Multidetector Computed Tomography Imaging Research Articles

Multidetector computed tomography with triple-bolus contrast medium administration protocol for preoperative anatomical and functional assessment of potential living renal donors

To evaluate multidetector computed tomography (MDCT) with a triple-bolus contrast administration protocol for preoperative anatomical and functional assessment of living renal donors. Fifty-five potential living renal donors underwent MDCT of which 27 proceeded to donor nephrectomy. A triple-bolus contrast administration protocol was used for simultaneous acquisition of arterial, nephrographic, and excretory phases. MDCT images were independently reviewed in random order by two radiologists blinded to surgical anatomy findings. Diagnostic accuracy for anatomical variants was quantified by sensitivity and specificity. Differential renal function (DRF) was derived from MDCT for 54 patients and compared with technetium-99m dimercaptosuccinic acid renography (Tc-99m DMSA). All triple-bolus MDCT examinations were technically adequate. Accessory renal arteries and veins were identified at surgery in 33% (n = 9/27) and 22% (n = 6/27) of donor kidneys. The mean difference between MDCT-derived DRF and DMSA was 0.8% (95% CI 0.1-1.6) with 95% limits of agreement of -4.6% (95% CI -3.3 to -5.9) to 6.3% (95% CI 5.0-7.6). MDCT delivered a mean (SD, range) radiation dose of 9.5 (3.6, 3.6-17.3)mSv. MDCT with a triple-bolus contrast administration provides accurate anatomical and functional evaluation of living renal donors.

Erdheim-Chester disease: CT findings of thoracic involvement

To retrospectively assess the association of mediastinal, cardiovascular and pleuropulmonary findings on chest CT of 40 patients with immunohistochemically and histologically proven Erdheim-Chester disease (ECD). The multidetector chest CT images of 40 ECD patients were reviewed in consensus by chest and cardiovascular radiologists. Thirty-four (85%) patients had periaortic infiltration that extended around the aortic branches of 29 (73%). Perivascular infiltration extended into the cardiac sulci in 22 (55%) (p < 0.005). Infiltration involved the right atrium wall in 12 patients, associated with severe narrowing of the atrial lumen in 8. Pericardial effusion and/or thickening were observed in 24 (60%) patients. Lung involvement, seen in 22 (55%) patients, was associated with mediastinal infiltration (20; p < 0.005) and pleural thickening or effusion (16; p = 0.001); it consisted of smooth interlobular septa (21), subpleural thickening (13), poorly defined centrilobular nodular opacities (9), ground-glass opacities (8) and/or lung cysts (5). The detailed description of thoracic ECD involvement seen in these patients showed that infiltration into the mediastinal spaces including the pericardium, coronary sulci and right atrium is frequently associated with pleural and interstitial lung diseases.

Prevalence, Distribution, and Risk Factor Correlates of High Pericardial and Intrathoracic Fat Depots in the Framingham Heart Study

Pericardial and intrathoracic fat depots may represent novel risk factors for obesity-related cardiovascular disease. We sought to determine the prevalence, distribution, and risk factor correlates of high pericardial and intrathoracic fat deposits. Participants from the Framingham Heart Study (n=3312; mean age, 52 years; 48% women) underwent multidetector CT imaging in 2002 to 2005; high pericardial and high intrathoracic fat were defined on the basis of the sex-specific 90th percentile for these fat depots in a healthy reference sample. For men and women, the prevalence of high pericardial fat was 29.3% and 26.3%, respectively, and high intrathoracic fat was 31.4% and 35.3%, respectively. Overall, 22.1% of the sample was discordant for pericardial and intrathoracic fat depots: 8.3% had high pericardial but normal intrathoracic fat and 13.8% had high intrathoracic but normal pericardial fat. Higher body mass index, higher waist circumference, and increased prevalence of metabolic syndrome were more prevalent in participants with high intrathoracic fat depots than with high pericardial fat (P<0.05 for all comparisons). High abdominal visceral adipose tissue was more frequent in participants with high intrathoracic adipose tissue compared with those with high pericardial fat (P<0.001). Intrathoracic fat but not waist circumference was more highly correlated with visceral adipose tissue (r=0.76 and 0.78 in men and women, respectively; P<0.0001) than with subcutaneous adipose tissue (SAT) (r=0.46 and 0.54 in men and women, respectively; P<0.0001). Although prevalence of pericardial fat and intrathoracic fat were comparable at 30%, intrathoracic fat correlated more closely with metabolic risk and visceral fat. Intrathoracic fat may be a potential marker of metabolic risk and visceral fat on thoracic imaging.

