Tissue Iodine Research Articles

Normal values and reference ranges for quantitative assessment of myocardial first-pass perfusion by spectral computed tomography. From the Cadami-Spectral study

Abstract Background Spectral computed tomography (SCT) can generate iodine concentration maps according to the tissue iodine uptake, serving as a surrogate marker of organ perfusion. Thus, assessment of the iodine distribution maps derived from SCT allows to detect deviations in normal myocardial perfusion. As of present, reference ranges for the iodine concentration in each myocardial segment of the left ventricle (LV) derived from the first-pass perfusion have not been published. Purpose To provide normal values of first pass perfusion in individuals without coronary artery disease (CAD). Additionally, we explored whether these values could vary according to gender, contrast dosing or the cardiac cycle phase assessed. Methods From October 2021 to January 2024, we retrospectively identified patients who underwent a CT Cardiac Angiography (CTCA) and had no evidence of CAD or structural heart disease. Subjects were scanned using a dual-layer SCT, following a standard local protocol which included a weight-based contrast medium dosing of 0.8 mL/Kg. Iodine density maps were reconstructed using the MCA filter at a phase of 78%. An additional sample of 18 subjects who received a dosing of contrast of 1 mL/Kg and 16 cases scanned using a systolic acquisition and reconstructed at phase of 35% were also included. Spectral reconstructions were combined with tissue segmentation to obtain the spatial distribution of iodine along the myocardium. Mean, median and standard deviations values of density of iodine (mg/ml) were quantified for each segment following the AHA-17 segment model. Results Perfusion data from 80 woman (median age: 60 [IQR: 54-65.6] years) and 47 males (median age: 47 [IQR: 43 – 54] years) were analysed. Despite receiving higher dose of contrast (67.9 vs 59.8 mL; p < 0.05), male subjects exhibited lower iodine density values in the myocardium compared to females (median concentration per segment 1.58 vs 2.01 mg/dL, p<0.001; figure 1). Notably, the volume of the LV myocardium was higher in male than in women (143 mL vs 92 mL, p<0.001). These differences could be partially explained in a mixed model considering the ratio contrast dose/myocardium volume (b = 1.500, p < 0.001). Higher contrast dosing (1 mL/Kg vs 0.8 mL/kg) correlated with higher iodine density values in the myocardium (2.03 vs 1.83 mg/dL, respectively; p = 0.023). No differences were noted when comparing reconstructions at systole vs diastole (1.86 vs 1.80 mg/dL, respectively; p = 0.484). Reference range values of each myocardial segment are listed in table 1. Conclusions Significant gender discrepancies are detected in the analysis of first-pass myocardial perfusion. These variations can be partially explained by differences in the LV myocardium volume. Our findings provide applicable reference ranges of the iodine concentration in myocardium at first pass perfusion in controls without coronary or structural heart disease.

Misinterpretations about CT numbers, material decomposition, and elemental quantification.

Quantitative CT imaging, particularly iodine and calcium quantification, is an important CT-based biomarker. This study quantifies sources of errors in quantitative CT imaging in both single-energy and spectral CT. This work examines the theoretical relationship between CT numbers, linear attenuation coefficient, and material quantification. We derive four understandings: (1) CT numbers are not proportional with element mass in vivo, (2) CT numbers are proportional with element mass only when contained in a voxel of pure water, (3) iodine-water material decomposition is never accurate in vivo, and (4) for error-free material decomposition a voxel must only consist of the basis decomposition vectors. Misinterpretation-based errors are calculated using the National Institute of Standards and Technology (NIST) XCOM database for: tissue chemical compositions, clinical concentrations of hydroxyapatite (HAP), and iodine. Quantification errors are also demonstrated experimentally using phantoms. In single-energy CT, misinterpretation-induced errors for HAP density in adipose, muscle, lung, soft tissue, and blood ranged from 0-132%, i.e., a mass error of 0-749 mg/cm3. In spectral CT, errors with iodine in the same tissues resulted in a range of < 0.1-33% error, resulting in a mass error of < 0.1-1.2 mg/mL. Our work demonstrates material quantification is fundamentally limited when measured in vivo due to measurement conditions differing from assumed and the errors are at or above detection limits for bone mineral density (BMD) and spectral iodine quantification. To define CT-derived biomarkers, the errors we demonstrate should either be avoided or built into uncertainty bounds. Improving error bounds in quantitative CT biomarkers, specifically in iodine and BMD quantification, could lead to improvements in clinical care aspects based on quantitative CT. CT numbers are only proportional with element mass only when contained in a voxel of pure water, therefore iodine-water material decomposition is never accurate in vivo. Misinterpretation-induced errors ranged from 0-132% for HAP density and < 0.1-33% in spectral CT with iodine. For error-free material decomposition, a voxel must only consist of the basis decomposition vectors.

