MDCT In Patients Research Articles

Low-Dose MDCT of Patients With Spinal Instrumentation Using Sparse Sampling: Impact on Metal Artifacts.

OBJECTIVE. The purpose of our study was to evaluate simulated sparse-sampled MDCT combined with statistical iterative reconstruction (SIR) for low-dose imaging of patients with spinal instrumentation. MATERIALS AND METHODS. Thirty-eight patients with implanted hardware after spinal instrumentation (24 patients with short- or long-term instrumentation-related complications [i.e., adjacent segment disease, screw loosening or implant failure, or postoperative hematoma or seroma] and 14 control subjects with no complications) underwent MDCT. Scans were simulated as if they were performed with 50% (P50), 25% (P25), 10% (P10), and 5% (P5) of the projections of the original acquisition using an in-house-developed SIR algorithm for advanced image reconstructions. Two readers performed qualitative image evaluations of overall image quality and artifacts, image contrast, inspection of the spinal canal, and diagnostic confidence (1 = high, 2 = medium, and 3 = low confidence). RESULTS. Although overall image quality decreased and artifacts increased with reductions in the number of projections, all complications were detected by both readers when 100% of the projections of the original acquisition (P100), P50, and P25 imaging data were used. For P25 data, diagnostic confidence was still high (mean score ± SD: reader 1, 1.2 ± 0.4; reader 2, 1.3 ± 0.5), and interreader agreement was substantial to almost perfect (weighted Cohen κ = 0.787-0.855). The mean volumetric CT dose index was 3.2 mGy for P25 data in comparison with 12.6 mGy for the original acquisition (P100 data). CONCLUSION. The use of sparse sampling and SIR for low-dose MDCT in patients with spinal instrumentation facilitated considerable reductions in radiation exposure. The use of P25 data with SIR resulted in no missed complications related to spinal instrumentation and allowed high diagnostic confidence, so using only 25% of the projections is probably enough for accurate and confident diagnostic detection of major instrumentation-related complications.

Evaluation of Anomalous Coronary Arteries on 64 Slice Multidetector Computerized Tomographic Angiography

Introduction: Anomalous Coronary arteries is a well-known congenital entity with variable effects. The majority of such patients are asymptomatic but some can have adverse effects like ischemia and arrhythmia. Its association with Sudden Cardiac Death in young is established.
 Objective: To determine the frequency of ACA on MDCT in patients referred for coronary artery disease assessment and to determine the origin, course, and morphological variable of SCD of ACA on MDCT.
 Materials and Methods: The study was done in the Department of Cardiovascular Imaging at the Punjab Institute of Cardiology. A retrospective data of patients undergoing CTA for CAD between a period of Jan 2009 and Dec 2017 were analyzed for the presence of Anomalous Coronary Artery (ACA). All patients having anomalous origin from opposite coronary cusp and its course were included. The patients with myocardial bridging and coronary artery fistula were excluded.
 Results: Total patients analyzed with MDCT for CAD and graft assessment between Jan 2009 and December 2017 were 8028. Fifty-three patients were excluded because of poor image quality. Among these ACA were found in 166 (2.08%). Gender distributions were 126 (75.9%) males and 40 (24.09%) females, the mean age in years was 49.31 ± 13.23. The most common ACA was Right coronary artery 83 followed by Left Circumflex 44 (26.50%), Left Anterior Descending Artery 22 (13.25%), and Left Main Stem 17 (10.24%) respectively. Fifty-three (31.92%) patients had previously unknown ACA and were found to have ACA on MDCT and 82 (49.39%) patients were referred following ICA for the confirmation of ACA. The Inter-arterial course was predominant in RCA and Left Coronary Artery 97% and 77% respectively. A retro artic course was predominant (100%) in LCx. Seven patients had associated cyanotic heart disease with ACA. Two patients(one LAD and one RCA) had origin from the Main Pulmonary artery.
 Conclusion: MDCT is the imaging modality of choice for the evaluation of ACA. It can identify the origin of ACA from opposite coronary cusp and defines the malignant course of ACA for the potential risk of sudden cardiac death.

MDCT in the Setting of Suspected Colonic Diverticulitis: Prevalence and Diagnostic Yield for Diverticulitis and Alternative Diagnoses.

