A case report of forensic personal identification by transposed teeth and dental treatment marks using multidetector row computed tomography.

Using postmortem computed tomography (CT) images, we achieved personal identification of a body using transposed teeth and dental treatment marks. Transposition of teeth is a rare malpositioning anomaly. CT images can clarify the malpositioning of the teeth's roots, which is difficult to discern from gross observation of the dentition. Because dental hygiene has reduced the incidence of caries in recent years, it might be difficult to use treatment marks for personal identification in the future. Transposed teeth, although rare, provide an important clue to personal identification.

Improvement of Imaging Conditions to Improve the Detection Rate of Head and Neck Cancer by Positron Emission Tomography/Computed Tomography Examination.

Positron emission tomography (PET)/computed tomography (CT) has improved sensitivity and resolution using silicon photomultiplier as a photosensor. Previously, only a fixed setting was available for the shooting time of 1 bed, but now, the shooting time can be changed for each bed. Time can be shortened or extended depending on the target area. A few studies reported on image reconstruction conditions for head and neck cancer in whole-body PET/CT examinations. Thus, this study aimed to optimize the imaging conditions of the head and neck region during whole-body imaging. A cylindrical acrylic container with a 200 mm diameter was used to simulate the head and neck area using a PET/CT system equipped with a semiconductor detector. Spheres of 6-30 mm in diameter were enclosed in the 200 mm diameter cylindrical acrylic vessel. Radioactivity in 18F solution (Hot:BG ratio 4:1) was enclosed in a phantom following the Japanese Society of Nuclear Medicine (JSNM) guidelines. Background radioactivity concentration was 2.53 kBq/mL. List mode acquisition of 1,800 s was collected at 60-1,800 s with the field of view of 700 mm and 350 mm. The image was reconstructed by resizing the matrix to 128 × 128, 192 × 192, 256 × 256, and 384 × 384, respectively. The imaging time per bed in the head and neck should be at least 180 s, and the reconstruction conditions should be a field of view (FOV) of 350 mm, matrix sizes of ≥ 192, and a Bayesian penalized likelihood (BPL) reconstruction with a ß-value of 200. This allows detection of > 70% of the 8-mm spheres in the images.

Post-ISCHEMIA Trial Era: Reconsideration of the Role of Nuclear Cardiology in Patients with Chronic Coronary Artery Disease.

The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial has had a great impact on the management of chronic coronary artery disease (CAD). One of the implications of this trial is the importance of close patient follow-up. To improve patient prognosis, evaluation of the residual extent of ischemia after treatment may be important because several studies have shown a close relationship between residual ischemia and cardiac events. For this assessment, myocardial perfusion single-photon emission computed tomography (MPS) has been utilized and is almost the only modality. Among the participants in the ISCHEMIA trial, more than 10% were excluded due to the absence of obstructive CAD. The pathophysiology of ischemia without non-obstructive coronary artery disease (INOCA) is gaining recognition; however, diagnosis is difficult, except for the assessment of myocardial flow reserve (MFR). Myocardial perfusion positron emission tomography (PET) is the most common modality for noninvasive evaluation of MFR; however, its availability in Japan is limited. For a breakthrough in this situation, a novel gamma camera with a cadmium zinc telluride (CZT) semiconductor might be one of the solutions that enables the evaluation of MFR with a commercially available perfusion tracer, similar to PET. Another solution is a novel PET tracer with a longer half-life. Clinical trials with 18F labeled perfusion agents have been initiated in Japan, and in a few years, delivery of this perfusion tracer will result in more frequent and easier assessment of MFR.

Diagnostic Accuracy of Liver Damage Based on Postmortem Computed Tomography Findings in High-Energy Trauma.

The liver is an organ that is frequently injured by blunt trauma. In clinical medicine, contrast-enhanced computed tomography (CT) is useful for diagnosing liver damage. However, detection of liver injury is difficult with postmortem CT (PMCT) that does not use contrast media. This study aims to identify findings that are useful for diagnosing liver injury with PMCT. This study included 97 high-energy trauma cases that underwent both PMCT without contrast and forensic autopsy between July 2009 and November 2020. PMCT findings in and around the liver in cases of liver injury were collected. The diagnostic accuracy of each finding was calculated. Of 97 cases, 62 had liver injury on autopsy. PMCT detected hepatic surface gas in 31 cases, intrahepatic focal gas in 19 cases, high-density fluid accumulation around the liver in 12 cases, and fracture of a right lower (9th-12th) rib in 48 cases. Abnormal PMCT findings in and around the liver had insufficient diagnostic sensitivity, ranging from 19.4% to 38.7%. By contrast, the finding of a right lower rib fracture was more sensitive for suspected liver injury. Our results indicate that abdominal liver findings (hepatic surface gas, intrahepatic focal gas, and high-density fluid accumulation around the liver) are of limited utility for the diagnosis of liver injury, whereas a right lower rib fracture is a useful indirect finding.

