Detectability of cold tumors by xSPECT bone technology compared with hot tumors: a supine phantom study.

Detecting cold as well as hot tumors is vital for interpreting bone tumors on single-photon emission computed tomography (SPECT) images. This study aimed to visually and quantitatively demonstrate the detectability of cold tumors using xSPECT technology compared with that of hot tumors in the phantom study. Five tumors of different sizes and normal bone contained a mixture of 99mTc and K2HPO4 in a spine phantom. We acquired SPECT data using an xSPECT protocol and transverse images were reconstructed using xSPECT Bone (xB) and xSPECT Quant (xQ). Mean standardized uptake values (SUVmean) in volumes of interest (VOI) were calculated. Recovery coefficients (RCs) for each tumor site were calculated with reference to radioactive concentrations. The SUVmeans of the whole vertebral body for hot tumor bone image in cortical bone phantom reconstructed by with xB and xQ were 5.77 and 4.86 respectively. The SUVmean of xB was similar to the true value. The SUVmeans for xB and xQ reconstructed images of cold tumors were both approximately 0.16. The RC of the cold tumor on xQ images increased as the tumor diameter decreased, whereas that of xB remained almost constant regardless of the tumor diameter. In conclusion, the quantitative accuracy of detecting hot and cold tumors was higher in the xB image than in the xQ image. Moreover, the visual detectability of cold tumors was also excellent in xB images.

Three-Dimensional Heart Segmentation and Absolute Quantitation of Cardiac 123I-metaiodobenzylguanidine Sympathetic Imaging Using SPECT/CT.

Background: A three-dimensional (3D) approach to absolute quantitation of 123I-metaiodobenzylguanidine (MIBG) sympathetic nerve imaging using single-photon emission tomography (SPECT) / computed tomography (CT) is not available. Therefore, we calculated absolute cardiac counts and standardized uptake values (SUVs) from images of 72 consecutive patients with cardiac and neurological diseases using 123I-MIBG SPECT/CT and compared them with conventional planar quantitation. We aimed to develop new methods for 3D heart segmentation and the quantitation of these diseases. Methods: We manually segmented early and late SPECT/CT images of the heart in 3D, then calculated mean (SUVmean) and maximum (SUVmax) SUVs. We analyzed correlations between SUVs and planar heart-to-mediastinum ratios (HMRs), and between washout rates (WRs) derived from the SUVs and planar data. We also categorized WRs as normal or abnormal using linear regression lines determined by the relationship between SPECT/CT and planar WRs, and assessed agreement between them. Results: We calculated SUVmean and SUVmax from all early and late 123I-MIBG SPECT/CT images. Planar HMRs correlated with early and late SUVmean (R2=0.59 and 0.73, respectively) and SUVmax (R2=0.46 and 0.60, respectively; both p<0.0001). The SPECT/CT WRs determined based on SUVmean and SUVmax (R2=0.79 and 0.45, p<0.0001) closely correlated with planar WRs. Agreement of high and low WRs between planar WRs and SPECT/CT WRs calculated using SUVmax and SUVmean reached 88.1% and 94.4% respectively. Conclusions: We found that sympathetic nervous activity could be absolutely quantified in 3D from 123I-MIBG SPECT/CT images. Therefore, we propose a new method for quantifying sympathetic innervation on SPECT/CT images.

Transthyretin amyloid cardiomyopathy disease burden quantified using 99mTc-pyrophosphate SPECT/CT: volumetric parameters versus SUVmax ratio at 1 and 3 hours.

