tracer uptake
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Tomography ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 180-188
Author(s):  
Harry Hothi ◽  
Arianna Cerquiglini ◽  
Lukas Büel ◽  
Johann Henckel ◽  
Lukas B. Moser ◽  
...  

Background: SPECT/CT distribution patterns in patients with total knee replacements have previously been correlated with factors such as time of implantation, implant type and alignment. It is unknown, however, if an increased and more extended bone tracer uptake (BTU) in SPECT/CT, representing loading of the joint, correlates with findings from retrieval studies. The aim of this study was to further understand this subject. Materials and Methods: 62 retrieved TKA were included. SPECT/CT was performed prior to revision. Quantitative and qualitative medio-lateral comparisons of BTU intensity and distribution in the tibia were performed. Retrieval analysis was performed with a micro-CT method to assess the thickness differences between medial and lateral sides of polyethylene inserts with symmetrical designs. Results: In the subgroup of TKA with asymmetrical SPECT/CT distribution, there was a significant correlation between retrieval and medical imaging data (p = 0.0355): patients showing a more extended BTU in the medial compartment also had a significantly thinner insert in the medial compartment, and vice versa in the lateral side. Conclusion: This is the first study comparing BTU distribution patterns and retrieval findings. Our results support the hypothesis that SPECT/CT is able to identify bone activity due to implant position and loading.


EMJ Oncology ◽  
2022 ◽  
Author(s):  
Sajjad Ali Khan ◽  
M. Mustansir Mehdi Khan ◽  
Matiullah Kamin ◽  
Azra Rizwan

Background: Concurrent thyroid cancer and hyperthyroidism is a rare finding. The frequency of this association is very variable. A rare case of papillary thyroid cancer associated with hyperthyroidism is described here. Case: A 49-year-old male presented to the authors’ outpatient clinic with complaints of a painless left-sided anterior neck swelling that had persisted for the past 8 months. He also reported weight loss for the same duration. The anterolateral swelling was non-tender, asymmetrical, mobile, and rubbery. Investigations: Biochemical analysis confirmed hyperthyroidism. Ultrasound examination of the neck showed a well-defined, solid, and cystic lesion in the left lobe and isthmus of thyroid gland. The solid portion had few specks of calcification. A radioactive thyroid scan showed increased tracer uptake in the left lobe. Papillary carcinoma of thyroid origin was discovered after fine-needle aspiration of the left anterior cervical lymph node. After preparation, a total thyroidectomy was done. Examination of histopathology confirmed papillary thyroid carcinoma. Treatment: Following radioactive thyroid ablation, the patient was started on suppressive doses of thyroxine daily. Conclusion: Although thyroid cancer with hyperthyroidism is a rare finding, it should not be disregarded. To avoid missing this unusual yet uncommon discovery, a detailed history and physical examination should be performed, as well as all required investigations.


2021 ◽  
pp. jnumed.121.262660
Author(s):  
Guilherme Domingues Kolinger ◽  
David Vállez García ◽  
Gerbrand Maria Kramer ◽  
Virginie Frings ◽  
Gerben Johannes Cornelis Zwezerijnen ◽  
...  

2021 ◽  
pp. 028418512110636
Author(s):  
Zita Képes ◽  
Márton Mikó ◽  
Kornél Kukuts ◽  
Regina Esze ◽  
Sándor Barna ◽  
...  

