Bone Scintigraphy in 2 Cases of Complex Regional Pain Syndrome.

ABSTRACT: A 59-year-old woman was presented to the outpatient clinic with persistent pain after a hyperextension/inversion trauma of the ankle. Six months after the incident, a 3-phase bone scan was performed. A second patient, a 54-year-old man, was referred for a 3-phase bone scan 2 months after his right hand was twisted while using a drill. In both patients, scintigraphy showed diffuse increased uptake in the affected limb in all 3 phases. The x-rays of the affected limbs showed osteopenia. These findings are consistent with (early phase) complex regional pain syndrome.

Quantitative analysis of standardized uptake values (SUV) of metastatic bone lesions in scintigraphy with [99mTc]Tc-EDDA/HYNIC-Tyr3-octreotide in patients with neuroendocrine tumours.

BACKGROUND: Neuroendocrine tumours (NETs) are a group of cancers that can produce hormones and other metabolically active compounds. The majority of NETs have specific tissue characteristics, such as the expression of somatostatin receptors (SSTR). Metabolic testing with [99mTc]Tc-EDDA/HYNIC-Tyr3-octreotide ([99mTc]Tc-EDDA/HYNIC-TOC) can be used in patients with NETs to visualize the presence of receptors in different locations of pathological lesions, including the skeletal system. The study aimed to calculate the body weight maximum standardized uptake value (SUVbwmax) of pathological bone lesions and healthy bone tissues, estimate the size of lesions, and identify a relationship between the SUVbwmax of the bone tissues, age and body mass of the study participants. MATERIAL AND METHODS: The somatostatin receptor scintigraphies (SRS) with [99mTc]Tc-EDDA/HYNIC-TOC were carried out at the Department of Nuclear Medicine, University Clinical Hospital No. 1, Pomeranian Medical University (PMU) in Szczecin from 2019 to 2022. Whole body and single photon emission computed tomography/computed tomography (SPECT/CT) scans were performed four hours after the injection of 700-800 MBq of [99mTc]Tc-EDDA/HYNIC-TOC in 344 patients with neuroendocrine tumours of various primary lesion locations. In 19 patients, who showed foci of increased radiopharmaceutical accumulation in bone location, the SUVbwmax was measured. The SUVbwmax of pathological bone lesions and healthy tissues were determined on SPECT/CT cross-sectional images using Xeleris 4 software. RESULTS: The total number of foci with increased SSTR expression in bone regions seen on scintigraphic images was 89. Among them, 32 bone lesions were visible on the corresponding CT scans. The mean SUVbwmax of these lesions was 31.39 [standard deviation (SD) 34.31]. For the other 57 lesions that were not visible on corresponding CT scans, the mean SUVbwmax was 19.12 (SD 24.24). The smallest bone lesion detected on the scintigram and visible on the corresponding CT location was 5 mm × 5 mm, measured in cross-section, and was located in the Th8 vertebral body; the largest, measuring 20 mm × 22 mm, was detected in the L3 vertebral body. The SUVbwmax of these lesions was 24.70 and 142.40, respectively. CONCLUSIONS: Bone lesions seen on SPECT/CT in [99mTc]Tc-EDDA/HYNIC-TOC scintigraphy can be quantitatively analysed using the SUV index. Even a very small pathological bone lesion can be detected on [99mTc]Tc-EDDA/HYNIC-TOC scintigraphy. It was shown that in cases where bone lesions were visible on CT scans, the SUVbwmax of bone tumour lesions was higher than when lesions were not visible on CT. Body mass does not affect the SUVbwmax of bone lesions. SUVbwmax of healthy bone tissue decreased with age.

A Novel Luciferase-Based Reporter Gene Technology for Simultaneous Optical and Radionuclide Imaging of Cells.

Multimodality reporter gene imaging combines the sensitivity, resolution and translational potential of two or more signals. The approach has not been widely adopted by the animal imaging community, mainly because its utility in this area is unproven. We developed a new complementation-based reporter gene system where the large component of split NanoLuc luciferase (LgBiT) presented on the surface of cells (TM-LgBiT) interacts with a radiotracer consisting of the high-affinity complementary HiBiT peptide labeled with a radionuclide. Radiotracer uptake could be imaged in mice using SPECT/CT and bioluminescence within two hours of implanting reporter-gene-expressing cells. Imaging data were validated by ex vivo biodistribution studies. Following the demonstration of complementation between the TM-LgBiT protein and HiBiT radiotracer, we validated the use of the technology in the highly specific in vivo multimodal imaging of cells. These findings highlight the potential of this new approach to facilitate the advancement of cell and gene therapies from bench to clinic.