Accuracy of virtual monochromatic images generated by the decomposition of photoelectric absorption and Compton scatter in dual-energy computed tomography.

The decomposition of the linear attenuation coefficient into photoelectric absorption and Compton scattering provides virtual monochromatic images (VMIs). The accuracy of the computed tomography (CT) number of VMI, which is obtained by decomposing the linear attenuation coefficient into photoelectric absorption and Compton scattering, was verified in the energy range of 40-200 keV. The possibility of improving the accuracy of CT numbers by using pre-energy-calibrated images as input was also investigated. The VMIs were generated in two groups of images: (i) dual-energy scanned images and (ii) high- and low-energy images generated by two-material decomposition (i.e., pre-energy-calibrated images). The object for analysis was solid iodine rods inserted in the center of the multi-energy CT phantom. The VMIs were generated from the dual-energy scanned images and pre-energy-calibrated images, and the theoretical and measured CT numbers of solid iodine rods were compared. Furthermore, the absolute error (AE) and relative error (RE) were calculated. With both images, the accuracy of the CT numbers was extremely high for regions close to the high- and low-tube-voltage X-ray energy or the high and low energy of the input images. By using the pre-energy-calibrated images, the maximum AE was reduced from 133 to 96 HU at an energy of 40 keV. Similarly, the maximum RE was reduced from 325 to 50% at an energy of 200 keV. The pre-energy-calibrated images reduced the overall error of the CT numbers and controlled the energy region where accurate CT numbers could be obtained.

Pathological Changes in the Lymphatic System of Patients with Secondary Lower Limb Lymphedema Based on Single Photon-Emission Computed Tomography/Computed Tomography/Lymphoscintigraphy Images.

Background: In patients with secondary upper limb lymphedema, positive correlations have been observed between the dermal back flow (DBF) type and visualization of lymph nodes around the clavicle, between the former and the lymph flow pathway type, and between the latter and the visualization of lymph nodes around the clavicle when using single photon-emission computed tomography/computed tomography/lymphoscintigraphy (SPECT-CT LSG). Methods and Results: We analyzed the associations between the visualization of inguinal lymph nodes, the lymph flow pathway type, and the DBF type using SPECT-CT LSG in 81 patients with unilateral secondary lower limb lymphedema by statistical analysis using Fisher's exact test. We revealed that the lymph flow pathways in the lower limb can be classified into nine types because the type in the lower leg is not always equal to the type in the thigh. Associations were observed between the visualization of inguinal lymph nodes and types of DBF (p < 0.01), between the types of lymph flow pathway in the thighs and visualization of the inguinal lymph nodes (p = 0.02), and between the lymph flow pathway types in the thighs and lower legs (p < 0.01). Conclusion: Detriment to the superficial lymph flow pathways in the lower limb appears to usually start from the proximal side, and deep pathways are considered to become dominant from a compensatory perspective as lymphedema severity increases.

Structural brain network correlations with amyloid burden in elderly individuals at risk of Alzheimer's disease.

Alzheimer's disease (AD) has a long preclinical phase during which beta-amyloid accumulates in the brain without cognitive impairment. However, the pattern of brain network alterations in this early stage of the disease remains to be clarified. In this study we examined the relationships between regional brain network indices and beta-amyloid deposits. Twenty-four elderly subjects with the APOE4 allele underwent both a 1.5-Tesla magnetic resonance imaging (MRI) scan and a positron emission tomography (PET) scan using [18F]Florbetapir. We computed network metrics such as the degree, betweenness centrality, and clustering coefficient, and examined the relationships between the beta-amyloid accumulation and these regional brain network connectivity metrics. We found a significant positive correlation between the global standardized uptake value ratio (SUVR) of [18F]Florbetapir and the betweenness centrality in the left parietal region. However, there were no significant correlations between the SUVR score and other network indices or the regional gray matter volume. Our data suggest a relationship between the beta-amyloid accumulation and the regional brain network connectivity in subjects at risk of AD. The brain connectome may provide an adjunct biomarker for the early detection of AD.

