Multi-slice CT of thyroid nodules: comparison with ultrasonography

PURPOSE: To evaluate the usefulness of multi-slice computed tomography (MSCT) in comparison with ultrasonography (US) for the differentiation of benign from malignant thyroid nodules and the evaluation of tumor extension. MATERIALS AND METHODS: Thirty patients with thyroid nodules (14 malignant, 16 benign) who underwent both MSCT and US participated in the present study. MSCT with contrast enhancement was performed, and 3D shaded volume rendering (SVR) and multiplanar reconstruction (MPR) were employed to differentiate benign from malignant nodules and to evaluate tumor extension. US images were obtained using a 7.5 MHz annular array probe. A three-point rating scale was used for image interpretation, and the kappa statistic was employed to evaluate agreement between MSCT and US. RESULTS: Sensitivity in differentiating benign from malignant nodules was found to be 85.7% for US and 78.6% for MSCT. Disagreement between MSCT and US occurred in assessing the homogeneity of the solid component and the presence of fibrous capsule. In two of seven T4 cases, MPR provided a more accurate diagnosis than US examination in detecting extracapsular invasion. CONCLUSION: For differential diagnosis of thyroid nodules, US was found to be better than MSCT. However, MSCT could be useful for the evaluation of advanced cases with suspicion of extracapsular extension.     

Late-arterial and portal-venous phase imaging of the liver with a multislice CT scanner in patients without circulatory disturbances: automatic bolus tracking or empirical scan delay?

The value of automatic bolus tracking in late-arterial and portal-venous phase imaging of the liver with a multislice CT scanner as compared with fixed time-delay examination in patients without circulatory disturbances is evaluated. For the evaluation of known or suspected liver disease, 98 multiphase contrast-enhanced CT examinations including double late-arterial phase imaging were randomized into either scanning with a scan delay of 30 s from the beginning of contrast material injection or scanning with automatic bolus tracking. Contrast material was injected at 0.07 ml/kg body weight/s over 30 s. Contrast enhancement in each acquisition was measured in the aorta, portal vein, liver, pancreas and hepatocellular carcinomas. The density difference between hepatocellular carcinomas and the hepatic parenchyma was calculated. The mean time to the first-pass acquisition as determined by automatic bolus tracking was 29.6 s. No statistically significant difference was observed between the two groups either in any enhancement in any acquisition or in the lesion-to-liver density difference. The use of automatic bolus tracking in late-arterial and portal-venous phase hepatic CT does not significantly improve the degree of contrast enhancement in the aorta, portal vein, liver and pancreas or lesion-to-liver conspicuity in patients without circulatory disturbances.     

Embolization of Collateral Vessels Using Mechanically Detachable Coils in Young Children with Congenital Heart Disease

Our objective was to evaluate the usefulness of embolizing collateral vessels using mechanically detachable coils (MDCs) in children aged 3 years or younger with congenital heart disease. The subjects were 8 children with congenital heart disease featuring collateral vessels (age 18 days–3 years): 3 with a single ventricle, 2 with the tetralogy of Fallot, 2 with pulmonary atresia, and 1 with a ventricular septal defect. The embolized vessels were the major aortopulmonary collateral artery (MAPCA) in 5 patients, the persistent left superior vena cava in 2, and the coronary arteriovenous fistula in 1. A 4 or a 5 F catheter was used as the guiding device, and embolization was performed using MDCs and other conventional coils introduced through the microcatheter. One patient had growth of new MAPCAs after embolization, and these MAPCAs were also embolized with MDCs. Thus, a total of 9 embolization procedures were performed in 8 patients. Complete occlusion of the collateral vessels was achieved in 8 of 9 procedures (89%). Seven of 8 patients (88%) had uneventful courses after embolization, and MDC procedures appeared to play important roles in avoiding coil migration and achievement of safe coil embolization. One patient who underwent MAPCA embolization showed no improvement in heart function and died 2 months and 19 days later. Embolization of collateral vessels using MDCs in young children with congenital heart disease can be an effective procedure and a valuable adjunct to surgical management.     