Detection of Aortic Regurgitation with 64-slice Multidetector Computed Tomography (MDCT)

To determine the diagnostic accuracy of 64-row multidetector cardiac computed tomography (MDCT) in detecting aortic regurgitation (AR) on prospectively acquired images with trans-thoracic echocardiography (TTE) as a reference standard. Forty-three consecutive patients underwent MDCT and TTE. AR was defined on MDCT images acquired at 75% phase of R-R interval as the lack of aortic cusps coaptation. The maximum regurgitant orifice area (ROA) was planimetered and compared to TTE. All 29 patients with AR on TTE were correctly identified by MDCT. The sensitivity, specificity, positive predictive value, and negative predictive value of MDCT were 100%, 85.7%, 93.5%, and 100%, respectively. Sixteen, nine, and four patients were found to have mild, moderate, and severe AR on TTE, respectively. The corresponding ROA by MDCT were 3.25 +/- 1.04 mm(2), 4.16 +/- 1.19 mm(2), and 11.30 +/- 6.13 mm(2), respectively. MDCT data acquired for the coronary artery evaluation can be used for the detection of aortic regurgitation with high diagnostic accuracy without additional scanning or radiation and can support appropriate referral for TTE.

Diagnostic Performance of 64-Channel Multidetector CT in the Evaluation of Gastric Cancer: Differentiation of Mucosal Cancer (T1a) from Submucosal Involvement (T1b and T2)

To identify the computed tomographic (CT) findings in T1a and T1b cancers and to evaluate the diagnostic performance of multidetector CT with two-dimensional multiplanar reconstruction and three-dimensional CT gastrography for evaluating the preoperative staging of gastric cancer, with special emphasis on the differentiation between T1a and T1b cancers. The institutional review board approved this retrospective study. A total of 148 patients with gastric cancer (64 T1a, 36 T1b, and 48 T2) were included. To identify CT findings in T1a and T1b cancers, two radiologists in consensus interpreted the preoperative CT images of the 100 T1 cancers to determine the morphologic characteristics to be used as staging criteria on CT images. By using univariate and multiple logistic regression analyses, the diagnostic criteria to identify T1a and T1b cancers were developed. To evaluate the diagnostic performance of multidetector CT by using the criteria, two other blinded reviewers independently analyzed the CT images of all 148 patients to assess the T (classifying the depth of invasion as T1a, T1b, or T2) and N (classifying nodal involvement as absent or present) stage. CT staging was correlated with histopathologic results. Interobserver agreement was assessed by using weighted kappa statistics. The detectability of T1b cancer was significantly higher than that of T1a cancer (P = .003). T1b cancer showed well-enhancing mucosal thickening more frequently than did T1a cancer (P = .002). By using the modified CT criteria, the overall accuracy values of T staging and N staging were 64.9% (96/148) and 79.1% (117/148) for reviewer 1 and 63.5% (94/148) and 83.8% (124/148) for reviewer 2, respectively. Weighted kappa values of T and N staging were 0.795 and 0.641, respectively. On multidetector CT images, T1a cancer shows different imaging features than does T1b cancer regarding enhancing characteristics and detectability. Multidetector CT provides relatively valuable results of T and N staging, including differentiation between T1a, T1b, and T2 gastric cancers.