Safety and efficacy of peptide receptor radionuclide therapy with 177Lu-DOTA0-Tyr3-octreotate in combination with amino acid solution infusion in Japanese patients with somatostatin receptor-positive, progressive neuroendocrine tumors.

PURPOSE: Peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTA0-Tyr3-octreotate (177Lu-DOTATATE) is one of the most reliable treatments for unresectable, progressive neuroendocrine tumors (NETs) with somatostatin receptor expression. We have, for the first time, reported the results of the tolerability, safety, pharmacokinetics, dosimetry, and efficacy of this treatment for Japanese patients with NET. METHODS: Patients with unresectable, somatostatin receptor scintigraphy (SRS)-positive NETs were enrolled in this phase I clinical trial. They were treated with 29.6 GBq of 177Lu-DOTATATE (four doses of 7.4 GBq) combined with amino acid solution infusion plus octreotide long-acting release (LAR) 30 mg. The primary objective of this study was to evaluate the tolerability, safety, pharmacokinetics, and dosimetry of a single administration of this treatment in patients with SRS-positive NETs. RESULTS: Six Japanese patients (three men and three women; mean age 61.5 years; range 50-70 years) with SRS-positive unresectable NETs were recruited. 177Lu-DOTATATE was eliminated from the blood in a two-phase manner. Cumulative urinary excretion of radioactivity was 60.1% (range 49.0%-69.8%) within the initial 6 h. The cumulative renal absorbed dose for 29.6 GBq of 177Lu-DOTATATE was 16.8 Gy (range 12.0-21.2 Gy), and the biological effective dose was 17.0 Gy (range 12.2-21.5 Gy). Administration of 177Lu-DOTATATE was well tolerated, with no dose-limiting toxicities. Grade 3 lymphopenia occurred in two (33.3%) cases, but there were no other severe toxicities. Four patients achieved partial response (objective response rate, 66.7%), one patient had stable disease, and one patient had progressive disease. CONCLUSION: PRRT with 177Lu-DOTATATE was well-tolerated and showed good outcomes in Japanese patients with unresectable NETs. Peptide receptor radionuclide therapy, 177Lu-DOTA0-Tyr3-octreotate .

Comparison of 18F-FDG PET/CT and 67Ga-SPECT for the diagnosis of fever of unknown origin: a multicenter prospective study in Japan.

OBJECTIVE: The aim of this multicenter prospective study was to compare the sensitivity of 18F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) with that of 67Ga single photon emission computed tomography (SPECT) for the identification of the site of greatest importance for the final diagnosis of the cause of fever of unknown origin (FUO). METHODS: The study participants consisted of patients with an axillary temperature ≥ 38.0 °C on ≥ 2 occasions within 1 week, with repeated episodes for ≥ 2 weeks prior to providing consent, and whose final diagnosis after undergoing specific examinations, including a chest-to-abdomen CT scan, was uncertain. All the patients underwent FDG-PET/CT imaging first, followed by 67Ga-SPECT imaging within 3 days. The results of the FDG-PET/CT and 67Ga-SPECT examinations were reviewed by the central image interpretation committee (CIIC), which was blinded to all other clinical information. The sensitivities of FDG-PET/CT and 67Ga-SPECT were then evaluated with regard to identifying the site of greatest importance for a final diagnosis of the cause of the fever as decided by the patient's attending physician. The clinical impacts (four grades) of FDG-PET/CT and 67Ga-SPECT on the final diagnosis were evaluated. RESULTS: A total of 149 subjects were enrolled in this study between October 2014 and September 2017. No adverse events were identified among the enrolled subjects. Twenty-one subjects were excluded from the study because of deviations from the study protocol. Among the 128 remaining subjects, a final diagnosis of the disease leading to the appearance of FUO was made for 92 (71.9%) subjects. The final diagnoses in these 92 cases were classified into four groups: noninfectious inflammatory disease (52 cases); infectious disease (31 cases), malignancy (six cases); and other (three cases). These 92 subjects were eligible for inclusion in the study's analysis, but one case did not meet the PET/CT image acquisition criteria; thus, PET/CT results were analyzed for 91 cases. According to the patient-based assessments, the sensitivity of FDG-PET/CT (45%, 95% CI 33.1-58.2%) was significantly higher than that for 67Ga-SPECT (25%, 95% CI 15.5-37.5%) (P = 0.0029). The clinical impact of FDG-PET/CT (91%) was also significantly higher than that for 67Ga-SPECT (57%, P < 0.001). CONCLUSIONS: FDG-PET/CT showed a superior sensitivity to 67Ga-SPECT for the identification of the site of greatest importance for the final diagnosis of the cause of FUO.

