Association of Toll-Like Receptor 4 on Human Monocyte Subsets and Vulnerability Characteristics of Coronary Plaque as Assessed by 64-Slice Multidetector Computed Tomography.

BACKGROUND: Although Toll-like receptor 4 (TLR-4) is involved in monocyte activation in patients with accelerated forms of atherosclerosis, the relationship between the expression of TLR-4 on circulating monocytes and coronary plaque vulnerability has not previously been evaluated. We investigated this relationship using 64-slice multidetector computed tomography (MDCT) in patients with stable angina pectoris (SAP).Methods and Results:We enrolled 65 patients with SAP who underwent MDCT. Three monocyte subsets (CD14++CD16-, CD14++CD16+, and CD14+CD16+) and expression of TLR-4 were measured by flow cytometry. Intracoronary plaques were assessed by 64-slice MDCT. We defined vulnerability of intracoronary plaques according to the presence of positive remodeling (remodeling index >1.05) and/or low CT attenuation (<35 HU). The circulating CD14++CD16+monocytes more frequently expressed TLR-4 than CD14++CD16-and CD14+CD16+monocytes (P<0.001). The relative proportion of the expression of TLR-4 on CD14++CD16+monocytes was significantly greater in patients with vulnerable plaque compared with those without (10.4 [4.1-14.5] % vs. 4.5 [2.8-7.8] %, P=0.012). In addition, the relative proportion of TLR-4 expression on CD14++CD16+monocytes positively correlated with the remodeling index (r=0.28, P=0.025) and negatively correlated with CT attenuation value (r=-0.31, P=0.013). CONCLUSIONS: Upregulation of TLR-4 on CD14++CD16+monocytes might be associated with coronary plaque vulnerability in patients with SAP.

Change in portal vein hemodynamics after chemoembolization for hepatocellular carcinoma: evaluation through multilevel dynamic multidetector computed tomography during arterial portography.

OBJECTIVE: This study aimed to clarify the effect of embolization with lipiodol on portal vein hemodynamics. METHODS: Time-density curves of the main portal vein on multilevel dynamic multidetector computed tomography during arterial portography were used to analyze peak computed tomography value (PV), time to PV (TPV), arrival time of contrast medium at the main portal vein (ATMPV), slope [(PV - 150) / (TPV - ATMPV)], and slope ratio (slope after embolization / slope before embolization). RESULTS: In 20 patients with hepatoma, ATMPV and TPV were significantly prolonged and the time-density curve slope was significantly less after embolization. The difference in TPV increased (P = 0.02) and the slope ratio decreased with increasing embolized volume rate (P < 0.001). Strong correlation (R = -0.86) was found between the slope ratio and the embolized volume rate. CONCLUSIONS: Time-density curves revealed significant portal vein flow delay after embolization; the degree of which was correlated with the extent of the embolized volume.

Prostate-supplying arteriogram created by multidetector-row CT during pelvic arteriography: contribution to the treatment strategy of prostatic artery embolization for prostatic hyperplasia.

We describe an 85-year-old man suffering lower urinary tract symptoms, who underwent prostatic artery embolization (PAE) based on a prostate-supplying arteriogram created with multidetector-row computed tomography during pelvic arteriography. This arteriogram was synthesized from a background bone volume-rendered (VR) image, an aorta-pelvic artery VR image, and a prostate-supplying artery VR image. Because the bone background VR image is combined with the aorta-pelvic artery VR image, the prostate-supplying arteriogram can simultaneously show the pelvic branch arteries present on the ventral side, inside, and the dorsal side of the pelvic bone. It showed that the left prostatic artery supplied the urethra at the outlet of the urinary bladder. PAE of the left prostatic artery was performed with catheter navigation based on the prostate-supplying arteriogram. There was marked relief of the lower urinary tract symptoms at the 12-month follow-up.

N-butyl cyanoacrylate embolization with blood flow control of an arterioportal shunt that developed after radiofrequency ablation of hepatocellular carcinoma.

