A novel use of CT attenuation value: increased bone marrow density in patients with acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults. Bone marrow computed tomography (CT) attenuation may increase in patients with myeloproliferative disorders; however, the actual threshold CT attenuation value predictive of myeloproliferative has not been reported. PURPOSE: To determine whether the unenhanced CT attenuation value of the bone marrow may be useful for predicting AML. MATERIAL AND METHODS: We retrospectively analyzed patients with AML (n = 56) who underwent unenhanced CT before treatment, and age- and sex-matched controls without any hematologic disease. For each patient, the CT attenuation value (HU) of the iliac bone was measured and compared between the two groups. Receiver operating characteristic (ROC) curve analysis was used to define the cutoff value for predicting AML on all patients, and only on late elderly patients (aged ≥75 years). RESULTS: Patients with AML showed higher bone marrow CT attenuation value (131.4 ± 58.3 vs. 53.9 ± 67.2 HU; P < 0.001), compared to the controls. The sensitivity and specificity for the diagnosis of AML in all patients were 78.6% and 80.4%, respectively, at a threshold value of 90 HU, whereas they were 83.3% and 91.7%, respectively, at 40 HU in late elderly patients. CONCLUSION: The iliac bone CT attenuation value was elevated in patients with AML and may be useful for predicting AML.

Single-cell dissection, hdWGCNA and deep learning reveal the role of oxidatively stressed plasma cells in ulcerative colitis.

Ulcerative colitis (UC) develops as a result of complex interactions between various cell types in the mucosal microenvironment. In this study, we aim to elucidate the pathogenesis of ulcerative colitis at the single-cell level and unveil its clinical significance. Using single-cell RNA sequencing and high-dimensional weighted gene co-expression network analysis, we identify a subpopulation of plasma cells (PCs) with significantly increased infiltration in UC colonic mucosa, characterized by pronounced oxidative stress. Combining 10 machine learning approaches, we find that the PC oxidative stress genes accurately distinguish diseased mucosa from normal mucosa (independent external testing AUC=0.991, sensitivity=0.986, specificity=0.909). Using MCPcounter and non-negative matrix factorization, we identify the association between PC oxidative stress genes and immune cell infiltration as well as patient heterogeneity. Spatial transcriptome data is used to verify the infiltration of oxidatively stressed PCs in colitis. Finally, we develop a gene-immune convolutional neural network deep learning model to diagnose UC mucosa in different cohorts (independent external testing AUC=0.984, sensitivity=95.9%, specificity=100%). Our work sheds light on the key pathogenic cell subpopulations in UC and is essential for the development of future clinical disease diagnostic tools.

rSO2 Measurement Using NIRS for Lower-Limb Blood Flow Monitoring and Estimation of Safe Balloon Occlusion/Deflation Time in Patients with PAS Who Underwent PBOA during CS.

We examined the utility of regional oxygen saturation (rSO2) measurement using near-infrared spectroscopy (NIRS) for monitoring lower-limb blood flow and estimate the safe balloon occlusion/deflation time in patients with PAS who underwent prophylactic balloon occlusion of the abdominal artery (PBOA) during cesarean section (CS). During CS, the NIRS probes were positioned on either of the anterior tibial muscles. rSO2 was measured continuously during balloon occlusion/deflation. A cycle consisted of inflating the aortic balloon for 30 min and deflating it for 5 min. The rSO2 before/during balloon occlusion and after 5 min of balloon deflation were evaluated. Sixty-two lower limbs (fifteen women and data from 31 sessions of balloon inflation/deflation) were evaluated. rSO2 during balloon occlusion was significantly lower than rSO2 before balloon occlusion (57.9% ± 9.6% vs. 80.3% ± 6.0%; p < 0.01). There were no significant differences between rSO2 before balloon occlusion and rSO2 after 5 min of balloon deflation (80.3% ± 6.0% vs. 78.7% ± 6.6%; p = 0.07). Postoperatively, the lower limbs showed no ischemic symptoms. NIRS can assess lower-limb rSO2 during PBOA for PAS in real time to determine ischemia severity, duration, and recovery capacity.

Synthetic double inversion recovery imaging in brain MRI: quantitative evaluation and feasibility of synthetic MRI and a comparison with conventional double inversion recovery and fluid-attenuated inversion recovery sequences.