BACKGROUND: Various parameters derived from technetium-99m pyrophosphate (99mTc-PYP) single-photon emission computed tomography (SPECT) correlate with the severity of transthyretin amyloid cardiomyopathy (ATTR-CM). However, the optimal metrics and image acquisition timing required to quantify the disease burden remain uncertain. METHODS AND RESULTS: We retrospectively evaluated 99mTc-PYP SPECT/CT images of 23 patients diagnosed with ATTR-CM using endomyocardial biopsies and/or gene tests. All patients were assessed by SPECT/CT 1 hour after 99mTc-PYP injection, and 13 of them were also assessed at 3 hours. We quantified 99mTc-PYP uptake using the volumetric parameters, cardiac PYP volume (CPV) and cardiac PYP activity (CPA). We also calculated the SUVmax ratios of myocardial SUVmax/blood pool SUVmax, myocardial SUVmax/bone SUVmax, and the SUVmax retention index. We assessed the correlations between uptake parameters and the four functional parameters associated with prognosis, namely left ventricular ejection fraction, global longitudinal strain, myocardial extracellular volume, and troponin T. CPV and CPA correlated more closely than the SUVmax ratios with the four prognostic factors. Significant correlations between volumetric parameters and prognostic factors were equivalent between 1 and 3 hours. CONCLUSIONS: The disease burden of ATTR-CM was quantified more accurately by volumetric evaluation of 99mTc-PYP SPECT/CT than SUVmax ratios and the performance was equivalent between 1 and 3 hours.

Dysfunctional Pro1 leads to female sterility in rice blast fungi.

Although sexual reproduction is widespread in eukaryotes, some fungal species can only reproduce asexually. In the rice blast fungus Pyricularia (Magnaporthe) oryzae, several isolates from the region of origin retain mating ability, but most isolates are female sterile. Therefore, female fertility may have been lost during its spread from the origin. Here, we show that functional mutations of Pro1, a global transcriptional regulator of mating-related genes in filamentous fungi, is one cause of loss of female fertility in this fungus. We identified the mutation of Pro1 by backcrossing analysis between female-fertile and female-sterile isolates. The dysfunctional Pro1 did not affect the infection processes but conidial release was increased. Furthermore, various mutations in Pro1 were detected in geographically distant P. oryzae, including pandemic isolates of wheat blast fungus. These results provide the first evidence that loss of female fertility may be advantageous to the life cycle of some plant pathogenic fungi.

Volumetric evaluation of 99mTc-pyrophosphate SPECT/CT for transthyretin cardiac amyloidosis: Methodology and correlation with cardiac functional parameters.

BACKGROUND: Volumetric evaluation of 99mTechnetium-pyrophosphate (99mTc-PYP) SPECT/CT is a useful method for assessing transthyretin cardiac amyloidosis (ATTR-CA). We investigated the methodology and assessed its relationship with conventional parameters. METHODS AND RESULTS: We retrospectively evaluated 99mTc-PYP SPECT/CT scans of 25 patients who underwent endomyocardial biopsy and/or gene testing. Fourteen (56%) patients were diagnosed with ATTR-CA. SPECT/CT images were acquired at 3 hours after injection. Total volumes of the myocardial regions where uptakes were > 1.2 and 1.4 × aortic blood pool SUVmax were evaluated and defined as cardiac pyrophosphate volume (CPV1.2 and CPV1.4). The heart-to-contralateral lung (H/CL) ratio and myocardial SUVmax were also calculated. CPV1.2 achieved the highest sensitivity and specificity in diagnosing ATTR-CA. In patients diagnosed with ATTR-CA (n = 14), CPV1.2 negatively correlated with left ventricular ejection fraction and positively correlated with left ventricular posterior wall thickness and QRS duration. The correlation was stronger in CPV1.2 than in the H/CL ratio and SUVmax. CONCLUSION: Volumetric evaluation of 99mTc-PYP SPECT/CT may be superior to the H/CL ratio and SUVmax in assessing the disease burden of ATTR-CA. Larger studies are warranted to clarify whether volumetric measurement can assess prognosis and disease progression.

Association between salt intake and long-term mortality in hemodialysis patients: A retrospective cohort study.