OBJECTIVE. The purpose of this study was to determine the prevalence and demographic distribution of colonic diverticulitis (CD) and alternative diagnoses (AD), as well as the diagnostic accuracy of MDCT in patients with suspected CD. MATERIALS AND METHODS. This study retrospectively included 1069 patients (560 women) undergoing MDCT for the evaluation of suspected CD. The prevalence of CD and AD was determined and the diagnostic accuracy of MDCT calculated. The final clinical diagnosis derived from the discharge report served as the standard of reference. Prevalence of diagnoses by age, sex, and admission status were compared using Cochran-Armitage, chi-square, and Fisher exact tests. RESULTS. Prevalence of CD was 52.5% (561/1069) and of AD was 39.9% (427/1069). In the remaining 7.6% (81/1069) no final clinical diagnosis was established. The most frequent AD were appendicitis (12.6%, 54/427), infectious colitis (10.5%, 45/427), infectious gastroenteritis (8.2%, 35/427), urolithiasis (6.1%, 26/427), and pyelonephritis (4.9%, 21/427). The prevalence of diverticulitis and AD varied statistically significantly according to both age (p < 0.001) and admission status (p < 0.001). Also, the prevalence of the 10 most frequent specific AD varied statistically significantly according to sex (p = 0.022). CT had a sensitivity and specificity of 99.1% and 99.8% for diagnosing CD and 92.7% and 98.8% for AD, respectively. CONCLUSION. In about 40% of patients with suspected diverticulitis a broad spectrum of AD is causative for symptoms. MDCT provides high diagnostic accuracy in the diagnosis of diverticulitis and AD. The prevalence of diagnoses is related to admission status and demographic data; in particular age-related AD have to be considered in patients with clinically suspected diverticulitis.

MDCT findings predicting post-operative residual tumor and survival in patients with pancreatic cancer.

To predict residual tumor (R) classification and overall survival (OS) on preoperative MDCT in patients who underwent first-line surgery for pancreatic ductal adenocarcinoma (PDA). Three hundred sixteen patients with PDA who underwent MDCT and first-line surgery were included. Patients were divided into a test (n = 216) and a validation group (n = 100). The R classification was categorized into R0 (no residual tumor) and R1/R2 (microscopic/macroscopic residual tumor). We assessed the correlation between the MDCT findings and the R classification. For survival analysis, we used the Kaplan-Meier estimation and Cox proportional hazard model to determine the prognostic factors for OS. Validation of the prediction models for the R classification and OS was performed using C statistics and calibration plot. Peritumoral fat stranding (odds ratio (OR) 3.826), suspicious distant metastasis (OR 2.916), portal vein involvement (OR 2.795), and tumor size (OR 1.045) were independent predictors for residual tumor (p < .05). On survival analysis, common hepatic artery involvement (hazard ratio (HR) 5.656), R1/R2 stage (HR 2.476), and N1 stage (HR 1.745) were predictors of poor OS (p < .05). C statistics for prediction models for R classification and OS were 0.816 and 0.662, respectively. Calibration plots showed good predictive performance in a high probability of the R1/R2 stage or poor OS. Preoperative MDCT is useful for predicting the R classification using the tumor size, peritumoral fat stranding, portal vein involvement, and suspicious distant metastasis, as well as for anticipating poor OS using the N1 stage, common hepatic artery involvement, and R1/R2 stage in patients with PDA. • Thorough assessment of the involvement of common hepatic artery or portal vein and peritumoral fat stranding is warranted for predicting prognosis in patients with pancreatic ductal adenocarcinoma. • Not only encasement but also abutment of common hepatic artery or portal vein by tumor predicts poor prognosis after upfront surgery. • If residual tumor or poor overall survival is anticipated on preoperative MDCT, neoadjuvant treatment can be performed.

Deep learning and radiomics: the utility of Google TensorFlow™ Inception in classifying clear cell renal cell carcinoma and oncocytoma on multiphasic CT.