TU‐D‐204B‐01: Scatter Correction for On‐Board Cone‐Beam CT in Radiation Therapy Using Planning MDCT Images

Purpose: The applications of cone‐beam CT (CBCT) imaging in radiation therapy are greatly hampered by the poor image quality mainly due to scatter artifacts. The current use of CBCT is only limited to treatment setup, and an optimal scatter correction solution still remains unclear. Here, we propose a new scatter correction method for CBCT based on the current workflow of radiation therapy. Methods and Materials: With much smaller inherent scatter signals, diagnostic multi‐detector CT (MDCT) provides more accurate CT images and is routinely used for radiation treatment planning. Using the MDCT image as the “free” prior information, we first estimate the primary projections in the CBCT scan via forward projection on MDCT data. Since the deviation between patient geometries in the CBCT and the registered MDCT data only leads to high‐frequency primary projection differences and scatter has dominant low‐frequency components, CBCT scatter signals are accurately estimated by low‐pass filtering and effectively corrected for after subtraction. The proposed method is evaluated using two phantom studies on tabletop systems. Results: On the Catphan©600 phantom, the reconstruction error is reduced from 348 HU to 4 HU around the phantom center. In the selected regions of interest, the average image contrast is increased by a factor of 3.3. This contrast increase improves low‐contrast detectability, as seen in the pelvis phantom study. Besides a significant improvement of image quality, a 25 HU object, which is otherwise buried in the scatter artifacts, can be clearly identified after the proposed scatter correction. Compared to the kernel‐based method, our approach shows an improved performance. Conclusions: Effective scatter correction is achieved on CBCT using our MDCT‐based approach. The increased accuracy of CBCT imaging substantially facilitates CBCT‐based clinical applications, such as tumor delineation and dose calculation. As such, the proposed method will be very attractive in current radiation therapy.

Percutaneous sacroplasty with the use of C-arm flat-panel detector CT: technical feasibility and clinical outcome

Sacroplasty for sacral insufficiency fractures (SIFs) has been performed mostly under computed tomography (CT) or fluoroscopy guidance. The purposes of this study are to describe technical tips and clinical outcomes of sacroplasty under C-arm flat panel detector CT (C-arm CT) guidance, and to compare the cement distributions shown on C-arm CT with those on multi-detector CT (MDCT). This study consisted of patients who underwent sacroplasty for SIF using C-arm CT from May 2006 to May 2009. Technical success was assessed in terms of cement filling and leakage. Clinical outcome was assessed at short-term (less than 1month) and long-term (more than 1month) follow-up using a four-grade patient satisfaction scale: poor, fair, good, and excellent. After sacroplasty, all patients underwent MDCT and three radiologists compared MDCT images with C-arm CT images in consensus, focusing on the cement distribution and cement leakage. Sacroplasties were performed on both sacral alae in all 8 patients (male:female = 2:6, mean age = 76.9, range = 63-82). The technical success rate was 100%. At short-term follow up, 6 patients (87.5%) reported significant improvement. Five patients (62.5%) were available for long-term follow-up and all 5 patients reported a reduced pain and an improved ability to ambulate. Using MDCT as the standard of reference, the cement distribution was visualized equally well by C-arm CT. Sacroplasty under C-arm CT showed excellent technical success and good clinical outcome. There was an excellent correlation between C-arm CT and MDCT in evaluating cement distribution and cement leakage.

Update on Multidetector Computed Tomography Imaging of the Airways

Recent advances in multidetector computed tomography (MDCT) technology have transformed the imaging evaluation of the trachea and bronchi. Multiplanar 2-dimensional and 3-dimensional volume reconstruction techniques, including external rendering and virtual bronchoscopy, can be generated in mere minutes, thereby complementing conventional axial CT imaging in the depiction of various central airway disease processes including airway stenoses, central airway neoplasms, and congenital airway disorders. Paired inspiratory and dynamic expiratory MDCT imaging, along with newer cine CT imaging methods, have enhanced the assessment of tracheobronchomalacia in both adults and the pediatric population. In addition, MDCT imaging plays an essential complementary role to conventional bronchoscopy, facilitating planning and guidance of bronchoscopic interventions, and providing a noninvasive method for postprocedural surveillance.

