (51/70) groups were 89.47% (17/19) and 29.14% (15/51) (χ2 = 20.12, p < 0.001), respectively. The target/background ratio (T/B ratio) of the radioactivity-uptake area of the talus vault was 2.0 ± 0.5 (1.5–2.5). The percentages of pathological new trabecular bone in those with a T/B ratio ≥ 2.0 (157/189) and T/B ratio < 2.0 (32/189) were 82.80% (130/157) and 25.00% (8/32; χ2 = 45.08, p < 0.001), respectively. Conclusions: Three-phase bone imaging could identify damage of the talus caused by cystic degeneration, while delayed SPECT/CT images showed advantages for displaying bone microstructure, blood supplement, and bone metabolism when examining the location, range of involvement, classification, and repair of cystic lesions of the talus. [ABSTRACT FROM AUTHOR]

• Incidental findings are common on PET and should not be ignored as the consequences can be perilous • FDG uptake on PET is non-specific for malignancy • There has to be strong, clear and direct communication of incidental findings from imaging specialists to referrers and treating clinicians • Incidental findings can often be seen on other modalities such as diagnostic CT and nuclear medicine SPECT • It is vital for doctors – no matter how senior or junior – to follow up on the investigations they order [ABSTRACT FROM AUTHOR]

Simple Summary: Uveal melanoma is the most prevalent intraocular tumor in adults, derived from melanocytes; the liver is the most common site of its metastases. Due to troublesome tumor localization, different imaging techniques are utilized in diagnostics, i.e., fundus imaging (FI), ultrasonography (US), optical coherence tomography (OCT), single-photon emission computed tomography (SPECT), positron emission tomography/computed tomography (PET/CT), magnetic resonance imaging (MRI), fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), or fundus autofluorescence (FAF). Specialists eagerly use these techniques, but sometimes the precision and quality of the obtained images are imperfect, raising diagnostic doubts and prompting the search for new ones. In addition to analyzing the currently utilized methods, this review also introduces experimental techniques that may be adapted to clinical practice in the future. Moreover, we raise the topic and present a perspective for personalized medicine in uveal melanoma treatment. Uveal melanoma is the most common primary intraocular malignancy in adults, characterized by an insidious onset and poor prognosis strongly associated with tumor size and the presence of distant metastases, most commonly in the liver. Contrary to most tumor identification, a biopsy followed by a pathological exam is used only in certain cases. Therefore, an early and noninvasive diagnosis is essential to enhance patients' chances for early treatment. We reviewed imaging modalities currently used in the diagnostics of uveal melanoma, including fundus imaging, ultrasonography (US), optical coherence tomography (OCT), single-photon emission computed tomography (SPECT), fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), fundus autofluorescence (FAF), as well as positron emission tomography/computed tomography (PET/CT) or magnetic resonance imaging (MRI). The principle of imaging techniques is briefly explained, along with their role in the diagnostic process and a summary of their advantages and limitations. Further, the experimental data and the advancements in imaging modalities are explained. We describe UM imaging innovations, show their current usage and development, and explain the possibilities of utilizing such modalities to diagnose uveal melanoma in the future. [ABSTRACT FROM AUTHOR]

Herein, we present a rare patient with hereditary spastic paraparesis (HSP) in whom significant parkinsonism was involved in the clinic. Besides, the dopamine transport single-photon emission computed tomography scan also showed decreased tracer uptake in the bilateral striatum. Via the presentation of this patient, we discuss the parkinsonian findings in patients with HSP. We think that the observations of dopaminergic neuron vulnerability in HSP patients raise the possibility that degeneration of central dopaminergic neurons may contribute to the phenotype of HSP. The documentation of these rare variants will aid to understand the unknown pathophysiology of the disease course. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the value of single-photon emission computed tomography (SPECT) based on the convolutional neural network (CNN) algorithm in thyroid diseases. Thirty-five patients with thyroid disease from the hospital were selected as the observation group, and another 35 healthy volunteers were selected as the control group. The constructed model of SPECT based on the CNN algorithm was compared with the backpropagation neural network (BPNN) algorithm, which was then applied to the SPECT of 35 patients with thyroid disease. It turned out that as the number of iterations increased, the parameter training of CNN was gradually sufficient, the network model was continuously optimized, and the accuracy gradually increased. From the data results, the Dice value of the proposed CNN algorithm was higher than that of the BPNN algorithm and the segmentation effect was relatively good. The visual index of the thyroid/neck of the observation group (2.68 ± 1.32) was remarkably inferior to that of the control group (12.347.54) (P < 0.05). The visual index of the thyroid/submandibular gland in the observation group (1.02 ± 0.41) was remarkably inferior to that of the control group (8.89 ± 4.86) (P < 0.05). The visual index of the thyroid/parotid gland in the observation group (1.04 ± 0.58) was remarkably inferior to that of the control group (8.53 ± 4.25) (P < 0.05). In addition, 99mTcO4-SPECT had a sensitivity of 95.2%, a specificity of 90.3%, and an accuracy of 91.5% in the diagnosis of thyroid diseases. The area under the curve of the receiver operating characteristic curve for 99mTcO4-SPECT diagnosis of thyroid disease is 0.958, and the 95% confidence interval is 0.834∼1. In summary, the SPECT based on the CNN algorithm proposed in this study has a good segmentation effect and can accurately locate the anatomical information of thyroid diseases, which can replace the traditional diagnostic methods for the diagnosis of thyroid diseases. [ABSTRACT FROM AUTHOR]

Purpose: Although inflammation has been recognized as a key process in the pathogenesis of osteoarthritis (OA), there remains no clinical noninvasive imaging modality that can specifically diagnose inflammatory activity of OA. In this study, a formyl peptide receptor 1 (Fpr1) targeting probe cFLFLF-PEG-HYNIC-99mTc and single-photon emission computed tomography (SPECT) imaging was used to detect inflammatory activity by targeting macrophages involved in the pathogenesis of OA. Procedures: In vitro experiments were performed to evaluate Fpr1 expression during macrophage inflammatory response. In the in vivo studies, anterior cruciate ligament transection (ACLT) surgery was performed, and magnetic resonance imaging (MRI) and histological data were assessed to analyze the OA model in both mice and rats. The radioactive probe cFLFLF-PEG-HYNIC-99mTc and SPECT imaging were used to corroborate OA-related inflammation and compare ACLT vs sham knees. Results: In vitro macrophage activation resulted in a remarkable increase in Fpr1 expression. In vivo experiments in mice and rats produced similar results. MRI and histological analysis demonstrated significant joint degeneration in the ACLT knee. The ACLT knee produced a much stronger signal from the probe when compared to the sham knee. It is important to note that the ratio of ACLT/sham knee signal intensity decreased with OA progression, indicating greater differences earlier in the progression of OA. Conclusion: The radioactive probe cFLFLF-PEG-HYNIC-99mTc and SPECT imaging are effective for detecting and monitoring inflammation during OA progression by targeting Fpr1 expression in the knee joint. [ABSTRACT FROM AUTHOR]