BACKGROUND AND PURPOSE: Synthetic MR imaging (SyMRI) allows the reconstruction of various contrast images, including double inversion recovery (DIR), from a single scan. This study aimed to investigate the advantages of SyMRI by comparing synthetic DIR images with synthetic T2-weighted fluid-attenuated inversion recovery (T2W-FLAIR) and conventional DIR images. MATERIALS AND METHODS: We retrospectively reviewed the imaging data of 100 consecutive patients who underwent brain MRI between December 2018 and March 2019. Synthetic DIR, T2W-FLAIR, T1-weighted, and phase-sensitive inversion recovery (PSIR) images were generated from SyMRI data. For synthetic DIR, the two inversion times required to suppress white matter and cerebrospinal fluid (CSF) were manually determined by two radiologists. Quantitative analysis was performed by manually tracing the region of interest (ROI) at the sites of the lesion, white matter, and CSF. Synthetic DIR, synthetic T2W-FLAIR, and conventional DIR images were compared on the basis of using the gray matter-to-white matter, lesion-to-white matter, and lesion-to-CSF contrast-to-noise ratios. RESULTS: The two radiologists showed no differences in setting inversion time (TI) values, and their evaluations showed excellent interobserver agreement. The mean signal intensities obtained with synthetic DIR were significantly higher than those obtained with synthetic T2W-FLAIR and conventional DIR. CONCLUSION: Synthetic DIR images showed a higher contrast than synthetic T2WFLAIR and conventional DIR images.

Usefulness of dual isotope 123I-IMP and 201Tl SPECT for the diagnosis of primary central nervous system lymphoma and glioblastoma.

BACKGROUND: Preoperative differential diagnosis between primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM) is important because these tumors require different surgical strategies. This study investigated the usefulness of dual isotope, iodine-123-labeled N-isopropyl-p-iodo-amphetamine (123I-IMP) and thallium-201 chloride single-photon emission computed tomography (201Tl SPECT) for the differential diagnosis. METHODS: Twenty-five PCNSL patients and 27 GBM patients who underwent dual isotope imaging, 123I-IMP and 201Tl SPECT, are included. Tumor-to-normal (T/N) ratio was calculated from the ratio of maximum tracer counts in the lesion to the mean counts in the contralateral cerebral cortex. The mean and minimum apparent diffusion coefficient values (ADCmean and ADCmin, respectively) on magnetic resonance imaging were also analyzed. RESULTS: Delayed phase 123I-IMP SPECT was the most useful imaging examination for the differentiation between PCNSL and GBM compared with early phase 123I-IMP SPECT, early and delayed phase 201Tl SPECT, ADCmean, and ADCmin. However, the median T/N ratios of PCNSL and GBM were 1.32 and 0.83, respectively, in the delayed phase 123I-IMP SPECT. On the other hand, the median T/N ratios of PCNSL and GBM were 3.10 and 2.34, respectively, in the delayed phase 201Tl SPECT, with excellent tumor detection. CONCLUSION: Delayed phase 123I-IMP SPECT could differentiate between PCNSL and GBM with high accuracy, but T/N ratio was low and tumor detection was poor. 201Tl SPECT was useful for estimation of the malignancy and localization of the tumors with high T/N ratio. Dual isotope 123I-IMP and 201Tl SPECT was useful for the preoperative diagnosis of PCNSL and GBM.

Difficulty factors of adrenal venous sampling based on patient characteristics and imaging findings.

BACKGROUND: Primary aldosteronism is one of the most common causes of secondary hypertension. Unilateral primary aldosteronism can be treated with adrenalectomy; therefore, determining laterality is essential, for which adrenal venous sampling is considered the gold standard. However, as catheter insertion and sampling at an appropriate venous point is occasionally difficult, it is a time-consuming procedure. PURPOSE: To evaluate the patient characteristics and imaging findings that influence the adrenal venous sampling procedure. MATERIAL AND METHODS: A total of 69 patients who underwent adrenal venous sampling between January 2013 and December 2017 were retrospectively analyzed. The procedure was considered difficult if the duration was > 142 min (mean ± standard deviation [SD] of procedure time in this study) and/or proper sampling failed. Anatomical factors such as belly diameter, presence of adrenal nodules, diameter of the right adrenal vein and inferior vena cava, ratio of the diameters of the right adrenal vein to diameter of the inferior vena cava, vertical direction of the right adrenal vein, and vertebral level of the right adrenal vein were evaluated as predictive factors on computed tomography. RESULTS: Fifteen patients (21.7%) were considered difficult cases. The factors associated with difficulty were the long transverse diameter of the belly (P = 0.004) and high vertebral level of the right adrenal vein (P = 0.032). No statistical differences were observed in any other factors. CONCLUSION: The long transverse diameter of the belly and high vertebral level of the right adrenal vein may prevent completion of the adrenal venous sampling procedure.