Iodine avidity in papillary and poorly differentiated thyroid cancer is predicted by immunohistochemical and molecular work-up.

Successful radioiodine treatment of differentiated thyroid cancer requires iodine avidity: that is, the concentration and retention of iodine in cancer tissue. Several parameters have previously been linked with lower iodine avidity. However, a comprehensive analysis of which factors best predict iodine avidity status, and the magnitude of their impact, is lacking. Quantitative measurements of iodine avidity in surgical specimens (primary tumour and lymph node metastases) of 28 patients were compared to immunohistochemical expression of the thyroid-stimulating hormone receptor, thyroid peroxidase (TPO), pendrin, sodium-iodide symporter (NIS) and mutational status of BRAF and the TERT promoter. Regression analysis was used to identify independent predictors of poor iodine avidity. Mutations in BRAF and the TERT promoter were significantly associated with lower iodine avidity for lymph node metastases (18-fold and 10-fold, respectively). Membranous NIS localisation was found only in two cases but was significantly associated with high iodine avidity. TPO expression was significantly correlated with iodine avidity (r = 0.44). The multivariable modelling showed that tumour tissue localisation (primary tumour or lymph node metastasis), histological subtype, TPO and NIS expression and TERT promoter mutation were each independent predictors of iodine avidity that could explain 68% of the observed variation of iodine avidity. A model based on histological subtype, TPO and NIS expression and TERT promoter mutation, all evaluated on initial surgical material, can predict iodine avidity in thyroid cancer tissue ahead of treatment. This could inform early adaptation with respect to expected treatment effect.

Iodine biofortification of four microgreens species and its implications for mineral composition and potential contribution to the recommended dietary intake of iodine

The World Health Organization has identified iodine deficiency as one of the nutritional problems that affect more than a third of the world's population. About 60% of the world's population suffers from ‘hidden hunger’ with subtle and nonspecific health effects, regardless of social and economic status. The agronomic biofortification of leafy vegetables with iodine could increase the uptake of this crucial element. The current study constitutes the first report of results on the agronomic biofortification with iodine of four different species of microgreens (tatsoi, coriander, green basil, and purple basil). Biofortification was applied through the nutrient solution, using two doses of I (4 and 8 µM) plus an untreated control. Iodine supplementation across species had no effect on the dry matter content, color parameters, and nitrate levels of harvested microgreens. However, the 8 µM dose of iodine increased tissue iodine concentration by 226.52% (on average), with the highest values obtained from tatsoi (15.03 µg g − 1 fw). Taking into account the iodine recommended dietary allowance (RDA), consuming one serving of tatsoi biofortified with 8 µM I solution would cover 100.19% and 37.57% of daily requirement for adults and children, respectively. Our results demonstrated significant differences in the response of the four species to biofortification with iodine, highlighting the significant potential of select microgreens species for contributing to the combating of hidden hunger as an efficient and sustainable dietary resource.