We present a case of a patient with rapid deterioration of esophageal varices caused by portal hypertension accompanied by a large arterioportal shunt that developed after radiofrequency ablation of hepatocellular carcinoma. We used n-butyl cyanoacrylate (NBCA) as an embolic material to achieve pinpoint embolization of the shunt, because the microcatheter tip was 2 cm away from the shunt site. Under hepatic arterial flow control using a balloon catheter, the arterioportal shunt was successfully embolized with NBCA, which caused an improvement in the esophageal varices.

Comparison of air kerma between C-arm CT and 64-multidetector-row CT using a phantom.

PURPOSE: To compare air kerma after scanning a phantom with C-arm CT and with 64-multidetector row CT (64MDCT). MATERIALS AND METHODS: A phantom was scanned using parameters based on data of ten patients with hepatocellular carcinoma who had C-arm CT during hepatic arteriography and 64MDCT during arterial portography. Radiation monitors were used to measure air kerma ten times at each of five points: the center (A), top (B), left side (C), bottom (D), and right side (E). RESULTS: For C-arm CT vs. 64MDCT, air kerma after scanning was 10.5 ± 0.2 vs. 6.4 ± 0.0 for A, 1.5 ± 0.0 vs. 11.6 ± 0.2 for B, 37.1 ± 0.2 vs. 11.1 ± 0.1 for C, 55.6 ± 1.0 vs. 10.6 ± 0.1 for D, and 40.5 ± 0.5 vs. 11.7 ± 0.1 for E, respectively. Air kerma for A, B, C, D, and E was 1.64, 0.13, 3.34, 5.24, and 3.46 times greater for C-arm CT than for 64MDCT, respectively. CONCLUSION: Using the same scanning parameters as for clinical cases, air kerma values were greater with C-arm CT than with 64MDCT; at the dorsal side of the phantom, they were 5.24 times greater with C-arm CT compared with 64MDCT.

Volume-rendered hemorrhage-responsible arteriogram created by 64 multidetector-row CT during aortography: utility for catheterization in transcatheter arterial embolization for acute arterial bleeding.

Aortography for detecting hemorrhage is limited when determining the catheter treatment strategy because the artery responsible for hemorrhage commonly overlaps organs and non-responsible arteries. Selective catheterization of untargeted arteries would result in repeated arteriography, large volumes of contrast medium, and extended time. A volume-rendered hemorrhage-responsible arteriogram created with 64 multidetector-row CT (64MDCT) during aortography (MDCTAo) can be used both for hemorrhage mapping and catheter navigation. The MDCTAo depicted hemorrhage in 61 of 71 cases of suspected acute arterial bleeding treated at our institute in the last 3 years. Complete hemostasis by embolization was achieved in all cases. The hemorrhage-responsible arteriogram was used for navigation during catheterization, thus assisting successful embolization. Hemorrhage was not visualized in the remaining 10 patients, of whom 6 had a pseudoaneurysm in a visceral artery; 1 with urinary bladder bleeding and 1 with chest wall hemorrhage had gaze tamponade; and 1 with urinary bladder hemorrhage and 1 with uterine hemorrhage had spastic arteries. Six patients with pseudoaneurysm underwent preventive embolization and the other 4 patients were managed by watchful observation. MDCTAo has the advantage of depicting the arteries responsible for hemoptysis, whether from the bronchial arteries or other systemic arteries, in a single scan. MDCTAo is particularly useful for identifying the source of acute arterial bleeding in the pancreatic arcade area, which is supplied by both the celiac and superior mesenteric arteries. In a case of pelvic hemorrhage, MDCTAo identified the responsible artery from among numerous overlapping visceral arteries that branched from the internal iliac arteries. In conclusion, a hemorrhage-responsible arteriogram created by 64MDCT immediately before catheterization is useful for deciding the catheter treatment strategy for acute arterial bleeding.

Optimal scanning timing by use of multi-detector row computed tomography during thoracic aortography for depiction of arteries causing hemoptysis.