Introduction: Advancements in cancer imaging are rapidly moving from the detection and size measurement of a lesion to the quantitative assessment of metabolic processes and cellular and molecular interactions. Tumor stroma as an important factor in tumor pathophysiology plays an important role in treatment strategies and targeting the tumor microenvironment. Therefore, successful cancer control requires the study of complex cellular and molecular interactions in cancer tissue. The integration of advances in molecular biology, synthetic chemistry, and imaging techniques has shifted imaging-based diagnosis to molecular function. Therefore, imaging science seeks to find applications in basic science, preclinical, and translational research in cancer. Positron emission tomography, single-photon emission computed tomography, optical imaging, and magnetic resonance imaging are the primary tools being developed for oncologic imaging. These techniques are being developed due to the development of molecular probes that have recently been improved to record in vivo molecular and physiological properties. Herein, we review molecular imaging techniques and common probes in preclinical studies, as well as their application strategies. [ABSTRACT FROM AUTHOR]

Dear Editor, [ SP 18 sp F]PM-pyridinyl-butadienyl-benzothiazole 3 (PBB3), a propanol variant of the first tau positron emission tomography (PET) tracer, [ SP 11 sp C]PBB3, is reportedly a reliable tool for detecting tau fibrils in non-Alzheimer's disease (AD) tauopathies [[1]]. In the present case, left-sided lesions were not evident in structural MRIs, but the left auditory cortex, medial geniculate body, or acoustic radiation projecting to the left auditory cortex may be functionally disturbed by tau deposition [[2]]. [Extracted from the article]

PSMA (prostate-specific membrane antigen) protein is heavily expressed in the proliferating microvasculature of high-grade gliomas (HGG) and brain metastases (BM). This research aimed to assess [99mTc]Tc-iPSMA SPECT brain imaging as a potential specific diagnosis of HGG and BM by PSMA-targeting in their proliferating vasculature. Forty-one patients, with suspected brain tumors, as detected by enhanced MRI scanning, were enrolled to undergo preoperative [99mTc]Tc-iPSMA SPECT brain imaging. Semiquantitative image analyses, to evaluate the maximum target-to-background ratio (TBRmax), were performed. All diagnoses were histopathologically confirmed. PSMA expression was evaluated by immunohistochemistry (IHC) in 11 brain tumor tissues. TBRmax values were correlated with IHC results and tumor WHO grade (HGG vs LGG). [99mTc]Tc-iPSMA images showed increased uptake in BM, HGG, and recurrent gliomas (TBRmax of 25.1 ± 7.1, 18.5 ± 9.0, 15.0 ± 9.9, respectively), and was negative in treatment-naive patients with LGG and reactive gliosis. PSMA was highly expressed in the vascular endothelium of grade IV gliomas and BM, while its expression was extremely low in LGG and completely absent in gliosis. By using 2.8 as a threshold value for TBRmax, the specificity, sensitivity, PPV, NPV and accuracy were 100%, 94%, 100%, 77% and 95%, respectively. The results of this pilot study show that [99mTc]Tc-iPSMA SPECT brain imaging is a specific and potentially useful neuroimaging tool for assessing tumoral neovasculature formation in gliomas and brain metastases. [Display omitted] [ABSTRACT FROM AUTHOR]

The integration of positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging techniques with machine learning (ML) algorithms, including deep learning (DL) models, is a promising approach. This integration enhances the precision and efficiency of current diagnostic and treatment strategies while offering invaluable insights into disease mechanisms. In this comprehensive review, we delve into the transformative impact of ML and DL in this domain. Firstly, a brief analysis is provided of how these algorithms have evolved and which are the most widely applied in this domain. Their different potential applications in nuclear imaging are then discussed, such as optimization of image adquisition or reconstruction, biomarkers identification, multimodal fusion and the development of diagnostic, prognostic, and disease progression evaluation systems. This is because they are able to analyse complex patterns and relationships within imaging data, as well as extracting quantitative and objective measures. Furthermore, we discuss the challenges in implementation, such as data standardization and limited sample sizes, and explore the clinical opportunities and future horizons, including data augmentation and explainable AI. Together, these factors are propelling the continuous advancement of more robust, transparent, and reliable systems. [Display omitted] • A comprehensive overview of the state-of-the-art in Machine Learning and Deep Learnig applications in SPECT and PET imaging. • ML algorithms in imaging systems offer opportunities for improved diagnostic accuracy and radiopharmaceutical optimization. • Challenges include interpretability of DL models, limited labeled datasets, imaging protocols or regulatory approval. • Ongoing efforts focus on algorithm's interpretability, multimodal data fusion and real-time decision support systems. [ABSTRACT FROM AUTHOR]

Background: 99mTc-PYP scintigraphy provides differential diagnosis of ATTR cardiomyopathy (ATTR-CM) from light chain cardiac amyloidosis and other myocardial disorders without biopsy. This study was aimed to assess the diagnostic feasibility and the operator reproducibility of 99mTc-PYP quantitative SPECT. Method: Thirty-seven consecutive patients who underwent a 99mTc-PYP thorax planar scan followed by SPECT and CT scans to diagnose suspected ATTR-CM were enrolled. For the quantitative SPECT, phantom studies were initially performed to determine the image conversion factor (ICF) and partial volume correction (PVC) factor to recover 99mTc-PYP activity concentration in the myocardium for calculating the standardized uptake value (SUV) (unit: g/ml). SUVmax was compared among groups of ATTR-CM, AL cardiac amyloidosis, and other pathogens (others) and among categories of Perugini visual scores (grades 0–3). The intra- and inter-operator reproducibility of quantitative SPECT was verified, and the corresponded repeatability coefficient (RPC) was calculated. Results: The ICF was 79,327 Bq/ml to convert count rate in pixel to 99mTc activity concentration. PVC factor as a function of the measured activity concentration ratio in the myocardium and blood-pool was [y = 1.424 × (1 − exp(− 0.759 × x)) + 0.104]. SUVmax of ATTR-CM (7.50 ± 2.68) was significantly higher than those of AL (1.96 ± 0.35) and others (2.00 ± 0.74) (all p < 0.05). SUVmax of grade 3 (8.95 ± 1.89) and grade 2 (4.71 ± 0.23) were also significantly higher than those of grade 1 (1.92 ± 0.31) and grade 0 (1.59 ± 0.39) (all p < 0.05). Correlation coefficient (R2) of SUVmax reached 0.966 to 0.978 with only small systematic difference (intra = − 0.14; inter = − 0.23) between two repeated measurements. Intra- and inter-operator RPCs were 0.688 and 0.877. Conclusions: 99mTc-PYP quantitative SPECT integrated with adjustable PVC factors is feasible to quantitatively and objectively assess the burden of cardiac amyloidosis for diagnosis of ATTR-CM. [ABSTRACT FROM AUTHOR]

