The purpose of this study was to determine the morphological and dynamic features of normal pulmonary valve by using dual-source CT. Thirty patients who underwent dual-source CT angiography with right ventricular outflow tract well-opacified were enrolled. Ten phases of images were reconstructed at 10% R-R interval, and pulmonary valve area and pulmonary annular diameter were measured on all 10 phases. As the pulmonary valve opened, its orifice appeared as oval or proximate triangle. As the pulmonary valve closed, it appeared as "Y-shape". Pulmonary valve opened from 10% to 30% phases, with maximum pulmonary valve area of (4.74 +/- 0.69) cm2 in 10% phase. Pulmonary valve closed from 40% to 90% phases. Pulmonary annular diameter varied with cardiac cycle, with maximum pulmonary annular diameter of (2.36 +/- 0.24) cm in 0% phase and minimum pulmonary annular diameter of (1.82 +/- 0.32) cm in 40% phase (P < 0.001). The proximal phase for assessing pulmonary valve was 70% phase. Dual-source CT may evaluate the morphological and dynamic features of normal pulmonary valve.
Adult ; Female ; Humans ; Iohexol ; analogs & derivatives ; Male ; Middle Aged ; Pulmonary Valve ; anatomy & histology ; diagnostic imaging ; physiology ; Tomography, Spiral Computed ; methods

OBJECTIVE: To evaluate the effect of thin overlapping reconstruction on the attenuation of small (< or = 3 cm) renal cysts in the nephrographic phase of multidetector CT (MDCT). MATERIALS AND METHODS: We scanned a phantom kidney containing spheres of various sizes (10, 20, and 30 mm) using both 4- and 16-channel MDCT scanners, and reconstructed images with various slice thickness (T, mm) and intervals (I, mm). The attenuation increase (AI) was measured for each sphere in 240-HU diluted solution of contrast material and compared with the attenuation in 35-HU solution. RESULTS: On the 4-channel MDCT, thin overlapping reconstruction (T/I = 3/1, compared with 5/5) lowered the AI as much as 17 HU in the 10 mm-sphere and 6 HU in the 20 mm-sphere (p < 0.05). Thin slicing alone was also effective; however overlapping alone was not. On the 16-channel MDCT, AI in the 10 mm-sphere was significantly lower than on the 4-channel MDCT with T/I = 5/5 (p < 0.05), however thinner slicing or overlapping did not affect the attenuation significantly in all of the spheres. CONCLUSION: The effect of thin overlapping reconstruction on minimizing falsely elevated attenuation in the nephrographic phase was significant only in cysts < or =20 mm on the 4-channel MDCT.
Tomography, X-Ray Computed/*methods ; *Radiographic Image Interpretation, Computer-Assisted ; Phantoms, Imaging ; Kidney Diseases, Cystic/*radiography ; Iohexol/analogs & derivatives/diagnostic use ; Humans ; Contrast Media

OBJECTIVE: To evaluate the nature and imaging appearance of incidental enhancing breast lesions detected on a routine contrast-enhanced chest CT. MATERIALS AND METHODS: Twenty-three patients with incidental enhancing breast lesions on contrast-enhanced chest CT were retrospectively reviewed. The breast lesions were reviewed by unenhanced and enhanced CT, and evaluated by observing the shapes, margins, enhancement patterns and backgrounds of breast lesions. A histopathologic diagnosis or long-term follow-up served as reference standard. RESULTS: Sixteen (70%) patients had malignant breast lesions and seven (30%) had benign lesions. In 10 patients, the breast lesions were exclusively detected on contrast-enhanced CT. Using unenhanced CT, breast lesions with fibroglandular backgrounds were prone to be obscured (p < 0.001). Incidental primary breast cancer showed an non-significant trend of a higher percentage irregular margin (p = 0.056). All of the four incidental breast lesions with non-mass-like enhancement were proven to be malignant. CONCLUSION: Routine contrast-enhanced chest CT can reveal sufficient details to allow for the detection of unsuspected breast lesions, in which some cases may be proven as malignant. An irregular margin of incidental enhancing breast lesion can be considered a suggestive sign of malignancy.
Aged ; Breast Diseases/radiography ; Breast Neoplasms/*radiography/secondary ; *Contrast Media ; Female ; Humans ; *Incidental Findings ; Iohexol/*analogs & derivatives/diagnostic use ; Middle Aged ; *Radiography, Thoracic ; *Tomography, X-Ray Computed