Background Sensitive imaging modalities in the diagnosis of microcircular complications of the lower extremities induced by metabolic diseases are becoming a focus of interest. Purpose To investigate the [99mTc]HMPAO uptake of the legs in type 2 diabetes mellitus (T2DM) and obesity, and to search for associations with clinical parameters and nerve conducting studies. Material and Methods A total of 57 patients with controlled T2DM and 46 obese participants without DM were enrolled in the study. [99mTc]HMPAO SPECT/CT examinations were performed to evaluate the radiopharmaceutical accumulation of the legs. For the quantitative assessment of tracer uptake, standardized uptake value (SUVpeak) was measured in fixed spheric volumes of interest placed on both sural muscles on the attenuation-corrected images. Measurement of current perception threshold applying Neurometer (NM-01/CPT) was used to evaluate peripheral nerve dysfunction. Laboratory parameters assessing the glucose homeostasis of the study participants were also measured. Results In the diabetic group, significantly lower leg SUV values were detected compared to the non-DM obese group (median: 0.517 vs. 0.607; P < 0.001). Body mass index (BMI) ( P < 0.0001), age ( P = 0.0283), HbA1c ( P = 0.0068), and glucose level ( P = 0.0044) proved to be significant predictors of muscle tracer uptake. Neurometer studies showed positive correlation with HbA1c levels in the T2DM group ( P = 0.0002). Conclusion We assume that [99mTc]HMPAO uptake of leg muscles is associated with microcirculation, so quantitative [99mTc]HMPAO SPECT/CT might be a sensitive method for evaluating lower limb microvascular alterations. BMI, age, HbA1c, and glucose level may be significant predictors of peripheral vascular abnormalities triggered by metabolic disturbances.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Franziska J. Vettermann ◽  
Caroline Diekmann ◽  
Lorraine Weidner ◽  
Marcus Unterrainer ◽  
Bogdana Suchorska ◽  
...  

Abstract Background O-(2-[18F]-fluoroethyl)-L-tyrosine (18F-FET) is a highly sensitive PET tracer for glioma imaging, and its uptake is suggested to be driven by an overexpression of the L-type amino-acid transporter 1 (LAT1). However, 30% of low- and 5% of high-grade gliomas do not present enhanced 18F-FET uptake at primary diagnosis (“18F-FET-negative gliomas”) and the pathophysiologic basis for this phenomenon remains unclear. The aim of this study was to determine the expression of LAT1 in a homogeneous group of newly diagnosed 18F-FET-negative gliomas and to compare them to a matched group of 18F-FET-positive gliomas. Forty newly diagnosed IDH-mutant astrocytomas without 1p/19q codeletion were evaluated (n = 20 18F-FET-negative (tumour-to-background ratio (TBR) < 1.6), n = 20 18F-FET-positive gliomas (TBR > 1.6)). LAT1 immunohistochemistry (IHC) was performed using SLC7A5/LAT1 antibody. The percentage of LAT1-positive tumour cells (%) and the staining intensity (range 0–2) were multiplied to an overall score (H-score; range 0–200) and correlated to PET findings as well as progression-free survival (PFS). Results IHC staining of LAT1 expression was positive in both, 18F-FET-positive as well as 18F-FET-negative gliomas. No differences were found between the 18F-FET-negative and 18F-FET-positive group with regard to percentage of LAT1-positive tumour cells, staining intensity or H-score. Interestingly, the LAT1 expression showed a significant negative correlation with the PFS (p = 0.031), whereas no significant correlation was found for TBRmax, neither in the overall group nor in the 18F-FET-positive group only (p = 0.651 and p = 0.140). Conclusion Although LAT1 is reported to mediate the uptake of 18F-FET into tumour cells, the levels of LAT1 expression do not correlate with the levels of 18F-FET uptake in IDH-mutant astrocytomas. In particular, the lack of tracer uptake in 18F-FET-negative gliomas cannot be explained by a reduced LAT1 expression. A higher LAT1 expression in IDH-mutant astrocytomas seems to be associated with a short PFS. Further studies regarding mechanisms influencing the uptake of 18F-FET are necessary.


2021 ◽  
Vol 23 (Supplement_G) ◽  
Author(s):  
Tiziano Graziani ◽  
Carla Cidda ◽  
Walter Serra ◽  
Maria Mattioli ◽  
A. Sammartano ◽  
...  