Machine Learning (ML) is a subfield of Artificial Intelligence (AI) that is increasingly applied to several medical diagnosis tasks, including a wide range of diseases. Importantly, various ML models were developed to address the complexity of Parkinson's Disease (PD) diagnosis. PD is a neurodegenerative disease characterized by motor and non-motor disorders where its syndromes affect the daily lives of patients. Several Computer Aided Diagnosis and Detection (CADD) systems based on hand-crafted ML algorithms achieved promising results in distinguishing PD patients from Healthy Control (HC) subjects and other Parkinsonian syndrome categories using clinical data (e.g., speech and gait impairments) and medical imaging [e.g., Position Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT)]. Despite the good performance of hand-crafted ML algorithms, there is still a problem linked to the features' extraction and selection. In fact, Deep Learning DL has provided an ultimate solution for the features' extraction and selection related issue. An important number of studies on the diagnosis of PD using DL algorithms were developed recently. This study provides an overview of the application of hand-crafted ML algorithms and DL techniques for PD diagnosis. It also introduces key concepts for understanding the application of ML methods to diagnose PD. [ABSTRACT FROM AUTHOR]

Background: Condylar Hyperplasia is slowly developing unilateral overgrowth of mandibular condyle for idiopathic causes with consequence of facial asymmetry. Commonly presents between age of 10-25 years with mean around puberty. It seems that UCH is common and frequently occurs in groups during the growth phase, especially in adolescence. Females also appear to be more sensitive to UCH than males, so sex may be considered a risk factor1. Correction of the abnormality is contributed to cosmetic or functional reasons. Imaging study play crucial role for determining the diagnosis. There is no treatment for mild cases, although the severe cases can be treated surgically. Materials and methods: Retrospective study was conducted with sample size of 15 patients. ROI was drawn on both sides of mandible condyle in transaxial section to determine the high activity. Multiple values were calculated. Results: SPECT imaging and 3D ROI quantification had a sensitivity, specificity and accuracy of 85, 100, and 85% respectively. Conclusion: SPECT imaging and 3D ROI quantification is feasible and accurate. [ABSTRACT FROM AUTHOR]

The aim of the study was to identify reporting patterns of ventilation and perfusion single‐photon emission computed tomography (V/Q SPECT) scans done in our department over 3 months in 2016. Factors impacting on reporting and patient groups that would most benefit from the addition of low‐dose computed tomography (CT) to V/Q SPECT were analysed. Among 178 patients, 173 (97.2%) had a definitive (positive/negative) report and 2.8% had an equivocal report. As the majority of the equivocal reports were seen in patients aged ≥70 years, we believe that addition of low‐dose CT with V/Q SPECT to this patient group will reduce the non‐diagnostic rate. [ABSTRACT FROM AUTHOR]

Purpose: To examine the diagnostic accuracy of spectral CT pulmonary angiography (S-CTPA) using ventilation-perfusions lung scintigraphy (V/Q-scan) as a reference standard in the diagnosis of acute or chronic pulmonary embolism (APE/CPE) and chronic thromboembolic pulmonary hypertension (CTEPH).Methods: PubMed, Embase, Scopus, and Web of Science were searched for the period from 1 Jan 2006 to 7 Feb 2019; eligible studies had > 10 patients over 18 years old, a diagnostic outcome of PE or CTEPH, and used V/Q scan as a reference standard. Bias and applicability were assessed using QUADAS-2 tools. Sensitivities, specificities, and predictive values were noted or calculated from available information. Meta-analysis employed a fixed-effects model of Mantel and Haenszel. Heterogeneity was assessed with I-squared statistics.Results: Four hundred ninety-three unique records were identified. Following screening by title, 53 studies were included in the abstract and full-text assessment. A total of six articles were included; four were suitable for a meta-analysis. Pooled sensitivity was 94.2% (95% CI, 88.3-100%), pooled specificity was 88.5% (95% CI, 81.3-95.6%), and positive and negative predictive values were 87.8% (95% CI, 80.3-95.4%) and 94.5% (95% CI, 89.3-99.7%), respectively.Conclusion: Data on S-CTPA for PE/CTEPH remains promising, but limited; only small studies with methodological issues are available. Evidence is best for CPE/CTEPH whereas no firm conclusions are possible for APE. There is a need for larger, prospective studies with a robust composite reference standard including state-of-the-art CTPA and V/Q-scans.Key Points: • S-CTPA has high sensitivity and specificity for perfusion defects in patients with PE or CPETH. • Methodological issues and diversity of reference standards were found in the small number of included studies. • There is a need for larger prospective studies with more robust composite reference standards. [ABSTRACT FROM AUTHOR]