Effectiveness of a flow confirmation study of a central venous port of the upper arm versus the chest wall in patients with suspected system-related mechanical complications.

BACKGROUND: If mechanical complications associated with a central venous port (CVP) system are suspected, evaluation with a flow confirmation study (FCS) using fluorescence fluoroscopy or digital subtraction angiography should be performed. Evaluations of mechanical complications related to CVP of the chest wall using FCS performed via the subclavian vein have been reported. However, the delayed complications of a CVP placed in the upper arm have not been sufficiently evaluated in a large population. We evaluated the effectiveness of FCS of CVPs implanted following percutaneous cannulation of the subclavian (chest wall group) or brachial (upper arm group) vein. METHODS: A CVP was implanted in patients with advanced cancer requiring chemotherapy. FCS was performed if there were complaints suggestive of CVP dysfunction when initiating chemotherapy. RESULTS: CVPs were placed in the brachial vein in 390 patients and in the subclavian vein in 800 patients. FCS was performed in 26/390 (6.7%) patients in the upper arm group and 40/800 (5.0%) patients in the chest wall group. The clinical characteristics of the patients were similar in both groups. The duration of CVP implantation until FCS was significantly shorter in the upper arm group (136 ± 96.6 vs. 284 ± 260, p = 0.022). After FCS, the incidence of CVP removal/reimplantation being deemed unnecessary was higher in the upper arm group (21/26 [80.8%] vs. 26/40 [65.0%], p = 0.27). In the upper arm group, no cases of catheter kinking or catheter-related injury were observed, and the incidence of temporary obstruction because of blood clots that could be continued using CVP was significantly higher than that in the chest wall group (10/26 [38.5%] vs. 4/40 [10.0%], p = 0.012). CONCLUSIONS: FCS was effective in evaluating CVP system-related mechanical complications and deciding whether removal and reimplantation were required in both groups.

Disrupted local beta band networks in schizophrenia revealed through graph analysis: A magnetoencephalography study.

AIMS: Schizophrenia (SZ) is characterized by psychotic symptoms and cognitive impairment, and is hypothesized to be a 'dysconnection' syndrome due to abnormal neural network formation. Although numerous studies have helped elucidate the pathophysiology of SZ, many aspects of the mechanism underlying psychotic symptoms remain unknown. This study used graph theory analysis to evaluate the characteristics of the resting-state network (RSN) in terms of microscale and macroscale indices, and to identify candidates as potential biomarkers of SZ. Specifically, we discriminated topological characteristics in the frequency domain and investigated them in the context of psychotic symptoms in patients with SZ. METHODS: We performed graph theory analysis of electrophysiological RSN data using magnetoencephalography to compare topological characteristics represented by microscale (degree centrality and clustering coefficient) and macroscale (global efficiency, local efficiency, and small-worldness) indices in 29 patients with SZ and 38 healthy controls. In addition, we investigated the aberrant topological characteristics of the RSN in patients with SZ and their relationship with SZ symptoms. RESULTS: SZ was associated with a decreased clustering coefficient, local efficiency, and small-worldness, especially in the high beta band. In addition, macroscale changes in the low beta band are closely associated with negative symptoms. CONCLUSIONS: The local networks of patients with SZ may disintegrate at both the microscale and macroscale levels, mainly in the beta band. Adopting an electrophysiological perspective of SZ as a failure to form local networks in the beta band will provide deeper insights into the pathophysiology of SZ as a 'dysconnection' syndrome.

Biosorption of different gadolinium (Gd) complexes from water by Eichhornia crassipes (water hyacinth).

