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

OBJECTIVETo investigate the feasibility of using lower iodine concentration (270 mgI/ml) contrast medium, lower X-ray tube voltage (100 kVp) and iterative reconstruction (IR) to reduce both iodine load and radiation dose but keep the image quality of coronary CT angiography (CCTA).

METHODSA total of 80 consecutive patients with suspected coronary artery disease were prospectively assigned to one of two groups via computer central system from January to May 2013. The control group (n = 40) was scanned using dual-source CCTA protocols of 120 kV, 370 mgI/ml Iopromide and filtered back projection reconstruction with a vascular algorithm (B26f). The study group (n = 40) was scanned using 100 kV, 270 mgI/ml Iodixanol and sinogram affirmed iterative reconstruction with a vascular algorithm (I26f). Other scan parameters and contrast injection protocol were similar between the two groups. Attenuation in the ascending aorta and coronary arteries along with image noise were measured. Images were reconstructed, measured and graded, and iodine load and effective radiation dose were calculated.

RESULTSThe body mass index ((25.3 ± 3.0) kg/m² vs. (25.4 ± 3.0)kg/m², P = 0.852), image quality scores (4.70 ± 0.52 vs. 4.63 ± 0.59, P = 0.545), mean signal-to-noise ratios (22.2 ± 5.5 vs. 23.6 ± 5.8, P = 0.277), and contrast-to-noise ratios (35.6 ± 17.6 vs. 41.1 ± 17.6, P = 0.163) were similar between the control group and study group. Mean iodine loads were significantly reduced in the study group ((18.49 ± 0.75)g) compared to control group ((25.27 ± 0.94)g), P< 0.001). Mean effective radiation doses were also significantly reduced in the study group ((2.31 ± 0.73) mSv) compared to that in control group ((3.52 ± 1.16) mSv), P< 0.001).

CONCLUSIONUse of low X-ray tube voltage and iterative reconstruction allows lower iodine load and effective radiation dose application at CCTA without image quality reduction.

Algorithms ; Aorta ; Body Mass Index ; Contrast Media ; Coronary Angiography ; Coronary Artery Disease ; Feasibility Studies ; Fluoroscopy ; Humans ; Injections, Intravenous ; Iodine ; Iohexol ; analogs & derivatives ; Tomography, X-Ray Computed ; Triiodobenzoic Acids

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

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

This study was undertaken to compare renal damage, as determined by serum creatinine and degree of apoptosis, caused by iodinated contrast or gadolinium in an acute renal failure (ARF) rat model. Rats were divided into three groups; controls (n=3), a CT contrast medium group (n=9), and an MR contrast medium group (n=9). The CT and MR groups were further subdivided into three groups, namely, low, standard, and high dose subgroups. Renal function was evaluated by determining serum creatinine levels; before ARF, and 48 hr after ARF and contrast administration. Apoptosis was assayed by terminal deoxynucleotidyl transferasemediated dUTP nick-end labeling (TUNEL). No significant creatinine level differences were observed between the CT and MR groups (p=0.116). Degrees of apoptosis in the renal cortex and medulla were more severe in the CT contrast medium group than in the control or MR contrast medium group (p<0.05). The study shows that CT contrast medium did not aggravate renal function more so than MR contrast medium in this ARF rat model. However, apoptosis examination in the renal cortex and medulla indicated that CT contrast medium induced more severe apoptosis than MR contrast medium (p<0.05). We conclude that CT contrast medium can be used for renal imaging studies when subjects are well hydrated and preventive medication is administered.
Animals ; Apoptosis/*drug effects ; Contrast Media/adverse effects ; Creatine/*blood ; Female ; Gadolinium DTPA/*adverse effects ; Iohexol/adverse effects/*analogs and derivatives ; Kidney/*drug effects/*pathology ; Kidney Failure, Acute/*blood/pathology/radiography ; Male ; Rats ; Rats, Sprague-Dawley ; Research Support, Non-U.S. Gov't

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