Aberrant right bronchial artery originating from right coronary artery – MDCT angiography findings

Aberrant bronchial arteries are rarely seen and may originate from various vascular structures. In our case, a 48-year-old man with recurrent chest pain underwent multidetector CT (MDCT) coronary angiography. MDCT images demonstrated an aberrant right bronchial artery originating from the right coronary artery. To our knowledge, this is the first case report of an aberrant right bronchial artery originating from the right coronary artery.

Cardiopatías congénitas en el adulto. Aportaciones de la tomografía computarizada multidetector

Congenital heart disease in adults: The contribution of multidetector CT Abstract Congenital heart disease is relatively common among adults. Patients' conditions have generally been diagnosed previously and imaging tests are requested for follow-up or for complications of the anomaly or of its surgical correction. Classically, these patients were studied with echocardiography and cardiac catheteriza- tion, but multidetector CT and magnetic resonance imaging have changed the approach because these techniques show the anatomy of heart defects and their correction very clearly.

Facet Orientation and Tropism

Cross-sectional study. To evaluate the association between lumbar spine facet joint orientation, facet joint tropism, and spondylolysis identified by multidetector computed tomography (CT) in the community-based Framingham Heart Study. The association between lumbar spondylolysis and facet orientation and tropism remains unclear. This study was an ancillary project to the Framingham Heart Study. Three thousand five hundred twenty-nine participants of the Framingham Heart Study aged 40 to 80 years underwent multidetector CT imaging to assess aortic calcification. One hundred ninety-one subjects were included in this ancillary study. Facet joint features and spondylolysis were evaluated on CT scans. The final analyzed sample included 104 men with mean age 51.90+/-11.25 years and 84 women with mean age 53.61+/-10.20 years. The association between spondylolysis and facet orientation and tropism was examined using univariate and multivariate analyses. Spondylolysis was prevalent in 11.5% of the total population. chi2 test demonstrated a significant sex difference in prevalence of spondylolysis (P=0.0154), with almost 3 times higher prevalence among men. There was no statistically significant difference in facet orientation and continuous facet tropism between individuals with and without spondylolysis at the L5 level (P=0.49 to 0.91). After adjustment for age, sex, and body mass index, no significant association between the occurrence of spondylolysis and facet orientation and tropism was found. In the studied sample the prevalence of facet joint osteoarthritis was significantly higher in individuals with spondylolysis than in those without spondylolysis at both sides of L4-L5 spinal level (P=0.044 at the right side and P=0.003 at the left side) and at left side of L5-S1 level (P=0.038). We did not find an association between facet orientation, facet tropism, and spondylolysis. One of the possible explanations for this is that the high prevalence of facet joint osteoarthritis in individuals with spondylolysis in the studied sample might have led to diminished differences in facet orientation.

A method to analyse observer disagreement in visual grading studies: example of assessed image quality in paediatric cerebral multidetector CT images

The purpose was to demonstrate a non-parametric statistical method that can identify and explain the components of observer disagreement in terms of systematic disagreement as well as additional individual variability, in visual grading studies. As an example, the method was applied to a study where the effect of reduced tube current on diagnostic image quality in paediatric cerebral multidetector CT (MDCT) images was investigated. Quantum noise, representing dose reductions equivalent to steps of 20 mA, was artificially added to the raw data of 25 retrospectively selected paediatric cerebral MDCT examinations. Three radiologists, blindly and randomly, assessed the resulting images from two different levels of the brain with regard to the reproduction of high- and low-contrast structures and overall image quality. Images from three patients were assessed twice for the analysis of intra-observer disagreement. The intra-observer disagreement in test-retest assessments could mainly be explained by a systematic change towards lower image quality the second time the image was reviewed. The inter-observer comparisons showed that the paediatric radiologist was more critical of the overall image quality, while the neuroradiologists were more critical of the reproduction of the basal ganglia. Differences between the radiologists regarding the extent to which they used the whole classification scale were also found. The statistical method used was able to identify and separately measure a presence of bias apart from additional individual variability within and between the radiologists which is, at the time of writing, not attainable by any other statistical approach suitable for paired, ordinal data.