Many studies have demonstrated the Eichhornia crassipes (water hyacinth) potency in removing heavy metals, but the plant's potential for sorption of gadolinium (Gd) has not yet been investigated. In this study, water hyacinth was grown in a glass container for 30 days with either GdCl3 or Gd-based contrast agent (GBCA; gadoterate) with water obtained from the Tone River. On the day 30, the Gd concentration in both the water and the plants was measured by mass spectrometry (ICP-MS). After 30 days, 98.5% of GdCl3 in the water had been absorbed by the roots, and 3.5% of Gd was transferred to the leaves. On the other hand, the water hyacinth roots absorbed only 12% of the gadoterate. When exposed to 5 mg/L of GdCl3, the roots of water hyacinth may effectively remove Gd ions in the aquatic environment, with no visible effect on the general health of the plant. However, the water hyacinth roots did not absorb GBCA. This may result in higher accumulation of Gd in the aqueous environment. The GBCA may be broken down by environmental factors and negatively affect the marine ecosystem.

This study highlights the potential capability of water hyacinths in reducing the increasing gadolinium in the environment, which may be of value in optimizing the phytoremediation of medical waste.

Successful Interventional Management of Life-Threatening Bleeding after Oocyte Retrieval: A Case Report and Review of the Literature.

Life-threatening bleeding after oocyte retrieval is unusual. We report a case of massive vaginal bleeding requiring transcatheter arterial embolization (TAE) after transvaginal US-directed follicle aspiration for oocyte retrieval and provide a brief review of cases in which the pseudoaneurysm of the injured artery was managed with a TAE approach. A 40-year-old woman presented massive vaginal bleeding after transvaginal ultrasonography-directed follicle aspiration for oocyte retrieval. Contrast-enhanced computed tomography revealed active bleeding from the uterine ostium. Transcatheter arterial embolization was performed for a pseudoaneurysm of the right pudendal artery to manage the hemorrhage. Potentially life-threatening bleeding should be recognized as a rare complication after oocyte retrieval to promptly establish the diagnosis and preserve the uterus.

Prediction with functional liver volume assessment to achieve the resection limit after portal vein embolization in patients scheduled major hepatectomy.

BACKGROUND: Preoperative portal vein embolization (PVE) stimulates liver hypertrophy and improves the safety of major hepatectomy. It is essential to predict the future remnant liver volume (FRLV) and resection limit following PVE. Previously, we reported that evaluating functional FRLV (fFRLV) using EOB-MRI could predict post-hepatectomy liver failure. In this study, we investigated the usefulness of fFRLV in predicting the achieving of adequate resection limit for safe hepatectomy following PVE. METHODS: We included 55 patients who underwent PVE and were scheduled for major hepatectomy. We calculated the liver-to-muscle ratio in the remnant liver and fFRLV using EOB-MRI. We investigated the pre-PVE variables in determining the nonachievement of the resection limit. RESULTS: The median observation period between PVE and the first evaluation was 21 days, and the median growth rate of FRLV was 26.4%. In 54.5% of patients, the resection limit of fFRLV (615 mL/m2) was achieved. In logistic regression and receiver-operating characteristic analyses, pre-PVE fFRLV (p < 0.001, area under the curve: 0.852) was the reliable predictor of achieving the resection limit; the cutoff value of pre-PVE fFRLV was 446 mL/m2. CONCLUSION: Pre-PVE fFRLV can be useful in predicting the achievement of adequate resection limit following PVE.

64Cu-ATSM and 99mTc(CO)3-DCM20 potential in the early detection of rheumatoid arthritis.

OBJECTIVES: Molecular imaging constitutes a promising technique for the early detection of rheumatoid arthritis (RA). Macrophages and hypoxia play significant roles in inflamed synovium. In the present study, we evaluated the efficacy of radiopharmaceuticals that target macrophage mannose receptors (99mTc-labeled mannosylated dextran or 99mTc(CO)3-DCM20) and hypoxia (copper(II) diacetyl-di(N4-methylthiosemicarbazone) or Cu-ATSM) for the early detection of RA in collagen-induced arthritis (CIA) mice models. METHODS: CIA model was developed in DBA/1 mice, and the clinical score for arthritis was visually assessed on a regular basis. Two biodistribution studies were performed in a paired-labeled format using 2-deoxy-2-18F-fluoro-D-glucose (18F-FDG) as a reference: (1) 99mTc(CO)3-DCM20 with 18F-FDG and (2) 67Cu-ATSM with 18F-FDG. RESULTS: The accumulation levels of 99mTc(CO)3-DCM20 and 67Cu-ATSM in forepaws, hindpaws, and knee joints of CIA mice were significantly higher than that of control mice. In contrast, 18F-FDG uptake in hindpaws and knee joints showed no significant difference between CIA and control mice. The radioactivity levels of 99mTc(CO)3-DCM20 and 67Cu-ATSM were significantly correlated with the clinical scores for the paws. CONCLUSION: These results suggest the potential usefulness of 99mTc(CO)3-DCM20 and radiolabeled Cu-ATSM for the imaging and early detection of RA.