OBJECTIVE: To assess the technical feasibility and local efficacy of biplane fluoroscopy plus US-guided percutaneous radiofrequency ablation (RFA) for viable hepatocellular carcinoma (HCC) around retained iodized oil after transcatheter arterial chemoembolization (TACE). MATERIALS AND METHODS: Our prospective study was approved by our institutional review board and informed consent was obtained from all participating patients. For patients with viable HCC around retained iodized oil after TACE, biplane fluoroscopy plus US-guided RFA was performed. We evaluated the rate of technical success and major complications on a post-RFA CT examination and local tumor progression with a follow-up CT. RESULTS: Among 40 consecutive patients, 19 were excluded due to one of the following reasons: poorly visible HCC on fluoroscopy (n = 13), high risk location (n = 2), RFA performed under monoplane fluoroscopy and US guidance (n = 2), and poorly identifiable new HCCs on US (n = 2). The remaining 21 patients with 21 viable HCCs were included. The size of total tumors ranged from 1.4 to 5.0 cm (mean: 3.2 cm) in the longest diameter. Technical success was achieved for all 21 HCCs, and major complications were observed in none of the patients. During the follow-up period (mean, 20.3 months; range, 6.5-29.9 months), local tumor progression was found in two patients (2/21, 9.5%). Distant intrahepatic metastasis developed in 76.2% (16/21) of patients. CONCLUSION: When retained iodized oil around the tumor after TACE hampers the targeting of the viable tumor for RFA, biplane fluoroscopy plus US-guided RFA may be performed owing to its technical feasibility and effective treatment for viable HCCs.
Aged ; Aged, 80 and over ; Carcinoma, Hepatocellular/radiography/*surgery/therapy ; *Catheter Ablation ; *Chemoembolization, Therapeutic ; Complex Mixtures ; *Contrast Media ; Female ; *Fluoroscopy/methods ; Humans ; Iodized Oil/*administration & dosage ; Iohexol/analogs & derivatives/diagnostic use ; Liver Neoplasms/radiography/*surgery/therapy ; Male ; Middle Aged ; *Ultrasonography, Interventional

OBJECTIVE: This study was designed to determine the optimal mixture ratio of gadolinium and iodinated contrast agent for simultaneous direct MR arthrography and CT arthrography. MATERIALS AND METHODS: An in vitro study was performed utilizing mixtures of gadolinium at six different concentrations (0.625, 1.25, 2.5, 5.0, 10 and 20 mmol/L) and iodinated contrast agent at seven different concentrations (0, 12.5, 25, 37.5, 50, 75 and 92-99.9%). These mixtures were placed in tissue culture plates, and were then imaged with CT and MR (with T1-weighted sequences, proton-density sequences and T2-weighted sequences). CT numbers and signal intensities were measured. Pearson's correlation coefficients were used to assess the correlations between the gadolinium/iodinated contrast agent mixtures and the CT numbers/MR signal intensities. Scatter diagrams were plotted for all gadolinium/iodinated contrast agent combinations and two radiologists in consensus identified the mixtures that yielded the optimal CT numbers and MR signal intensities. RESULTS: The CT numbers showed significant correlation with iodinated contrast concentrations (r = 0.976, p < 0.001), whereas the signal intensities as measured on MR images showed a significant correlation with both gadolinium and iodinated contrast agent concentrations (r = -484 to -0.719, p < 0.001). A review of the CT and MR images, graphs, and scatter diagram of 42 combinations of the contrast agent showed that a concentration of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was the best combination for simultaneous CT and MR imaging. CONCLUSION: A mixture of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was found to be optimal for simultaneous direct MR arthrography and CT arthrography.
*Arthrography ; Contrast Media/*administration & dosage ; Gadolinium/administration & dosage/*diagnostic use ; Iohexol/administration & dosage/*analogs & derivatives/diagnostic use ; *Magnetic Resonance Imaging ; Meglumine/administration & dosage/*diagnostic use ; Organometallic Compounds/administration & dosage/*diagnostic use ; Phantoms, Imaging ; *Tomography, X-Ray Computed