Background and purpose: Biomarkers support the aetiological diagnosis of neurocognitive disorders in vivo. Incomplete evidence is available to drive clinical decisions; available diagnostic algorithms are generic and not very helpful in clinical practice. The aim was to develop a biomarker‐based diagnostic algorithm for mild cognitive impairment patients, leveraging on knowledge from recognized national experts. Methods: With a Delphi procedure, experienced clinicians making variable use of biomarkers in clinical practice and representing five Italian scientific societies (neurology – Società Italiana di Neurologia per le Demenze; neuroradiology – Associazione Italiana di Neuroradiologia; biochemistry – Società Italiana di Biochimica Clinica; psychogeriatrics – Associazione Italiana di Psicogeriatria; nuclear medicine – Associazione Italiana di Medicina Nucleare) defined the theoretical framework, relevant literature, the diagnostic issues to be addressed and the diagnostic algorithm. An N–1 majority defined consensus achievement. Results: The panellists chose the 2011 National Institute on Aging and Alzheimer's Association diagnostic criteria as the reference theoretical framework and defined the algorithm in seven Delphi rounds. The algorithm includes baseline clinical and cognitive assessment, blood examination, and magnetic resonance imaging with exclusionary and inclusionary roles; dopamine transporter single‐photon emission computed tomography (if no/unclear parkinsonism) or metaiodobenzylguanidine cardiac scintigraphy for suspected dementia with Lewy bodies with clear parkinsonism (round VII, votes (yes‐no‐abstained): 3‐1‐1); 18F‐fluorodeoxyglucose positron emission tomography for suspected frontotemporal lobar degeneration and low diagnostic confidence of Alzheimer's disease (round VII, 4‐0‐1); cerebrospinal fluid for suspected Alzheimer's disease (round IV, 4‐1‐0); and amyloid positron emission tomography if cerebrospinal fluid was not possible/accepted (round V, 4‐1‐0) or inconclusive (round VI, 5‐0‐0). Conclusions: These consensus recommendations can guide clinicians in the biomarker‐based aetiological diagnosis of mild cognitive impairment, whilst guidelines cannot be defined with evidence‐to‐decision procedures due to incomplete evidence. [ABSTRACT FROM AUTHOR]

Facet joint osteoarthritis/arthropathy of the spine is a common cause of back and neck pain that frequently overlaps clinically with other diseases of the spine. Because of the possible overlap, it is crucial to have an accurate diagnostic strategy, especially when determining the management approach. Various strategies have been suggested and adopted, with several these still being used in clinics. Over the years, because of the disadvantages of single-modality imaging methods (computed tomography, magnetic resonance imaging, single-photon emission computed tomography), the interest in radiologic examination started to move toward hybrid imaging techniques. Although the data are mixed, many initial studies have shown promise. However, there are relatively few data with comparative medial branch blocks, and further investigation is needed. Given the advantages and disadvantages of these new techniques, the imaging results have to be interpreted within clinical context and with consideration of the current state of knowledge in the decision-making process. [ABSTRACT FROM AUTHOR]

• 99mTc-antigranulocyte SPECT/CT has a high diagnostic accuracy (88.5%). • It may help if standard diagnostics are not applicable or inconclusive. • 99mTc-antigranulocyte SPECT/CT is now recommended by current guidelines. Conventional imaging techniques are routinely used in the diagnostic work-up of patients with suspected osteomyelitis or orthopaedic implant-associated infections. Hybrid nuclear medicine imaging techniques are a suitable alternative to routine imaging modalities as they provide anatomical and functional information within one procedure. Our study investigated the performance of anti-granulocyte SPECT/CT using 99mTc-labelled monoclonal antibodies in the diagnosis of osteomyelitis and orthopaedic implant-associated infections. In this retrospective analysis, we included patients with 99mTc-antigranulocyte SPECT/CT acquired in the context of a suspected bone and joint infection. All patients underwent routine diagnostics and/or had a clinical follow-up of at least 12 months. 26 episodes were included. Fifteen exams were performed for suspected osteomyelitis, and 11 for suspected orthopaedic implant-associated infection. SPECT/CT was ordered most often if standard diagnostic tests or conventional imaging modalities remained inconclusive. The overall sensitivity and specificity for the diagnosis of an infection were 77.8% and 94.1%, respectively. The positive predictive value was 87.5% and the negative predictive value 88.9%. Diagnostic accuracy was 88.5%. 99mTc-antigranulocyte SPECT/CT imaging has a high accuracy in the diagnosis of osteomyelitis and orthopaedic implant-associated infections and is a suitable non-invasive diagnostic tool if standard diagnostic examinations are inconclusive or not applicable. [ABSTRACT FROM AUTHOR]

In this work, the preparation of 111In radiolabeled bleomycin (111In-BLM) was optimized systematically and used for SPECT imaging of liver cancer xenograft models. 111In-BLM with a high radiochemical yield (> 99%) could be obtained at pH 0.5–1 at a mixture ratio of 9:1 (111In/BLM, mCi/mg). The radiochemical purity of 111In-BLM retained > 99% in either buffers or serum for 3 days. Biodistribution of 111In-BLM revealed its excellent stability in vivo. The SPECT imaging studies showed 111In-BLM has great specificity to liver tumor xenograft. All the results implied 111In-BLM is a potential radiopharmaceutical for targeting diagnosis and therapy of liver tumor. [ABSTRACT FROM AUTHOR]

A 66-year-old female underwent preoperative evaluation for primary hyperparathyroidism. Ultrasound (US) neck and technetium (Tc)-99m-sestamibi planar scintigraphy were negative, but single photon emission computed tomography/computed tomography (SPECT/CT) demonstrated a tracer-avid retropharyngeal nodule compatible with parathyroid adenoma (PTA). A retrospective review of CT neck angiogram (CTA) and neck magnetic resonance imaging (MRI) performed 4 months earlier for stroke evaluation revealed arterial phase hyperenhancing retropharyngeal tissue, which had been dismissed as a nonpathological lymph node. "Polar vessel sign" seen in two-thirds of PTA was also present on retrospective review of the CTA. The concordant findings between SPECT/CT and CTA were indicative of a solitary undescended ectopic PTA in the retropharyngeal space, an uncommon location. A successful surgical cure was achieved after minimally invasive parathyroidectomy. This case highlights the retropharyngeal space as an important ectopic site of PTA, limitation of US, and Tc-99m-sestamibi planar scintigraphy in identifying retropharyngeal PTA. We also discuss the role of CT and MRI and the challenge in differentiating retropharyngeal PTA from a lymph node. [ABSTRACT FROM AUTHOR]

