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 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 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: We wanted to evaluate the mural changes by CT on the follow-up examination of patients with active Takayasu arteritis. MATERIALS AND METHODS: The study included 18 patients, (4 males and 14 females), with active Takayasu arteritis. A total of 44 CT examinations were done during the follow-up period (mean: 55.6 months). At the time of the last follow-up CT, the disease, on the basis of the erythrocyte sedimentation rate (ESR), was found to be inactive in five patients and the disease was active and persistent in 13 patients. The thickness and CT attenuation of the aortic wall on the precontrast, arterial and venous phases were measured on the initial and the follow-up CT examinations. The ratio of the mural attenuation over that of the back muscle on the initial CT was compared with the ratio found on the follow-up CT. RESULTS: The initial CT findings included high density and calcifications of the aortic wall in the precontrast images and a thickened wall with enhancements in the arterial and the venous phases. A low-attenuation ring was demonstrated in the venous phase in 15 patients (83%). On the follow-up evaluation, the mean mural thickness decreased significantly from 4.1 mm to 2.4 mm. The mean mural attenuation ratio in the venous phase decreased significantly from 1.9 to 1.3 (p = 0.001). The low attenuation ring was identified in seven patients (39%) who had only with active, persistent Takayasu arteritis. CONCLUSION: The mural changes demonstrated by the follow-up CT evaluations for the patients with active Takayasu arteritis included a decrease of the mural thickness and enhancement, disappearance of the low-attenuation ring on the venous phase, and an increase of the mural attenuation and calcification on the precontrast phase.
Adolescent ; Adult ; *Aortography ; Blood Sedimentation ; Child ; Contrast Media/administration & dosage ; Female ; Follow-Up Studies ; Humans ; Iohexol/administration & dosage/analogs & derivatives ; Male ; Middle Aged ; Pulmonary Artery/radiography ; Retrospective Studies ; Takayasu Arteritis/*radiography ; Tomography, X-Ray Computed

OBJECTIVE: The aim of this study was to use fractal dimension (FD) analysis on multidetector CT (MDCT) images for quantifying the morphological changes of the pulmonary artery tree in patients with pulmonary hypertension (PH). MATERIALS AND METHODS: Fourteen patients with PH and 17 patients without PH as controls were studied. All of the patients underwent contrast-enhanced helical CT and transthoracic echocardiography. The pulmonary artery trees were generated using post-processing software, and the FD and projected image area of the pulmonary artery trees were determined with ImageJ software in a personal computer. The FD, the projected image area and the pulmonary artery pressure (PAP) were statistically evaluated in the two groups. RESULTS: The FD, the projected image area and the PAP of the patients with PH were higher than those values of the patients without PH (p < 0.05, t-test). There was a high correlation of FD with the PAP (r = 0.82, p < 0.05, partial correlation analysis). There was a moderate correlation of FD with the projected image area (r = 0.49, p < 0.05, partial correlation analysis). There was a correlation of the PAP with the projected image area (r = 0.65, p < 0.05, Pearson correlation analysis). CONCLUSION: The FD of the pulmonary arteries in the PH patients was significantly higher than that of the controls. There is a high correlation of FD with the PAP.
Adult ; Aged ; Case-Control Studies ; Contrast Media/diagnostic use ; Female ; *Fractals ; Humans ; Hypertension, Pulmonary/*radiography ; Iohexol/analogs & derivatives/diagnostic use ; Male ; Middle Aged ; Pulmonary Artery/*radiography ; Radiographic Image Interpretation, Computer-Assisted/*methods ; *Tomography, Spiral Computed

We describe the enhancement patterns of myoepithelioma in two patients with a soft palate mass. In the first case, helical CT revealed a faintly enhancing mass. Histologically, the tumor was composed of plasmacytoid cells in a background of rich myxoid stroma. Immunostaining for CD34 showed scanty blood vessels. In the second case, helical CT revealed an intensely enhancing mass. Histologically, the mass was a cellular tumor with fibrous stroma. Immunostaining for CD34 also showed frequent blood vessels.
Aged ; Contrast Media/administration & dosage ; Diagnosis, Differential ; Female ; Humans ; Iohexol/analogs & derivatives/diagnostic use ; Male ; Middle Aged ; Myoepithelioma/*diagnosis/surgery ; Palatal Neoplasms/*diagnosis/surgery ; Palate, Soft/*radiography/surgery ; Radiographic Image Enhancement/methods ; Rare Diseases ; Tomography, Spiral Computed/*methods

OBJECTIVE: To evaluate the depiction rate and morphologic features of myocardial bridging (MB) of the left anterior descending coronary artery (LAD) using dual-source CT (DSCT). MATERIALS AND METHODS: CT scans from a total of 1,353 patients who underwent DSCT were reviewed retrospectively for LAD-MB. Seventy-eight patients were excluded due to poor image quality or poor enhancement of the coronary artery. The length and depth of the MB were analyzed and classified as superficial or deep with respect to the depth (< or = 1 or > 1 mm) of the LAD tunneled segment. Superficial MB was subdivided into complete or incomplete types according to full or partial encasement of the myocardium. RESULTS: Of the 1,275 patients included in this study, 557 cases of MB were found from 536 patients (42%). Superficial MB was observed in 368 of 557 (66%) cases, and deep MB was seen in 189 of 557 (34%) cases. Superficial MB showed 2 types: complete (128 of 368, 35%) and incomplete (240 of 368, 65%). The mean length of a tunneled segment for superficial MB was 16.4 +/- 8.6 mm. The mean length and depth of a tunneled segment for deep MB were 27.6 +/- 12.8 mm and 3.0 +/- 1.4 mm, respectively. The incidence of atherosclerotic plaques in a 2-cm-long segment proximal to MB was 16%. CONCLUSION: The depiction rate of LAD-MB using DSCT in a large series of patients was 42%, with two-thirds of MB segments being the superficial type.
Contrast Media/diagnostic use ; Coronary Angiography/*methods ; Electrocardiography ; Female ; Humans ; Iohexol/analogs & derivatives/diagnostic use ; Male ; Middle Aged ; Myocardial Bridging/*radiography ; Radiographic Image Interpretation, Computer-Assisted ; Retrospective Studies ; Tomography, X-Ray Computed/*methods

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: 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: 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