Comparison of Standard-Dose and Reduced-Dose Expiratory MDCT Techniques for Assessment of Tracheomalacia in Children

The aim of this study was to assess the effects of radiation dose reduction on the assessment of the tracheal lumen on expiratory multidetector computed tomographic (MDCT) images of pediatric patients referred for evaluation for tracheomalacia (TM). The hospital information system was used to retrospectively identify 20 standard-dose and 20 reduced-dose paired inspiratory and expiratory MDCT studies performed for the evaluation of suspected TM in pediatric patients (aged <or= 18 years). The reduced-dose technique used a 50% reduction of the tube current for the expiratory portion of the study compared to the standard-dose technique. Two experienced pediatric radiologists, who were blinded to the tube current of the study, reported their levels of confidence for measuring the tracheal lumen using a four-point scale ranging from zero (no confidence) to three (highest level of confidence). The difference in confidence level between the two groups of studies was analyzed using the Mann-Whitney U test. The percentage of radiation dose reduction using the reduced-dose technique in comparison to the standard-dose technique was estimated using anthropomorphic thorax phantoms. The presence or absence of TM (>or=50% expiratory reduction in tracheal cross-sectional luminal area) on MDCT imaging was compared to bronchoscopic results for the subset of 32 patients who underwent both procedures. A high level of confidence was reported for measuring the tracheal lumen on MDCT imaging for both standard-dose (median, 3.0) and reduced-dose (median, 3.0) expiratory sequences (P = .80). The total radiation dose of the paired inspiratory-expiratory computed tomographic (CT) exam was decreased by 23% with the reduced-dose technique. TM was diagnosed by CT imaging in seven patients who underwent standard-dose and six patients who underwent reduced-dose paired inspiratory and expiratory MDCT studies. CT results for the presence or absence of TM were concordant with the results of bronchoscopy in all 32 patients who underwent both procedures. The radiation dose of paired inspiratory-expiratory CT imaging can be reduced by 23% while maintaining similar diagnostic confidence for assessment of the tracheal lumen compared to a standard-dose technique in pediatric patients. Thus, a reduced-dose technique is recommended for evaluating TM in children.

Heterogeneous Microinfarcts Caused by Coronary Microemboli: Evaluation with Multidetector CT and MR Imaging in a Swine Model

To directly compare the sensitivity of 64-section multidetector computed tomography (CT) with that of 1.5-T magnetic resonance (MR) imaging in the depiction and measurement of heterogeneous 7-8-week-old microinfarcts and the quantification of regional left ventricular (LV) function and perfusion in the territory of coronary intervention in a swine model. Approval was obtained from the institutional animal committee. An x-ray/MR system was used to catheterize the left anterior descending (LAD) coronary artery with x-ray guidance and to delineate the perfusion territory. The vessel was selectively microembolized in six pigs with small-diameter embolic material (40-120 microm, 250000 count). At 7-8 weeks after microembolization, multidetector CT and MR imaging were used to assess LV function, first-pass perfusion, and delayed contrast enhancement in remote myocardium and microinfarct scars. Histochemical staining with triphenyltetrazolium chloride (TTC) was used to confirm and quantify heterogeneous microinfarct scars. The two-tailed Wilcoxon signed rank test was used to detect differences between modalities and myocardial regions. The LAD territory was 32.4% +/- 3.8(stadard error of the mean) of the LV mass. Multidetector CT and MR imaging have similar sensitivity in the detection of regional and global LV dysfunction and extent of microinfarct. The mean LV end-diastolic volume, end-systolic volume, and ejection fraction were 93 mL +/- 8, 46 mL +/- 4, and 50% +/- 3, respectively, on multidetector CT images and 92 mL +/- 8, 48 mL +/- 5, and 48% +/- 3, respectively, on MR images (P > or = .05). The extent of heterogeneous microinfarct was not significantly different between multidetector CT (6.3% +/- 0.8 of the LV mass), MR imaging (6.6% +/- 0.5 of the LV mass), and TTC staining (7.0% +/- 0.6 of the LV mass). First-pass multidetector CT and MR imaging demonstrated significant regional differences (P < .05) in time to peak between the heterogeneous microinfarct and remote myocardium (17.0 seconds +/- 0.3 and 12.4 seconds +/- 0.6, respectively, for multidetector CT and 17.2 seconds +/- 0.8 and 12.5 seconds +/- 1.0, respectively, for MR imaging). Modern multidetector CT and MR imaging are sensitive modalities with which to depict heterogeneous microinfarcts and determine regional LV dysfunction and decreased perfusion in the territory of intervention. (c) RSNA, 2010.