Assessment of the pancreatic and intrapancreatic bile ducts using 0.5-mm collimation and multiplanar reformatted images in multislice CT

Our objective was to evaluate the ability of multiplanar reformatted (MPR) images combined with 0.5-mm axial images to depict the pancreatic and intrapancreatic bile ducts and compare the results with those of 0.5-mm axial, 2-mm axial, and 6-mm axial images alone. Seventy-seven patients without obstruction of the main pancreatic ducts (MPD) underwent dual-phase helical scanning of the pancreas using multislice computed tomography (MSCT). The MPR images were generated from 0.5-mm-thick images. Visualization of the pancreatic and intrapancreatic bile ducts and their confluence was graded on a four-point scale by a consensus of two radiologists. The results for 0.5-mm axial images in early-phase CT, 2-mm axial images in early-phase CT, MPR images combined with 0.5-mm axial images in early-phase CT, and 6-mm axial images in late-phase CT were then compared. The relationships of the focal pancreatic lesions with the pancreatic ducts were analyzed. The MPR images combined with 0.5-mm axial images were significantly superior to the other three types of images for the visualization of the pancreatic and intrapancreatic bile ducts and their confluence (p<0.01). The depiction rate of the MPD using MPR images combined with 0.5-mm axial images was 94, 94, 95, and 75%, respectively in the head, neck, body, and tail of the pancreas. Accessory pancreatic ducts, intrapancreatic bile ducts, and duct confluence were depicted in 48, 99, and 92%, respectively. In comparison with evaluation based on axial images alone, the use of MPR images more clearly demonstrated the relationship between the lesions and the pancreatic ducts in 14 of 19 lesions. The MPR images combined with 0.5-mm axial images improve the CT depiction of the pancreatic and intrapancreatic bile ducts in comparison with 0.5-mm axial, 2-mm axial, and 6-mm axial images alone. Electronic Publication     

Dammarane-type triterpenes from the Brazilian medicinal plant Cordia multispicata

From the Brazilian medicinal plant Carucaá (Cordia multispicata), oleanane- and ursane-type triterpenoids were previously reported as anti-androgenic constituents of the plant. In this study, purification of the polar elements of the EtOAc-soluble fraction of the plant revealed nine novel dammarane-type triterpenes, named cordianols A-I (1-9) along with the known compound cordialin A (10). The structures of these new compounds were elucidated by means of spectral methods including HRFABMS, (1)H NMR, (13)C NMR, and 2D NMR (HMQC, HMBC, NOESY). Absolute configuration at C-23 of compound 7 was determined by an excitone chirality method. Some of these new compounds revealed a hemiketal structure on the A ring and a hydroxylated or epoxidated 20(22)-(E)-ene side chain and showed weak anti-androgenic activity.     

The development of new immunoisolatory devices possessing the ability to induce neovascularization

The transplantation of a bioartificial pancreas has been regarded as a potential method for successful islet transplantation without any immunosuppressive agents. The subcutaneous site is a very attractive site for transplantation of a bioartificial pancreas because of its advantage of an easy operation site. Our group has been reporting that transplantation of a bioartificial pancreas to the subcutaneous site can reverse hyperglycemia in diabetic recipients. Regarding shapes of a bioartificial pancreas, it is believed that a bag form has an advantage because it is easy to prepare a large quantity. Our group previously reported successful transplantation of a bioartificial pancreas in bag form, a mesh-reinforced polyvinyl alcohol bag (MRPB), implanted in the peritoneal cavity. We also reported that the effect of subcutaneous islet transplantation can be greatly improved with prevascularization treatment. In the present study, we attempted to combine MRPB to our protocol of subcutaneous prevascularization. The main problem of this trial is that the procedure of MRPB implantation injures the prevascularized blood vessel networks. To solve this problem, we made a slight alternation in our protocol, and designed new devices on the basis of MRPB. The new devices, possessing the ability to induce neovascularization, were prepared by collagen coating on the surface of MRPB and were implanted with/without different doses of FGF-2 impregnated in gelatin microspheres. When using 5 microg of FGF-2, more blood vessels were observed on the surface of type I/IV collagen-coated MRPB compared with the original MRPB and type I collagen-coated MRPB. Quite a few blood vessels were observed either around the injection site of 50 microg of FGF-2 impregnated in gelatin microspheres alone or around the implantation site of FGF-2-free gelatin microspheres and type I collagen-coated MRPB or type I/IV collagen-coated MRPB. Here we demonstrated that the combination of both FGF-2 impregnated in gelatin microspheres and collagen-coated MRPB could give an effective system of neovascularization suitable for subcutaneous implantation of a bioartificial pancreas.     