Feasibility of prognosis assessment for cancer of unknown primary origin using texture analysis of 18F-fluorodeoxyglucose PET/computed tomography images of largest metastatic lymph node.

OBJECTIVE: Cancers of unknown primary origin cannot be staged using images, making the prognosis difficult. We attempted to predict prognosis of patients with unknown primary origin using tumour heterogeneity recently introduced in F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT). METHODS: Overall, 30 patients with unknown primary origin who underwent whole-body F-FDG PET/CT scans were retrospectively enrolled for texture analysis. The volume of interest was placed in the largest metastatic lymph nodes and conventional parameters and grey-level co-occurrence matrix (GLCM) were calculated. Statistical analysis of image-based variables was performed using Cox regression analyses. Patients were stratified into two groups based on cutoff values of GLCMentropy obtained using receiver operating characteristics (ROCs). Patients were analyzed, and overall survival (OS) was compared using Kaplan-Meier analysis. RESULTS: Univariate Cox regression analysis showed significant differences in prognosis for parenchymal organ metastasis (P < 0.01), GLCM homogeneity (P = 0.01), GLCMcontrast (P < 0.01), GLCMentropy (P < 0.01) and GLCMdissimilarity (P < 0.01). Multivariate Cox regression analysis showed a significant difference in reduced prognosis for GLCMentropy positive (P < 0.01). Stratification was performed based on the GLCMentropy cutoff value, determined using ROCs analysis, with smaller groups showing better OS. CONCLUSIONS: Despite previous difficulties in predicting prognosis in patients with unknown primary origin, F-FDG PET/CT texture features may enable stratification of prognosis. This could be useful for appropriate patient selection and management and help identify a subset of patients with favourable outcomes. These novel findings may be helpful for prognostication and improving patient care.

Cardiac Resynchronization Therapy for Improving Non-Uniform Thickening of Left Ventricular Wall: Assessment by Quantitative Gated Myocardial Perfusion SPECT.

Cardiac resynchronization therapy (CRT) improves cardiac dyssynchrony in heart failure patients with a wide QRS electrocardiogram (ECG). Assessment of left ventricular (LV) dyssynchrony using echocardiography or other imaging modalities is important to predict CRT effectiveness. In this study, we retrospectively evaluated cardiac nuclear imaging of ECG-gated myocardial perfusion single-photon emission computed tomography (SPECT) with 99mTc-sestamibi for CRT candidate (n = 120) with severe heart failure and wide QRS (> 120 msec) in ECG. To analyze LV non-uniformity, we used the quantitative gated SPECT (QGS) software to calculate changes in regional LV wall thickness during a cardiac cycle (i.e., wall thickening scores). Cardiac events (heart failure, ventricular arrhythmias and cardiac death) after CRT during 38 ± 22 (SD) months were also evaluated. In 97 of 120 patients who underwent QGS before and 6 months after CRT, CRT homogenized non-uniform wall thickening between septal and lateral of the LV especially in CRT responders. This observation was indicated as increase in the lateral deflection (XWT) of wall thickening scores before CRT and its decrease after CRT. In 120 patients with QGS before CRT, the larger XWT before CRT (≥ 16.5) predicted better prognoses after CRT. This finding was similarly observed even in patients with narrower baseline QRS (≤ 140 msec; n = 41 of 120), who usually have less benefits from CRT. In conclusion, CRT improved non-uniformity of wall thickening between the LV septal and lateral regions evaluated using QGS, which is predictive of better prognosis in the chronic phase after CRT.

PET and SPECT imaging of the brain: a review on the current status of nuclear medicine in Japan.