BACKGROUND: The association between salt intake and clinical outcomes in hemodialysis patients has been controversial. This study aimed to clarify the association between salt intake and mortality in hemodialysis patients. METHOD: The present study included patients who underwent hemodialysis from June 1st 2016 to May 31st 2020. Corrected salt intake by ideal body weight was the main predictor of outcomes. Ideal body weight was calculated assuming that the ideal body mass index is 22 kg/m2 for the Japanese population. The multivariate Cox proportional hazards model was used to determine the association between corrected salt intake and mortality, adjusting for potential confounders. The outcomes considered were all-cause mortality and cumulative incidence of cardiovascular events at year 4. RESULT: A total of 492 adult patients were enrolled in the study. The mean daily salt intake and corrected salt intake at baseline were 9.5 g/day and 0.17 g/kg/day, respectively. The low corrected salt intake group (< 0.13 g/kg/day) demonstrated the highest 4-year all-cause mortality. No association was observed between corrected salt intake and the cumulative incidence of cardiovascular events. In multivariate Cox proportional hazards analysis, only the group with corrected salt intake of 0.16-0.20 g/kg/day was associated with a decreased hazard risk for all-cause death compared with the low corrected salt intake group. CONCLUSION: The present study found that a low salt intake was associated with high all-cause mortality in hemodialysis patients. Reduced long-term survival may be attributed to malnutrition resulting from excessive salt restriction.

[Surgical Treatment for Congenital Bronchial Atresia and Intralobar Sequestration in the Same Lobe].

A 21-year-old man who had a history of pneumonia twice presented with chest discomfort. Computed tomography( CT) revealed dilatation of the atretic bronchus that was not continuous with the proximal one, and surrounding hyper-lucent lung fields in the outer and mediastinal sides of the right basal segment, and the absence of B10b+c. CT also demonstrated the presence of A10b+c in the former field and the aberrant artery from the inferior phrenic artery in the latter. Right basal segmentectomy was performed under the diagnosis of congenital bronchial atresia and intralobar sequestration. Pathological diagnosis accorded with preoperative one.

Emergent carotid artery stenting for cervical internal carotid artery injury during carotid endarterectomy: A case report.

BACKGROUND: Carotid endarterectomy (CEA) has been the standard preventive procedure for cerebral infarction due to cervical internal carotid artery stenosis, and internal shunt insertion during CEA is widely accepted. However, troubleshooting knowledge is essential because potentially life-threatening complications can occur. Herein, we report a case of cervical internal carotid artery injury caused by the insertion of a shunt device during CEA. CASE DESCRIPTION: A 78-year-old man with a history of hypertension, diabetes, and hyperuricemia developed temporary left hemiplegia. A former physician had diagnosed the patient with a transient cerebral ischemic attack. The patient's medical history was significant for the right internal carotid artery stenosis, which was severe due to a vulnerable plaque. We performed CEA to remove the plaque; however, there was active bleeding in the distal carotid artery of the cervical region after we removed the shunt tube. Hemostasis was achieved through compression using a cotton piece. Intraoperative digital subtraction angiography (DSA) revealed severe stenosis at the internal carotid artery distal to the injury site due to hematoma compression. The patient underwent urgent carotid artery stenting and had two carotid artery stents superimposed on the injury site. On DSA, extravascular pooling of contrast media decreased on postoperative day (POD) 1 and then disappeared on POD 14. The patient was discharged home without sequela on POD 21. CONCLUSION: In the case of cervical internal carotid artery injury during CEA, hemostasis can be achieved by superimposing a carotid artery stent on the injury site, which is considered an acceptable troubleshooting technique.

Performance of SwiftScan planar and SPECT technology using low-energy high-resolution and sensitivity collimator compared with Siemens SPECT system.