Abstract Aims The importance of cardiac scan with phosphonate-based radiotracers in the diagnosis of cardiac amyloidosis is now well established. Standard imaging is performed 3 h after tracer injection with a planar view on the cardiac region. This study sought to evaluate the predictive role of early-phase myocardial uptake (10 min after injection) of 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) compared compared with standard late acquisition, in patients with suspected hereditary transthyretin-related cardiac amyloidosis (TTR-CA). Methods and results Fifty five patients with suspected of TTR-CA with typical aspects of the relative apical sparing at two-dimensional speckle-tracking echocardiography, reported as a specific pattern for cardiac amyloidosis, were enrolled after having signed informed written consent. They have been subjected to a 99mTc-DPD cardiac scintigraphy with planar acquisition at 10 min and 3 h after tracer injection (13 Mbq/Kg). Patients with cardiac uptake on the planar images concluded the examination with a SPECT-CT (cardiac protocol) to assess the affected myocardial segments. On planar images the heart-to-mediastinum-ratio was measured. Subsequently, the diagnosis of amyloidosis has to be confirmed with morphologic examinations such as biopsy and genetic tests. Of the enrolled patients with clinical and echocardiographic aspect of TTR-CA, 22 were positive for cardiac amyloidosis. All of them showed tracer uptake in both early and late images. In patients with positive results, the early-phase showed a Heart-to-mediastinum-ratio &gt;1.2. SPECT/CT showed involvement of almost two myocardial segments: in all patients the ventricular septum showed significant tracer uptake. Conclusions Our small group of patients showed that 99mTc-DPD myocardial uptake intensity on early-phase scintigraphy can be used to anticipate the results of late images in diagnosis of TTR cardiac amyloidosis.


Author(s):  
Affendy Hassan ◽  
Dorte Bodin Dresbøll ◽  
Kristian Thorup-Kristensen

The objective of this study was to evaluate the usage of species with coloured roots to study root growth patterns during intercropping. Red beet (Beta vulgaris L. cv. Detroit), having clear red roots, was used in a semi-field and field experiment to allow identification and quantification of roots of the individual species in the mixture. In the field experiment, red beet was strip intercropped with lucerne (Medicago sativa L. cv. Creno) and kale (Brassica oleracea L. var. Sabellica), respectively while the red beet-lucerne intercropping was conducted in large rhizoboxes where root growth distribution and <sup>15</sup>N isotope uptake was determined. The study confirmed that the direct visual measurement of root growth using species with coloured roots and indirect tracer uptake measurements contributed to the success of studying root growth dynamics in intercropping systems. Red beet root intensity was not considerably affected by the strip intercropping when the crops were established at the same time, but when established between existing lucerne strips, a reduction in roots at the border row was shown. Lucerne and kale were both observed to be able to exploit the deep soil layers beneath the red beet border row.  


Author(s):  
Yu. N. Vinogradova ◽  
M. S. Tlostanova ◽  
A. A. Ivanova ◽  
A. Yu. Pakhomov ◽  
N. V. Ilyin

Introduction: Metabolic Tumor Volume (MTV) and Total Tumor Lesion Glycolysis (TLG) are used in 18F-fluorodeoxyglucose Positron-Emission Tomography combined with Computed Tomography (18F-FDG PET/CT) as functional markers, indicating tracer uptake in whole tumor. MTV and TLG are not yet engaged in clinical practice, because volume measurement accuracy depends on the selected measurement method, and optimal MTV and TLG segmentation is not established.Purpose: Assessment of accuracy of metabolic tumor volume measurement ways, using 18F-FDG PET/CT in patients with Diffuse Large B-Cell Lymphoma (DLBCL).Material and methods: Baseline 18F-FDG PET/CT performed in 21 patients with DLBCL. Tumor Volume (TV), measured on contrast enhanced CT (CTTV), considered as reference. While measuring MTV, we aimed to achieve a 1:1 ratio between CTTV and MTV. If anatomical and metabolic tumor contours matched, MTV was considered true (MTVtrue). Overall MTV and TLG measurements are 254. Tumor contouring, using relative thresholds, was made around Standardized Uptake Value (SUVmax) of tracer in tumor and intact liver.Results: On CT, the size of the lesions varied from 24 to 241 mm, M = 103.4±62.3, Me = 93 (48.5–155.5). In 15 (71.4 %) foci, hypodense areas of necrosis were determined. PET imaging revealed high tracer uptake in all foci of varying degrees of intensity. SUVmax values in tumors ranged from 5.8 to 30.5, Me = 20.4 (17.3–23.2). No significant correlation was found between the size of the foci and SUVmax (ρ = 0.17, p = 0.4744). The best accuracy in measuring MTV was observed when several thresholds were applied: VOIPERCIST, VOI2.5, VOIauto-contour, as well as VOI10 %, VOI15 % and VOI20 %. The optimal absolute threshold values were SUV values in the range from 2 to 3, and relative values in the range from 10 % to 20 % of the SUVmax in the tumor. MTV underestimation was more often determined using relative cut-off indices in the range of25–50 % and SUV thresholds ≥ 5.3.Conclusion: The results obtained showed that the use of a single threshold value for MTV segmentation in patients with DLBCL is not advisable. The choice of the MTV measurement method should be carried out individually for each lesion, taking into account its shape, size and structure, as well as the intensity and uniformity of tracer uptake in the tumor and adjacent anatomical structures.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260482
Author(s):  
Ina Jahreis ◽  
Pablo Bascuñana ◽  
Tobias L. Ross ◽  
Jens P. Bankstahl ◽  
Marion Bankstahl