Labelled leucocyte scintigraphy (LS) is regarded as helpful when exploring bone and joint infections. The aim of this study was to evaluate the utility of LS for the diagnosis of chronic periprosthetic joint infections (PJIs) in patients exhibiting arthroplastic loosening. One hundred sixty-eight patients were referred to centres for treatment of complex PJI. One hundred fifty underwent LS using 99mTc-HMPAO (LLS); 18 also underwent anti-granulocyte scintigraphy (AGS) and 13 additional SPECT with tomodensitometry imaging (SPECT-CT). The LS results were compared with bone scan data. For all, the final diagnoses were determined microbiologically; perioperative samples were cultured. LS values were examined, as well as sensitivity by microorganism, anatomical sites, and injected activity. LS results were also evaluated according to the current use of antibiotics or not. The sensitivity, specificity, and positive predictive value of LLS were 72%, 60%, and 80%, respectively. LLS performed better than did AGS. SPECT-CT revealed the accurate locations of infections. The sensitivity of LS was not significantly affected by the causative pathogen or the injected activity. No correlation was evident between the current antibiotic treatment and the LS value. The test was more sensitive for knee (84%) than hip arthroplasty (57%) but was less specific for knee (52% vs. 75%). Sensitivity and specificity of LLS varied by the location of infection bone scan provide no additional value in PJI diagnosis. Current antibiotic treatment seems to have no influence on LS sensitivity as well as labelling leukocyte activity or pathogens responsible for chronic PJI. [ABSTRACT FROM AUTHOR]

Background: Stress testing in patients with low pretest probability (PTP) of coronary artery disease (CAD) has become an increasing practice, potentially leading to underestimation of its true clinical value. Our aim was to describe the current use of most employed imaging functional tests and their prognostic value. Methods and Results: We selected patients with low PTP of CAD (CAD consortium clinical score < 15%) who underwent exercise or dipyridamole stress echocardiography or single photon emission computed tomography for suspected angina. Main exclusions were age < 45, known CAD, and abnormal rest wall motion. Of the 2279 subjects undergoing stress test, 883 (39%) had low PTP, and 91 (10.3%) had a positive test for ischemia. After a median follow‐up of 5.8 years, 36 patients had events (21 died, 14 had nonfatal myocardial infarction). The percentage of events in the abnormal and normal stress test groups were similar (5 [5.5%] vs 31 [3.9%], P = ns), as the annualized event rate (0.87% vs 0.62%, P = ns). Age was the only variable associated with outcome in the regression analysis (hazard ratio 1.072, 95% CI 1.034–1.113, P < 0.001). An abnormal result was not associated with worse outcome in each of the subgroups of functional tests. Conclusions: In our geographical area, a considerable proportion of patients undergoing imaging functional tests for stable chest pain have a low estimated PTP of CAD. Of these, 1 in 10 resulted positive for inducible ischemia. However, none of the most common imaging functional tests, single photon emission computed tomography (SPECT), and stress echocardiography offer prognostic information in these patients. [ABSTRACT FROM AUTHOR]

Background: Acute encephalopathy (AE) is defined by the Japanese guidelines as the acute disturbance of consciousness (Glasgow coma scale [GCS] score ≤11) that persists for >24 h. We have often encountered, however, cases of prolonged mild disturbance of consciousness (PMDC) with GCS score >11, meaning that they do not fit the guideline definition of AE. The reports of these cases have been relatively sparse, and the nosological position, prognosis, and other characteristics remain unknown. To clarify the characteristics of PMDC we compared cases of PMDC with cases of AE. Methods: This study was a retrospective observational study at a tertiary children's hospital in Japan. We studied children with a diagnosis of AE or PMDC between January 2011 and August 2016. Results: Thirteen cases of PMDC and 19 cases of AE were identified during the study period. PMDC patients more frequently had hyponatremia (P < 0.01), paradoxical arousal response on electroencephalogram (P = 0.010), normal computed tomography (CT; P = 0.025), and normal magnetic resonance imaging (MRI; P < 0.01) than the AE patients. Sequelae were more frequently observed in AE than in PMDC patients (P = 0.011). Conclusions: PMDC has different characteristics to AE with regard to hyponatremia, paradoxical arousal response, CT or MRI findings, and prognosis. Despite the differences, PMDC might also be regarded as being a milder member of the wide variety of AE and related diseases. [ABSTRACT FROM AUTHOR]

Genetic mutations of sporadic hemiplegic migraine (SHM) are mostly unknown. SHM pathophysiology relies on cortical spreading depression (CSD), which might be responsible for ischemic brain infarction. Cystic fibrosis (CF) is caused by a monogenic mutation of the chlorine transmembrane conductance regulator (CFTR), possibly altering brain excitability. We describe the case of a patient with CF, who had a migrainous stroke during an SHM attack. A 32‐year‐old Caucasian male was diagnosed with CF, with heterozygotic delta F508/unknown CFTR mutation. The patient experiences bouts of coughing sometimes triggering SHM attacks with visual phosphenes, aphasia, right‐sided paresthesia, and hemiparesis. He had a 48‐hour hemiparesis triggered by a bout of coughing with hemoptysis, loss of consciousness, and severe hypoxia‐hypercapnia. MRI demonstrated transient diffusion hyperintensity in the left frontal‐parietal‐occipital regions resulting in a permanent infarction in the primary motor area. Later, a brain perfusion SPECT showed persistent diffuse hypoperfusion in the territories involved in diffusion‐weighted imaging alteration. Migrainous infarction, depending on the co‐occurrence of 2 strictly related phenomena, CSD and hypoxia, appears to be the most plausible explanation. Brain SPECT hypoperfusion suggests a more extensive permanent neuronal loss in territories affected by aura. CF may be then a risk factor for hemiplegic migraine and stroke since bouts of coughing can facilitate brain hypoxia, triggering auras. [ABSTRACT FROM AUTHOR]

Thyroid disease has now become the second largest disease in the endocrine field; SPECTimaging is particularly important for the clinical diagnosis of thyroid diseases. However, there is little research on the application of SPECT images in the computer-aided diagnosis of thyroid diseases based on machine learning methods. A convolutional neural network with optimization-based computer-aided diagnosis of thyroid diseases using SPECT images is developed. Three categories of diseases are considered, and they are Graves' disease, Hashimoto disease, and subacute thyroiditis. A modified DenseNet architecture of convolutional neural network is employed, and the training method is improved. The architecture is modified by adding the trainable weight parameters to each skip connection in DenseNet. And the training method is improved by optimizing the learning rate with flower pollination algorithm for network training. Experimental results demonstrate that the proposed method of convolutional neural network is efficient for the diagnosis of thyroid diseases with SPECT images, and it has superior performance than other CNN methods. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to elucidate the specific regional cerebral blood flow (rCBF) alterations for idiopathic normal pressure hydrocephalus (iNPH) by comparing the proportional rCBF and gray matter change from those of a normal database at the same point of SPECT and MRI examinations.Methods: Thirty subjects with iNPH underwent both CBF SPECT and MRI. After normalization, voxel-wise two-sample t tests between patients and 11 normal controls were conducted to compare the regional alteration in the gray matter density and rCBF.Results: The rCBF reduction and the gray matter decrease were seen in almost similar regions surrounding Sylvian fissure, the left parietotemporal region and frontal lobes, whereas we did not find rCBF increase at the top of the high convexity, where the increase of the gray matter density was the highest (p < 0.05).Conclusion: Our study showed regional associations and dissociations between the relative gray matter density and rCBF in patients with iNPH. [ABSTRACT FROM AUTHOR]

