Kyu Ri Son

Demonstration of decreased gray matter concentration in the midbrain encompassing the dorsal raphe nucleus and the limbic subcortical regions in major depressive disorder: An optimized voxel-based morphometry study

BACKGROUND Previous neuroimaging studies in patients with major depressive disorder (MDD) have reported changes in several brain areas, such as the medial and dorsolateral orbital cortex, amygdala, hippocampus, and basal ganglia. However, the results of these studies are inconsistent, and relatively few studies have been conducted using voxel-based morphometry (VBM) to detect gray matter concentration (GMC) abnormalities in patients with MDD. METHODS We examined 47 MDD patients and 51 healthy controls to investigate structural abnormalities using a 1.5 T magnetic resonance imaging system, which was normalized to a customized T1 template and segmented with optimized VBM. Analysis of covariance with age and gender as covariates was adopted for the VBM statistics; the level of statistical significance was set at P<0.05 for the corrected false discovery rate. RESULTS Decreased GMC was found in MDD patients in the bilateral amygdalae, hippocampi, fusiform gyri, lingual gyri, insular gyri, middle-superior temporal gyri, thalami, cingulate gyri, the central lobule of the cerebellum, and the midbrain encompassing the dorsal raphe nuclei (DRN). LIMITATIONS Half of our study subjects were taking antidepressants. This may have been a potential confounding factor if any of the medications affected cortical volume. CONCLUSIONS The results suggest that the GMC of several regions associated with emotion regulation was lower in MDD patients. In particular, we found decreased GMC in the DRN. These findings may provide a better understanding of the anatomical properties of the neural mechanisms underlying the etiology of MDD.

Diagnostic Benefit of Thyroglobulin Measurement in Fine-Needle Aspiration for Diagnosing Metastatic Cervical Lymph Nodes from Papillary Thyroid Cancer: Correlations with US Features

Objective Our goals were to determine the added value of fine-needle aspiration biopsy (FNAB)-thyroglobulin (Tg) measurements over FNAB-cytology alone for diagnosing metastatic nodes, and to determine whether the ultrasound features of lymph nodes can be used to identify lymph nodes that may benefit from FNAB-Tg measurement in patients with papillary thyroid cancer. Materials and Methods We retrospectively evaluated 76 surgically proven cervical lymph nodes. Twenty-nine patients were awaiting surgery and 18 patients had undergone thyroid surgery for papillary thyroid cancer. Ultrasound-guided FNAB and Tg measurements were performed and the ultrasound features were evaluated. Results The accuracies, sensitivities, and specificities of FNAB-cytology, FNAB-Tg, and combined FNAB-Tg/cytology were 90%, 80%, and 100%; 92%, 95%, and 90%; and 93%, 96%, and 90%, respectively. The diagnostic sensitivity of FNAB-Tg for metastatic nodes was significantly higher than that of FNAB-cytology (p = 0.011). Furthermore, combined FNAB-Tg/cytology significantly increased sensitivity (p = 0.002) and accuracy (p = 0.03) as compared with FNAB-cytology. Conclusion Combined FNAB-Tg/cytology is significantly more sensitive and accurate at detecting metastatic nodes than FNAB-cytology alone. FNAB-Tg was better at diagnosing metastases in small lymph nodes.

Fat in Liver/Muscle Correlates More Strongly With Insulin Sensitivity in Rats Than Abdominal Fat

Intrahepatic or intramuscular lipid (IHL/IML) content has been reported to be correlated with insulin resistance. Visceral fat has also been shown to be associated with insulin resistance. Thus, we investigated whether IHL/IML or visceral fat content is more closely associated with insulin resistance. Twenty Sprague‐Dawley rats were divided into two groups based on regular chow diet (RCD) or high‐fat diet (HFD; 40% fat). The insulin‐sensitivity index (ISI) was determined by euglycemic glucose clamp study, the amount of visceral fat by computed tomography (CT), and the IHL/IML content by magnetic resonance spectroscopy (MRS). Weight, food, and water intake, physical activity, energy expenditure, lipid profile, adiponectin, and high‐sensitivity C‐reactive protein (hsCRP) levels were measured. At the study end point, visceral fat, and the IHL/IML content were higher in the HFD group than in the RCD group. The IHL/IML content was more highly correlated with ISI than was visceral fat amount. Stronger correlations were also found between adiponectin or hsCRP level and IML/IHL content than visceral fat, especially in the HFD group. Furthermore, the IHL/IML content was significantly associated with the ISI in the multiple regression models but visceral fat was not. There was clear discrimination between RCD and HFD groups in scatter plots of IML/IHL against the ISI, but substantial overlap in that of visceral fat against the ISI. This result suggests that IHL/IML contents are closely related with insulin resistance or atherosclerosis and is a better metabolic index of insulin sensitivity than the visceral fat.

Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma: Prospective Assessment of the Right Inferior Phrenic Artery with C-arm CT

PURPOSE To assess the usefulness of C-arm computed tomography (CT) of the right inferior phrenic artery (RIPA) in transcatheter arterial chemoembolization of patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS From December 2007 to April 2008, C-arm CT of the RIPA was prospectively performed in 32 patients with HCC. Two interventional radiologists who performed C-arm CT assessed the additional information provided with C-arm CT as grade 1 (no additional information), grade 2 (added information without an effect on the treatment plan), or grade 3 (added information with an effect on the treatment plan). Tumor feeders and feeders of a systemic-to-pulmonary shunt were recorded. RESULTS The information provided by C-arm CT was classified as grade 1 for nine of the 32 patients (28%), grade 2 for 20 patients (63%), and grade 3 for three patients (9%). The most common additional information from C-arm CT scans of the RIPA was the differentiation between the tumor and the systemic-to-pulmonary shunt. A systemic-to-pulmonary shunt from the RIPA was observed in 22 patients (69%), and the most common feeder of a systemic-to-pulmonary shunt was the azygoesophageal branch. CONCLUSIONS C-arm CT of the RIPA provides additional imaging information for the differentiation of a tumor from a nontumorous condition during chemoembolization for HCC with a suspected blood supply from an RIPA.

Diffusion-weighted MR: therapeutic evaluation after chemoembolization of VX-2 carcinoma implanted in rabbit liver.

RATIONALE AND OBJECTIVES The study goal was to evaluate the ability of diffusion-weighted imaging (DWI) in assessing the viability of rabbit liver VX-2 tumor after transcatheter arterial chemoembolization (TACE). MATERIALS AND METHODS VX-2 tumors were grown in the livers of 19 rabbits, and chemoembolization was performed. MR imaging was acquired 1 week after TACE. The rabbits were killed for histologic investigation immediately after MR imaging, and the proportion of viable tumor was calculated based on histopathologic examination. Apparent diffusion coefficient (ADC) values were measured in viable and necrotic tumor portion, and were compared using the paired Students t test. RESULTS Viable tumors were absent (n = 3), less than 5% (n = 6), and 5% or more (n = 10) at pathology examination. On DWI, three tumors with no viable portion were interpreted as having no viable portion, but three of six tumors with a viable portion of less than 5% were considered as having no viable portion. The mean ADC values of necrotic and viable tumor were 1.653 +/- 0.126 mm(2)/sec and 0.883 +/- 0.407 mm(2)/sec (b = 1000 sec/mm(2)), respectively, and the ADC values of necrotic tumors were significantly greater than those in viable tumors (p < .01). CONCLUSION Although DWI is a useful tool for assessing tumor viability, viable tumor may not be detected on DWI when it is too small.

Association between reduced white matter integrity in the corpus callosum and serotonin transporter gene DNA methylation in medication-naive patients with major depressive disorder

Previous evidence suggests that the serotonin transporter gene (SLC6A4) is associated with the structure of brain regions that are critically involved in dysfunctional limbic-cortical network activity associated with major depressive disorder (MDD). Diffusion tensor imaging (DTI) and tract-based spatial statistics were used to investigate changes in white matter integrity in patients with MDD compared with healthy controls. A possible association between structural alterations in white matter tracts and DNA methylation of the SLC6A4 promoter region was also assessed. Thirty-five medication-naive patients with MDD (mean age: 40.34, male/female: 10/25) and age, gender and education level matched 49 healthy controls (mean age: 41.12, male/female: 15/34) underwent DTI. SLC6A4 DNA methylation was also measured at five CpG sites of the promoter region, and the cell type used was whole-blood DNA. Patients with MDD had significantly lower fractional anisotropy (FA) values for the genu of the corpus callosum and body of the corpus callosum than that in healthy controls (family-wise error corrected, P<0.01). Significant inverse correlations were observed between SLC6A4 DNA methylation and FA (CpG3, Pearsons correlation: r=−0.493, P=0.003) and axial diffusivity (CpG3, Pearsons correlation: r=−0.478, P=0.004) values of the body of the corpus callosum in patients with MDD. These results contribute to evidence indicating an association between epigenetic gene regulation and structural brain alterations in depression. Moreover, we believe this is the first report of a correlation between DNA methylation of the SLC6A4 promoter region and white matter integrity in patients with MDD.

Intercostal artery supplying hepatocellular carcinoma: demonstration of a tumor feeder by C-arm CT and multidetector row CT.

This study was designed to describe tumor feeders from the intercostal artery supplying hepatocellular carcinoma (HCC) on C-arm CT and multidetector row CT. From March 2008 to May 2009, C-arm CT of the intercostal artery was prospectively performed in 24 HCC patients. Two interventional radiologists, who performed C-arm CT, evaluated tumor feeders on C-arm CT and multidetector row CT scans by consensus. In total, 35 intercostal arteries were examined by C-arm CT. All tumor feeders except one showed a sharp upward turn at or near the costochondral junction. On axial C-arm CT images, all tumor feeders were observed as an enhancing dot in the upper intercostal space along the diaphragm. On multidetector CT scans, 17 tumor feeders were observed and 18 were not. Tumor feeders from the intercostal artery are observed as an enhancing dot along the diaphragm on C-arm CT and can be seen on multidetector row CT in approximately half of patients.