Uptake of positron emission tomography tracers reflects the tumor immune status in esophageal squamous cell carcinoma.

The relationship between the local immune status and cancer metabolism regarding 18 F-FDG and 18 F-FAMT uptake in esophageal squamous cell carcinoma (ESCC) remains unknown. The present study examined the correlations between tumor immune status, clinicopathological factors, and positron emission tomography (PET) tracer uptake in ESCC. Forty-one ESCC patients who underwent 18 F-FDG PET and 18 F-FAMT PET before surgery were enrolled in the study. Immunohistochemistry was conducted for programmed death 1 (PD-1), CD8, Ki-67, CD34, GLUT1 (18 F-FDG transporter) and LAT1 (18 F-FAMT transporter). ESCC specimens with high tumoral PD-L1 and high CD8-positive lymphocytes were considered to have "hot tumor immune status." High PD-L1 expression (53.7%) was significantly associated with tumor/lymphatic/venous invasion (P = 0.028, 0.032 and 0.018), stage (P = 0.041), CD8-positive lymphocytes (P < 0.001), GLUT1 (P < 0.001), LAT1 expression (P = 0.006), Ki-67 labelling index (P = 0.009) and CD34-positive vessel counts (P < 0.001). SUVmax of 18 F-FDG was significantly higher in high PD-L1 cases than in low PD-L1 cases (P = 0.009). SUVmax of 18 F-FAMT was significantly higher in high PD-L1 (P < 0.001), high CD8 (P = 0.012) and hot tumor groups (P = 0.028) than in other groups. High SUVmax of 18 F-FAMT (≥4.15) was identified as the only predictor of hot tumor immune status. High PET tracer uptake was significantly associated with cancer aggressiveness and hot tumor immune status in ESCC. PET imaging may be an effective tool to predict tumor immune status in ESCC with respect to immune checkpoint inhibitor sensitivity.

Prognostic significance of semi-quantitative FDG-PET parameters in stage I non-small cell lung cancer treated with carbon-ion radiotherapy.

PURPOSE: Prognostic significance of volumetric 18F-fluorodeoxyglucose (FDG) positron emission tomography/computer tomography (PET/CT) parameters in carbon-ion radiotherapy (C-ion RT) treated stage I non-small cell lung cancer, and need of histology-wise separate cut-off values for risk stratification were assessed. METHODS: Thirty-nine patients (29 men and 10 women, 71.9 ± 8.3 years) who underwent FDG PET/CT examinations before C-ion RT were retrospectively evaluated. FDG-PET parameters: standardized uptake values (SUVmax, SUVpeak, and SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), and clinicopathological variables were assessed for prognosis using Cox proportional hazards regression analysis. Mann-Whitney test compared medians of significant parameters between adenocarcinoma (AC) and squamous cell carcinoma (SCC), and Kaplan-Meier curves were plotted for median-based low- and high-risk groups. RESULTS: Median follow-up period was 44.8 months. 1/2/3-year overall survival (OS), progression-free survival (PFS) and local control (LC) rates were 94.9/84.3/70.8, 82.1/69.2/58.4 and 97.3/85.7/82.3%. Multivariate analysis revealed age (hazard ratio, HR: 1.09; 95% confidence interval, CI: 1.0-1.19, p < 0.05) and MTV (HR 4.83, 95% CI 1.21-19.27, p < 0.03) predicted OS, and only MTV predicted PFS (HR 5.3, CI 1.32-21.35, p < 0.02) independently. Compared with AC, SCC had higher MTV (median, 6.625cm3 vs 0.2 cm3, p < 0.01). Single MTV cut-off based on overall cohort was insignificant in SCC for PFS (p > 0.02); separate cut-offs of MTV, 0.2 cm3 for AC (p < 0.03) and 6.625 cm3 for SCC (p < 0.05) were relevant. CONCLUSION: Among all FDG PET/CT parameters, only MTV beared prognostic ability for stage I NSCLC treated with C-ion RT, and its histological variation may need consideration for risk-adapted therapeutic management.

Diffusion-Weighted MRI Predicts Lymph Node Metastasis and Tumor Aggressiveness in Resectable Pancreatic Neuroendocrine Tumors.