Purpose: To explore the feasibility of using correlation-based time-delay (CTD) maps produced from time-resolved MR angiography (TRMRA) to diagnose perfusion abnormalities in patients suspected to have steno-occlusive lesions in the craniocervical arteries.Materials and Methods: Twenty-seven patients who were suspected to have steno-occlusive lesions in the craniocervical arteries underwent both TRMRA and brain single-photon emission computed tomography (SPECT). TRMRA was performed on the supra-aortic area after intravenous injection of a 0.03 mmol/kg gadolinium-based contrast agent. Time-to-peak (TTP) maps and CTD maps of the brain were automatically generated from TRMRA data, and their quality was assessed. Detection of perfusion abnormalities was compared between CTD maps and the time-series maximal intensity projection (MIP) images from TRMRA and TTP maps. Correlation coefficients between quantitative changes in SPECT and parametric maps for the abnormal perfusion areas were calculated.Results: The CTD maps were of significantly superior quality than TTP maps (p < 0.01). For perfusion abnormality detection, CTD maps (kappa 0.84, 95% confidence interval [CI] 0.67-1.00) showed better agreement with SPECT than TTP maps (0.66, 0.46-0.85). For perfusion deficit detection, CTD maps showed higher accuracy (85.2%, 95% CI 66.3-95.8) than MIP images (66.7%, 46-83.5), with marginal significance (p = 0.07). In abnormal perfusion areas, correlation coefficients between SPECT and CTD (r = 0.74, 95% CI 0.34-0.91) were higher than those between SPECT and TTP (r = 0.66, 0.20-0.88).Conclusion: CTD maps generated from TRMRA were of high quality and offered good diagnostic performance for detecting perfusion abnormalities associated with steno-occlusive arterial lesions in the craniocervical area.Key Points: • Generation of perfusion parametric maps from time-resolved MR angiography is clinically useful. • Correlation-based delay maps can be used to detect perfusion abnormalities associated with steno-occlusive craniocervical arteries. • Estimation of correlation-based delay is robust for low signal-to-noise 4D MR data. [ABSTRACT FROM AUTHOR]

Background: Cardiac shockwave therapy (CSWT) is a new potential option for the treatment of patients with chronic coronary disease and refractory angina (RA). We aimed to study the effects of CSWT on left ventricular myocardial perfusion and mechanics in patients with RA. Method: We prospectively studied 19 patients who underwent CSWT. Left ventricular mechanics were evaluated by speckle tracking echocardiography (STE), and myocardial perfusion by single‐photon emission computed tomography, using stress/rest–Technetium‐99 m Sestamibi, for determination of summed stress score (SSS). Canadian Cardiac Society (CCS), New York Heart Association (NYHA), and quality of life by Seattle Angina Questionnaire (SAQ) were assessed at baseline and 6 months after therapy. Results: CSWT therapy was applied without major side effects. At baseline, 18 patients (94.7%) had CCS class III or IV, and after CSWT there was reduction to 3 (15.8%), P = .0001, associated with improvement in SAQ (38.5%; P < .001). Thirteen (68.4%) had class NYHA III or IV before treatment, with significant reduction to 7 (36.8%); P = .014. No change was observed in the global SSS from baseline to 6‐month follow‐up (15.33 ± 8.60 vs 16.60 ± 8.06; P = .157). However, there was a significant reduction in the average SSS of the treated ischemic segments (2.1 ± 0.87 pre vs 1.6 ± 1.19 post CSWT; P = .024). Global longitudinal strain by STE remained unaltered (‐13.03 ± 8.96 pre vs ‐15.88 ± 3.43 6‐month post CSWT; P = .256). Conclusion: CSWT is a safe procedure for the treatment of patients with RA that results in better quality of life, improvement in myocardial perfusion of the treated segments with preservation of left ventricular mechanics. [ABSTRACT FROM AUTHOR]

Purpose: In this prospective study we compared the accuracy of 18F-fluorocholine PET/CT with that of 99mTc-MIBI or99mTc-tetrofosmin SPECT/CT in the preoperative detection of parathyroid adenoma in patients with primary hyperparathyroidism. We also assessed the value of semiquantitative parameters in differentiating between parathyroid hyperplasia and adenoma.Methods: Both 18F-fluorocholine PET/CT and 99mTc-MIBI/tetrofosmin SPECT/CT were performed in 100 consecutive patients with biochemical evidence of primary hyperparathyroidism. At least one abnormal focus on either 18F-fluorocholine or 99mTc-MIBI/tetrofosmin corresponding to a parathyroid gland or ectopic parathyroid tissue was considered as a positive finding. In 76 patients with positive findings on at least one imaging modality, surgical exploration was performed within 6 months, and the results were related to histopathological findings and clinical and laboratory findings at 3-6 months as the standard of truth. In 24 patients, no surgery was performed: in 18 patients with positive imaging findings surgery was refused or considered risky, and in 6 patients imaging was negative. Therefore, data from 82 patients (76 undergoing surgery, 6 without surgery) in whom the standard of truth criteria were met, were used in the final analysis.Results: All patients showed biochemical evidence of primary hyperparathyroidism with a mean serum calcium level of 2.78 ± 0.34 mmol/l and parathormone (PTH) level of 196.5 ± 236.4 pg/ml. The study results in 76 patients with verified histopathology and 3 patients with negative imaging findings were analysed. Three of six patients with negative imaging showed normalized serum PTH and calcium levels on laboratory follow-up at 3 and 6 months, and the results were considered true negative. In a patient-based analysis, the detection rate with 18F-fluorocholine PET/CT was 93% (76/82), but was only 61% (50/82) with 99mTc-MIBI/tetrofosmin SPECT/CT. In a lesion-based analysis, the sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of 18F-fluorocholine PET/CT in the detection of parathyroid adenoma were 93.7%, 96.0%, 90.2%, 97.4% and 95.3%, respectively, and of 99mTc-MIBI/tetrofosmin SPECT/CT were 60.8%, 98.5%, 94.1%, 86.3% and 87.7%, respectively. Although 18F-fluorocholine PET-positive adenomatous lesions showed higher SUVmax values than the hyperplastic glands (6.80 ± 3.78 vs. 4.53 ± 0.40) in the semiquantitative analysis, the difference was not significant (p = 0.236). The mean size (measured as the length of the greatest dimension) and weight of adenomas were 15.9 ± 7.6 mm (median 15 mm, range 1-40 mm) and 1.71 ± 1.86 g (median 1 g, range: 0.25-9 g), respectively. Among the analysed parameters including serum calcium and PTH and the size and weight of parathyroid adenomas, size was significantly different between patients with negative 99mTc-MIBI/tetrofosmin SPECT/CT and those with positive 99mTc-MIBI/tetrofosmin SPECT/CT (mean size 13.4 ± 7.6 mm vs. 16.9 ± 7.4 mm, respectively; p = 0.042).Conclusion: In this prospective study, 18F-fluorocholine PET/CT showed promise as a functional imaging modality, being clearly superior to 99mTc-MIBI/tetrofosmin SPECT/CT, especially in the detection and localization of small parathyroid adenomas in patients with primary hyperparathyroidism. SUVmax was higher in parathyroid adenomas than in hyperplasia. However, further evaluation of this modality is needed. [ABSTRACT FROM AUTHOR]