FDG-PET for evaluating the antitumor effect of intraarterial 3-bromopyruvate administration in a rabbit VX2 liver tumor model

Objective We wanted to investigate the feasibility of using FDG-PET for evaluating the antitumor effect of intraarterial administration of a hexokinase II inhibitor, 3-bromopyruvate (3-BrPA), in a rabbit VX2 liver tumor model. Materials and Methods VX2 carcinoma was grown in the livers of ten rabbits. Two weeks later, liver CT was performed to confirm appropriate tumor growth for the experiment. After tumor volume-matched grouping of the rabbits, transcatheter intraarterial administration of 3-BrPA was performed (1 mM and 5 mM in five animals each, respectively). FDG-PET scan was performed the day before, immediately after and a week after 3-BrPA administration. FDG uptake was semiquantified by measuring the standardized uptake value (SUV). A week after treatment, the experimental animals were sacrificed and the necrosis rates of the tumors were calculated based on the histopathology. Results The SUV of the VX2 tumors before treatment (3.87 ±1.51 [mean ±SD]) was significantly higher than that of nontumorous liver parenchyma (1.72 ±0.34) (p < 0.0001, Mann-Whitney U test). The SUV was significantly decreased immediately after 3-BrPA administration (2.05 ±1.21) (p = 0.002, Wilcoxon signed rank test). On the one-week follow up PET scan, the FDG uptake remained significantly lower (SUV 1.41 ±0.73) than that before treatment (p = 0.002), although three out of ten animals showed a slightly increasing tendency for the FDG uptake. The tumor necrosis rate ranged from 50.00% to 99.90% (85.48% ±15.87). There was no significant correlation between the SUV or the SUV decrease rate and the tumor necrosis rate in that range. Conclusion Even though FDG-PET cannot exactly reflect the tumor necrosis rate, FDG-PET is a useful modality for the early assessment of the antitumor effect of intraarterial administration of 3-BrPA in VX2 liver tumor.

Hepatocellular Carcinoma: Detection of Blood Supply from the Right Inferior Phrenic Artery by the Use of Multi–Detector Row CT

PURPOSE To evaluate retrospectively the ability of multi-detector row computed tomography (CT) to detect blood supply from the right inferior phrenic artery (RIPA) in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS Between July 2006 and June 2007, angiography of the RIPA was performed in 178 patients (151 men, 27 women; mean age, 59 years) with HCC who also had undergone multi-detector row CT. CT scans and digital subtraction angiograms of these patients were retrospectively reviewed by consensus by two investigators to evaluate tumor feeder vessels. RESULTS Tumor staining fed by the RIPA was noted on angiography in 113 patients (63%). Readers interpreted that the tumor feeder vessels were evident on CT images in 63 of these 113 patients (56%). Young age (odds ratio [OR], 0.934; P < .0001), exophytic growth pattern (OR, 2.702; P = .009), and presence of a visible feeder vessel on CT (OR, 6.933; P < .0001) were significant factors for predicting parasitic blood supply from the RIPA. In a subgroup of tumors smaller than 5 cm, multivariate analysis revealed that young age (OR, 0.94; P = .03) and repeated chemoembolization sessions (OR, 8.65; P = .01) were significant factors. CONCLUSIONS Visualization of a tumor feeding vessel from the RIPA on multi-detector row CT could be a clue of a parasitic supply of a large tumor. In patients who have received repeated chemoembolization, small tumors in the dorsal hepatic area can be supplied by the RIPA.

Serial MR Analysis of Early Permanent and Transient Ischemia in Rats: Diffusion Tensor Imaging and High b Value Diffusion Weighted Imaging

Objective To evaluate the temporal evolution and diagnostic values of the diffusion tensor imaging (DTI) and the high b value diffusion weighted imaging (DWI) in the early permanent and transient cerebral ischemia. Materials and Methods For permanent or 30-minute transient-ischemia induced 30 rats, DTI and DWIs at both high b (b = 3000 s/mm2) and standard b value (b = 1000 s/mm2) were obtained at the following conditions: at 15, 30, 45, 60 minutes after the occlusion of what for hyperacute permanent ischemia; at 1, 3, 5, 7, 9 hours after the occlusion for acute permanent ischemia; and at 15 minutes before reperfusion, 0.5, 2.5, and 24 hours after reperfusion for transient ischemia. The diffusion parameters and their ratios were obtained and compared between different b values, and among different time points and groups, respectively. Results For both b values, the apparent diffusion coefficient (ADC) ratio decreased for first three hours, and then slightly increased until 9 hours after the occlusion during a gradual continuous increase of DWI signal intensity (SI) ratio, with excellent correlation between ADC ratios and DWI SI ratios. The DWI showed a higher contrast ratio, but the ADC map showed a lower contrast ratio for permanent ischemia at high b value than at standard b value. Fractional anisotropy (FA) increased for 1 hour, then gradually decreased until 9 hours after the occlusion in permanent ischemia and showed transient normalization and secondary decay along with change in ADC in transient ischemia. Conclusion This study presents characteristic initial elevation and secondary decay of FA, higher contrast ratio of DWI, and lower contrast ratio of ADC map at high b value, in addition to the time evolutions of diffusion parameters in early permanent and transient ischemia.