Currently, all solid enhancing renal masses without microscopic fat are considered malignant until proven otherwise and there is substantial overlap in the imaging findings of benign and malignant renal masses, particularly between clear cell RCC (ccRCC) and benign oncocytoma (ONC). Radiomics has attracted increased attention for its utility in pre-operative work-up on routine clinical images. Radiomics based approaches have converted medical images into mineable data and identified prognostic imaging signatures that machine learning algorithms can use to construct predictive models by learning the decision boundaries of the underlying data distribution. The TensorFlow™ framework from Google is a state-of-the-art open-source software library that can be used for training deep learning neural networks for performing machine learning tasks. The purpose of this study was to investigate the diagnostic value and feasibility of a deep learning-based renal lesion classifier using open-source Google TensorFlow™ Inception in differentiating ccRCC from ONC on routine four-phase MDCT in patients with pathologically confirmed renal masses. With institutional review board approval for this 1996 Health Insurance Portability and Accountability Act compliant retrospective study and a waiver of informed consent, we queried our institution's pathology, clinical, and radiology databases for histologically proven cases of ccRCC and ONC obtained between January 2000 and January 2016 scanned with a an intravenous contrast-enhanced four-phase renal mass protocol (unenhanced (UN), corticomedullary (CM), nephrographic (NP), and excretory (EX) phases). To extract features to be used for the machine learning model, the entire renal mass was contoured in the axial plane in each of the four phases, resulting in a 3D volume of interest (VOI) representative of the entire renal mass. We investigated thirteen different approaches to convert the acquired VOI data into a set of images that adequately represented each tumor which was used to train the final layer of the neural network model. Training was performed over 4000 iterations. In each iteration, 90% of the data were designated as training data and the remaining 10% served as validation data and a leave-one-out cross-validation scheme was implemented. Accuracy, sensitivity, specificity, positive (PPV) and negative predictive (NPV) values, and CIs were calculated for the classification of the thirteen processing modes. We analyzed 179 consecutive patients with 179 lesions (128 ccRCC and 51 ONC). The ccRCC cohort had a mean size of 3.8cm (range 0.8-14.6cm) and the ONC cohort had a mean lesion size of 3.9cm (range 1.0-13.1cm). The highest specificity and PPV (52.9% and 80.3%, respectively) were achieved in the EX phase when we analyzed the single mid-slice of the tumor in the axial, coronal and sagittal plane, and when we increased the number of mid-slices of the tumor to three, with an accuracy of 75.4%, which also increased the sensitivity to 88.3% and the PPV to 79.6%. Using the entire tumor volume also showed that classification performance was best in the EX phase with an accuracy of 74.4%, a sensitivity of 85.8% and a PPV of 80.1%. When the entire tumor volume, plus mid-slices from all phases and all planes presented as tiled images, were submitted to the final layer of the neural network we achieved a PPV of 82.5%. The best classification result was obtained in the EX phase among the thirteen classification methods tested. Our proof of concept study is the first step towards understanding the utility of machine learning in the differentiation of ccRCC from ONC on routine CT images. We hope this could lead to future investigation into the development of a multivariate machine learning model which may augment our ability to accurately predict renal lesion histology on imaging.

Evaluation of Left Atrial Anatomy and Function using Multidetector Computed Tomography in Patients Undergoing Catheter Ablation for Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Сatheter ablation (CA) of arrhythmogenic foci is supposed to be an established treatment option for symptomatic patients with AF, refractory to antiarrhythmic therapy. Pre-procedural imaging is indispensable for the assessment of left atrium, pulmonary veins and adjacent anatomy, and facilitates selection of the ablation strategy to achieve an optimal result and minimize the risk of complications.Purpose: to evaluate the role of contrast-enhanced MDCT in patients with AF; also to present the prospects for further development of this method according to the systemic review of world research data.Materials and methods. 140 free access articles requested as “MDCT left atrium”, “MDCT pulmonary veins”, “MDCT atrial appendage” from 01.2009 until 01.2017 were analyzed in PubMed, as well as a number of Russianlanguage articles in eLibrary.Results.This literature review reports and systematizes available data on epidemiology and mechanisms of AF, represents current classification. In addition were analyzed advantages of MDCT over other methods of visualization while planning the CA and follow-up.Conclusion.MDCT is precise, effective and accessible option, which satisfies visualization requirements during the preparation for CA. Moreover, using MDCT in combination with electro-mapping systems increases safety and effectiveness of the procedure. In postoperative period MDCT can be used for complications diagnostic and results assessment.

Are novel non-invasive imaging techniques needed in patients with suspected prosthetic heart valve endocarditis? A systematic review and meta-analysis.