Abstract: The differential diagnosis of Parkinsonian syndromes is challenging, especially in the elderly as they often have complex presentations. Nuclear imaging modalities can increase diagnostic accuracy. Single‐photon emission tomography (SPECT) using the ligand (99mTc)‐TRODAT‐1 is used overseas but is yet to be approved in Australia. Three pilot cases of clinically unclear Parkinsonian syndromes from the Royal North Shore Hospital Aged Care Department who underwent (99mTc)‐TRODAT‐1 scans are described. From experience overseas, the (99mTc)‐TRODAT‐1 scan has clinical utility in the differential diagnosis of Parkinsonian syndromes. (99mTc)‐TRODAT‐1 has a lower cost and greater availability than other ligands. Our initial scan findings are largely consistent with the clinical picture, but low specific binding can affect scan interpretation. (99mTc)‐TRODAT‐1 is a potential tool in the differential diagnosis of Parkinsonian syndromes. Further experience regarding its effect on patient outcomes and cost effectiveness is required before routine clinical use can be recommended. [ABSTRACT FROM AUTHOR]

Purpose: Traditionally, interpretation of myocardial perfusion imaging (MPI) is based on visual assessment. Computer-based automated analysis might be a simple alternative obviating the need for extensive reading experience. Therefore, the aim of the present study was to compare the diagnostic performance of automated analysis with that of expert visual reading for the detection of obstructive coronary artery disease (CAD).Methods: 206 Patients (64% men, age 58.2 ± 8.7 years) with suspected CAD were included prospectively. All patients underwent 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) and invasive coronary angiography with fractional flow reserve (FFR) measurements. Non-corrected (NC) and attenuation-corrected (AC) SPECT images were analyzed both visually as well as automatically by commercially available SPECT software. Automated analysis comprised a segmental summed stress score (SSS), summed difference score (SDS), stress total perfusion deficit (S-TPD), and ischemic total perfusion deficit (I-TPD), representing the extent and severity of hypoperfused myocardium. Subsequently, software was optimized with an institutional normal database and thresholds. Diagnostic performances of automated and visual analysis were compared taking FFR as a reference.Results: Sensitivity did not differ significantly between visual reading and most automated scoring parameters, except for SDS, which was significantly higher than visual assessment (p < 0.001). Specificity, however, was significantly higher for visual reading than for any of the automated scores (p < 0.001 for all). Diagnostic accuracy was significantly higher for visual scoring (77.2%) than for all NC images scores (p < 0.05), but not compared with SSS AC and S-TPD AC (69.8% and 71.2%, p = 0.063 and p = 0.134). After optimization of the automated software, diagnostic accuracies were similar for visual (73.8%) and automated analysis. Among the automated parameters, S-TPD AC showed the highest accuracy (73.5%).Conclusion: Automated analysis of myocardial perfusion SPECT can be as accurate as visual interpretation by an expert reader in detecting significant CAD defined by FFR. [ABSTRACT FROM AUTHOR]

Objectives: To examine neuropsychological test performance among individuals clinically diagnosed with Parkinson’s disease (PD) without evidence of dopaminergic deficiency on [123]I-CIT single photon emission computed tomography imaging. Methods: Data were obtained from the Parkinson’s Progression Marker Initiative. The sample included 59 participants with scans without evidence of dopaminergic deficiency (SWEDD), 412 with PD, and 114 healthy controls (HC). Tests included Judgment of Line Orientation, Letter-Number Sequencing, Symbol Digit Modalities, Hopkins Verbal Learning Test-Revised, and Letter and Category Fluency. Multivariate analysis of variance was used to compare standardized scores between the groups. Results: There was a statistically significant difference in performances between the groups, F(14,1155)=5.04; p<.001; partial η2=.058. Pairwise comparisons revealed significant differences in Category Fluency between SWEDD (M=0.22; SD=1.08) and HC (M=0.86; SD=1.15) and in Symbol Digit Modalities Test performance between SWEDD (M=45.09; SD=11.54) and HC (M=51.75; SD=9.79). No significant differences between SWEDD and PD were found. Using established criteria, approximately one in four participants in the SWEDD and PD groups met criteria for mild cognitive impairment (MCI). Conclusions: Individuals with SWEDD demonstrate significantly worse mental processing speed and semantic fluency than HC. The neuropsychological test performances and rates of MCI were similar between the SWEDD group and PD groups, which may reflect a common pathology outside of the nigrostriatal pathway. (JINS, 2018, 24, 646–651) [ABSTRACT FROM AUTHOR]