Utility of non-contrast Dual Energy Computed Tomography in diagnosis of differentiated thyroid cancer – two case study

BackgroundDual Energy Computed Tomography (DECT) is a technology that allows for viewing computed tomography spectral images. This method, due to ability of presenting specific elements and substances (like water, calcium and iodine), can be used to locate selected type of tissues. Thyroid tissue due to being rich in endogenous iodine, can be located even without administration of contrast agent.Case presentationIn presented cases authors used a feature of accumulating endogenous iodine in thyroid derivative tissue for diagnosis of differentiated thyroid cancer metastases. In Patient One DECT was a decisive parameter qualifying for the surgery. Due to use of DECT in Patient Two it was possible to directly localize thyroid cancer metastases, which was unfeasible using standard techniques (scintigraphy and [18 F]FDG PET/CT). It helped to perform targeted biopsy and confirm diagnosis of thyroid cancer metastases, allowing to introduce treatment with sorafenibe.ConclusionDECT confirmed its utility in locating thyroid tissues, including differentiated thyroid cancer (DTC) metastases. The method could be used in the future, especially in borderline or ambiguous cases with no localization of DTC in ultrasonography, RAI scintigraphy, or [18 F]FDG PET/CT, and among patients having contraindications for contrast-CT.

Comparison of Chemical Element Contents in Thyroid Goiter, Adenoma, and Thyroiditis investigated using Neutron Activation Analysis

Thyroid benign nodules (TBNs) are the most common lesions of this endocrine gland. Among TBNs the colloid goiter (CG), thyroiditis (T), and thyroid adenoma (TA) are the most frequent diseases. An evaluation of the variant of TBNs is clinically important for subsequent therapeutic interventions, as well as for more clear understanding the etiology of these disorders. The aim of this exploratory study was to examine differences in the content of bromine (Br), calcium (Ca), chlorine (Cl), iodine (I), potassium (K), magnesium (Mg), manganese (Mn), and sodium (Na) in tissues of CG, TA, and T. Thyroid tissue levels of eight chemical elements (ChE) were prospectively evaluated in 46 patients with CG, 19 patients with TA, and 12 patients with T. Measurements were performed using non-destructive instrumental neutron activation analysis with high resolution spectrometry of short-lived radionuclides. Tissue samples were divided into two portions. One was used for morphological study while the other was intended for ChE analysis. It was observed that in CG, TA and T tissues content of Br was significantly higher, while level of I was lower than in normal thyroid tissue. I accumulation in T tissue was lower than in normal thyroid and CG. Abnormal increase in Br level and decrease in I level in all TBNs might demonstrate an involvement of these ChE in etiology and pathogenesis of TBNs. It was suosed that great losses of I in thyroid with T, in contract to little reduced levels of I content in thyroid with CG and TA, could possibly be explored for differencial diagnosis of T.

The presence of contrast agent increases organ radiation dose in contrast-enhanced CT

ObjectivesRoutine dosimetry calculations do not account for the presence of iodine in organs and tissues during CT acquisition. This study aims to investigate the impact of contrast agent (CA) on radiation dose.MethodsFirst, relation between absorbed radiation dose and iodine concentrations was investigated using a cylindrical water phantom with iodine-saline dilution insertions. Subsequently, a retrospective study on abdominal dual-energy CT (DECT) patient data was performed to assess the increase of the local absorbed radiation dose compared to a non-contrast scan. Absorbed doses were estimated with Monte Carlo simulations using the individual CT voxel data of phantom and patients. Further, organ segmentations were performed to obtain the dose in liver, liver parenchyma, left kidney, right kidney, aorta, and spleen.ResultsIn the phantom study, a linear relation was observed between the radiation dose normalized by computed tomography dose index (CTDI) and CA concentrations Iconc (mg/ml) for three tube voltages; frac{D_{80 kVp}}{CTDI_{vol}} = 0.14 × Iconc + 1.02, frac{D_{120 kVp}}{CTDI_{vol}} = 0.16 × Iconc + 1.21, frac{D_{140 kVp}}{CTDI_{vol}} = 0.16 × Iconc + 1.24, and for DECT acquisition; frac{D_{DECT}}{CTDI_{vol}} = 0.15 × Iconc + 1.09. Similarly, a linear relation was observed between the dose increase and the organ iodine contents (R2 = 0.86 and pvalue < 0.01) in the patient study. The relative doses increased in the liver (21 ± 5%), liver parenchyma (20 ± 5%), right kidney (37 ± 7%), left kidney (39 ± 7%), aorta (34 ± 6%) and spleen (26 ± 4%). In addition, the local dose distributions changed based on patient’s anatomy and physiology.ConclusionsCompared to a non-contrast scan, the organ doses increase by 30% in contrast-enhanced abdominal CT. This study suggests considering CA in dosimetry calculations, epidemiological studies, and organ dose estimations while developing new CT protocols.Key Points• The presence of contrast media increases radiation absorption in CT, and this increase is related to the iodine content in the organs.• The increased radiation absorption due to contrast media can lead to an average 30% increase in absorbed organ dose.• Iodine should be considered in CT radiation safety studies.