ObjectivesMultimodal non-invasive imaging plays a key role in establishing a diagnosis of PHV endocarditis. The objective of this study was to provide a systematic review of the literature and meta-analysis of the diagnostic accuracy of TTE, TEE, and MDCT in patients with (suspected) PHV endocarditis.MethodsStudies published between 1985 and 2013 were identified via search and cross-reference of PubMed/Embase databases. Studies were included if (1) they reported on the non-invasive index tests TTE, TEE, or MDCT; (2) data was provided on PHV endocarditis as the condition of interest; and (3) imaging results were verified against either surgical inspection/autopsy or clinical follow-up reference standards, thereby enabling the extraction of 2-by-2 tables.ResultsTwenty articles (including 496 patients) met the inclusion criteria for PHV endocarditis. TTE, TEE, and MDCT + TEE had a pooled sensitivity/specificity for vegetations of 29/100 %; 82/95 %, and 88/94 %, respectively. The pooled sensitivity/specificity of TTE, TEE, and MDCT + TEE for periannular complications was 36/93 %, 86/98 %, and 100/94 %, respectively.ConclusionsTEE showed good sensitivity and specificity for establishing a diagnosis of PHV endocarditis. Although MDCT data are limited, this review showed that MDCT in addition to TEE may improve sensitivity in detecting life-threatening periannular complications.Key Points• Multimodal imaging is an important ingredient of diagnostic workup for PHV endocarditis.• Transthoracic and transesophageal echography may miss life-threatening periannular complications.• MDCT can improve sensitivity for the detection of life-threatening periannular complications.Electronic supplementary materialThe online version of this article (doi:10.1007/s00330-015-3605-7) contains supplementary material, which is available to authorized users.

Value of gadoxetic acid-enhanced and diffusion-weighted MR imaging in evaluation of hepatocellular carcinomas with atypical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease

ObjectiveThe purpose of this study was to investigate the value of enhancement kinetics and ancillary imaging findings on gadoxetic acid-enhanced and diffusion-weighted (DW) MR imaging for diagnosing hepatocellular carcinomas (HCCs) without the typical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease. Materials and methodsEighty-two surgically confirmed HCCs without the typical enhancement pattern (hypervascular in the arterial phase, followed by washout on the portal or equilibrium phases) on triple-phase MDCT were enrolled in this study. The patients were classified into four categories based on the CT density pattern of arterial and equilibrium phases (isodense–isodense, hypodense–hypodense, isodense–hypodense, and hyperdense–isodense) compared to liver parenchyma. Signal intensity of HCCs on T2-weighted images (T2WI), arterial phase, 3min late-phase, hepatobiliary phase (HBP) and DW images with a b value of 800s/mm2 were qualitatively evaluated, and ADC values were measured. Fisher's exact test and Chi-square test were used to compare the frequency and trend of hyperintensity on T2WI, hypointensity on HBP images, hyperintensity on DW images, and histopathologic grades between groups with different CT density patterns. Kruskal–Wallis test was used to compare the ADC value between groups. ResultsThirty and 52 HCCs were categorized as hypervascular (hyperdense–isodense) and non-hypervascular HCCs (3, isodense–isodense; 37, hypodense–hypodense; 12, isodense–hypodense), respectively. Most HCCs showed hyperintensity on T2WI (77/82, 93.9%) and DW images (81/82, 98.8%) and hypointensity on HBP images (80/82, 97.6%). Thirty-eight HCCs (38/82, 46.3%) showed typical HCC enhancement pattern on dynamic MR images. There were no significant differences in the frequency and trend of signal intensity on T2WI, HBP images, DW images, and histopathologic grades with regard to the four CT density patterns (p<0.05). No significant difference in mean ADC values between groups was identified (p<0.05). ConclusionGadoxetic acid-enhanced and DW MR imaging can help diagnose HCCs with atypical enhancement patterns on multiphasic CT in patients with chronic liver disease.

Iterative reconstruction technique vs filter back projection: utility for quantitative bronchial assessment on low-dose thin-section MDCT in patients with/without chronic obstructive pulmonary disease.

