Molecular Hosts for the Sensing and Separation of 99TcO4.

In recent years, European Union member states have hastened energy policy deliberations to address supply and sustainability concerns, placing a significant emphasis on nuclear energy as a means to achieve decarbonization goals. However, despite its significant role in power generation, nuclear energy faces significant challenges linked to fuel reprocessing and waste disposal, that hinder its broader expansion. In this context, the separation of technetium represents a concerning issue. Indeed, technetium's catalytic activity can impede the extraction of uranium, neptunium, and plutonium, affecting waste reprocessing efficiency. Additionally, the stable form of technetium in aerobic conditions, pertechnetate (TcO4 -), poses risks of groundwater contamination due to its mobility and solubility. Hence, sensing and separation of TcO4 - is imperative for both nuclear fuel processing and minimising radioactive contamination in the environment. However, the binding of TcO4 - and its separation from contaminated solutions present challenges due to the acidic (or basic) waste components and the high ionic strength in real matrices. Supramolecular chemists have addressed these issues by designing receptors inspired by molecular recognition principles. This article explores recent advancements and future directions in TcO4 - sensing and separation (using extraction and sorption) with a focus on molecular hosts. Metal-organic receptors will also be discussed.

Investigating Recurrent Matere Bonds in Pertechnetate Compounds.

In this manuscript we evaluate the X-ray structure of five new pertechnetate derivatives of general formula [M(H2O)4(TcO4)2], M=Mg, Co, Ni, Cu, Zn (compounds 1-5) and one perrhenate compound Zn(H2O)4(ReO4)2 (6). In these complexes the metal center exhibits an octahedral coordination with the pertechnetate units as axial ligands. All compounds exhibit the formation of directional Tc⋅⋅⋅O Matere bonds (MaBs) that propagate the [M(H2O)4(TcO4)2], into 1D supramolecular polymers in the solid state. Such 1D polymers are linked, generating 2D layers, by combining additional MaBs and hydrogen bonds (HBs). Such concurrent motifs have been analyzed theoretically, suggesting the noncovalent σ-hole nature of the MaBs. The interaction energies range from weak (~ -2 kcal/mol) for the MaBs to strong (~ -30 kcal/mol) for the MaB+HB assemblies, where HB dominates. In case of M=Zn, the corresponding perrhenate Zn(H2O)4(ReO4)2 complex, has been also synthesized for comparison purposes, resulting in the formation of an isostructural X-ray structure, corroborating the structure-directing role of Matere bonds.

Chalcogen Bonding in Selective Recognition and Liquid-Liquid Extraction of Perrhenate.

Efficient recognition and extraction of hazardous anionic pollutants from water medium is of great significance for environmental concerns, representing a challenging area of research in supramolecular chemistry. In this study, we present, for the first time, a comprehensive demonstration of the ability of chalcogen bonding (ChB) to recognize and remove the ReO4- from 100% water medium. The anion recognition ability is well elucidated through solution phase NMR and ITC studies, which clearly reveal the selective binding of ReO4- over other oxo-anions. Moreover, the selenoimidazolium scaffold effectively engages in Se•••O ChB interaction with ReO4- as confirmed by X-ray crystal structure and XPS analysis. More importantly, the binding of ReO4- with different prolongations of the σ-holes, along with Se•••Se chalcogen bonding interactions, lead to the formation of a 1D supramolecular assembly. Eventually, ChB receptor Se4Me-Br exhibits ~62% ReO4- extraction efficiency through precipitation as the extraction method. Furthermore, in efforts to enhance efficiency, a hydrophobic ChB receptor Se4Do-PF6 has been prepared, achieving an efficiency of up to ~93% at a very low concentration (~5ppm) by liquid-liquid extraction.

Photocatalytic Reduction of Perrhenate and Pertechnetate in a Strongly Acidic Aqueous Solution.