Mass spectrometry – based imaging techniques for iodine-127 and iodine-129 detection and localization in the brown alga Laminaria digitata

129I is one of the main radioisotopes of iodine derived from the nuclear fuel cycle that can be found sustainably in the environment due to its long half-life. In coastal marine environment, brown macroalgae, such laminariales (or kelps), are known to naturally feature highest rates of iodine accumulation, and to be an important source of biogenic volatile iodinated compounds released to the atmosphere. These seaweeds are therefore likely to be significantly marked by but also potential vectors of radioactive iodine. In order to better understand the chemical and isotopic speciation of iodine in brown algal tissues, we combined mass spectrometry-based imaging approaches in natural samples of Laminaria digitata young sporophytes, collected at two different locations along the south coast of the English Channel (Roscoff and Goury). Laser desorption ionization (LDI) and desorption electrospray-ionization techniques (DESI), coupled with mass spectrometry, confirmed the predominance of inorganic I− species on the surface of fresh algae, and a peripheral iodine localization when applied on micro-sections. Moreover, radioactive isotope 129I was not detected on plantlet surface or in stipe sections of algal samples collected near Roscoff but was detected in L. digitata samples collected at Goury, near La Hague, where controlled liquid radioactive discharges from the ORANO La Hague reprocessing plant occur. At the subcellular scale, cryo-fixed micro-sections of algal blade samples from both sites were further analyzed by secondary ion mass spectrometry (nano-SIMS), leading to similar results. Even if the signal detected for 129I was much weaker than for 127I in samples from Goury, the chemical imaging revealed some differences in extracellular distribution between radioactive and stable iodine isotopes. Altogether LDI and nano-SIMS are complementary and powerful techniques for the detection and localization of iodine isotopes in algal samples, and for a better understanding of radioactive and stable iodine uptake mechanisms in the marine environment.

Вміст поліненасичених жирних кислот і Йоду в тканинах та інтенсивність росту відгодівельних бугайців за введення до раціону добавок олій і калію йодиду

Вміст поліненасичених жирних кислот і Йоду в тканинах та інтенсивність росту відгодівельних бугайців за введення до раціону добавок олій і калію йодиду

Особенности накопления йода в мышцах кроликов на фоне использования антиоксидантов в липосомальной форме

Abstract. The problem of iodine saturation of livestock products for residents of most regions of our country requires a detailed study. One of the factors is the obtaining of livestock products enriched with organic iodine. The study of the degree of accumulation of iodine in the muscle tissue of rabbits at the background of the use of liposomal form of antioxidants enriched with organic iodine (LFA) was the main purpose of the research. Methods. An experiment on rabbits of the California breed were used. The first control group received the main diet (MD) in the form of a granular mixture. The experimental second group was given LFA based on White sea laminarias at the rate of 250 g per ton of feed mixture of MD. The third experimental group was injected with MD the LFA with Black sea Cystoseira. The formation of meat indicators, chemical analysis of muscle tissue, the level of accumulation of trace elements, including iodine in muscle tissue was studied indicators. Results. Based on the somatometric method of evaluating rabbits, it was found that the young animals of the experimental groups form a more eirisomus-type body (from 60 to 70 % of the total population). All indicators of the interactions of somatic parameters in the young groups II and III positive and highly significant correlation, and the correlation index of the density of the body correlated positively with body length (r = +0,67, p ≤ 0.01), chest girth (r = +0,86, p ≤ 0.001), length of loin (r = +0,61, p ≤ 0,01), the length of the backside (r = +0.71, p ≤ 0.001) and head measurement (r = +0,57, p ≤ 0.05). An improvement of the indicators of slaughter of experimental groups of young animals was stated. The slaughter weight increases by 12.2 %, and the mass of internal organs responsible for digestion by 4.5–43.8 %. A percentage of increase in muscle tissue during boning by 10.0–15.9 % and a decrease in the proportion of low-value parts in the carcass-bone tissue by 8.6–9.9 % was stated. Iodine in the average sample of muscle tissue of the experimental groups increases by 91.8 mcg (p ≤ 0.05) in animals of the second group and by 113.3 mcg (p ≤ 0.05) of the third group.