The aim of this study was to evaluate the utility of the iterative reconstruction (IR) technique for quantitative bronchial assessment during low-dose computed tomography (CT) as a substitute for standard-dose CT in patients with/without chronic obstructive pulmonary disease. Fifty patients (mean age, 69.2; mean % predicted FEV1, 79.4) underwent standard-dose CT (150mAs) and low-dose CT (25mAs). Except for tube current, the imaging parameters were identical for both protocols. Standard-dose CT was reconstructed using filtered back-projection (FBP), and low-dose CT was reconstructed using IR and FBP. For quantitative bronchial assessment, the wall area percentage (WA%) of the sub-segmental bronchi and the airway luminal volume percentage (LV%) from the main bronchus to the peripheral bronchi were acquired in each dataset. The correlation and agreement of WA% and LV% between standard-dose CT and both low-dose CTs were statistically evaluated. WA% and LV% between standard-dose CT and both low-dose CTs were significant correlated (r > 0.77, p < 0.00001); however, only the LV% agreement between SD-CT and low-dose CT reconstructed with IR was moderate (concordance correlation coefficient = 0.93); the other agreement was poor (concordance correlation coefficient <0.90). Quantitative bronchial assessment via low-dose CT has potential as a substitute for standard-dose CT by using IR and airway luminal volumetry techniques. • Quantitative bronchial assessment of COPD using low-dose CT is possible. • Airway luminal volumetry with iterative reconstruction is insusceptible to dose reduction. • Filtered back-projection is susceptible to the effect of dose reduction. • Wall area percentage assessment is easily influenced by dose reduction.

Abnormal Medullary Lesions in Appendicular Skeletons Detected by Whole Body Low-Dose Multidetector CT Associated with Higher Tumor Burden and Poorer Prognosis in Patients with Myeloma

Abstract 4051 BACKGROUND:Imaging is playing an increasing role in the diagnosis, staging and treatment response monitoring of patients with multiple myeloma (MM) because of limitation of hematological parameters and uneven distribution of MM lesions in the bone marrow. Although MRI and 18F-FDG-PET/CT have been utilized for visualization of medullary and extra-medullary lesions in patients with MM, both are too time-consuming and expensive for routine clinical use. Whole body Low-dose multidetector CT (WBLD MD-CT) can provide information on the degree of myeloma cell infiltration, especially in the appendicular skeleton. This study was performed to determine the incidence and prognostic implications of abnormal medullary lesions in the appendicular skeleton detected by WBLD MD-CT in patients with monoclonal gammopathy of undetermined significance (MGUS), and asymptomatic and symptomatic MM. We also compared the various hematological parameters with the development of these abnormalities. PATIENTS AND METHODS:Between January 2008 and July 2012, WBLD MD-CT was performed in 89 patients with MM and MGUS as an initial evaluation of lytic bone lesion and medullary and extra-medullary MM lesions. CT image acquisition and analysis were as follows. WBLD MD-CT was performed in an non-enhanced manner on a 16—Salmon staging system (DS), and were 11, 26 and 37 in International Staging System (ISS), respectively. Medullary abnormalities were found in 61 of 73 patients (83.6%). Patients with symptomatic MM had significantly higher mean HU than patients with MGUS/asymptomatic MM (−5.64 vs. −69.99, p < 0.001, Fig. 1). In the symptomatic MM, laboratory variables such as albumin, hemoglobin, creatinine, beta-2-microglobulin and presence of poor cytogenetic abnormalities (del17p, IGH-FGFR3, or IGH/MAF on FISH) were not correlated with the mean HU values. Positive correlations between the mean HU value and the amount of intact immunoglobulin (Ig) with IgG and IgA subtypes were observed (correlation coefficient: 0.330 and 0.694, p = 0.049 and 0.005, respectively), but it was not observed in patients with light chain only MM (correlation coefficient: 0.133, p = 0.598). Patients with DS stage 3 showed significantly high HU values compared to those with DS stage 1 and 2 (−35.30 vs. 1.11, p < 0.001, Fig. 2) whereas the mean HU value was not significantly different between ISS 3 and 1 or 2 (p = 0.186). Patients with abnormal medullary lesions occupying >25% of boney canals had significantly poorer progression-free survival compared to those with < 25% (12.5 vs. 15.1 months, p = 0.011, Fig. 3). Moreover, patients with mean HU value >0 had significantly shorter median overall survival (40.6 months vs. not reached, p = 0.040, Fig. 4) and tended to have shorter progression-free survival (9.8 vs. 15.7 months, p = 0.106, Fig. 5) compared to those with mean HU value <0. Complete disappearance of abnormal medullary lesion did not usually achieved even after obtaining complete response, marked decrease of HU value was observed in most of the patients. CONCLUSIONS:This study indicated that medullary abnormalities in the appendicular skeleton detected by WBLD MD-CT might be associated with high tumor burden of MM independent of ISS stage and laboratory variables. In addition, it also has possible prognostic relevance in patients with newly diagnosed MM. [Display omitted] [Display omitted] [Display omitted] Disclosures:No relevant conflicts of interest to declare.

