The acute effects of smoking on the cyclic variations in blood echogenicity of carotid artery

The objective of this research is to study the cyclic variations in echogenicity (CVE) as an acute response to smoking. CVEs, caused by the aggregation of red blood cells (RBC) were measured from the cross-sectional images of the common carotid artery using coded harmonic imaging of a commercial ultrasound system. The amplitude of the CVE (A_cve) was analyzed among 28 smokers before and after smoking. A_cve was increased in 22 smokers and decreased in six smokers after 1-2 cigarettes were smoked. Heart rate (HR) was also estimated from the ultrasonic images before and after smoking. The smokers were optimally divided into two clusters with respect to the change in A_cve and the intrinsic characteristics of smokers (i.e., daily consumed cigarettes and smoking years) through a two-step cluster analysis (TSCA). The increase in A_cve after smoking was significantly higher in the heavy smoker cluster compared with the light smoker cluster. The results suggest that the acute changes in A_cve in response to smoking are different between heavy smokers and light smokers. This preliminary study demonstrates the potential application of coded harmonic ultrasound imaging to detect or characterize RBC aggregation. In addition, the results may be useful for understanding the acute physiologic changes caused by smoking. (E-mail: paeng@jejunu.ac.kr)     

Imaging features of bilateral breast abnormalities

There are various-causes, broad-spectrum, heterogeneous groups with various biologic profiles, and imaging features of bilateral breast abnormalities. As imaging modalities continue to be developed, the ability to detect subtle or tiny abnormalities is improved in the contralateral breast of patients already diagnosed with unilateral breast disease, especially in breast cancer patients when using magnetic resonance imaging. Furthermore, some diseases involved bilateral breast, simultaneously. The purpose of this review is to describe imaging features of the bilateral breast abnormalities—common diseases and simultaneously involving diseases. In order to provide adequate treatment and to prevent misdiagnosis, a complete understanding of the imaging and clinical features of bilateral breast abnormalities of common diseases as well as those of simultaneously involving diseases is necessary.     

Feasibility and kinetic characteristics of 68Ga-NOTA-RGD PET for in vivo atherosclerosis imaging

Objective

In this study, the feasibility and kinetic characteristics of the ⁶⁸Ga-NOTA-RGD, a recently developed RGD peptide agent, were investigated for atherosclerosis imaging in comparison with ¹⁸FDG.

Methods

ApoE^?/? mice were fed a high-fat diet for more than 20 weeks. To evaluate the feasibility, tissue uptakes of ⁶⁸Ga-NOTA-RGD and ¹⁸FDG in the major organs were measured and compared between ApoE^?/? and control mice. Animal PET imaging was also performed and relative uptake values in the thoracic aorta were compared between ApoE^?/? and control mice. In humans, the kinetic characteristics and feasibility of ⁶⁸Ga-NOTA-RGD PET were assessed in 4 patients with known coronary artery disease.

Results

In the tissue uptake study, the thoracic aorta showed higher uptake in ApoE^?/? than in control mice with both ⁶⁸Ga-NOTA-RGD and ¹⁸FDG (P < 0.001). On PET scans, the relative uptake values of the thoracic aorta were significantly higher in ApoE^?/? with both ⁶⁸Ga-NOTA-RGD (P = 0.024) and ¹⁸FDG (P = 0.038). In human PET, the appropriateness of reversible binding model and Logan plotting was clearly demonstrated. The aorta-to-jugular ratios were measured up to 1.25 and showed a tendency to correlate with the serum high-sensitivity C-reactive protein level (r = 0.899, P = 0.102).

Conclusions

⁶⁸Ga-NOTA-RGD has potential as an in vivo atherosclerosis imaging agent. However, the lower imaging contrast and sensitivity of ⁶⁸Ga-NOTA-RGD PET compared with ¹⁸FDG PET may be a limitation for clinical application.     

Effect of carotid artery stenting on cerebral blood flow: evaluation of hemodynamic changes using arterial spin labeling

Introduction

The purpose of this work was to quantitatively evaluate the hemodynamic changes after carotid artery stenting (CAS) by measuring cerebral blood flow (CBF) using arterial spin labeling (ASL).

Methods

Twenty sets of pre- and postprocedural CBF maps were acquired using ASL in patients who underwent CAS. Vascular territory- and anatomical structure-based regions of interest were applied to the CBF maps. Relative CBF (rCBF) was calculated by adjusting ipsilateral CBF with contralateral CBF. To assess the changes in rCBF after CAS (ΔrCBF), we calculated the following difference: $ \Delta\mathrm{rCBF}=\mathrm{rCB}{{\mathrm{F}}_{\mathrm{postprocedural}}}-\mathrm{rCB}{{\mathrm{F}}_{\mathrm{preprocedural}}} $ .