OBJECTIVES: The aim of this study was to identify whether diffusion-weighted magnetic resonance imaging (DW-MRI) can predict the malignant behavior of preoperative well-differentiated pancreatic neuroendocrine tumors (PanNETs). METHOD: Forty patients with PanNETs who underwent pancreatectomy were enrolled in this study. The apparent diffusion coefficient (ADC) values were measured. Clinicopathological factors were compared in patients with high ADC and low ADC values and in patients with and without lymph node metastasis (LNM). RESULT: The low ADC group was significantly associated with higher Ki-67 index, higher mitotic count, larger tumor size, higher rate of LNM, and venous invasion. In patients with low ADC values, the incidence of LNMs was 33.3%. In patients with high ADC values, there were no patients with LNM being 0%. A significant negative correlation was found between the mean ADC values and the Ki-67 index and between the mean ADC values and the mitotic count. In multivariate analysis, neural invasion and mean ADC values ≤ 1458 were independent predictors of LNM. CONCLUSION: ADC values obtained using DW-MRI in the preoperative assessment of patients with PanNETs might be a useful predictor of malignant potential, especially LNM.

Efficiency of regional functional liver volume assessment using Gd-EOB-DTPA-enhanced magnetic resonance imaging for hepatocellular carcinoma with portal vein tumor thrombus.

PURPOSE: We investigated whether functional future remnant liver volume (fFRLV), assessed using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI), could evaluate regional liver function in hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT) and help establish the indication for hepatectomy. METHODS: The subjects of this study were 12 patients with PVTT [PVTT(+) group] and 58 patients without PVTT [PVTT(-) group], from among 191 patients who underwent hepatectomy of more than one segment for HCC. We calculated the liver-to-muscle ratio (LMR) in the remnant liver, using EOB-MRI and fFRLV. Preoperative factors and surgical outcome were compared between the groups. The LMR of the area occluded by PVTT was compared with that of the non-occluded area. RESULTS: The indocyanine green retention rate at 15 min (ICG-R15) and liver fibrosis indices were increased in the PVTT(+) group, but the surgical outcomes of patients in this group were acceptable, with no liver failure, no mortality, and no differences from those in the PVTT(-) group. The fFRLV in the PVTT(+) group was not significantly different from that in the PVTT(-) group (p = 0.663). The LMR was significantly lower in the occluded area than in the non-occluded area (p = 0.004), indicating decreased liver function. CONCLUSION: Assessing fFRLV using EOB-MRI could be useful for evaluating regional liver function and establishing operative indications for HCC with PVTT.

Selective synthesis of L-2-[18 F]fluoro-alpha-methylphenylalanine via copper-mediated 18 F-fluorination of (mesityl)(aryl)iodonium salt.

L-2-[18 F]fluoro-alpha-methylphenylalanine (2-[18 F]FAMP) is a promising amino acid tracer for positron emission tomography (PET) imaging, yet the low production yield of direct electrophilic radiofluorination with [18 F]F2 necessitates further optimization of the radiolabeling process. This paper describes a two-step preparation method for L-2-[18 F]fluoro-alpha-methylphenylalanine (2-[18 F]FAMP) starting from [18 F]fluoride. The (Mesityl)(L-alpha-methylphenylalanine)-2-iodonium tetrafluoroborate precursors with various protecting groups were prepared. The copper-mediated 18 F-fluorination of the iodonium salt precursors successfully produced 2-[18 F]FAMP. The highest radio chemical conversion of 57.6% was noted with N-Piv-protected (mesityl)(aryl)iodonium salt in the presence of 5 equivalent of Cu (OTf)2 . Subsequent deprotection with 57% hydrogen iodide produced 2-[18 F]FAMP within 120 min in 21.4 ± 11.7% overall radiochemical yield with >95% radiochemical purity and an enantiomeric excess >99%. The obtained 2-[18 F]FAMP showed comparable biodistribution profiles in normal mice with that of the carrier-added 2-[18 F]FAMP. These results indicate that usefulness of copper mediated 18 F-fluorination for the production of 2-[18 F]FAMP, which would facilitate clinical translation of the promising tumor specific amino acid tracer. Individual facilities could adopt either production method based on radioactivity demand and equipment availability.

Functional remnant liver volumetry using Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) predicts post-hepatectomy liver failure in resection of more than one segment.