EFFECT OF ORGANIC AND INORGANIC IODINE COMPOUNDS ON PIG PRODUCTIVITY AND MEAT QUALITY

The aim of this study was designed to examine the efficiency of various iodine compounds in pigs’ diets. The impact of inorganic and organic iodine compounds – potassium iodate and iodated milk protein, which is a part of the "ProstTM" feed additive ("Innbiotech", Russia) – on the growth, meat productivity and lean meat yield of fattening pigs was studied. The physico-chemical composition and biological value of the meat were studied. The accumulation of iodine in animal muscle tissue was assessed. It was found that iodized milk protein contributed to more intensive growth than the inorganic iodine source. Specifically, animals fed the organic form of iodine were superior in terms of carcass weight and yield value of muscle and fat tissue. Compared to the control group, the experimental groups of pigs demonstrated a muscle tissue yield of 0.45%. Organic sources of iodine were also found to have a positive impact on the chemical composition of meat; animals fed the organic form of iodine surpassed those receiving inorganic iodine in terms of their meat’s dry substance, protein content and fat content. The level of iodine in the muscle tissue of pigs receiving organic iodine was considerably higher, and these pigs surpassed those receiving the inorganic iodine source in terms of the presence of essential amino acids in their muscle tissue.

Iodide Transporters in the Endometrium: A Potential Diagnostic Marker for Women with Recurrent Pregnancy Failures

Objective: The element iodine is an essential nutrient utilized by the thyroid glands, and deficiency of this element has been linked to reproductive failures. Iodide transporters are also present in reproductive tissues and cells of embryonic origin such as the endometrium and trophoblasts, respectively. The aim of this study is to understand if levels of iodide transporters are linked to pregnancy outcomes. Subjects and Methods: RNA derived from endometrial biopsies from controls or women with recurrent reproductive failures was analyzed utilizing RT-PCR and targeted RNASeq. Results: When compared to controls, women with 2 or more reproductive failures had a significant increase (>5 fold) in mRNA levels of the iodine transporters NIS and PENDRIN, but not thyroglobulin when probed vis RT-PCR. Targeted RNASeq analysis confirmed these findings when another group of patients were analyzed. Conclusion: These findings suggest possible abnormal iodine metabolism and a deficiency of iodine in endometrial tissues from some of the women with reproductive failures. We hypothesize from these findings that inorganic iodide and/or iodine is required for optimal cellular function in reproductive tissues, and that iodide transporters may potentially be used as a marker for infertility or for probing potential localized iodine deficiency that may not present in a typical thyroid panel analysis.

Iodine Accumulation and Tolerance in Sweet Basil (Ocimum basilicum L.) With Green or Purple Leaves Grown in Floating System Technique.