Results

Postprocedural CBFs were significantly higher than preprocedural CBFs for internal carotid artery and middle cerebral artery territories (P?<?0.05 in both). Postprocedural rCBFs were also significantly higher than preprocedural rCBFs for internal carotid artery and middle cerebral artery territories (P?<?0.05 in both). Significant correlations were observed between preprocedural rCBF and ΔrCBF for the internal carotid artery and middle cerebral artery territories (r?=??0.7211, P?=?0.0003 and r?=??0.6427, P?=?0.0022, respectively). Areas in which the ΔrCBF values were >5.00 ml?100 g^?1 min^?1 were the precentral, postcentral, middle frontal, middle temporal (caudal), superior parietal, and angular gyri.

Conclusions

ASL has potential as a noninvasive imaging tool for the quantitative evaluation of hemodynamic changes after CAS. CAS improves cerebral perfusion in patients with carotid artery stenosis, and patients with greater perfusion deficits prior to CAS have greater improvement in perfusion after CAS. In addition, eloquent areas show the greatest improvement in perfusion.     

High Spatial and Temporal Resolution Observations of Pulsatile Changes in Blood Echogenicity in the Common Carotid Artery of Rats

Previous studies have found that ultrasound backscatter from blood in vascular flow systems varies under pulsatile flow, with the maximum values occurring during the systolic period. This phenomenon is of particular interest in hemorheology because it is contrary to the well-known fact that red blood cell (RBC) aggregation, which determines the intensity of ultrasound backscatter from blood, decreases at a high systolic shear rate. In the present study, a rat model was used to provide basic information on the characteristics of blood echogenicity in arterial blood flow to investigate the phenomenon of RBC aggregation under pulsatile flow. Blood echogenicity in the common carotid arteries of rats was measured using a high-frequency ultrasound imaging system with a 40-MHz probe. The electrocardiography-based kilohertz visualization reconstruction technique was employed to obtain high-temporal-resolution and high-spatial-resolution time-course B-mode cross-sectional and longitudinal images of the vessel. The experimental results indicate that blood echogenicity in rat carotid arteries varies during a cardiac cycle. Blood echogenicity tends to decrease during early systole and reaches its peak during late systole, followed by a slow decline thereafter. The time delay of the echogenicity peak from peak systole in the present results is the main difference from previous in vitro and in vivo observations of backscattering peaks during early systole, which may be caused by the very rapid heart rates and low RBC aggregation tendency of rats compared with humans and other mammalian species. The present study may provide useful information elucidating the characteristics of RBC aggregation in arterial blood flow.     

Simultaneous determination of cannabidiol, cannabinol, and \gD9-tetrahydrocannabinol in human hair by gas chromatography-mass spectrometryin human hair by gas chromatography-mass spectrometry

An analytical method was developed for evaluating the cannabidiol (CBD), cannabinol (CBN), and delta9-tetrahydrocannabinol (delta9-THC) level in human hair using gas chromatography-mass spectrometry (GC-MS). Hair samples (50 mg) were washed with isopropyl alcohol and cut into small fragments (< 1 mm). After adding a deuterated internal standard, the hair samples were incubated in 1.0 M NaOH for 10 min at 95 degrees C. The analytes from the resulting hydrolyzed samples were extracted using a mixture of n-hexane-ethyl acetate (75:25, v/v). The extracts were then evaporated, derivatized, and injected into the GC-MS. The recovery ranges of CBD, CBN, and delta9-THC at three concentration levels were 37.9-94.5% with good correlation coefficients (r2 >0.9989). The intra-day precision and accuracy ranged from -9.4% to 17.7%, and the inter-day precision and accuracy ranged from -15.5% to 14.5%, respectively. The limits of detection (LOD) for CBD, CBN, and delta9-THC were 0.005, 0.002, and 0.006 ng/mg, respectively. The applicability of this method of analyzing the hair samples from cannabis abusers was demonstrated.     

Measurement of <Superscript>68</Superscript>Ga-DOTATOC Uptake in the Thoracic Aorta and Its Correlation with Cardiovascular Risk

Purpose

⁶⁸Ga-labeled 1,4,7,10-tetraazacyclododecane-N,N′,N″,N?-tetraacetic acid-d-Phe¹-Tyr³-octreotide (⁶⁸Ga-DOTATOC) is taken up by activated macrophages, which accumulate in active inflammatory lesions. The purpose of this study was to investigate the feasibility of ⁶⁸Ga-DOTATOC PET/CT for assessment of vulnerable plaque, by evaluating correlation between aortic uptake of ⁶⁸Ga-DOTATOC and cardiovascular risk factors.