PURPOSE: A new low-energy high-resolution-sensitivity (LEHRS) collimator was developed by General Electric (GE) Healthcare. SwiftScan planar and single photon emission computed tomography (SPECT) systems using LEHRS collimator were developed to achieve the low-dose and/or short-time acquisition. We demonstrated the performance of SwiftScan planar and SPECT system with LEHRS collimator using phantoms. METHODS: Line source, cylindrical and flat plastic dish phantoms were used to evaluate the performance of planar and SPECT images for four patterns of Siemens LEHR, GE LEHR, GE LEHRS and SwiftScan using two SPECT-CT scanners. Each phantom was filled with 99mTc solution, and the spatial resolution, sensitivity and image uniformity were calculated from the planar and SPECT data. RESULTS: The full-width at half maximum (FWHM) values as a system spatial resolution of Siemens LEHR, GE LEHR and GE LEHRS were approximately 7.4 mm. GE LEHRS showed a lower FWHM value by increasing the blend ratio in Clarity2D processing. The system sensitivity of GE LEHRS increased by approximately 30% compared with that of GE LEHR and was similar to that of Siemens LEHR. The FWHM values of SPECT with an filtered back projection (FBP) method were approximately 10.3 mm. The FWHM values of the ordered subset expectation maximization (OSEM) method were better with an increase in iteration values. The differential uniformities of Siemens LEHR, GE LEHR, GE LEHRS and GE SwiftScan using the FBP method were approximately 15.1%. The differential uniformity of OSEM method was higher with an increase in the iteration value. CONCLUSION: The SwiftScan planar and SPECT have a high sensitivity while maintaining the spatial resolution compared with the conventional system.

Metabolic fingerprinting for discrimination of DNA-authenticated Atractylodes plants using 1H NMR spectroscopy.

Identifying different species of the genus Atractylodes which are commonly used in Chinese and Japanese traditional medicine, using chromatographic approaches can be difficult. 1H NMR metabolic profiling of DNA-authenticated, archived rhizomes of the genus Atractylodes was performed for genetic and chemical evaluation. The ITS region of the nuclear rDNA was sequenced for five species, A. japonica, A. macrocephala, A. lancea, A. chinensis, and A. koreana. Our samples had nucleotide sequences as previously reported, except that part of the A. lancea cultivated in Japan had a type 5, hybrid DNA sequence. Principal component analysis (PCA) using 1H NMR spectra of extracts with two solvent systems (CD3OD, CDCl3) was performed. When CDCl3 extracts were utilized, the chemometric analysis enabled the identification and classification of Atractylodes species according to their composition of major sesquiterpene compounds. The 1H NMR spectra using CD3OD contained confounding sugar peaks. PCA removal of these peaks gave the same result as that obtained using CDCl3 and allowed species distinction. Such chemometric methods with multivariate analysis of NMR spectra will be useful for the discrimination of plant species, without specifying the index components and quantitative analysis on multi-components.

Metal artifact reduction for improving quantitative SPECT/CT imaging.

OBJECTIVE: This study aimed to evaluate the effect of the metal artifact reduction (MAR) method on quantitative single-photon emission computed tomography (SPECT)/computed tomography (CT) to reveal the usefulness of MAR in patients with metal implants. METHODS: We performed a phantom experiment simulating patients with artificial hip prostheses using SPECT/CT equipped with the iterative MAR (iMAR). The phantom was filled with Tc-99m solution (29.5 kBq/mL). For the CT scan conditions, tube current time products were applied to obtain volume CT dose indexes (CTDIvols) of 1.4, 2.8, and 5.6 mGy. Six types of quantitative SPECT images were reconstructed using data from different doses of CT processed with and without iMAR for CT attenuation correction. Thirty circular regions of interest (ROIs) were placed in each of the dark-band artifact areas, the white-streak artifact areas, and the non-artifact areas. We calculated radioactivity concentrations from quantitative SPECT images with and without iMAR to evaluate the quantitative accuracy. The differences of the effect of iMAR with different CT doses were also evaluated. RESULTS: The results obtained using CT data with a CTDIvol of 2.8 mGy are described below. For quantitative SPECT data without iMAR, we observed the underestimation of radioactivity concentration in the dark-band artifact areas and overestimation in the white-streak artifact areas. We observed quantification errors ranging from - 41.1% to + 20.0% without iMAR, depending on the ROI localization. When iMAR was used, these errors were reduced to a range of - 22.8% to + 14.2%. The mean absolute error from the true value in the artifact regions was also significantly reduced from 4.00 to 1.74 kBq/mL. In the non-artifact areas, the radioactivity concentrations obtained from the quantitative SPECT data with and without iMAR were equivalent to the true value and did not differ significantly between the two conditions. Similar results were observed for procedures with CTDIvols of 1.4 and 5.6 mGy. CONCLUSIONS: This study indicated that iMAR could improve the quantitative accuracy of SPECT/CT independent of the CT dose. iMAR can serve as a practicable technique for quantitative SPECT/CT in patients with metal implants.