BACKGROUND: Gd-EOB-DTPA-enhanced magnetic resonance imaging (EOB-MRI) can be used for evaluating liver functional reserve. We assessed whether functional remnant liver volumetry (FRLV) using EOB-MRI predicted post-hepatectomy liver failure (PHLF) in resection of more than one segment. METHODS: We retrospectively analyzed 155 cases of hepatectomy of more than one segment. For assessment of FRLV, signal intensity (SI) of remnant liver was measured in T1-weighted images. Functional remnant liver score was derived by division of SI of liver by SI of muscle (or spleen), resulting in liver-to-muscle ratio (LMR) and liver-to-spleen ratio (LSR). FRLV were calculated by multiplying LMR (or LSR) and remnant liver volume. We investigated preoperative factors predicting PHLF (≥grade B) in study cohort (all cases except for portal vein embolization [PVE], n = 129) and validation cohort (PVE cases, n = 26). RESULTS: In study cohort, PHLF occurred in 5 patients (3.9%). In multivariate analysis, FRLV (LMR) was the most reliable predictor of PHLF (P = 0.013). The cutoff value of FRLV (LMR) predicting PHLF was 615 mL/m2 (AUC: 0.939). In validation cohort (n = 26), the cutoff value of FRLV (LMR) indicated reliable results, sensitivity (100%), specificity (77.3%), and accuracy (80.8%). CONCLUSIONS: FRLV using LMR could precisely predict PHLF of more than one segment, and was useful even in patients who underwent PVE.

[Improved Neural Imaging Sequence and Comparison with Conventional Methods].

The purpose of this study was to improve the contrast between the nerves and blood by reconsidering the imaging parameters of the sampling perfection with application-optimized contrasts using different flip angle evolutions (SPACE) method, and to compare it with conventional methods, including the constructive interference in steady state (CISS) and T2-weighted SPACE (T2-SPACE) methods. In the phantom study, the repetition time (TR), echo time (TE), flip angle (FA), and turbo factor (TF) of SPACE were varied using the restore pulse. The parameters for which the nerve-blood contrast (C1) and cerebrospinal fluid-nerve contrast (C2) were equal were selected. Though multiple conditions resulted in C1 and C2 equivalence, we determined/set the TR=500 ms, TE=21 ms,  FA=120°, and  TF=30, considering the acquisition time, specific absorption rate (SAR), and artifacts. This sequence was called "short TR and short TE SPACE with restore pulse (SSSR)". In the phantom and healthy volunteer studies, the contrast between the nerves and blood in the SSSR method was statistically superior in both the physical and visual assessments compared with conventional methods. In the healthy volunteer study, C1 improved from 0.08 for CISS and 0.18 for T2-SPACE to 0.43 for SSSR. This is because the nerve signals in conventional methods were low due to the heavy T2-weighted, while those in the SSSR method were high due to the short TE and effect of the restore pulse. In conclusion, the contrast between the nerves and blood was significantly higher in the SSSR method compared with conventional methods.

Immuno-PET imaging for non-invasive assessment of cetuximab accumulation in non-small cell lung cancer.

BACKGROUNDS: Overexpression of epidermal growth factor receptor (EGFR) has been established as a valid therapeutic target of non-small cell lung cancer (NSCLC). However, the clinical benefit of cetuximab as an EGFR-targeting drug is still controversial, partially due to the lack of effective means to identify suitable patients. This study aimed to investigate the potential of radiolabeled cetuximab as a non-invasive tool to predict cetuximab accumulation in NSCLC tumor xenografts with varying EGFR expression levels. METHODS: The NSCLC tumors in model mice were subjected to in vivo biodistribution study and positron emission tomography (PET) imaging 48 h after injection of either 111In- or 64Cu-labeled cetuximab. The EGFR expression levels of NSCLC tumors were determined by ex vivo immunoblotting. RESULTS: We found that tumors with high EGFR expression had significantly higher [111In]In-DOTA-cetuximab accumulation than tumors with moderate to low EGFR expression (P < 0.05). Strong correlations were found between [111In]In-DOTA-cetuximab tumor uptake and EGFR expression level (r = 0.893), and between [64Cu]Cu-DOTA-cetuximab tumor uptake with EGFR expression level (r = 0.915). PET imaging with [64Cu]Cu-DOTA-cetuximab allowed clear visualization of tumors. CONCLUSION: Our findings suggest that this immuno-PET imaging can be clinically translated as a tool to predict cetuximab accumulation in NSCLC cancer patients prior to cetuximab therapy.