OBJECTIVE: We wanted to evaluate the CT findings of epithelial origin ovarian carcinoma according to the degree of histologic differentiation. MATERIALS AND METHODS: This study enrolled 124 patients with 31 well differentiated, 44 moderately differentiated and 95 poorly differentiated carcinomas with epithelial origin. The CT images were retrospectively evaluated with regard to bilateral ovarian involvement, the tumor's nature, lymphadenopathy, adjacent organ invasion, peritoneal tumor seeding, a large amount of ascites and distant metastasis. In cystic, predominantly cystic and mixed tumors, the tumor wall, septa, papillary projection and necrosis in the solid portion were assessed. RESULTS: Bilateral ovarian involvement was more common in the poorly (48%) and moderately (42%) differentiated carcinomas than in the well differentiated carcinomas (7%) (p < 0.05). The frequency of a predominantly solid or solid nature was greater in the moderately and poorly differentiated carcinomas than in the well differentiated carcinomas (p < 0.0001). In the 87 tumors with a cystic, predominantly cystic or mixed nature, septa greater than 3 mm, papillary projection and necrosis in the solid portion were more common in the poorly differentiated carcinoma (91%, 91% and 77%, respectively) than in the moderately (64%, 68% and 34%, respectively) and well differentiated carcinomas (63%, 47% and 27%, respectively) (p < 0.05). Lymphadenopathy, organ invasion, tumor seeding and a large amount of ascites were more common in the poorly differentiated carcinomas (38%, 27%, 73% and 69%, respectively) than in the moderately (13%, 10%, 48% and 45%, respectively) and well differentiated carcinomas (3%, 0%, 10% and 17%, respectively) (p < 0.05). CONCLUSION: Epithelial origin ovarian carcinoma shows different CT findings according to the degree of histologic differentiation.
Ascites/radiography ; Carcinoma/*pathology/*radiography ; Contrast Media ; Female ; Humans ; Iohexol/analogs & derivatives ; Iopamidol ; Lymphatic Metastasis ; Middle Aged ; Neoplasm Invasiveness ; Ovarian Neoplasms/*pathology/*radiography ; Retrospective Studies ; Tomography, Spiral Computed/*methods

OBJECTIVE: The purpose of this study was to describe the myocardial enhancement patterns in patients with myocardial infarction using two-phase contrast-enhanced multidetector-row computed tomography (MDCT). MATERIALS AND METHODS: Twenty-three patients with clinically proven myocardial infarction (17 acute myocardial infarction [AMI] and 6 chronic myocardial infarction [CMI]) were examined with two-phase contrast-enhanced ECG-gated MDCT. The presence, location, and patterns of myocardial enhancement on two-phase MDCT images were compared with infarcted myocardial territories determined by using electrocardiogram, echocardiography, thallium-201 single photon emission computed tomography, catheter and MDCT coronary angiography. RESULTS: After clinical assessment, the presence of myocardial infarctions were found in 27 territories (19 AMI and 8 CMI) of 23 patients. Early perfusion defects were observed in 30 territories of all 23 patients. Three territories not corresponding to a myocardial infarction were detected in three patients with AMI and were associated with artifacts. Fourteen of perfusion defects were in the left anterior descending artery territory, four in the left circumflex artery territory, and nine in the right coronary artery territory. Delayed enhancement was observed in 25 territories (17 AMI and 8 CMI) of 21 patients. Delayed enhancement patterns were variable. Transmural early perfusion defects (n =12) were closely associated with transmural late enhancement (n = 5) and subendocardial residual defect with subepicardial late enhancement (n = 5). CONCLUSION: Myocardial infarction showed early perfusion defects and variable delayed enhancement patterns on two-phase contrast-enhanced MDCT. Delayed enhancement technique of MDCT could provide additional information of the location and extent of infarcted myocardium, and could be useful to plan appropriate therapeutic strategies in patients with AMI.
Adult ; Aged ; Aged, 80 and over ; Contrast Media ; Coronary Angiography ; Echocardiography ; Electrocardiography ; Female ; Humans ; Iohexol/analogs & derivatives/diagnostic use ; Male ; Middle Aged ; Myocardial Infarction/*radiography ; Tomography, Emission-Computed, Single-Photon ; Tomography, X-Ray Computed/*methods

OBJECTIVE: To investigate the validity of the 100 kVp setting in CT venography (CTV) in the diagnosis of deep vein thrombosis (DVT), and to evaluate the feasibility of reducing the amount of administered iodine in this setting. MATERIALS AND METHODS: After receiving the contrast medium (CM) of 2.0 mL/kg, 88 patients underwent CTV of the pelvis and lower extremities by using one of four protocols: Group A, 120 kVp setting and 370 mgI/mL CM; group B, 120 kVp and 300 mgI/mL; group C, 100 kVp and 370 mgI/mL; group D, 100 kVp and 300 mgI/mL. The groups were evaluated for venous attenuation, vein-to-muscle contrast-to-noise ratio (CNRVEIN), DVT-to-vein contrast-to-noise ratio (CNRDVT), and subjective degree of venous enhancement and image quality. RESULTS: Venous attenuation and CNRVEIN were significantly higher in group C (144.3 Hounsfield unit [HU] and 11.9), but there was no significant difference between group A (118.0 HU and 8.2) and D (122.4 HU and 7.9). The attenuation value of DVT was not significantly different among the four groups, and group C had a higher absolute CNRDVT than the other groups. The overall diagnostic image quality and venous enhancement were significantly higher in group C, but there was no difference between groups A and D. CONCLUSION: The 100 kVp setting in CTV substantially help improve venous enhancement and CNRVEIN. Furthermore, it enables to reduce the amount of administered iodine while maintaining venous attenuation, as compared with the 120 kVp setting.
Contrast Media/administration & dosage ; Feasibility Studies ; Female ; Humans ; Iohexol/administration & dosage/analogs & derivatives ; Linear Models ; Lower Extremity/blood supply/*radiography ; Male ; Middle Aged ; Phantoms, Imaging ; Phlebography/*methods ; Statistics, Nonparametric ; Tomography, X-Ray Computed/*methods ; Venous Thrombosis/*radiography