Brain Death Scintigraphy: Do Not Blow the Flow.

Brain death denotes the loss of function in both the cerebrum and the brain stem, leading to coma, absence of spontaneous respiration in the setting of adequate stimulus, and the cessation of all brain stem reflexes. Although spinal reflexes such as deep tendon, plantar flexion, and withdrawal reflexes may persist, recovery is not possible. The cessation of brain function qualifies as death because of its central role in coordinating vital bodily functions. Although brain death is largely determined by a clinical and neurologic examination, confounding variables may necessitate ancillary testing such as cerebral brain perfusion imaging.

Radionuclide Imaging of Cardiac Amyloidosis: An Update and Future Aspects.

Cardiac amyloidosis (CA) is caused by the misfolding, accumulation and aggregation of proteins into large fibrils in the extracellular compartment of the myocardium, leading to restrictive cardiomyopathy, heart failure and death. The major forms are transthyretin (ATTR) CA and light-chain (AL) CA, based on the respective precursor protein. Each of them requires early diagnosis for a timely treatment initiation that will improve patient outcomes. For this, radionuclide imaging is essentially used as single-photon emission computed tomography (SPECT) with bone-avid radiotracers or as positron emission tomography (PET) with amyloid-binding radiotracers. Both offer unprecedented specificity for the diagnostic of CA. SPECT has even revolutionized the diagnosis of ATTR-CA by making it non-invasive. Indeed, SPECT has now entered the standard diagnostic pathway to CA and has led to earlier diagnosis of the disease. SPECT also modified the epidemiology of ATTR-CA, highlighting that the disease is much more frequent than previously believed, and showing that ATTR-CA plays a substantial role in HFpEF and aortic stenosis, particularly among elderly patients. In parallel, amyloid-binding radiotracers for PET have accumulated a substantial amount of evidence, but are not approved for clinical use in CA yet. Further studies are needed to refine acquisition protocols and validate results in broader populations. Unlike bone-avid SPECT radiotracers, PET radiotracers have been specifically created to bind to amyloid fibrils. Thus, PET is the only imaging method that is truly specific for amyloid deposits and very sensitive to any amyloid type. Indeed, PET can not only detect ATTR-CA, but also AL-CA and rare hereditary forms. For both SPECT and PET, advances in quantitation of myocardial uptake have generated more granular and reproducible findings, paving the way for progress in earlier diagnosis, risk stratification and therapeutic response monitoring. Encouraging findings have shown that SPECT and PET are sensitive to early CA when other diagnostic methods are negative. Both radionuclide imaging techniques can predict adverse outcomes, but more evidence is needed to determine how to use them in conjunction with usual prognostic staging scores. Studies on follow-up imaging after therapy suggested that SPECT and PET can capture myocardial changes in CA, but again, more data are needed to meaningfully interpret such changes. Based on all these promising results, radionuclide imaging has the potential to further impact the landscape of CA in diagnosis, prognosis and follow-up, but also to substantially contribute to the assessment of novel therapies that will improve the lives of patients with CA.

Risk of TIRADS-based inappropriate FNAC in autonomous thyroid nodules is clinically negligible.

Objective: Thyroid nodule (TN) is usually managed according to Thyroid Imaging And Reporting Data Systems (TIRADS) with the major aim to reduce as much as possible unnecessary fine-needle aspiration cytologies (UN-FNACs). Since the assessment of autonomously functioning thyroid nodule (AFTN) according to TIRADS is heterogeneous, that virtually benign entity may increase the rate of UN-FNAC. This study retrospectively analyzed the appropriateness of TIRADS-based FNAC indication in AFTNs, also looking at the impact of TSH and nodule size. Methods: Cases diagnosed with AFTN on scintigraphy were searched. Patients who had undergone AFTN treatment, were on medications or supplementation that could affect thyroid function, or had multiple AFTNs were excluded. The AFTNs were assessed according to ACR-TIRADS. Results: Forty-eight AFTNs were included of which 37.5% had FNAC indication according to TIRADS. The FNAC indication rate in the case of TSH lower than 0.4 mIU/L was significantly higher than in other cases (P = 0.0078). The most accurate TSH cut-off and AFTN size associated with UN-FNAC were ≤ 0.41 mIU/L and > 22 mm, respectively. The multivariate analysis showed that both TSH and nodule size were independent predictors of UN-FNAC with OR of 6.65 and 6.46, respectively. According to these data, the rate of FNAC indication dropped to 4.16%. Conclusion: Inappropriate FNACs in AFTNs are primarily observed in patients with low TSH and large AFTN. Since these cases typically undergo scintigraphy, the risk of TIRADS-based UN-FNAC is clinically negligible. There is no need for integrating other imaging procedures into the TIRADS model.