440 Role of Pre-Procedural Multidetector Cardiac CT Scan in Left Ventricular Lead Placement in Cardiac Resynchronization Therapy (CRT): A Pilot Study

Cardiac Resynchronization Therapy (CRT) has become a standard therapy in patients with refractory heart failure. Acute procedure success is determined by appropriate placement of the left ventricular lead in the coronary sinus. Coronary sinus anatomy is variable and may be affected by dilatation of cardiac chambers. The purpose of this randomized pilot study was to determine the role of pre procedural multidetector coronary sinus CT Scan and its impact on coronary sinus lead implantation success rate in patients receiving CRT. A randomized pilot study including 40 patients referred for CRT-ICD, were randomized to either MDCT guided CRT-implant group or the standard CRT implant (control group). 18 patients underwent MDCT for imaging and 3D reconstruction of the coronary sinus and tributary veins. See table 1.Tabled 1 See figure 1 This pilot feasibility study demonstrated that coronary sinus anatomy can be defined in detail using MDCT. No advantages with MDCT regarding LV lead positioning were observed. Further research is needed to determine the role of preprocedural MDCT in patients undergoing CRT-ICD implantation.

Contrast-induced nephropathy in patients with renal insufficiency undergoing contrast-enhanced MDCT

To evaluate the safety of contrast-enhanced MDCT in patients with renal impairment. We conducted a retrospective review of 938 patients with stable renal insufficiency (eGFR between 15 and 60ml/min) who underwent contrast-enhanced MDCT. SCr levels were measured at baseline and 48-72h after contrast medium administration. The incidence of contrast-induced nephropathy (CIN) in the total study population was assessed. As a control group, 1,164 separate patients with renal insufficiency who did not receive contrast medium for CT were also reviewed. The overall incidence of CIN in the patient population with renal insufficiency was 6.1%; the incidence was 4.4%, 10.5% and 10.0% for patients whose eGFR was 45-60, 30-45 and ≤30ml/min, respectively (P < 0.01). In the control group, 5.8% of patients showed an increase in the SCr level from the baseline. The increase in the SCr level showed no significant difference between the patients who received CM and those who did not (P = 0.82) CONCLUSIONS: The risk of CIN from contrast-enhanced MDCT in patients with renal insufficiency appeared to be low, and there was no significant difference in the incidence of CIN in comparison with patients who did not receive CM. • The contrast medium used for multidetector CT can induce nephropathy. • Contrast-induced nephropathy (CIN) developed in 6.1% of patients with renal insufficiency. • However, nephropathy developed in 5.8% of similar patients not receiving contrast medium. • Thus, the risk of CIN associated with MDCT appears to be low. • Special care should still be taken in patients with renal insufficiency.

Role of MDCT angiography in the preoperative evaluation of anomalous pulmonary venous connection associated with complex cardiac abnormality

To evaluate the diagnostic accuracy of MDCT in patients with APVC associated with complex cardiac abnormality. The clinical and imaging data of 39 patients with APVC confirmed by surgery were retrospectively reviewed. According to accompanied cardiac malformations, patients with APVC were classified as isolated and complex group. Using surgical findings as the reference standard, diagnostic agreement of MDCT, TTE (transthoracic echocardiography) and cardiac catheterization for detection of APVC were calculated. At surgery, 27 patients were considered as complex APVCs. MDCT correctly diagnosed APVC in all patients and the diagnostic agreements between MDCT and surgery were both 100% in isolated and complex groups. All 5 APVCs which could not be detected at cardiac catheterization were in complex group, and the diagnostic agreements were 100% and 76.2% in isolated and complex groups, respectively. At TTE, eight of nine disagreed patients were complex cases. The diagnostic agreements of TTE were 91.7% and 66.7% in isolated and complex groups, respectively. The dysmorphic pulmonary veins were identified in 11 patients by MDCT. MDCT is superior to catheterization and TTE in evaluation of APVC associated with complex cardiac defects.