Iodine deficiency is a serious world-wide public health problem, as it is responsible for mental retardation and other diseases. The use of iodine-biofortified vegetables represents a strategic alternative to iodine enriched salt for people with a low sodium diet. However, at high concentrations iodine can be toxic to plants. Therefore, research on plant iodine toxicity is fundamental for the development of appropriate biofortification protocols. In this work, we compared two cultivars of sweet basil (Ocimum basilicum L.) with different iodine tolerance: “Tigullio,” less tolerant, with green leaves, and “Red Rubin,” more tolerant and with purple leaves. Four greenhouse hydroponic experiments were conducted in spring and in summer with different concentrations of iodine in the nutrient solution (0.1, 10, 50, 100, and 200 μM), supplied as potassium iodide (KI) or potassium iodate (KIO3). Plant growth was not affected either by 10 μM KI or by 100 μM KIO3, while KI concentrations higher than 50 μM significantly reduced leaf area, total plant dry matter and plant height. The severity of symptoms increased with time depending on the cultivar and the form of iodine applied. Growth inhibition by toxic iodine concentrations was more severe in “Tigullio” than in “Red Rubin,” and KI was much more phytotoxic than KIO3. Leaf iodine concentration increased with the iodine concentration in the nutrient solution in both varieties, while the total antioxidant power was generally higher in the purple variety. In both basil cultivars, a strong negative correlation was found between the photosynthesis and the leaf iodine content, with significant differences between the regression lines for “Tigullio” and “Red Rubin.” In conclusion, the greater tolerance to iodine of the “Red Rubin” variety was associated with the ability to withstand higher concentrations of iodine in leaf tissues, rather than to a reduced accumulation of this element in the leaves. The high phenolic content of “Red Rubin” could contribute to the iodine tolerance of this purple cultivar.

High iodine effects on the proliferation, apoptosis, and migration of papillary thyroid carcinoma cells as a result of autophagy induced by BRAF kinase

Papillary thyroid carcinoma (PTC) is a common endocrine tumor. This study found that different iodine concentrations affected the proliferation, apoptosis, and migration of PTC. For this study, we collected clinical information from PTC patients and monitored the levels of urinary iodine, LC3-II, and caspase-3 in cancer tissue, and BRAF kinase in peripheral blood from PTC patients. We also monitored the proliferation, apoptosis and migration ability of human papillary-thyroid carcinoma (BCPAP) cells at different iodine concentrations and their association with changes in autophagy and BRAF kinase activity of BCPAP cells at high iodine levels (10−3 mol/l). We found that the proportion of tumor diameters ≥ 1 cm in the iodine excess group were lower than that in the iodine non-excess group. The proportion of PTC patients with infiltration in the iodine excess group was higher than that in the iodine non-excess group. Levels of the autophagy-related protein LC3-II and the apoptosis-related protein caspase-3 in cancer tissues, and activity of BRAF kinase in peripheral blood, were positively correlated with urinary iodine concentrations from PTC patients. At high iodine levels, the proliferation rate decreased, and apoptosis percentage and migration rates increased compared with the no-iodine group. At high iodine levels, the frequencies of autophagosomes (Aph) and autophagosome-lysosomes (Apl) in BCPAP cells increased significantly, and activities of LC3-II and BRAF kinase increased, respectively. The activity of LC3-II decreased when BRAF kinase was inhibited. The activity of LC3-II and the proliferation and migration rates of BCPAP cells decreased, and the apoptosis percentage increased when autophagy was inhibited at high iodine concentrations. Our results demonstrated that, in the presence of excessive iodine, the mean tumor size of PTC patients was smaller and easier to invade than tumors in patients not supplied with excessive iodine. The levels of autophagy and apoptosis in PTC cancer tissues, and activities of BRAF kinase in peripheral blood increased with increasing urinary iodine concentrations. High iodine levels inhibited cell proliferation and promoted apoptosis and migration of PTC cells. Autophagy induced by BRAF kinase in PTC cells was involved in anti-apoptosis, and promoted proliferation and migration at high iodine concentrations. This study provides a rationale for iodine supplementation in PTC patients.

Effects of Iodine Agronomic Bio- fortification on selected Physiological Characteristics of Cassava in Calabar, Southeastern Nigeria