Pertechnetate (99TcO4-), a physiologically toxic radioactive anion, is of great concern due to its high mobility in environmental contamination remediation. Although the soluble oxyanion can be photoreduced to sparingly soluble TcO2·nH2O, its effective removal from a strongly acidic aqueous solution remains a challenge. Here, we found that low-crystalline nitrogen-doped titanium oxide (N-TiO2, 0.6 g L-1) could effectively uptake perrhenate (ReO4-, 10 mg L-1, a nonradioactive surrogate for TcO4-) with 50.8% during 360 min under simulated sunlight irradiation at pH 1.0, but P25 and anatase could not. The nitrogen active center formed by trace nitrogen doping in N-TiO2 can promote the separation and transfer of photogenerated carriers. The positive valence band value of N-TiO2 is slightly higher than those of P25 and anatase, which means that the photogenerated holes have a stronger oxidizability. These holes are involved in the formation of strong reducing •CO2- radicals from formic acid oxidation. The active radicals convert ReO4- to Re(VI), which is subsequently disproportionated to Re(IV) and Re(VII). Effective photocatalytic reduction/removal of Re(VII)/Tc(VII) is performed on the material, which may be considered a potential and convenient strategy for technetium decontamination and extraction in a strongly acidic aqueous solution.

Quantification of [99Tc]TcO4- in urine by means of anion-exchange chromatography-aerosol desolvation nebulization-inductively coupled plasma-mass spectrometry.

To sensitively determine 99Tc, a new method for internal quantification of its most common and stable species, [99Tc]Tc O 4 - , was developed. Anion-exchange chromatography (IC) was coupled to inductively coupled plasma-mass spectrometry (ICP-MS) and equipped with an aerosol desolvation system to provide enhanced detection power. Due to a lack of commercial Tc standards, an isotope dilution-like approach using a Ru spike and called isobaric dilution analysis (IBDA) was used for internal quantification of 99Tc. This approach required knowledge of the sensitivities of 99Ru and 99Tc in ICP-MS. The latter was determined using an in-house prepared standard manufactured from decayed medical 99mTc-generator eluates. This standard was cleaned and preconcentrated using extraction chromatography with TEVA resin and quantified via total reflection X-ray fluorescence (TXRF) analysis. IC coupled to ICP-MS enabled to separate, detect and quantify [99Tc]Tc O 4 - as most stable Tc species in complex environments, which was demonstrated in a proof of concept. We quantified this species in untreated and undiluted raw urine collected from a patient, who previously underwent scintigraphy with a 99mTc-tracer, and determined a concentration of 19.6 ± 0.5 ng L-1. The developed method has a high utility to characterize a range of Tc-based radiopharmaceuticals, to determine concentrations, purity, and degradation products in complex samples without the need to assess activity parameters of 99(m)Tc.

Treatment of tetracycline in an aqueous solution with an iron-biochar/periodate system: Influencing factors and mechanisms.

In this study, a potassium ferrate (K2FeO4)-modified biochar (Fe-BC) was prepared and characterized. Afterwards, Fe-BC was applied to activated periodate (PI) to degrade tetracycline (TC), an antibiotic widely used in animal farming. The degradation effects of different systems on TC were compared and the influencing factors were investigated. In addition, several reactive oxygen species (ROS) generated by the Fe-BC/PI system were identified, and TC degradation pathways were analyzed. Moreover, the reuse performance of Fe-BC was evaluated. The results exhibited that the Fe-BC/PI system could remove almost 100% of TC under optimal conditions of [BC] = 1.09 g/L, initial [PI] = 3.29 g/L, and initial [TC] = 20.3 mg/L. Cl-, HCO3-, NO3-, and humic acid inhibited TC degradation to varying degrees in the Fe-BC/PI system due to their quenching effects on ROS. TC was degraded into intermediates and even water and carbon dioxide by the synergistic effect of ROS generated and Fe on the BC surface. Fe-BC was reused four times, and the removal rate of TC was still maintained above 80%, indicating the stable nature of Fe-BC.