Scanning timing for multi-detector row computed tomography during thoracic aortography (MDCT-TA) was explored for depiction of arteries responsible for hemoptysis. The mean time (MT) from contrast medium (CM) injection to peak enhancement (PE) in the descending aorta at the level of the diaphragm on thoracic aortography was investigated. The MT to PE of the descending aorta at the level of diaphragm was 4.86 ± 0.42 s, with 30 mL CM at an injection rate of 10 mL/s. CM injection was completed 1.86 s before the final slice was obtained. The CM injection duration can be calculated as follows: 4.86 s + scan time - 1.86 s. The optimal scanning timing is a scan delay of approximately 5 s from the start of CM injection, and the CM injection duration is expressed as scan time plus 3 s. MDCT-TA depicted the branching sites of the bronchial arteries in all cases.

Hepatoma feeding arteriogram created by CT during aortography using IVR 64-multidetector-row CT for catheterization in transcatheter arterial chemoembolization for hepatocellular carcinoma.

CT during aortography (CTAo) using IVR 64-multidetector-row CT (IVR-64MDCT) enables the rapid and simultaneous depiction of both the hepatic and extrahepatic feeding arteries in hepatocellular carcinoma (HCC), and can be achieved using a reasonable volume of contrast medium. The scan time is approximately 6 s from the diaphragm to the kidney using CTAo with 64MDCT with a slice thickness and slice interval of 0.5 mm. The hepatoma feeding arteriogram appears in the angiographic monitor after CTAo, and can then be used to guide catheterization. We introduce the process for creating a hepatoma feeding arteriogram, synthesized from the following three volume-rendered images: background bone, aorta to hepatic-branch artery, and hepatoma to feeding artery. Uniquely, the hepatoma feeding arteriogram enables investigation of the feeding artery from the tumor side, rather than from the aorta side, and appears superior to selective arteriography in terms of detecting small HCC and its accompanying fine feeding arteries. Identification of these arteries by CT angiography with intravenous contrast medium injection is difficult because of the similarity in CT values between the feeding artery and the surrounding liver, thereby preventing the creation of a hepatoma feeding arteriogram. CTAo accelerates the process of deciding upon the catheter treatment strategy, shifting the decision to the point at which the feeding artery is investigated, because the hepatoma feeding arteriogram enables instant identification of the feeding artery and its connection to the hepatic branch artery. CTAo with IVR-64MDCT can potentially contribute to remarkable advances in IVR, especially transcatheter arterial chemoembolization for HCC.

Optimum CT reconstruction parameters for vascular and hepatocellular carcinoma models in a liver phantom with multi-level dynamic computed tomography with 64 detector rows: a basic study.

We quantified to clarify the optimum factors for CT image reconstruction of an enhanced hepatocellular carcinoma (HCC) model in a liver phantom obtained by multi-level dynamic computed tomography (M-LDCT) with 64 detector rows. After M-LDCT scanning of a water phantom and an enhanced HCC model, we compared the standard deviation (SD, 1 ± SD), noise power spectrum (NPS) values, contrast-noise ratios (CNR), and the M-LDCT image among the reconstruction parameters, including the convolution kernel (FC11, FC13, and FC15), post-processing quantum filters (2D-Q00, 2D-Q01, and 2D-Q02) and slice thicknesses/slice intervals. The SD and NPS values were lowest with FC11 and 2D-Q02. The CNR values were highest with 2D-Q02. The M-LDCT image quality was highest with FC11 and 2D-Q02, and with slice thicknesses/slice intervals of 0.5 mm/0.5 mm and 0.5 mm/0.25 mm. The optimum factors were the FC11 convolution kernel, 2D-Q02 quantum filter, and 0.5 mm slice thickness/0.5 mm slice interval or less.

Optimal injection rate and volume of contrast medium for observing hemodynamics of a hepatocellular carcinoma structure model.