Radiolabeled tracers allow visualization of not only perfusion, but receptors, function, and metabolism as well. Although spatial resolution is lower than that of computed tomography and magnetic resonance imaging, positron emission tomography (PET) and single photon emission computed tomography (SPECT) have great potential for target-specific imaging. In this review, we discuss several SPECT and PET tracers used in brain imaging, specifically focusing on tracers currently available, or developed, in Japan. Several important and sophisticated methods exist for analysis of brain PET and SPECT images. Two of them, quantitative cerebral blood flow measurement and voxel-based statistical analysis are discussed in this review. The former method, which employs acetazolamide loading, is useful for evaluation of the brain perfusion reserve for ischemic brain diseases. The latter is useful in diagnosing dementing diseases. Additionally, great strides have been made in the development of the technology used in the scanners. New SPECT systems based on cadmium-zinc-telluride, PET/MRI, and semiconductor PET/CT may provide higher spatial resolution with an acquisition time shorter than ever before. Such developments of both tracers and scanners can be integrated for unprecedented imagery of the brain, providing valuable insight into underlying causes of some fatal brain disorders.

Pathological changes in the lymphatic system of patients with secondary upper limb lymphoedema.

Secondary upper limb lymphoedema is usually caused by lymphatic system dysfunction. Diagnosis is primarily based on clinical features. However, there are no distinct diagnostic criteria for lymphoedema. Although conventional lymphoscintigraphy is a useful technique to diagnose the severity of lymphoedema, the resultant data are two-dimensional. In this study, we examined the pathology of lymphoedema using single photon emission computed tomography-computed tomography lymphoscintigraphy (SPECT-CT LSG), a new technique that provides 3-dimensional information on lymph flow. We observed lymph flow pathways in the subcutaneous and muscle layers of the upper limbs. A significant positive correlation was found between the dermal back flow (DBF) type and the visualization of lymph nodes around the clavicle (p = 0.000266), the type of lymph flow pathways and the visualization of lymph nodes around the clavicle (p = 0.00963), and the DBF type and the lymph flow pathway (p = 0.00766). As the severity of lymphoedema increased, the DBF appeared more distally in the upper limb and the flow into the lymph nodes around the clavicle decreased, whereas the lymph flow pathways in the muscle layer became dominant. These findings demonstrate the features of lymphoedema pathology and the functional anatomy and physiology of the lymphatic system without the need for cadaver dissection.

Harmonization of standardized uptake values between two scanners, considering repeatability and magnitude of the values in clinical fluorine-18-fluorodeoxyglucose PET settings: a phantom study.

OBJECTIVE: The standardized uptake value (SUV) is a quantitative imaging biomarker which has been used the most widely in the field of PET. Current harmonization strategies commonly include image blurring by application of an additional extent of post-reconstruction Gaussian filtering in the aim of recovery coefficient adjustment. The objective of this study was to harmonize SUVmax and SUVpeak measured by an older PET/computed tomography scanner with a newer scanner without depending on image blurring. MATERIALS AND METHODS: We performed multiple phantom studies using a count-based method, in which SUVs can be calculated in a repeatable manner. We measured SUVmax and SUVpeak for spheres of various sizes (10, 13, 18, 22, 28, and 37-mm diameter) and actual SUVs (2, 4, 8, and 16) under standard clinical settings. The measured SUVs were compared with the actual SUVs, and the approximate equations were obtained. The relationships of the equations between two different PET/computed tomography scanners, Aquiduo and Celesteion, were examined to obtain conversion equations. RESULTS: The SUVmax and SUVpeak measured by Aquiduo were lower than those measured by Celesteion. For both scanners, the relationships between the actual and measured SUVs were linearly fit (R>0.99) for each sphere size. The equations varied depending on the sphere size. Also, for large spheres (>2 cm), SUVmax and SUVpeak could be harmonized by simple multiplication, regarding the small absolute values of y-intercept (<0.2) as negligible. CONCLUSION: Size-specific equations to convert SUVmax and SUVpeak measured by Aquiduo into the estimated values on Celesteion were obtained. Also, for large lesions (>2 cm), SUVs may be converted by simple multiplication. These methods might enable simple SUV harmonization which is not based on post-reconstruction Gaussian filtering.

Early assessment with 18F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography to predict short-term outcome in clear cell renal carcinoma treated with nivolumab.