Modulating Anion Nanotraps via Halogenation for High-Efficiency 99TcO4-/ReO4- Removal under Wide-Ranging pH Conditions.

Efficient and sustainable methods for 99TcO4- removal from acidic nuclear waste streams, contaminated water, and highly alkaline tank wastes are highly sought after. Herein, we demonstrate that ionic covalent organic polymers (iCOPs) possessing imidazolium-N+ nanotraps allow the selective adsorption of 99TcO4- under wide-ranging pH conditions. In particular, we show that the binding affinity of the cationic nanotraps toward 99TcO4- can be modulated by tuning the local environment around the nanotraps through a halogenation strategy, thereby enabling universal pH 99TcO4- removal. A parent iCOP-1 possessing imidazolium-N+ nanotraps showed fast kinetics (reaching adsorption equilibrium in 1 min), a high adsorption capacity (up to 1434.1 ± 24.6 mg/g), and exceptional selectivity for 99TcO4- and ReO4- (nonradioactive analogue of 99TcO4-) removal in contaminated water. By introducing F groups near the imidazolium-N+ nanotrap sites (iCOP-2), a ReO4- removal efficiency over 58% was achieved in 60 min in 3 M HNO3 solution. Further, introduction of larger Br groups near the imidazolium-N+ binding sites (iCOP-3) imparted a pronounced steric effect, resulting in exceptional adsorption performance for 99TcO4- under super alkaline conditions and from low-activity waste streams at US legacy Hanford nuclear sites. The halogenation strategy reported herein guides the task-specific design of functional adsorbents for 99TcO4- removal and other applications.

Meckel diverticulum scintigraphy: technique, findings and diagnostic pitfalls.

Meckel diverticulum, the most common congenital anomaly of the gastrointestinal tract, results from the aberrant involution of the omphalomesenteric duct and accounts for more than 50% of unexplained lower gastrointestinal bleeding in the pediatric population. The most accurate imaging tool to identify a Meckel diverticulum containing ectopic gastric mucosa is the Technetium-99m pertechnetate Meckel scan, a scintigraphic study with a reported accuracy of 90% in the pediatric population. In addition to depicting a Meckel diverticulum with ectopic gastric mucosa, careful attention to the normal biodistribution of the radiotracer can lead to the identification of unexpected pathology with implications for patient management. This article serves to review the embryological origin and anatomical features of Meckel diverticulum, highlight the role of scintigraphy in evaluating Meckel diverticulum, and discuss the proper imaging technique when performing this test. We will focus on pitfalls that can lead to an erroneous diagnosis as well as incidental findings that can affect patient management.

New Preparative Approach to Purer Technetium-99 Samples-Tetramethylammonium Pertechnetate: Deep Understanding and Application of Crystal Structure, Solubility, and Its Conversion to Technetium Zero Valent Matrix.

99Tc is one of the predominant fission products of 235U and an important component of nuclear industry wastes. The long half-life and specific activity of 99Tc (212,000 y, 0.63 GBq g-1) makes Tc a hazardous material. Two principal ways were proposed for its disposal, namely, long-term storage and transmutation. Conversion to metal-like technetium matrices is highly desirable for both cases and for the second one the reasonably high Tc purity was important too. Tetramethylammonium pertechnetate (TMAP) was proposed here as a prospective precursor for matrix manufacture. It provided with very high decontamination factors from actinides (that is imperative for transmutation) by means of recrystallisation and it was based on the precise data on TMAP solubility and thermodynamics accomplished in the temperature range of 3-68 °C. The structure of solid pertechnetates were re-estimated with precise X-ray structure solution and compared to its Re and Cl analogues and tetrabutylammonium analogue as well. Differential thermal and evolved gas analysis in a flow of Ar-5% H2 gas mixture showed that the major products of thermolysis were pure metallic technetium in solid matrix, trimethylammonium, carbon dioxide, and water in gas phase. High decontamination factors have been achieved when TMAP was used as an intermediate precursor for Tc.