OBJECTIVE: To evaluate the pattern of right gastric venous drainage by use of digital subtraction angiography. MATERIALS AND METHODS: A series of 100 consecutive patients who underwent right gastric arteriography during transcatheter arterial chemoembolization for hepatocellular carcinoma were included in this study. Angiographic findings were retrospectively analyzed with respect to the presence or absence of the right and aberrant gastric veins, multiplicity of draining veins, aberrant right gastric venous drainage sites, and the termination pattern of aberrant right gastric veins (ARGVs). We also compared the relative size of the right and left gastric veins. RESULTS: A total of 49 patients collectively had 66 ARGVs. The common drainage sites for the ARGVs included the hepatic segment IV (n = 35) and segment I (n = 15). The termination pattern of ARGV could be classified into 4 different types. The most common type was termination as a superficial parenchymal blush formation in small areas without demonstrable portal branches. A statistically significant difference was found for the dominancy of the right gastric vein in gastric venous drainage between the two groups with or without ARGV (p < 0.05, Fisher's exact test). In the group of patients without ARGV (n = 51), the right gastric vein was equal to (n = 9) or larger than (n = 17) the left gastric vein in 26 patients (26 of 51, 51%). CONCLUSION: The incidence of ARGV is higher than expected with four distinct types in its termination pattern. The right gastric vein may play a dominant role in gastric venous drainage.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Angiography, Digital Subtraction/*methods ; Carcinoma, Hepatocellular/therapy ; Chemoembolization, Therapeutic/methods ; Contrast Media/diagnostic use ; Female ; Humans ; Iohexol/analogs & derivatives/diagnostic use ; Liver Neoplasms/therapy ; Male ; Middle Aged ; Stomach/*blood supply ; *Veins

OBJECTIVE: To evaluate the therapeutic efficacy of a new liquid embolic materi-al,Embol, in embolization of the renal artery. MATERIALS AND METHODS: Embol is a new embolic material obtained by partial hydrolysis of polyvinyl acetate mixed in absolute ethanol and Iopromide 370 and manufactured by Schering Korea, Kyonggido, Korea. Six patients who underwent embolization of the renal artery using Embol were evaluated. Four were male and two were female and their ages ranged from 11 to 70 (mean, 53) years. Clinical and radiologic diagnoses referred for renal artery embolization were renal cell carcinoma (n = 3), renal angiomyolipoma (n = 2) and pseudoaneurysm of the renal artery (n = 1). After selective renal angiography, Embol was injected through various catheters, either with or without a balloon occlusion catheter. Changes in symptoms and blood chemistry which may have been related to renal artery embolization with Embol were analyzed. RESULTS: The six patients showed immediate total occlusion of their renal vas-cular lesions. One of the three in whom renal cell carcinoma was embolized with Embol underwent radical nephrectomy, and the specimen thus obtained revealed 40% tumor necrosis. In the two patients with angiomyolipomas, the tumors decreased in size and abdominal pain subsided. Bleeding from pseudoaneurysm of the renal artery was successfully controlled. Four patients showed symptoms of post-embolization syndrome, and one of these also showed increased levels of blood urea nitrogen and creatinine. One patient experienced transient hyperten-sion. CONCLUSION: Embol is easy to use, its radiopacity is adequate and it is a safe and effective embolic material which provides immediate and total occlusion of renal vascular lesions.
Aged ; Aneurysm, False/therapy ; Angiomyolipoma/therapy ; Carcinoma, Renal Cell/therapy ; Child ; *Embolization, Therapeutic ; Ethanol ; Female ; Human ; Iohexol/*analogs & derivatives ; Kidney Neoplasms/*therapy ; Male ; Middle Age ; Polyvinyls/therapeutic use ; *Renal Artery