BACKGROUND: We reported previously the usefulness of 18F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) to predict prognosis of renal cell carcinoma (RCC) treated with molecular targeted agents. Herein we describe a preliminary research of nine patients who underwent FDG-PET/CT before and after initiation of nivolumab. METHODS: Patients with metastatic RCC who were treated by nivolumab from October 2016 to March 2017 were enrolled in this study. All patients underwent FDG-PET/CT at baseline and 1 month as a first response assessment, and contrast-enhanced or non-contrast-enhanced CT scan at 4 month as a second response assessment. Logistic regression analysis was performed to assess the association of potential predictors, including age, gender, baseline diameter, baseline maximum standardized uptake value (SUVmax), lung or not lung metastasis, elevation of SUVmax at 1st assessment, and decrease in diameter at 1st assessment with the response at 2nd assessment (decrease in the diameter ≥ 30% or not). RESULTS: There were 9 patients and 30 lesions. Mean days of first assessment with FDG-PET/CT and second assessment by CT scan from initiation of treatment were 32.3 ± 6.4, 115.5 ± 14.9, respectively. Lesions whose diameter decreased ≥30% at second assessment were defined as responding, and lesions whose diameter did not decrease ≥30% were defined as non-responding. There were 18 responding lesions, and 12 non-responding lesions. We compared change in diameter and SUVmax at first assessment with FDG-PET/CT, respectively. All lesions with decreased diameter and elevated SUVmax at first assessment with FDG-PET/CT showed responding at second assessment by CT scan, while most lesions with increased diameter and declined SUVmax at first assessment showed non-responding at second assessment. The multivariate logistic regression analyses revealed that only the elevation of SUVmax at 1 month was an independent predictor (P = 0.025, OR: 13.087, 95%CI: 1.373-124.716). CONCLUSION: Our findings suggest that the early assessment using FDG-PET/CT can be effective to predict the response of RCC to nivolumab. However, larger prospective studies are needed to confirm these preliminary results. TRIAL REGISTRATION: Registered in University Hospital Medical Information Network in JAPAN [ UMIN0000008141 ], registration date: 11 Jun 2012.

[18F]fluorodeoxyglucose-positron emission tomography study of genetically confirmed patients with Dravet syndrome.

OBJECTIVE: To understand cerebral brain dysfunction in patients with Dravet syndrome (DS), we conducted a [18F]fluorodeoxyglucose-positron emission tomography (FDG-PET) study in patients with DS whose SCN1A gene variant was confirmed. METHODS: FDG-PET was performed on eight patients with DS. A SCN1A mutation analysis revealed missense variants in four patients and truncation variants in four patients. The patients' ages at the time of the PET study were 2, 2, 2, 3, 6, 13, 20, and 29 years old, respectively. The patients' developmental/intelligence quotient at the time of the PET study were 62, 52, 64, 35, 30, 15, and <25, respectively. The mean standardized uptake value (SUV) was calculated in four segments (frontal, temporal, parietal, and occipital) for the semi-quantitative analysis of 18F-FDG uptake. This value represents the average of the regions of interest in each lobe and was divided by the average SUV of the cerebellar hemisphere of each patient and compared between the patients with DS and the diseased controls. RESULTS: Glucose uptake in patients with DS decreased significantly, particularly in those ≥6 years old. Importantly, a comparison between the younger and older patients with DS revealed that glucose uptake was normal in patients who were ≤3 years (2, 2, 2, and 3 years), whereas a profound reduction in glucose uptake in the fronto-temporo-parietal-occipital cortices was observed in patients ≥ 6 years (6, 13, 20, and 29 years). Magnetic resonance imaging revealed no detectable atrophic legions or other changes in the cerebral cortices of patients ≥ 6 years of age. SIGNIFICANCE: The present study showed a remarkable reduction in cerebral glucose metabolism in multiple lobes for the first time, which became obvious after the late infantile period. These findings may indicate a functional neuroimaging aspect of epileptic encephalopathy of DS or a feature of the SCN1A variant itself.

New microwave ablation system for unresectable liver tumors that forms large, spherical ablation zones.

BACKGROUND AND AIM: The aim of this study was to assess the efficacy of a new microwave ablation (MWA) system, the Emprint Ablation System, for the ablation of unresectable large liver tumors (≥ 30 mm). METHODS: Twenty-one hepatic tumors (mean diameter, 34.7 mm) from 21 patients who underwent percutaneous MWA were included in this cross-sectional study. A volume analyzer based on computed tomography imaging was used for all patients within the month before and month after the procedure to evaluate the shape and volume of ablation zones. In addition, computed tomography imaging was performed again 3 months after the procedure to evaluate the presence of residual tumors and local recurrence. RESULTS: Mean ablation time was 11.3 min, and mean overall procedure time was 33.4 min. An ablated adrenal gland-induced Takotsubo (stress) cardiomyopathy occurred immediately after MWA as a major complication in one patient. Roundness index A, B, and C presented a mean value of 0.94, 0.94, and 1.01, respectively (all values near 1 is a perfect sphere), indicating that a spherical ablation zone was achieved. The mean ablation volume was larger than the volume of tumors (24.5 vs 41.7 cm3 ). Residual tumors were confirmed in only 4.8% of tumors after a single ablation session. There was no local recurrence. CONCLUSIONS: In our experience, the new MWA system provides an effective treatment option for unresectable large liver tumors. However, to ablate the liver tumors safely, it is necessary to consider the surrounding organs, such as the adrenal glands.