Removal of CrO42-, a Nonradioactive Surrogate of 99TcO4-, Using LDH-Mo3S13 Nanosheets.

Removal of chromate (CrO42-) and pertechnetate (TcO4-) from the Hanford Low Activity Waste (LAW) is beneficial as it impacts the cost, life cycle, operational complexity of the Waste Treatment and Immobilization Plant (WTP), and integrity of vitrified glass for nuclear waste disposal. Here, we report the application of [MoIV3S13]2- intercalated layer double hydroxides (LDH-Mo3S13) for the removal of CrO42- as a surrogate for TcO4-, from ppm to ppb levels from water and a simulated LAW off-gas condensate of Hanford's WTP. LDH-Mo3S13 removes CrO42- from the LAW condensate stream, having a pH of 7.5, from ppm (∼9.086 × 104 ppb of Cr6+) to below 1 ppb levels with distribution constant (Kd) values of up to ∼107 mL/g. Analysis of postadsorbed solids indicates that CrO42- removal mainly proceeds by reduction of Cr6+ to Cr3+. This study sets the first example of a metal sulfide intercalated LDH for the removal of CrO42-, as relevant to TcO4-, from the simulated off-gas condensate streams of Hanford's LAW melter which contains highly concentrated competitive anions, namely F-, Cl-, CO32-, NO3-, BO33-, NO2-, SO42-, and B4O72-. LDH-Mo3S13's remarkable removal efficiency makes it a promising sorbent to remediate CrO42-/TcO4- from surface water and an off-gas condensate of nuclear waste.

Meckel's Diverticulum - Clinical Presentation and Pitfalls in Diagnosis in the Pediatric Age Group in Singapore.

Purpose: The purpose of this study was to study the presentation of patients who underwent Meckel's diverticulectomy (MD) and utility of pertechnetate Meckel's scan in the diagnosis of MD. Methods: The clinical presentation of a retrospective cohort of patients who underwent MD from January 2007 to December 2019 was studied. The modes of presentation, treatment, and the diagnostic utility of pertechnetate Meckel's scans were evaluated. False-positive and false-negative scans were reviewed. The presence of gastric mucosa on histology of Meckel's was correlated with presentation as gastrointestinal bleeding and positive scan results. Results: Ninety-nine patients underwent MD. Thirty-five out of 263 (13.3%) Meckel's scans done were positive. There was a male preponderance (86.9%). The peak age of presentation was 0-4 years (rectal bleeding or intestinal obstruction). Only a third of the patients with Meckel's diverticulum Meckel's had a preoperative diagnosis of Meckel's. The sensitivity/specificity of Meckel's scan was higher in patients presenting with painless rectal bleeding. Seven patients were false positive (weak tracer uptake or ectopic uptake) and five were false negative. Two patients with false-negative Meckel's scan, having gastrointestinal bleeding had gastric mucosa on histology of Meckel's. Conclusion: Meckel's diverticulum has a male predominance. Meckel's scan has a high sensitivity in the children presenting with fresh painless rectal bleeding but is of limited use in the diagnosis of Meckel's diverticulum in other forms of presentations. False-positive scans can be anticipated in the presence of weak or ectopic uptake. False-negative scans can occur even in the presence of bleeding and in spite of the presence of gastric mucosa in the Meckel's diverticulum. Laparoscopy is a useful tool in diagnosis and treatment.

Ammonium Pertechnetate in Mixtures of Trifluoromethanesulfonic Acid and Trifluoromethanesulfonic Anhydride.