Purpose Alterations in brain glucose metabolism detected by 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) positron emission tomography (PET) may serve as an early predictive biomarker and treatment target for epileptogenesis. Here, we aimed to investigate changes in cerebral glucose metabolism before induction of epileptogenesis, during epileptogenesis as well as during chronic epilepsy. As anesthesia is usually unavoidable for preclinical PET imaging and influences the distribution of the radiotracer, four different protocols were compared. Procedures We investigated 18F-FDG uptake phase in conscious rats followed by a static scan as well as dynamic scans under continuous isoflurane, medetomidine-midazolam-fentanyl (MMF), or propofol anesthesia. Furthermore, we applied different analysis approaches: atlas-based regional analysis, statistical parametric mapping, and kinetic analysis. Results At baseline and compared to uptake in conscious rats, isoflurane and propofol anesthesia resulted in decreased cortical 18F-FDG uptake while MMF anesthesia led to a globally decreased tracer uptake. During epileptogenesis, MMF anesthesia was clearly best distinctive for visualization of prominently increased glucometabolism in epilepsy-related brain areas. Kinetic modeling further increased sensitivity, particularly for continuous isoflurane anesthesia. During chronic epilepsy, hypometabolism affecting more or less the whole brain was detectable with all protocols. Conclusion This study reveals evaluation of anesthesia protocols for preclinical 18F-FDG PET imaging as a critical step in the study design. Together with an appropriate data analysis workflow, the chosen anesthesia protocol may uncover otherwise concealed disease-associated regional glucometabolic changes.


Lymphology ◽  
2021 ◽  
Vol 54 (2) ◽  
Author(s):  
N. Sampathirao ◽  
M. Indirani ◽  
G. Manokaran ◽  
A. Jaykanth ◽  
A. Patel ◽  
...  

Lymphoscintigraphy with combined qualitative and quantitative analysis is reported to be a more sensitive approach to diagnose lymphedema in comparison with the conventional clinical analysis. Our study seeks to evaluate the diagnostic performance of lower limb lymphoscintigraphy with amalgamation of qualitative and quantitative analysis by measuring the ilio-inguinal nodal uptake. This prospective observational study was comprised of 86 patients (172 limbs) diagnosed with lower limb lymphedema. After a thorough clinical grading of edema, radionuclide lymphoscintigraphy was performed as per a dedicated institutional protocol. Ilio-inguinal nodal quantification of tracer uptake was computed along with the visual study of the scans. Additionally, the corresponding mean nodal uptake percentage for each grade of lymphedema was assessed and a cut off nodal uptake percentage to differentiate between normal and abnormal limbs was defined. Although quantitative analysis with nodal uptake percentage provides objective criteria to diagnose lymphedema, it can only act as an adjunct to qualitative method without replacing it. Finally, standardization of procedure for quantitative lymphoscintigraphy is needed including the potential for combining both rate of clearance of tracer from injection site and nodal uptake for quantification.


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