FDG PET/CT after first molecular targeted therapy predicts survival of patients with renal cell carcinoma.

PURPOSE: We investigated prospectively whether 18F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT) can predict the overall survival (OS) of patients with advanced renal cell carcinoma (RCC) previously treated by molecular targeted therapies. METHODS: Between 2009 and 2016, 81 patients who had received single molecular targeted therapies (43 sorafenib, 27 sunitinib, 8 temsirolimus and others) and were scheduled for second line molecular targeted therapies for advanced RCC were enrolled in this prospective study. FDG PET/CT was performed after first line molecular targeted therapies, the max SUVmax (highest standardized uptake value for each patient) recorded, and its association with OS compared with those of known risk factors. The median follow-up was 15.4 months (range 0.9-97.4 months). RESULTS: The max SUVmax of the 81 subjects ranged from undetectable to 23.0 (median 7.1). Patients with high max SUVmax had a poor prognosis and multivariate analysis with established risk factors showed that it was an independent predictor of survival (p < 0.001; hazard ratio 1.156; 95% confidence interval 1.080-1.239). Subclassification of patients by max SUVmax showed that the median OS of patients with max SUVmax < 7.0 (39), 7.0-12.0 (30), and ≥ 12.0 (12) were 32.8, 15.2, and 6.0 months, respectively. These differences are statistically significant (< 7.0 versus 7.0-12.0: p = 0.0333, 7.0-12.0 versus ≥ 12.0: p = 0.0235). CONCLUSIONS: The max SUVmax by FDG PET/CT of patients with RCC evaluated after their first molecular targeted therapy predicts OS. FDG PET/CT is a useful "imaging biomarker" for patients with advanced RCC planning sequential molecular targeted therapies.

Use of count-based image reconstruction to evaluate the variability and repeatability of measured standardised uptake values.

Standardized uptake values (SUVs) are the most widely used quantitative imaging biomarkers in PET. It is important to evaluate the variability and repeatability of measured SUVs. Phantom studies seem to be essential for this purpose; however, repetitive phantom scanning is not recommended due to the decay of radioactivity. In this study, we performed count-based image reconstruction to avoid the influence of decay using two different PET/CT scanners. By adjusting the ratio of 18F-fluorodeoxyglucose solution to tap water, a NEMA IEC body phantom was set for SUVs of 4.0 inside six hot spheres. The PET data were obtained using two scanners (Aquiduo and Celesteion; Toshiba Medical Systems, Tochigi, Japan). We set the start time for image reconstruction when the total radioactivity in the phantom was 2.53 kBq/cc, and employed the counts of the first 2-min acquisition as the standard. To maintain the number of counts for each image, we set the acquisition time for image reconstruction depending on the decay of radioactivity. We obtained 50 images, and calculated the SUVmax and SUVpeak of all six spheres in each image. The average values of the SUVmax were used to calculate the recovery coefficients to compare those measured by the two different scanners. Bland-Altman analyses of the SUVs measured by the two scanners were also performed. The measured SUVs using the two scanners exhibited a 10-30% difference, and the standard deviation (SD) of the measured SUVs was between 0.1-0.2. The Celesteion always exhibited higher values than the Aquiduo. The smaller sphere exhibited a larger SD, and the SUVpeak had a smaller SD than the SUVmax. The Bland-Altman analyses showed poor agreement between the SUVs measured by the two scanners. The recovery coefficient curves obtained from the two scanners were considerably different. The Celesteion exhibited higher recovery coefficients than the Aquiduo, especially at approximately 20-mm-diameter. Additionally, the curves were lower than those calculated from the standard 30-min acquisition images. We propound count-based image reconstruction to evaluate the variability and repeatability of measured SUVs. These results are also applicable for the standardization and harmonization of SUVs in multi-institutional studies.