Ammonium pertechnetate reacts in mixtures of trifluoromethanesulfonic anhydride and trifluoromethanesulfonic acid under final formation of ammonium pentakis(trifluoromethanesulfonato)oxidotechnetate(V), (NH4 )2 [TcO(OTf)5 ]. The reaction proceeds only at exact concentrations and under the exclusion of air and moisture via pertechnetyl trifluoromethanesulfonate, [TcO3 (OTf)], and intermediate TcVI species. 99 Tc nuclear magnetic resonance (NMR) has been used to study the TcVII compound and electron paramagnetic resonance (EPR), 99 Tc NMR and X-ray absorption near-edge structure (XANES) experiments indicate the presence of the reduced technetium species. In moist air, (NH4 )2 [TcO(OTf)5 ] slowly hydrolyses under formation of the tetrameric oxidotechnetate(V) (NH4 )4 [{TcO(TcO4 )4 }4 ] ⋅10 H2 O. Single-crystal X-ray crystallography was used to determine the solid-state structures. Additionally, UV/Vis absorption and IR spectra as well as quantum chemical calculations confirm the identity of the species.

Unveiling the Uncommon Fluorescent Recognition Mechanism towards Pertechnetate Using a Cationic Metal-Organic Framework Bearing N-Heterocyclic AIE Molecules.

As one of most problematic radionuclides, technetium-99, mainly in the form of anionic pertechnetate (TcO4 - ), exhibits high environmental mobility, long half-life, and radioactive hazard. Due to low charge density and high hydrophobicity for this tetrahedral anion, it is extremely difficult to recognize it in water. Seeking efficient and selective recognition method for TcO4 - is still a big challenge. Herein, a new water-stable cationic metal-organic framework (ZJU-X8) was reported, bearing tetraphenylethylene pyrimidine-based aggregation-induced emission (AIE) ligands and attainable silver sites for TcO4 - detection. ZJU-X8 underwent an obvious spectroscopic change from brilliant blue to flavovirens and exhibited splendid selectivity towards TcO4 - . This uncommon fluorescent recognition mechanism was well elucidated by batch sorption experiments and DFT calculations. It was found that only TcO4 - could enter into the body of ZJU-X8 through anion exchange whereas other competing anions were excluded outside. Subsequently, after interaction between TcO4 - and silver ions, the electron polarizations from pyrimidine rings to Ag+ cations significantly lowered the energy level of the π* orbital and thus reduced the π-π* energy gap, resulting in a red-shift in the fluorescent spectra.

New-onset graves' disease after the initiation of nivolumab therapy for gastric cancer: a case report.

BACKGROUND: Immune checkpoint inhibitors (ICIs) can induce immune-related adverse events (irAEs) including thyroid dysfunction. There are only a few reports on Graves' disease induced by ICIs. We report a case of new-onset Graves' disease after the initiation of nivolumab therapy in a patient receiving gastric cancer treatment. CASE PRESENTATION: The patient was a 66-year-old Japanese man, who was administered nivolumab (240 mg every 3 weeks) as a third-line therapy for stage IVb gastric cancer. His thyroid function was normal before the initiation of nivolumab therapy. However, he developed thyrotoxicosis before the third administration of nivolumab. Elevated, bilateral, and diffuse uptake of radioactive tracer was observed in the 99mTc-pertechnetate scintigraphy. Furthermore, the thyroid-stimulating hormone receptor antibody (TRAb) and thyroid-stimulating antibody (TSAb) test results, which were negative before the first administration of nivolumab, were positive after starting the therapy. The patient was diagnosed with Graves' disease, and the treatment with methimazole and potassium iodide restored thyroid function. CONCLUSIONS: This is the first complete report of a case of new-onset Graves' disease after starting nivolumab therapy, confirmed by diffusely increased thyroid uptake in scintigraphy and the positive conversion of antibodies against thyroid-stimulating hormone receptor. It is important to perform thyroid scintigraphy and ultrasonography to accurately diagnose and treat ICI-induced thyrotoxicosis, because there are various cases in which Graves' disease is developed with negative and positive TRAb titres.

Scintigraphic evaluation of salivary gland function in thyroid cancer patients after radioiodine remnant ablation.