Utility of Bone Scan in Evaluating Patients with Clinically Indeterminate Diagnosis of Cancer in a Low-resource Practice.

CONTEXT: A major indication for referrals for bone scans (BS) to establish or exclude skeletal metastases. Few patients are referred with clinically indeterminate diagnosis or cancer of unknown primary (CUP), to search for bony metastases or primary tumor. AIMS: This study aimed to assess the usefulness or otherwise for BS in such instances. SETTINGS AND DESIGN: A retrospective cross-sectional study of BS performed for CUP and indeterminate diagnosis from 2012 to 2016 in the nuclear medicine unit of a tertiary teaching hospital. SUBJECTS AND METHODS: The study involved reviews of technetium-99m diphosphonate BS for patients with CUP. BSs were reported by nuclear physicians as normal, normal variants, suspicious for metastases or as malignant, and with solitary or multiple skeletal metastases. STATISTICAL ANALYSIS USED: Data were analyzed using SPSS version 21 for descriptive analysis. Continuous data were displayed as means along with their standard deviation; categorical data were tabulated as frequencies and percentages. RESULTS: Of 2156 BS, 42 (0.02%) were eligible. Patients were aged 27-86 years, mainly in the sixth and seventh decades of life. Bone metastases were identified in 14 (33%) of these patients, whereas 17 BS (40%) were normal, BS appeared equivocal in 10 (23.8%). CONCLUSIONS: Single-photon emission computed tomography/computed tomography availability would resolve the clinical dilemma in patients with equivocal and apparently normal BS.

Résumé Contexte:Une indication majeure pour les références à des scintigraphies osseuses (BS) pour établir ou exclure des métastases squelettiques. Peu de patients sont référés avec diagnostic cliniquement indéterminé ou cancer primitif inconnu (CUP), pour rechercher des métastases osseuses ou une tumeur primitive.Objectifs:Cette étude visait à évaluer l'utilité ou non de la BS dans de tels cas.Paramètres et conception:Une étude transversale rétrospective sur le BS réalisée pour CUP et diagnostic indéterminé de 2012 à 2016 dans l'unité de médecine nucléaire d'un hôpital universitaire tertiaire.Sujets et Méthodes:L'étude comprenait des examens du diphosphonate de technétium-99m BS pour les patients atteints de CUP. Des BS ont été signalés par des médecins nucléaires comme normales, variantes normales, suspectes de métastases ou malignes, et avec métastases squelettiques solitaires ou multiples.Analyses statistiques utilisé:Les données ont été analysées à l'aide de SPSS version 21 pour une analyse descriptive. Les données continues ont été affichées comme moyennes avec leur l'ecarts t; les données catégorielles ont été présentées sous forme de fréquences et de pourcentages.Résultats:Sur 2156 BS, 42 (0,02%) étaient éligibles. Les patients étaient âgés 27 à 86 ans, principalement dans les sixième et septième décennies de la vie. Des métastases osseuses ont été identifiées chez 14 (33 %) de ces patients, alors que 17 BS (40 %) étaient normaux, la BS semblait équivoque dans 10 cas (23,8 %).Conclusions:Tomodensitométrie par émission de photons uniques/tomodensitométrie la disponibilité résoudrait le dilemme clinique chez les patients atteints de BS équivoque et apparemment normale.

Impaired Cardiac Sympathetic Activity Is Associated With Myocardial Remodeling and Established Biomarkers of Heart Failure.