Von Hippel-Lindau syndrome, an autosomal dominant genetic disorder with high penetrance, is a rare genetic cause of pheochromocytoma and various other tumors, such as hemangioblastomas of retina and cerebellum, renal cell carcinoma, islet cell tumors, endolymphatic sac tumors, etc. Conventionally, Von Hippel-Lindau is diagnosed with the help of biochemical and structural imagining techniques, such as magnetic resonance imaging and computed tomography scans. However, the recent advent of the functional imaging techniques, such as meta-iodo-benzylguanidine, has significantly added to the armamentarium available for the diagnosis as well as localization of these tumors. In this report, we describe a case of a 22-year-old male with VHL syndrome, where functional 68Ga-DOTANOC PET/CT, 99mTc-HYNIC-TOC SPECT/CT, and 131I-MIBG SPECT/CT aided in the diagnostic evaluation of this disease. This patient presented with bilateral pheochromocytoma, retinal angioma, cerebellar hemangioblastoma, pancreatic neuroendocrine tumor, and pancreatic cysts. This case highlights the emerging role of functional imaging as an adjuvant to conventional tools in the diagnostic evaluations of diseases, an area that has not been addressed to date. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to demonstrate the capacity for noninvasive localisation and characterisation of myocardial infarction (MI) in vivo using a hemispherical photoacoustic imaging (PAI) system. MI remains a leading cause of morbidity and mortality worldwide. To enable optimal treatment of patients, timely and accurate diagnosis and longitudinal monitoring is critical.Methods: Ischaemia was induced in Balb/c mice by ligation of the left anterior descending artery. The hemispherical PAI system, equipped with 128 ultrasonic transducers spirally distributed on the surface, along with parallel data acquisition, was applied for imaging of the mouse heart.Results: Our study showed that hemispherical PAI can delineate thoracic vessels and the morphology of the entire heart. Longitudinal PAI images revealed gradual expansion of the infarcted area along with necrosis and fibrosis, which were quantitatively validated by triphenyltetrazolium chloride staining. After MI modelling, the photoacoustic (PA) signal intensity decreased by 399.1 ± 56.3 (p < 0.001), a ~2.5-fold reduction compared to that of healthy cardiac tissue. The calculated size of the enlarged heart, 10.4 ± 6.0 mm2 (p < 0.001), represents an increase of ~18% versus that of a healthy heart.Conclusions: PAI enables MI diagnosis and injury localisation with its capabilities for both deep organ imaging and lesion region differentiation.Key Points: • Photoacoustic imaging (PAI), combining optical absorption and ultrasonic resolution, can delineate cardiac anatomy. • PAI can diagnose myocardial infarction lesions with 10 mm imaging depth in vivo. • Quantified results are in excellent agreement with enzyme and histological examinations. • PAI can serve as a complementary modality to SPECT and ultrasound imaging. • This study will encourage further PAI development for clinical use. [ABSTRACT FROM AUTHOR]

Purpose: Apoptosis is a key factor in unstable plaques. The aim of this study is to evaluate the utility of visualizing atherosclerotic plaques with radiolabeled duramycin and Annexin V.Procedures: ApoE-/- mice were fed with a high-fat diet to develop atherosclerosis, C57 mice as a control. Using a routine conjugation protocol, highly pure [99mTc]duramycin and [99mTc]Annexin V were obtained, which were applied for in vitro cell assays of apoptosis and in vivo imaging of atherosclerotic plaques in the animal model. Oil Red O staining, TUNEL, hematoxylin-eosin (HE), and CD68 immunostaining were used to evaluate the deposition of lipids and presence of apoptotic macrophages in the lesions where focal intensity positively correlated with the uptake of both tracers.Results: [99mTc]duramycin and [99mTc]Annexin V with a high radiochemical purity (97.13 ± 1.52 and 94.94 ± 0.65 %, respectively) and a well stability at room temperature were used. Apoptotic cells binding activity to [99mTc]duramycin (Kd, 6.92 nM and Bmax, 56.04 mol/1019 cells) was significantly greater than [99mTc]Annexin V (Kd, 12.63 nM and Bmax, 31.55 mol/1019 cells). Compared with [99mTc]Annexin V, [99mTc]duramycin bound avidly to atherosclerotic lesions with a higher plaque-to-background ratio (P/B was 8.23 ± 0.91 and 5.45 ± 0.48 at 20 weeks, 15.02 ± 0.23 and 12.14 ± 0.22 at 30 weeks). No plaques were found in C57 control mice. Furthermore, Oil Red O staining showed lipid deposition areas were significantly increased in ApoE-/- mice at 20 and 30 weeks, and TUNEL and CD68 staining confirmed that the focal uptake of both tracers contained abundant apoptotic macrophages.Conclusions: This stable, fast clearing, and highly specific [99mTc]duramycin, therefore, can be useful for the quantification of vulnerable atherosclerotic plaques. [ABSTRACT FROM AUTHOR]

We report a 47-year-old woman who developed an ischemic stroke with diplopia and dysarthria. Emergency computed tomography (CT) showed no pathological findings, and magnetic resonance (MR) showed mild ischemic-degenerative lesions. MR angiography and angiogram showed severe stenosis of both internal carotid and main intracranial arteries with plenty collateral vessels with "puff of smoke" suggesting a moyamoya disease (MMD). Brain perfusion single-photon emission CT showed global diminished perfusion in the brain lobes and a marked relative hyperperfusion in the cerebellum. However, brain 18F-fluorodeoxyglucose-positron emission tomography showed physiological metabolism in the brain cortex with only slightly relative cerebellar hypermetabolism. MMD is a well-known arterial pathology that frequently develops with only mild symptoms until the middle age. Functional neuroimaging findings indicate a mismatch between brain glucose metabolism and brain perfusion, probably due to neuronal subclinical chronic ischemia in the brain cortex with preserved viability of neurons. [ABSTRACT FROM AUTHOR]

Objective:A parathyroid multidisciplinary team meeting was set up at East Sussex Healthcare Trust, from November 2014 to November 2015, in order to improve and streamline services for patients with parathyroid pathology.Methods:Data were collected on all new referrals for hyperparathyroidism, and on the outcomes for each patient discussed at the meeting, including the number of operations and management outcomes. A survey was sent out to the members of the multidisciplinary team meeting to determine their perception of its effectiveness.Results:Seventy-nine new referrals were discussed throughout the year; 43 per cent were recommended for surgery, 41 per cent had a trial of conservative or medical management before re-discussion, and 16 per cent required further imaging. Ninety-two per cent of patients underwent an ultrasound, single-photon emission computed tomography/computed tomography or nuclear medicine (sestamibi) scan prior to the meeting. All ultrasound scans were performed by a consultant radiologist.Conclusion:The multidisciplinary team meeting has been successful, with perceived benefits for patients, improved imaging evaluation and efficiency of referral pathways, leading to more appropriate patient management. [ABSTRACT FROM AUTHOR]