Radioiodine (131 I, RAI) has traditionally been used in thyroid cancer treatment but its benefit should be balanced against possible risks. Among them, salivary gland dysfunction has often been discussed, although the reported data have been inconsistent. The aim of our prospective study was to evaluate salivary gland function in 31 thyroidectomised patients (6 men, 25 women; median age 52 yr) before and 4-6 months after RAI remnant ablation (RRA), using activity of 3.7 GBq 131 I-NaI. Salivary gland uptake and excretion fractions were quantitatively assessed with 99m Tc - pertechnetate salivary gland scintigraphy. Pre- and post-treatment values were compared using Wilcoxon signed rank test. No statistically significant difference in the pre- and post-treatment values was observed in parotid or submandibular glands uptake, or in the parotid or submandibular excretion fractions. The calculated power for minimum relevant difference of 25% with the sample size of 31 ranged between 86% and 96% for the individual variables, making our negative results reasonably reliable. The results suggest that RRA with the most commonly used activity of 3.7 GBq has no important impact on salivary gland function. Therefore, the concerns about putative salivary gland functional deterioration following RRA are probably unjustified.

Non-variceal gastrointestinal bleed in children: surgical experience with emphasis on management challenges.

PURPOSE: This exclusively surgical series on pediatric non-variceal gastrointestinal bleed (NVGIB) defines three levels of bleed site and describes etiology, bleed severity, diagnostic algorithm, and surgical management for each bleed site. Management challenges are detailed. METHODS: Patients aged ≤ 18 years treated surgically for NVGIB were analysed. RESULTS: Bleed site (n = 87) was classified as: upper gastrointestinal bleed (UGIB; n = 11); small bowel bleed (SBB: n = 52); and lower GIB (n = 24). Four etiology-based groups were identified: lesions with ectopic gastric mucosa (EGM; n = 33), tumours (n = 23), ulcers (n = 21), and vascular pathology (n = 8). Bleed severity spectrum was: acute severe bleed (n = 12); subacute overt bleed (n = 59); and occult GIB (n = 16). Preoperative diagnosis was obtained in all UGIB and LGIB lesions. Eighty-two percent of surgical SB lesions were diagnosed preoperatively on Tc99m pertechnetate scan, computed tomography enterography-angiography, and capsule endoscopy; remaining 18% were diagnosed at laparotomy with intra-operative enteroscopy (IOE). Surgical management was tailored to bleed site, severity, and etiology. Indications of IOE and approach to management challenges are detailed. CONCLUSIONS: The commonest site-specific bleed etiologies were duodenal ulcers for UGIB, EGM lesions for SBB, and tumours for LGIB. SBB presented diagnostic challenge. Diagnostic algorithm was tailored to bleed site, age-specific etiology, bleed severity, and associated abdominal/systemic symptoms. Management challenges were acute severe bleed, occult GIB, SBB, obscure GIB, and rare etiologies. IOE has a useful role in SBB management.

Successful Decontamination of 99 TcO4 - in Groundwater at Legacy Nuclear Sites by a Cationic Metal-Organic Framework with Hydrophobic Pockets.

99 Tc contamination at legacy nuclear sites is a serious and unsolved environmental issue. The selective remediation of 99 TcO4 - in the presence of a large excess of NO3 - and SO4 2- from natural waste systems represents a significant scientific and technical challenge, since anions with a higher charge density are often preferentially sorbed by traditional anion-exchange materials. We present a solution to this challenge based on a stable cationic metal-organic framework, SCU-102 (Ni2 (tipm)3 (NO3 )4 ), which exhibits fast sorption kinetics, a large capacity (291 mg g-1 ), a high distribution coefficient, and, most importantly, a record-high TcO4 - uptake selectivity. This material can almost quantitatively remove TcO4 - in the presence of a large excess of NO3 - and SO4 2- . Decontamination experiments confirm that SCU-102 represents the optimal Tc scavenger with the highest reported clean-up efficiency, while first-principle simulations reveal that the origin of the selectivity is the recognition of TcO4 - by the hydrophobic pockets of the structure.