BACKGROUND: 123Iodine-meta-iodobenzylguanidine scintigraphy is useful for assessing cardiac autonomic dysfunction and predict outcomes in heart failure (HF). The relationship of cardiac sympathetic function with myocardial remodeling and diffuse fibrosis remains largely unknown. We aimed to evaluate the cardiac sympathetic function of patients with HF and its relation with myocardial remodeling and exercise capacity. METHODS AND RESULTS: Prospectively enrolled patients with HF (New York Heart Association class II-III) were stratified into HF with preserved left ventricular ejection fraction [LVEF] ≥45%) and reduced LVEF. Ventricular morphology/function and myocardial extracellular volume (ECV) fraction were quantified by cardiovascular magnetic resonance, global longitudinal strain by echocardiography, cardiac sympathetic function by heart-to-mediastinum ratio from 123iodine-meta-iodobenzylguanidine scintigraphy. All participants underwent cardiopulmonary exercise testing. The cohort included 33 patients with HF with preserved LVEF (LVEF, 60±10%; NT-proBNP [N-terminal pro-B-type natriuretic peptide], 248 [interquartile range, 79-574] pg/dL), 28 with HF with reduced LVEF (LVEF, 30±9%; NT-proBNP, 743 [interquartile range, 250-2054] pg/dL) and 20 controls (LVEF, 65±5%; NT-proBNP, 40 [interquartile range, 19-50] pg/dL). Delayed (4 hours) 123iodine-meta-iodobenzylguanidine heart-to-mediastinum ratio was lower in HF with preserved LVEF (1.59±0.25) and HF with reduced LVEF (1.45±0.16) versus controls (1.92±0.24; P<0.001), and correlated negatively with diffuse fibrosis assessed by ECV (R=-0.34, P<0.01). ECV in segments without LGE was increased in HF with preserved ejection fraction (0.32±0.05%) and HF with reduced left ventricular ejection fraction (0.31±0.04%) versus controls (0.28±0.04, P<0.05) and was associated with the age- and sex-adjusted maximum oxygen consumption (peak oxygen consumption); (R=-0.41, P<0.01). Preliminary analysis indicates that cardiac sympathetic function might potentially act as a mediator in the association between ECV and NT-proBNP levels. CONCLUSIONS: Abnormally low cardiac sympathetic function in patients with HF with reduced and preserved LVEF is associated with extracellular volume expansion and decreased cardiopulmonary functional capacity.

Digoxin treatment does not reinduce radioiodine uptake in radioiodine refractory non-medullary thyroid carcinoma.

Objective: Patients with non-medullary thyroid carcinoma (NMTC) that are refractory to radioactive iodine (RAI) have a poor prognosis. Strategies for restoring the ability to take up iodine, so-called redifferentiation, are promising but not suitable for all patients. Preclinical studies, in human cell lines just as in a murine model, have shown that the cardiac glycoside digoxin restored RAI uptake. This prospective single-center open-label study aimed to investigate whether treatment with digoxin could reinduce clinically relevant RAI uptake in patients with metastasized RAI-refractory NMTC. Methods: Eight patients with metastasized RAI-refractory NMTC were included between November 2022 and June 2023. Before treatment, a baseline [123I]NaI scintigraphy was performed. Thereafter, patients were treated with digoxin for 3 weeks. Starting doses depended on age and weight. For safety reasons, the usual therapeutic range was aimed for. After 1 week, the digoxin plasma concentration was measured, and the digoxin dose was adjusted if necessary. After 3 weeks of digoxin treatment, a second [123I]NaI scintigraphy was performed. RAI uptake was compared between the two scintigraphies. Results: Seven patients completed the digoxin treatment and were evaluable. None of the seven patients showed clinically relevant RAI uptake after digoxin treatment. No digoxin-related serious adverse events occurred during this trial. Conclusion: Contrary to results from preclinical trials, in this trial, 3 weeks of digoxin treatment did not reinduce RAI uptake in patients with NMTC. This highlights essential challenges regarding the approach toward optimization of studies aimed to restore the RAI uptake and its therapeutic efficacy through drug repurposing.

Long-term disease-free survival after MIBG therapy for metastatic pheochromocytoma.