The usefulness of SwiftScan technology for bone scintigraphy using a novel anthropomorphic phantom.

The aim of this study was to demonstrate the usefulness of SwiftScan with a low-energy high-resolution and sensitivity (LEHRS) collimator for bone scintigraphy using a novel bone phantom simulating the human body. SwiftScan planar image of lateral view was acquired in clinical condition; thereafter, each planar image of different blend ratio (0-80%) of Crality 2D processing were created. SwiftScan planar images with reduced acquisition time by 25-75% were created by Poisson's resampling processing. SwiftScan single photon emission computed tomography (SPECT) was acquired with step-and-shoot and continuous mode, and SPECT images were reconstructed using a three-dimensional ordered subset expectation maximization incorporating attenuation, scatter and spatial resolution corrections. SwiftScan planar image showed a high contrast to noise ratio (CNR) and low percent of the coefficient of variance (%CV) compared with conventional planar image. The CNR of the tumor parts in SwiftScan SPECT was higher than that of the conventional SPECT image of step and shoot acquisition, while the %CV showed the lowest value in all systems. In conclusion, SwiftScan planar and SPECT images were able to reduce the image noise compared with planar and SPECT image with a low-energy high-resolution collimator, so that SwiftScan planar and SPECT images could be obtained a high CNR. Furthermore, the SwiftScan planar image was able to reduce the acquisition time by 25% when the blend ratio of Clarity 2D processing set to more than 40%.

Hybrid surgical and endovascular repair for anastomotic pseudoaneurysms after total arch replacement.

An 83-year-old woman who had undergone total arch replacement for a thoracic aortic aneurysm seven years prior experienced concurrent rupture of second and third branch anastomotic pseudoaneurysms. A stent graft was initially deployed across the pseudoaneurysm from the third branch to the left subclavian artery. Following the left axillary and left carotid arterial bypass, the origin of the second branch was embolized with metallic coils. As a result, both anastomotic pseudoaneurysms were undetectable by both completion angiogram and postoperative CT. By combining surgical and endovascular procedures, ruptured anastomotic pseudoaneurysms after total arch replacement can be repaired without a risky resternotomy.

The utility of heart-to-mediastinum ratio using a planar image created from IQ-SPECT with Iodine-123 meta-iodobenzylguanidine.

AIMS: 123I-labeled meta-iodobenzylguanidine (MIBG) has used a planar image to measure the heart-to-mediastinum ratio (HMR). However, planar images are not available from IQ-SPECT with SMARTZOOM collimator due to its multi-focal collimation. Since we created the planar-equivalent (IQ-planar) images by adding all slices of the IQ-SPECT coronal image. The aim of this study was to demonstrate the utility of the new method for calculating HMR. METHODS: The planar image and transverse images of IQ-SPECT with attenuation and scatter corrections (ACSC) and without ACSC (NC) were obtained. Multi-planar reconstruction and ray-summation processing were applied to create IQ-planar images with NC and ACSC. Linear regression between the measured HMR from the planar image and the mathematically calculated HMR was used to calibrate HMR to standardized values. RESULTS: Scatterplots and linear regression lines between planar and IQ-planar HMRs before and after cross-calibration showed systematic differences in both NC and ACSC conditions. The IQ-planar HMR with NC and ACSC was significantly higher compared with that of the conventional planar image. However, the IQ-planar HMR with NC and ACSC after cross-calibration was similar to the standardized HMR calculated by planar image. CONCLUSION: The IQ-planar HMR using the new ray-summation processing method could be used along with the conventional planar HMR.