Effects of combined therapy with interleukin 2 and interleukin 12 gene-transfected tumor vaccine for head and neck carcinoma

BACKGROUND: The biological effects of cytokines are coming to be understood. The therapeutic effects of interleukin (IL) 2, IL-12, and interferon gamma (IFN-gamma) in cancer treatment have been reported, but there are problems when these cytokines are systemically used as therapeutic agents. OBJECTIVE: To examine the efficacy of IL-2 and IL-12 gene-transfected tumor cell vaccines for head and neck squamous cell carcinoma (SCC). METHODS: Homozygous mice with the autosomal recessive nude gene (BALB/c nu/nu mice) were inoculated subcutaneously in the right flank with cells from a human oral floor SCC cell line (KB cells). The mice were then injected with IL-2 and IL-12 gene-transfected KB cells (KB/IL-2 and KB/IL-12 cells, respectively) irradiated with 2000 rad (20 Gy). RESULTS: No mice died soon after the injection of the gene immunotherapy. The treatment with either KB/human IL-2 (hIL-2) or KB/murine IL-12 (mIL-12) was not very effective. However, the treatment with both KB/hIL-2 and KB/mIL-12 cells significantly and safely inhibited the growth of established tumors (P =.04). There was no significant difference in antitumor effect between once-weekly and twice weekly injections of both KB/hIL-2 and KB/mIL-12 cells. CONCLUSION: Double gene immunotherapy is safe and effective treatment for SCC in mice.     

Evaluation of absorbed dose-distribution in the X-ray or gamma-irradiator for blood products

Irradiation of blood products abrogates the proliferation of lymphocytes present in cellular component, which is currently the only accepted methodology to prevent transfusion-associated graft versus host disease (TA-GVHD). A range of irradiation dose levels between 15 Gy and 50 Gy is being used, but the majority of facilities are employing 15 Gy. It should, however, be recognized that the delivered dose in the instrument canister might differ from the actual dose absorbed by the blood bag. This study have evaluated the actual dose distribution under practical conditions where a container was loaded with blood products or water bags, or filled with distilled water. This approach provides data that the maximum attenuation occurred when the container was completely filled with a blood-compatible material. Thus, an error of approximately 20 percent should be considered in the dose measured in the in-air condition. A dose calibration in an in-air condition may lead to substantial underexposure of the blood products. A dose distribution study using adequately prearranged exposure period verified that the absorbed dose of 15 Gy was attained at any point in the container for both linear accelerator and gamma-irradiator. The maximal difference in the absorbed dose between measured points was 1.5- and 1.6-fold for linear accelerator and gamma-irradiator, respectively. In conclusion, using blood-compatible materials, a careful dose calibration study should be employed in which the absorbed dose of 15 Gy is obtained at the point where the lowest dose could be expected.     

Mediastinal cystic lesions: CT and MRI findings

In this article we describe various approaches to the evaluation of mediastinal cystic lesions using CT and MRI. Although cystic lesions generally appear to be uncomplicated and not difficult to diagnose, we consider that there are certain pitfalls in differentiating them from solid lesions. It is important to pay careful attention to the location (including ectopic occurrence), CT attenuation and/or MR intensity, thickness of the wall, tear-drop shape or alternation of shape owing to intrathoracic pressure, and pseudoenhancement. We suggest that MR be recommended when the findings of CT are equivocal, as they were in 32 of our cases.