Pheochromocytomas are rare tumours originating in chromaffin cells, representing 0.1%-1% of all secondary hypertension cases. The majority are benign and unilateral, characterised by the production of catecholamines and other neuropeptides. Mainly located in the adrenal gland, they are more frequent between the third and fifth decades of life. Iodine-131 metaiodobenzylguanidine (131I-MIBG), a radiopharmaceutical agent used for scintigraphic localisation of pheochromocytomas, has been employed to treat malignant pheochromocytomas since 1983 in a few specialised centres around the world. We reviewed our clinical experience in one such case of a young lady who presented with history of abdominal pain, headache and lower back pain. On evaluation, ultrasonography revealed a right adrenal mass and elevated urine vanillylmandelic acid levels. Following surgical resection and histopathological confirmation of pheochromocytoma, MIBG scintigraphy revealed osseous metastases and hence, she underwent 131I-MIBG therapy.

Application of small bowel capsule endoscopy in children with Meckel's diverticulum.

BACKGROUND: Meckel diverticulum (MD) is an important cause of gastrointestinal bleeding in children. Small bowel capsule endoscopy (SBCE) is a first-line examination method applied to patients with obscure gastrointestinal bleeding, but there are few studies on its application in children with MD. This article aims to provide evidence in favor of the auxiliary diagnosis of MD in children by analyzing its characteristics using SBCE. METHODS: We retrospectively collected the clinical data of patients with suspected MD. RESULTS: A total of 58 children were included in this study. All 58 children presented overt gastrointestinal bleeding (bloody stool or melena). Capsule endoscopy identified protruding lesions in 2 cases, double-lumen changes in 30 cases (all considered as MD), vascular lesions in 7 cases, intestinal mucosal inflammatory lesions in 3 cases, ulcers or erosion in 3 cases, and no obvious abnormalities in SBCE in 12 cases. Both SBCE and technetium-99 scans were performed for 24 cases, 22 of which were diagnosed MD by their combined results, giving a diagnostic coincidence rate of 91.7%. Eight cases were highly suspected as MD but were negative for the technetium-99 scan and positive for SBCE. CONCLUSION: SBCE has high accuracy in the diagnosis of MD in children, especially when performed in combination with a technetium-99 scan, which can greatly improve the diagnostic rate of MD in children.

The Role of Scintigraphy with Bone Radiotracers in Cardiac Amyloidosis.

Cardiac amyloidosis (CA) is caused by the myocardial deposition of misfolded proteins, either amyloid transthyretin (ATTR) or immunoglobulin light chains (AL). The paradigm of this condition has transformed, since CA is increasingly recognized as a relatively prevalent cause of heart failure. Cardiac scintigraphy with bone tracers is the unique noninvasive technique able to confirm CA without performing tissue biopsy or advanced imaging tests. A moderate-to-intense myocardial uptake (Perugini grade ≥2) associated with the absence of a monoclonal component is greater than 99% specific for ATTR-CA, while AL-CA confirmation requires tissue biopsy.

Inverse correlation between age of onset and myocardial amyloid deposition quantified by 99mTc-PYP scintigraphy in patients with wild-type transthyretin amyloid cardiomyopathy.

OBJECTIVE: Wild-type transthyretin amyloidosis cardiomyopathy (ATTRwt-CM) is increasingly recognized as a contributing factor to cardiac insufficiency in the elderly population. We aimed to identify the factors affecting age of onset of ATTRwt-CM, encompassing the assessment of amyloid deposition in myocardial tissue through the use of 99mTc-pyrophosphate (PYP) and clinical parameters. METHODS: A retrospective investigation involving a consecutive cohort of 107 cases, each having been diagnosed with ATTRwt-CM confirmed through histopathological and genetic analysis, was performed. All patients underwent PYP scintigraphy, and the heart-to-contralateral (H/CL) ratio was calculated to measure amyloid deposition in the myocardium. Univariate and multivariate analyses were performed to identify independent predictors of the age of onset of ATTRwt-CM, considering the H/CL ratio and various clinical risk factors for heart failure. RESULTS: Gender (p = 0.03), Creatinine (Cr) (r = 0.32, p < 0.01), hemoglobin (Hb) (r = - 0.44, p < 0.01), albumin (Alb) (r = - 0.32, p < 0.01), brain natriuretic peptide (BNP) (r = 0.21, p = 0.03), low-density lipoprotein-cholesterol (LDL-C) (r = - 0.27, p < 0.01), and H/CL ratio (r = - 0.44, p < 0.01) were all significantly associated with the onset age. In multiple regression analysis, the independent predictive factors for the onset age of ATTRwt-CM were identified as the H/CL ratio (p < 0.01), Hb (p < 0.01), and Cr (p < 0.01). CONCLUSION: The H/CL ratio, Hb, and Cr independently affect age of onset in patients with ATTRwt-CM. The H/CL ratio is inversely correlated with age of onset, and may be the sole factor in the development of heart failure in early onset patients, while it may have a synergistic effect on heart failure with anemia and renal dysfunction in late-onset patients.