Efficacy of 3D Pulmonary Vein Image Acquired Non-Enhanced MDCT in Patients with Chronic Kidney Disease without Dialysis who Underwent Atrial Fibrillation Ablation

Introduction: Precise anatomical images of pulmonary vein (PV) and left atrium (LA) are essential for atrial fibrillation (AF) ablation. These images are usually acquired with enhanced MDCT using contrast medium (CM). However, CM is relatively contra-indication for patients with chronic kidney disease (CKD). Aim: To access whether AF ablation could be possible with both only 3D-PV/LA images acquired with non-enhanced MDCT and without using CM during AF ablation procedure. Patients and Methods: We compared the AF ablation results between consecutive 15 patients with CKD who underwent AF ablation (group 1) and 30 patients without CKD who underwent AF ablation (group 2). 3D-PV/LA images were acquired with non-enhanced MDCT in group 1, and with enhanced MDCT in group 2. In group 1, AF ablation was performed mainly with fluoroscopic guidance. In group 2, AF ablation was performed with 3D electroanatomical mapping system (CARTO-XP or EnSite NavX). Results: Procedure and fluoroscopic time were relatively longer in group 1 (136±24 min vs 115±18 min, P=0.09 and 32±9 min vs 25±7 min, P=0.12, respectively). However, there were no significant differences in ablation success (100% vs 100%), complications (0% vs 0%) and AF recurrence rate (24% vs 22%) after 3 months AF ablation. Conclusions: AF ablation could be possible in patients with CKD using 3D-PV/LA image acquired with only non-enhanced MDCT without using CM.

冠動脈ＭＤＣＴの画質に影響を与える因子の検討

Although it is well known that we usually cannot acquire a high quality coronary MDCT in patients with arrhythmia or incomplete breath-hold, we sometimes also cannot obtain a high quality coronary MDCT in patients without arrhythmia or incomplete breath-hold. We studied what factors other than arrhythmia or incomplete breath-hold affected image quality. Coronary MDCT and echocardiography were performed within one month in 2145 patients, and 452 cases of arrhythmia or 102 cases of incomplete breath-hold during scanning were eliminated. The remaining 1591 patients were studied. Those patients were divided into two groups (mid-diastolic phase reconstruction (MD) group (N=1377) and end-systolic phase reconstruction (ES) group (N=214)). Age, body weight, mean heart rate (HR) during scanning, temporal resolution (TR) and left ventricular ejection fraction (LVEF) by echocardiography were estimated. Image quality (A: Excellent (3 points), B: Acceptable (2 points), C: Unacceptable (1 point)) was evaluated. The mean image quality points of the MD group (2.9±0.3) were significantly (P<0.0001) higher than the mean image quality points of the ES group (2.3±0.7), and the mean HR of the MD group (57±6 bpm) was significantly (P<0.0001) lower than that of the ES group (81±15 bpm). In the MD group, HR and TR were selected as significant factors affecting image quality by stepwise regression analysis. In the ES group, TR and HR were selected. In the ES subgroup with HR<90 bpm, TR and HR were selected; however, in the ES subgroup with HR≥90 bpm, TR and LVEF were selected. In the MD group, low HR was important for high quality coronary MDCT. In the ES subgroup with HR<90, short TR and low HR were important; however, in the ES subgroup with HR≥90 bpm, TR and LVEF were more important than HR.

Assessment of global left ventricular function and volumes with 320-row multidetector computed tomography: A comparison with 2D-echocardiography

BackgroundMultidetector computed tomography (MDCT) has been demonstrated as a feasible imaging modality for noninvasive assessment of coronary artery disease and left ventricular (LV) function. Recently, 320-row systems have become available with 16 cm anatomical coverage allowing image acquisition of the entire heart within a single heartbeat. The purpose of this study was to evaluate the accuracy of 320-row MDCT in the assessment of global LV function compared to two-dimensional (2D) echocardiography as the standard of reference. Methods and ResultsA head-to-head comparison between 320-row MDCT and 2D-echocardiography was performed in 114 patients (68 men; mean age 62 ± 13 years) who were clinically referred for MDCT coronary angiography. The entire heart was imaged in a single heartbeat, using prospective dose modulation. LV end-diastolic volumes (LVEDV) and LV end-systolic volumes (LVESV) were determined and the LV ejection fraction (LVEF) was derived. Average LVEF was 60 ± 10% (range 26-78%) as determined on MDCT, compared with 59 ± 10% (range 25-77%) on 2D-echocardiography. Evaluation of LVEF by linear regression analysis showed a good correlation between MDCT and 2D-echocardiography (r2 = .87; P < .001). Good correlations between MDCT and 2D-echocardiography were demonstrated for the assessment of LVEDV (r2 = .91; P < .001) and LVESV (r2 = .94; P < .001). At Bland-Altman analysis, mean differences (±SD) of 7.3 ± 12.1 mL (P < .05) and 1.8 ± 7.4 mL (P < .05) were observed between MDCT and 2D-echocardiography for LVEDV and LVESV, respectively. LVEF was slightly overestimated with MDCT (.9 ± 3.6%; P < .05). ConclusionsAccurate assessment of LV function and volumes is feasible with single heartbeat 320-row MDCT in patients referred for MDCT coronary angiography.