64-Slice MDCT imaging of endocardial cushion defect associated with other cardiac and extracardiac abnormalities

Electrocardiographic-gated 64-slice multidetector computed tomography (MDCT) was performed on a 30-year-old man who presented with a complete endocardial cushion defect (ECD) and severe pulmonary hypertension diagnosed when he was 3 years old. Multiplanar reconstruction image showed the common atrium without an atrial septum, a large ventricular septum defect, and a small right ventricle due to a complete atrioventricular canal defect. Three-dimensional CT volume-rending imaging showed a patent ductus arteriosus, dilation of the ascending aorta, and an anomalous-origin right coronary artery. This patient also had heterotaxy syndrome with polysplenia and azygos continuation. MDCT proved to be a good noninvasive imaging method for the evaluation of ECD associated with cardiac as well as extracardiac abnormalities.

MDCT Imaging Findings of Extramedullary Granulocytic Sarcoma of the Heart

Granulocytic sarcoma, also known as chloroma, is an uncommon tumor typically seen in patients with acute myelogenous leukemia (AML). Extramedullary cardiac involvement of granulocytic sarcoma is rare and there is a paucity of information regarding its multidetector computed tomography (MDCT) imaging appearance. We present a case of extramedullary granulocytic sarcoma of the heart detected on MDCT in a young adult male with AML. An understanding of how extramedullary granulocytic sarcoma of the heart appears on MDCT may decrease or prevent delays in diagnosing this uncommon, although important, complication from AML.

Multidetector Computed Tomography Images of Right Aortic Arch and a Left Subclavian Artery Arising From a Kommerell Diverticulum

![Figure][1] A 49-year-old man was incidentally found to have a right-sided descending thoracic aorta and multidetector computed tomography was performed. There was a right aortic arch with separate arch branches arising in the following order: left common carotid artery (Lt.CCA), right

Reperfusion injury components and manifestations determined by cardiovascular MR and MDCT imaging

Advances in magnetic resonance (MR) and computed tomography (CT) imaging have improved visualization of acute and scar infarct. Over the past decade, there have been and continues to be many significant technical advancements in cardiac MR and multi-detector computed tomography (MDCT) technologies. The strength of MR imaging relies on a variety of pulse sequences and the ability to noninvasively provide information on myocardial structure, function and perfusion in a single imaging session. The recent technical developments may also allow CT technologies to rise to the forefront for evaluating clinical ischemic heart disease. Components of reperfusion injury including myocardial edema, hemorrhage, calcium deposition and microvascular obstruction (MO) have been demonstrated using MR and CT technologies. MR imaging can be used serially and noninvasively in assessing acute and chronic consequences of reperfusion injury because there is no radiation exposure or administration of radioactive materials. MDCT is better suited for assessing coronary artery stenosis and as an alternative technique for assessing viability in patients where MR imaging is contraindicated. Changes in left ventricular (LV) volumes and function measured on cine MR are directly related to infarct size measured on delayed contrast enhanced images. Recent MR studies found that transmural infarct, MO and peri-infarct zone are excellent predictors of poor post-infarct recovery and mortality. Recent MR studies provided ample evidence that growth factor genes and stem cells delivered locally have beneficial effects on myocardial viability, perfusion and function. The significance of deposited calcium in acute infarct detected on MDCT requires further studies. Cardiac MR and MDCT imaging have the potential for assessing reperfusion injury components and manifestations.