Splenic Dysfunction in Children With Sickle Cell Disease: A Single Centre Experience From Central India.

OBJECTIVE: To assess the prevalence and predictors of splenic dysfunction in children with sickle cell disease (SCD). METHODS: A cross-sectional study was conducted between June 2019 and December 2020 where children aged 1 to 15 years of age with SCD were screened for splenic dysfunction. Children who were splenectomised, those with other diseases known to affect splenic function like congenital malformations, immunodeficiencies, and chronic diseases like tuberculosis, nephrotic syndrome, diabetes mellitus, chronic liver disease, celiac disease or malignancy were excluded. Splenic size was assessed by clinical examination and ultrasonography. Splenic dysfunction was assessed by Technetium-99m (99mTc) labeled autologous RBCs and by the presence of Howell Jolly bodies in the peripheral smear. Laboratory and clinical predictors of splenic dysfunction were assessed by multiple logistic regression. RESULTS: We evaluated 66 children with SCD with a mean (SD) age of 7.41 (3.3) years. Impaired and absent splenic function as assessed by 99mTc scintigraphy was found in 13 (19.7%), and 3 (4.6%) children, respectively. Howell Jolly bodies in peripheral smear were found in 5 (7.5%) children; 3 of them had abnormal uptake on scintigraphy; all five had splenomegaly. Age > 5 years, > 4 episodes of vaso-occlusive crisis (VOC), > 3 hospitalization events in the past, > 5 blood transfusions, children not receiving hydroxyurea, reticulocyte count > 4%, and HbS > 70% were independent predictors of splenic dysfunction. CONCLUSION: The prevalence of splenic dysfunction in children with SCD in Central India is lower than that reported from the West. The decision to start antibiotic prophylaxis can be individualized in these children.

A case of renal sarcoidosis complicated by parotid gland and uterine lesions.

BACKGROUND: Sarcoidosis is a systemic disease that can affect multiple organs. While pulmonary sarcoidosis is most commonly observed, renal sarcoidosis occurs less frequently. We herein report a case of sarcoidosis with an exceptionally rare distribution including renal lesions. CASE PRESENTATION: A 51-year-old Japanese female was referred because of bilateral parotid swelling and renal dysfunction. Computed tomography scan showed the swelling of bilateral kidneys, parotid glands, and uterus. Ga scintigraphy also showed remarkable accumulation in these organs. Renal biopsy and cytological evaluations of parotid gland and uterus were performed and she was diagnosed as sarcoidosis of these organs. Treatment was initiated with prednisolone 40 mg/day and then renal dysfunction subsequently improved. In addition, the swelling of parotid glands and uterus improved and Ga accumulation in each organ had disappeared. CONCLUSION: This is a first case of renal sarcoidosis complicated by parotid glands and uterus lesions. Pathological findings and the reactivity observed in Ga scintigraphy indicated the presence of lesions in these organs.

Can CT or MRI volumetry substitute scintigraphy in living kidney donor evaluation? A systematic review.