Field experiments were conducted between November 2011 and May 2014 at the Crop Science Teaching and Research Farm of the University of Calabar, (Southeastern rainforest agro-ecological zone of Nigeria) to determine the effectiveness of Iodine agronomic fortification of cassava. The field experiment was a 2x3x4 factorial experiment arranged in randomized complete block design replicated three times, conducted using two cassava varieties,( TME 419 and TMS 30555); four iodine rates( 0, 2.5, 5.0 and 10.0) kg/ha KI; applied at 8, 10 and 12 WAP. Physiological data were obtained by determination of Iodine content [in cassava tuber]; tuber cyanide content (HCN); Carbohydrate content of tuber; starch content of tuber and tuber protein contents. Iodine absorption and retention in cassava tuber flesh was significantly positively correlated with Iodine doses at the times of application (p0.05 and 0.01). TME 419 retained more Iodine in tissues than TMS 30555 and recorded highest correlation co-efficient at 10WAP. Iodine doses and time of application did not significantly control (P≥0.05) contents of cyanide, carbohydrate and starch in cassava tubers. Protein content was significantly varied in cassava varieties and rate and time of Iodine application influenced tuber protein content. TME 419 produced more tuber protein, Iodine doses of 2.5kg/ha KI and 0kg/ha KI had higher protein content than 5kg and 10kg/ha KI. Application at 8WAP and 10WAP were not significantly different. For favourable physiological cassava characteristics, 2.5kg/ha KI is recommended applied 10 weeks after planting (WAP).

What is the underestimation of radiation dose to the pediatric thyroid gland from contrast enhanced CT, if contrast medium uptake is not taken into account?

PurposeTo assess the underestimation of radiation dose to the thyroid of children undergoing contrast enhanced CT if contrast medium uptake is not taken into account. Methods161 pediatric head, head & neck and chest CT examinations were retrospectively studied to identify those involving pre- and post-contrast imaging and thyroid inclusion in imaged volume. CT density of thyroid tissue in HU was measured in non-enhanced (NECT) and corresponding contrast-enhanced CT (CECT) images. Resulting CT number increase (ΔHU) was recorded for each patient and corresponded to a % w/w iodine concentration. The relation of %w/w iodine concentration to %dose increase induced by iodinated contrast uptake was derived by Monte Carlo simulation experiments. ResultsThe thyroid gland was visible in 11 chest and 3 neck CT examinations involving both pre- and post-contrast imaging. The %w/w concentration of iodine in the thyroid tissue at the time of CECT acquisition was found to be 0.13%–0.58% w/w (mean = 0.26%). The %increase of dose to thyroid tissue was found to be linearly correlated to%w/w iodine uptake. The increase in radiation dose to thyroid due to contrast uptake ranged from 12% to 44%, with a mean value of 23%. ConclusionsThe radiation dose to the pediatric thyroid from CECT exposure may be underestimated by up to 44% if contrast medium uptake is not taken into account. Meticulous demarcation of imaged volume in pediatric chest CT examinations is imperative to avoid unnecessary direct exposure of thyroid, especially in CT examinations following intravenous administration of contrast medium.

The Concentration of Iodine in Perigastric Adipose Tissue: A Novel Index for the Assessment of Serosal Invasion in Patients with Gastric Cancer after Neoadjuvant Chemotherapy

Objective: This study aims to explore the association between iodine concentration (IC) in perigastric adipose tissue (PAT), quantified by dual-energy computed tomography (DECT) and serosal invasion (SI) in patients with gastric cancer post-neoadjuvant chemotherapy (NAC). Methods: Forty-three patients with T4-staged gastric cancer were enrolled. IC and standardized IC in PAT (IC_PAT and SIC_PAT) were quantified by DECT pre and post NAC. A postoperative pathologic examination was performed to stage gastric cancer. Results: After NAC, a total of 43 participants were assigned to group A with 13 patients and group B with 30 patients according to the results of the postoperative pathologic examination. The accuracy of conventional CT in identifying SI was 74.42%. Differences of variations between pre- and post- NAC IC_PAT, SIC_PAT, ∆IC_PAT, and ∆SIC_PAT were observed respectively (p < 0.05). Intragroup IC_PAT and SIC_PAT also changed significantly after NAC (p < 0.05). The area under the ROC curve was 0.929, with the threshold of ∆SIC_PAT reaching 0.095. The sensitivity, specificity, and accuracy of SIC_PAT in identifying post-NAC SI were 92.30, 86.70, and 88.37% respectively. Moreover, the 2 measurements in the same patient maintain a high level of consistency. Conclusion: These results showed that SIC_PAT is a reliable index for identifying post-NAC SI.