Methods

Fifty patients with neuroendocrine tumors who underwent ⁶⁸Ga-DOTATOC PET/CT were retrospectively enrolled. The uptakes in the thoracic aorta were measured by two methods: multi-sample region-of-interest (ROI) method and single volume-of-interest (VOI) method. TBR_max-avg, TBR_mean-avg, TBR_max-VOI, and TBR_mean-VOI were defined by maximum and mean target-to-background ratio (TBR) from the multi-sample ROI method and the single VOI method, respectively.

Results

Framingham risk score (FRS) exhibited significant correlations with TBR_max-avg and TBR_mean-avg, as well as TBR_max-VOI (r?=?0.3389–0.4593, P?<?0.05 for all). TBR_max-avg and TBR_max-VOI were significantly higher in high FRS group than in low FRS group (1.48?±?0.21 vs. 1.70?±?0.17, P?<?0.001 for TBR_max-avg and 1.90?±?0.33 vs. 2.25?±?0.36, P?=?0.002 for TBR_max-VOI). TBR exhibited high correlations between the two measuring methods (r?=?0.9684, P?<?0.001 for TBR_mean-avg and TBR_mean-VOI and r?=?0.8681, P?<?0.001 for TBR_max-avg and TBR_max-VOI).

Conclusions

⁶⁸Ga-DOTATOC uptake in the thoracic aorta exhibited a significant correlation with cardiovascular risk factors, which suggests the feasibility of ⁶⁸Ga-DOTATOC PET for vulnerable plaque imaging, with a simple measurement of the single VOI method that is comparable to the multi-sample ROI-based approach.

     

Correlation of VEGF with contrast enhancement on dual-phase dynamic helical CT in liver tumors: preliminary study

The purpose of this preliminary study is to elucidate that vascular endothelial growth factor (VEGF) influences contrast enhancement of hepatic tumors on computed tomography (CT). Fourteen patients with hepatic tumors (11 hepatocellular carcinomas; 3 metastatic cancers) underwent a dual-phase dynamic helical CT or computed tomographic hepatic arteriography. The attenuation of each mass was determined as hyperattenuation, isoattenuation or hypoattenuation with respect to the adjacent nontumorous parenchyma. Gun-needle biopsy was done for each tumor, and paraffin sections were immunostained with anti- VEGF antibody by the avidin-biotin-peroxidase complex method. The pathologic grade was made by intensity (1 +, 2+, 3+) and area (+/-, 1 +, 2+). The tumor ranged 2.0-14.0 cm in size (mean, 5.8 cm). In arterial phase, the intensity was not correlated with the degree of enhancement (p=0.086). However, the correlation between the attenuation value of hepatic arterial phase and the area of positive tumor cells was statistically significant (p=0.002). VEGF may be the factor that enhances the hepatic mass with water-soluble iodinated contrast agent in CT.     

Transcatheter arterial embolization with 188Rhenium-HDD-labeled iodized oil in rabbit VX2 liver tumor

PURPOSE: To evaluate the antitumor effect of transcatheter arterial embolization (TAE) with use of rhenium 188 HDD (4-hexadecyl 2,2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol)-labeled iodized oil and to compare it with that of transcatheter arterial chemoembolization (TACE) with use of an established chemotherapeutic agent and iodized oil in experimentally induced liver tumor. MATERIALS AND METHODS: VX2 carcinoma was grown in the livers of 57 rabbits. TAE was performed with (188)Re-HDD-labeled iodized oil (Re-Lp group; n = 21), doxorubicin/iodized oil emulsion (Dx-Lp group; n = 21), and iodized oil alone (n = 15). Sequential conjugated planar imaging was performed for dosimetry of the radioisotope in the Re-Lp group (n = 15). Growth ratio and percentage of viable tumor were estimated by computed tomography and histopathologic examination. Hepatic and hematologic toxicities were evaluated by biochemical analysis. RESULTS: On conjugated planar imaging, radioactivity was concentrated on the tumor (effective half-life, 16.2 hours), and mean radiation dose to the tumor was 147.7 Gy. The mean growth ratios 1, 2, and 3 weeks after TAE and the percentage of viable tumor in the Re-Lp group (-3.4, -7.6, -11.1, and 0.3%) and the Dx-Lp group (-3.2, -5.3, 29.0, and 2.6%) were significantly lower than the respective values in the iodized oil group (45.5, 145.4, 283.0, and 30.1%; P < .001). However, the differences between the values in the Re-Lp group and those in the Dx-Lp group were not significant (P values of .165-0.497 for growth ratios; P = .134 for percentage of viable tumor). There was similar transient hepatotoxicity in all three groups. CONCLUSIONS: TAE with (188)Re-HDD-labeled iodized oil has potent antitumor effect in VX2 liver tumor that is comparable with that of TACE with an established chemotherapeutic agent.