BACKGROUND: Current potential living kidney donor's assessment includes functional and anatomical evaluation. Scintigraphy is recommended in some cases and some centers include this test in the donor's protocol. Recent studies advocate for the avoidance of this test as CT or MRI volumetry showed to accurately assess donor's renal function. OBJECTIVE: To summarize scientific evidence on image tests for pre-donation and/or post-nephrectomy renal function evaluation. EVIDENCE ACQUISITION: This review followed the guidelines set by the European Association of Urology and adhered to PRISMA 2020 recommendations. The protocol was registered in PROSPERO on 10th December 2022 (ID: CRD42022379273). EVIDENCE SYNTHESIS: Twenty-one studies met the inclusion criteria after thorough screening and eligibility assessment. According to QUADAS-2, patient selection and flow/timing domains showed a predominant low risk of bias. The correlation between split renal function (SRF) using CT and scintigraphy varied from weak (r = 0.21) to remarkably strong (r = 0.949). Bland-Altman agreement demonstrated moderate to excellent results, with mean differences ranging from -0.06% to 1.76%. The correlation between split renal volume (CT) and estimated glomerular filtration rate (eGFR) at 6 months or 1 year after nephrectomy showed a moderate correlation, with coefficients ranging from 0.708 to 0.83. The correlation between SRF (MRI) and renal scintigraphy reported a moderate correlation, with correlation coefficients of 0.58 and 0.84. MRI and scintigraphy displayed a good agreement, with a 66% agreement observed and mean differences of ± 0.3%. CONCLUSIONS: Despite study heterogeneity, MRI or CT-based renal volumetry appears promising compared to scintigraphy, with favorable correlations and agreement.

Efficacy of Empirical 131 I Radioiodine Therapy in Well-Differentiated Thyroid Carcinoma Patients With Thyroglobulin-Elevated Negative Iodine Scintigraphy Syndrome : A Systematic Review and Meta-analysis.

OBJECTIVES: This study aimed to perform a systematic review and meta-analysis on the efficacy of empirical high-dose radioiodine therapy in treating differentiated thyroid cancer patients with thyroglobulin (Tg)-elevated negative iodine scintigraphy (TENIS) syndrome. METHODS: We searched PubMed, EMBASE, and the Cochrane Library to identify relevant studies published until April 2022. This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist and registered in an international prospective register of systematic reviews (PROSPERO). Meta-analyses of proportions and odds ratios were performed to assess the beneficial effect of empirical high-dose radioiodine therapy in patients with TENIS syndrome. Subgroup analysis was also performed according to the presence of micrometastasis or macrometastasis. RESULTS: We identified 14 studies including 690 patients who received empirical high-dose radioiodine therapy for TENIS syndrome. Those who had micrometastasis exhibited additional lesions not previously observed on diagnostic whole-body scan (prop = 0.64, 95% confidence interval [CI], 0.51-0.77) and had reduced serum Tg levels (prop = 0.69; 95% CI, 0.52-0.84) after empirical radioiodine treatment. No such findings were observed among patients with macrometastasis. Moreover, we found that the empirical radioiodine treatment group had lower serum Tg levels than did controls (odds ratio = 0.27; 95% CI, 0.09-0.87), which suggests a lower risk of disease progression. CONCLUSIONS: Our findings indicate that empirical high-dose radioiodine therapy promoted beneficial effects and could be recommended for patients with TENIS syndrome, especially those with micrometastasis.

Scintigraphy of Gastrointestinal Motility: Best Practices in Assessment of Gastric and Bowel Transit in Adults.

Various radiologic examinations and other diagnostic tools exist for evaluating gastrointestinal diseases. When symptoms of gastrointestinal disease persist and no underlying anatomic or structural abnormality is identified, the diagnosis of functional gastrointestinal disorder is frequently applied. Given its physiologic and quantitative nature, scintigraphy often plays a central role in the diagnosis and treatment of patients with suspected functional gastrointestinal disorder. Most frequently, after functional gallbladder disease is excluded, gastric emptying scintigraphy (GES) is considered the next step in evaluating patients with suspected gastric motility disorder who present with upper gastrointestinal symptoms such as dyspepsia or bloating. GES is the standard modality for detecting delayed gastric emptying (gastroparesis) and the less commonly encountered clinical entity, gastric dumping syndrome. Additionally, GES can be used to assess abnormalities of intragastric distribution, suggesting specific disorders such as impaired fundal accommodation or antral dysfunction, as well as to evaluate gastric emptying of liquid. More recently, scintigraphic examinations for evaluating small bowel and large bowel transit have been developed and validated for routine diagnostic use. These can be performed individually or as part of a comprehensive whole-gut transit evaluation. Such scintigraphic examinations are of particular importance because clinical assessment of suspected functional gastrointestinal disorder frequently fails to accurately localize the site of disease, and those patients may have motility disorders involving multiple portions of the gastrointestinal tract. The authors comprehensively review the current practice of gastrointestinal transit scintigraphy, with diseases and best imaging practices illustrated by means of case review. ©RSNA, 2024 See the invited commentary by Maurer and Parkman in this issue.