This study aimed to identify the optimal concentration, injection rate, and total volume of contrast medium (CM) for evaluating the hemodynamics of a hepatocellular carcinoma (HCC) structure model of diameter 35 mm, using multi-level dynamic computed tomography (M-LDCT) with 64 detector rows. A tube was inserted in the model as a simulated vessel. Five CM concentrations were used: non-diluted, 2-, 3-, 6-, and 9-fold diluted. Five regions of interest were placed within the HCC structure model. Time-density curves were created for CM injection rates of 1, 2, and 3 ml/s for 10 s, and for a total volume of 10 ml, followed by saline injection at 1 ml/s. M-LDCT maximum intensity projection images were evaluated by four appraisers using a three-point scale (excellent, 2; good, 1; poor, 0). There was no significant difference between maximum CT values at 2 ml/s for 10 s and those at 3 ml/s; these values were both greater than those at 1 ml/s. The duration of the peak was maintained for longer at 3 ml/s for 10 s (5.2 ± 2.3 s) than at 2 ml/s (3.6 ± 0.9 s). Maximum CT values at 2 ml/s of a total volume of 10 ml were greater than those at 3 ml/s. The highest scores of 7 and 8 were found at 2 and 3 ml/s for 10 s, using 2-, 3-, or 6-fold diluted CM. The most appropriate CM rate for evaluating hemodynamics was 2 ml/s for 10 s, using 2-, 3-, or 6-fold diluted CM.

Comparison of contrast media and low-molecular-weight dextran for frequency-domain optical coherence tomography.

BACKGROUND: Although an intracoronary frequency-domain optical coherence tomography (FD-OCT) system overcomes several limitations of the time-domain OCT (TD-OCT) system, the former requires injection of contrast media for image acquisition. The increased total amount of contrast media for FD-OCT image acquisition may lead to the impairment of renal function. The safety and usefulness of the non-occlusion method with low-molecular-weight dextran L (LMD-L) via a guiding catheter for TD-OCT image acquisition have been reported previously. The aim of the present study was to compare the image quality and quantitative measurements between contrast media and LMD-L for FD-OCT image acquisition in coronary stented lesions. METHODS AND RESULTS: Twenty-two patients with 25 coronary stented lesions were enrolled in this study. FD-OCT was performed with the continuous-flushing method via a guiding catheter. Both contrast media and LMD-L were infused at a rate of 4 ml/s by an autoinjector. With regard to image quality, the prevalence of clear image segments was comparable between contrast media and LMD-L (97.9% vs. 96.5%, P=0.90). Furthermore, excellent correlations were observed between both flushing solutions in terms of minimum lumen area, mean lumen area, and mean stent area. The total volumes of contrast media and of LMD-L needed for OCT image acquisition were similar. CONCLUSIONS: FD-OCT image acquisition with LMD-L has the potential to reduce the total amount of contrast media without loss of image quality.

Optimal contrast material concentration for distinguishing among carotid artery lumen, carotid stent, and neck in cone-beam computed tomography during carotid angiography: basic and clinical studies.

PURPOSE: To explore the optimal contrast material (CM) concentration for distinguishing CM, carotid stent (CS), and neck components in cone-beam computed tomography (CBCT) during carotid angiography (CBCT-CA). MATERIALS AND METHODS: A neck phantom containing CS and contrast-filled imitation vessels of 9 mm diameter was scanned using CBCT. CM (300 mgI/ml) was used in concentrations of 100, 50, 33, 10, 5, and 1%. In a clinical study, 30 patients with a CS (Precise or Wallstent) underwent CBCT-CA with CM injected at a rate of 3 ml/s and a concentration of 10 or 20%. RESULTS: In the basic study, CBCTA using 5% CM enabled clear distinction among the three components under windowing at 1500 width and 300 center, and showed the exact diameter of the imitation vessel. Pixel values of CM inside the Precise and the Wallstent were 622.2 ± 32.9 (mean ± SD) and 746.0 ± 27.9, respectively. In the clinical study using CM at concentrations of 10 and 20%, pixel values of CM inside the Wallstent were 632.3 ± 69.2 and 1024.5 ± 99.0, respectively. CONCLUSION: Optimal CM concentration for distinguishing among the three components was 5% in the basic study; the optimal concentration was 10% in the clinical study.