Correlation of dynamic multidetector CT findings with pathological grades in hepatocellular carcinoma

Our objective was to examine whether different vascularization patterns seen during three phases of dynamic multidetector computed tomography (MDCT) of the liver correlated with the histopathological differentiation findings of hepatocellular carcinoma (HCC) in chronic liver disease patients. Dynamic MDCT images from 46 patients (38 males and 8 females; ages between 1 and 90 years; mean age, 53) pathologically diagnosed with HCC were retrospectively evaluated. Lesions were divided into three groups according to MDCT enhancement patterns. Pathologically determined differentiation degrees were compared with contrast enhancement patterns in the hepatic arterial, portal venous, and hepatic venous phases. Lesion characterization was as follows: Type 1 (6 patients), hypoattenuating in the hepatic arterial and hepatic venous phases and hyperattenuating in the portal venous phase; Type 2 (10 patients), hypoattenuating in all phases; and Type 3 (30 patients), hyperattenuating in the hepatic arterial and portal venous phases and hypoattenuating in the hepatic venous phase. Patients were pathologically classified as having either well-differentiated (n=32) or poorly differentiated HCC (n=14). All patients with poorly differentiated HCC had a Type 3 enhancement pattern. All patients with Type 1 and 2 enhancement patterns had well-differentiated HCC. There was a significant correlation between pathological differentiation degrees and radiological enhancement (P = 0.003). Dynamic MDCT revealed that poorly differentiated HCC patients all had hypervascular enhancement patterns, and hypovascular- type enhancement was present in all patients with well-differentiated HCC. Imaging patterns of dynamic MDCT scanning in HCC patients may be helpful for follow-up examinations and for determining clinical prognosis.

Evaluation of Reperfused Myocardial Infarction by Low-Dose Multidetector Computed Tomography Using Prospective Electrocardiography (ECG)-Triggering: Comparison with Magnetic Resonance Imaging

PurposeTo evaluate the potential of prospective electrocardiography (ECG)-gated 64-slice multidetector computed tomography (MDCT) for evaluation of myocardial enhancement, infarct size, and stent patency after percutaneous coronary intervention (PCI) with stenting in patients with myocardial infarction.Materials and MethodsSeventeen patients who were admitted with acute myocardial infarction were examined with prospective ECG-gated 64-slice cardiac MDCT and magnetic resonance (MR) imaging after reperfusion using PCI with stenting. Cardiac MDCT was performed with two different phases: arterial and delayed phases. We evaluated the stent patency on the arterial phase, and nonviable myocardium on the delayed phase of computed tomography (CT) image, and they were compared with the results from the delayed MR images.ResultsTotal mean radiation dose was 7.7 ± 0.5 mSv on the two phases of CT images. All patients except one showed good patency of the stent at the culprit lesion on the arterial phase CT images. All patients had hyperenhanced area on the delayed phase CT images, which correlated well with those on the delayed phase MR images, with a mean difference of 1.6% (20 ± 10% vs. 22 ± 10%, r = 0.935, p = 0.10). Delayed MR images had a better contrast-to-noise ratio (CNR) than delayed CT images (27.1 ± 17.8% vs. 4.3 ± 2.1%, p < 0.001).ConclusionProspective ECG-gated 64-slice MDCT provides the potential to evaluate myocardial viability on delayed phase as well as for stent patency on arterial phase with an acceptable radiation dose after PCI with stenting in patients with myocardial infarction.