99 Tc NMR determination of the oxygen isotope content in 18 O-enriched water.

99 Tc NMR has been suggested as an original method of evaluating the content of oxygen isotopes in oxygen-18-enriched water, a precursor for the production of radioisotope fluorine-18 used in positron emission tomography. To this end, solutions of NH4 TcO4 or NaTcO4 (up to 0.28 mol/L) with natural abundance of oxygen isotopes in virgin or recycled 18 O-enriched water have been studied by 99 Tc NMR. The method is based on 16 O/17 O/18 O intrinsic isotope effects in the 99 Tc NMR chemical shifts, and the statistical distribution of oxygen isotopes in the coordination sphere of TcO4- and makes it possible to quantify the composition of enriched water by measuring the relative intensities of the 99 Tc NMR signals of the Tc16 O4-n18 On- isotopologues. Because the oxygen exchange between TcO4- and enriched water in neutral and alkaline solutions is characterized by slow kinetics, gaseous HCl was bubbled through a solution for a few seconds to achieve the equilibrium distribution of oxygen isotopes in the Tc coordination sphere without distortion of the oxygen composition of the water. Pertechnetate ion was selected as a probe due to its high stability in solutions and the significant 99 Tc NMR shift induced by a single 16 O→18 O substitution (-0.43 ± 0.01 ppm) in TcO4- and spin coupling constant 1 J(99 Tc-17 O) (131.46 Hz) favourable for the observation of individual signals of Tc16 O4-n18 On- isotopologues.

Diagnosis of Raynaud's phenomenon by 99mTc-pertechnetate hand perfusion scintigraphy: a pilot study.

We assess the usefulness of 99mTc-pertechnetate hand perfusion scintigraphy in patients with Raynaud's phenomenon (RP). The study population consisted of 18 patients with primary RP, 25 patients with secondary RP within systemic sclerosis (SSc), and ten healthy individuals. Gamma camera dynamic first-pass study during the first 60 s and a static scintigraphy after 5 min were recorded following a bolus injection of 99mTc-pertechnetate via a cubital vein. Regions of interest were drawn on the summed images around the fingers and the palmar region. The fingers-to-palm ratios were then calculated. The mean fingers-to-palm ratio for dynamic study (blood flow) was 0.58 ± 0.19 for the healthy group, 0.45 ± 0.18 for the primary RP, and 0.43 ± 0.21 for the SSc patients. The mean fingers-to-palm ratio for static study (blood pool) was 0.44 ± 0.06 for the healthy group, 0.42 ± 0.06 for the primary RP, and 0.36 ± 0.07 for the SSc patients. Analysis of variance showed these differences to be significant (p = 0.039 from blood flow and p = 0.004 from blood pool). The receiver operating characteristic curve showed sensitivity of 80% and a specificity of 60% when using cutoff values of 0.40 for blood flow and sensitivity of 79% and a specificity of 70% when using cutoff values of 0.37 for blood pool. Our method is able to differentiate between patients with normal and those with abnormal microcirculation of the hands. Dynamic study separates the healthy subjects from patients with RP, while static study separates primary from secondary RP.

Extensive heterotopic gastric mucosa of the small intestine: imaging with 99mTc-sodium pertechnetate SPECT/CT enterography.

Extensive heterotopic gastric mucosa of the small intestine is a rare, but potentially life-threatening condition characterized by multifocal or long-segment heterotopic gastric mucosa within the bowel lumen that is often associated with other anomalies including malrotation and annular pancreas. Although the imaging findings are characteristic, this entity may be unrecognized due to its unusual imaging appearance and rarity. CT or MR enterography and 99mTc-sodium pertechnetate scintigraphy can provide complementary information that enables specific diagnosis and accurate assessment of disease extent. We present a case of extensive heterotopic gastric mucosa of the small intestine imaged by simultaneous, combined 99mTc-sodium pertechnetate single photon-emission computed tomography (SPECT)/CT enterography to both familiarize the reader with the condition and describe an imaging strategy that enables specific diagnosis and assists with treatment planning.