The effect of iodine uptake on radiation dose absorbed by patient tissues in contrast enhanced CT imaging: Implications for CT dosimetry.

To investigate the effect of iodine uptake on tissue/organ absorbed doses from CT exposure and its implications in CT dosimetry. The contrast-induced CT number increase of several radiosensitive tissues was retrospectively determined in 120 CT examinations involving both non-enhanced and contrast-enhanced CT imaging. CT images of a phantom containing aqueous solutions of varying iodine concentration were obtained. Plots of the CT number increase against iodine concentration were produced. The clinically occurring iodine tissue uptake was quantified by attributing recorded CT number increase to a certain concentration of aqueous iodine solution. Clinically occurring iodine uptake was represented in mathematical anthropomorphic phantoms. Standard 120kV CT exposures were simulated using Monte Carlo methods and resulting organ doses were derived for non-enhanced and iodine contrast-enhanced CT imaging. The mean iodine uptake range during contrast-enhanced CT imaging was found to be 0.02-0.46% w/w for the investigated tissues, while the maximum value recorded was 0.82% w/w. For the same CT exposure, iodinated tissues were found to receive higher radiation dose than non-iodinated tissues, with dose increase exceeding 100% for tissues with high iodine uptake. Administration of iodinated contrast medium considerably increases radiation dose to tissues from CT exposure. • Radiation absorption ability of organs/tissues is considerably affected by iodine uptake • Iodinated organ/tissues may absorb up to 100 % higher radiation dose • Compared to non-enhanced, contrast-enhanced CT may deliver higher dose to patient tissues • CT dosimetry of contrast-enhanced CT imaging should encounter tissue iodine uptake.

Soybean Meal Reduces Tissue Iodine Concentration in Rats Administered Kombu

Soybean Meal Reduces Tissue Iodine Concentration in Rats Administered Kombu

Comparison of variability in pork carcass composition and quality between barrows and gilts.

Pigs ( = 8,042) raised in 8 different barns representing 2 seasons (cold and hot) and 2 production focuses (lean growth and meat quality) were used to characterize variability of carcass composition and quality traits between barrows and gilts. Data were collected on 7,684 pigs at the abattoir. Carcass characteristics, subjective loin quality, and fresh ham face color (muscles) were measured on a targeted 100% of carcasses. Fresh belly characteristics, boneless loin weight, instrumental loin color, and ultimate loin pH measurements were collected from 50% of the carcasses each slaughter day. Adipose tissue iodine value (IV), 30-min loin pH, LM slice shear force, and fresh ham muscle characteristic measurements were recorded on 10% of carcasses each slaughter day. Data were analyzed using the MIXED procedure of SAS as a 1-way ANOVA in a randomized complete block design with 2 levels (barrows and gilts). Barn (block), marketing group, production focus, and season were random variables. A 2-variance model was fit using the REPEATED statement of the MIXED procedure, grouped by sex for analysis of least squares means. Homogeneity of variance was tested on raw data using Levene's test of the GLM procedure. Hot carcass weight of pigs (94.6 kg) in this study was similar to U.S. industry average HCW (93.1 kg). Therefore, these data are representative of typical U.S. pork carcasses. There was no difference ( ≥ 0.09) in variability of HCW or loin depth between barrow and gilt carcasses. Back fat depth and estimated carcass lean were more variable ( ≤ 0.0001) and IV was less variable ( = 0.05) in carcasses from barrows than in carcasses from gilts. Fresh belly weight and thickness were more variable ( ≤ 0.01) for bellies of barrows than bellies of gilts, but there was no difference in variability for belly length, width, or flop distance ( ≥ 0.06). Fresh loin subjective color was less variable ( < 0.01) and subjective marbling was more variable ( < 0.0001) in loins from barrows than in those from gilts, but there were no differences ( ≥ 0.08) in variability for any other loin traits or fresh ham traits. Overall, traits associated with carcass fatness, including back fat depth, belly thickness, and marbling, but not IV, were more variable in carcasses from barrows than in carcasses from gilts, whereas minimal differences in variability existed between carcasses of barrows and carcasses of gilts for traits associated with carcass muscling and lean quality.