Comparison of Myocardial Ischemia Detection Between Semiconductor and Conventional Anger-type Three-detector SPECT.

Objective: Although semiconductor single-photon emission computed tomography (D-SPECT) has been used for myocardial perfusion imaging, few studies have compared its ability to detect myocardial ischemia with that of 3-detector SPECT (GCA9300R). This study used invasive coronary angiography to determine whether the detectability of myocardial ischemia differs between D-SPECT and GCA9300R. Materials and methods: This study included 24 patients who were assessed by coronary angiography within 60 days of myocardial perfusion D-SPECT and GCA9300R. Two nuclear medicine physicians interpreted myocardial perfusion D-SPECT and GCA9300R images with five grades of confidence, then defined regions of ischemia on polar maps. The gold standard was determined by another nuclear cardiology specialist based on integrated assessment of the coronary angiography findings and other clinical information derived from medical charts. The concordance rate and the Cohen kappa (κ) between D-SPECT and GCA9300R were calculated. Results: The sensitivity, specificity, negative and positive predictive values, and the accuracy of patient-based diagnoses were 66.7%, 91.7%, 89.2%, 72.8%, and 85.5%, respectively, for GCA9300R, and 83.3%, 83.3%, 93.7%, 62.4%, and 83.3%, respectively, for D-SPECT. Interpretations of ischemia did not uncover any significant differences between D-SPECT and GCA9300R. The Cohen κ values of D-SPECT and GCA9300 agreed substantially, moderately and marginally for the left circumflex coronary artery (LCX) (0.68), right coronary artery (RCA) (0.43), and left anterior descending coronary artery (LAD) (0.39), respectively. Conclusions: The detectability of myocardial ischemia is comparable between D-SPECT and GCA9300R. Sensitivity is better for D-SPECT than GCA9300R. However, false-positive D-SPECT findings, especially in the apex and inferior wall should be interpreted with caution.

Asymmetric Synthesis of a 5,6,7,8-Tetrahydro-1,6-naphthyridine Scaffold Leading to Potent Retinoid-Related Orphan Receptor γt Inverse Agonist TAK-828F.

An asymmetric synthesis of the tetrahydronaphthyridine scaffold of TAK-828F as a RORγt inverse agonist has been developed. The synthesis features a newly discovered atom-economical protocol for Heck-type vinylation of chloropyridine using ethylene gas, an unprecedented formation of dihydronaphthyridine directly from 2-vinyl-3-acylpyridine mediated by ammonia, and a ruthenium-catalyzed enantioselective transfer hydrogenation as key steps. This represents the first example of the enantioselective synthesis of a 5,6,7,8-tetrahydro-1,6-naphthyridine compound. The new synthesis is also free of chromatography or distillation purification processes and therefore qualifies for extension to large-scale manufacture.

Stent-Jack Technique for Ruptured Vertebral Artery Dissecting Aneurysm Involving the Origin of Posterior Inferior Cerebellar Artery.

We herein report a case of a ruptured vertebral artery dissecting aneurysm involving the origin of the posterior inferior cerebellar artery that was treated using the stent-jack technique. After parent artery occlusion of the distal vertebral artery, stenting of the posterior inferior cerebellar artery was performed. Further coiling was needed because distal vertebral artery recanalization occurred due to transformation of the coil mass. The stent-jack technique for a ruptured vertebral artery dissecting aneurysm involving the origin of the posterior inferior cerebellar artery is effective; however, careful attention to recanalization after stenting is needed due to transformation of the coil mass.