Significance of aortic atherosclerotic disease in possibly embolic stroke: 64-multidetector row computed tomography study

The usefulness of 64-multidetector row computed tomography (MDCT) for the evaluation of aortic atherosclerotic disease (AAD), a potential source of cerebral emboli, has recently been suggested. We aimed to assess the significance of AAD by using MDCT in patients who are suspected to have had embolic stroke clinically or radiologically but without evident cardioembolic source (possibly embolic stroke, or PES). From 5/2007 to 10/2007, patients who were presented with acute ischemic stroke, met predefined criteria for PES, and underwent MDCT, were found in a prospective stroke registry (PES group). High-risk AAD was defined as thrombus, ulceration, and a >or=4 mm thickness of atherosclerotic plaque in the ascending aorta and aortic arch on MDCT. For comparison, patients who were hospitalized due to non-embolic stroke (NES) during the study period and who underwent MDCT for the purpose of screening of coronary artery disease were selected (NES group). Among a total of 336 patients with acute ischemic stroke, 57 (20.0%) satisfied the criteria for PES, and MDCT was performed in 50 of these 57 patients. One-hundred six patients were selected as the NES group. The PES group had significantly higher prevalence of high-risk AAD than the NES group did (38.0 vs. 13.2%, P < 0.01). The odds ratio of high-risk AAD was 4.03 (95% confidence interval, 1.81-8.98) and this result remained significant after adjustment for risk factors of atherosclerosis. This study suggests the etiologic role of aortic atherosclerosis detected by MDCT in patients who are assumed to have had embolic stroke but without evident embolic source.

Comprehensive Evaluation of Patients with Suspected Renal Hypertension Using MDCT: From Protocol to Interpretation

The objectives of this article are to, first, describe the reasons for and details of the MDCT protocol for patients with suspected renal hypertension; second, explain the importance of comprehensive evaluation by MDCT in patients with suspected renal hypertension; third, review the image appearances of important conditions that may be encountered in the reader's clinical practice; and, fourth, explain what information should be included in a comprehensive MDCT report for patients with suspected renal hypertension. MDCT is widely used for renal artery evaluation in patients with resistant hypertension. Because the regions outside the renal arteries might also have diseases that contribute to the symptoms, a comprehensive interpretation including the renal arteries, renal parenchyma, adrenal glands, and scanned abdomen is very important. The scanning parameters should be adjusted according to the patient's body habitus because some patients with suspected renal hypertension are children or young women. In this article, cases with illustrations showing the process from protocol to interpretation are provided.

76: Analysis of Mitral Annular Geometry by MDCT in Patients with Degenerative Mitral Valve Disease

76: Analysis of Mitral Annular Geometry by MDCT in Patients with Degenerative Mitral Valve Disease

Unenhanced MDCT in Patients with Suspected Urinary Stone Disease: Do Coronal Reformations Improve Diagnostic Performance?

The objectives of our study were to assess whether coronal reformations improve the diagnostic performance of MDCT in patients with acute flank pain and suspected urinary stone disease; and to determine if performing such reformations from 3-mm-thick sections is sufficient or if it is necessary to perform reformations from thinner sections. We included 147 consecutive patients (72 women and 75 men; mean age +/- SD, 58 +/- 18.1 years) with suspected urinary stone disease who underwent unenhanced MDCT. Scans were obtained with a 4 x 1 mm collimation and were reconstructed with a section thickness of 1.25 and 3 mm. We compared the diagnostic yield of 3-mm axial sections with that of coronal reformations reconstructed from 1.25- and 3-mm axial sections. Imaging data were evaluated in random order by two radiologists. The significance of the difference between the axial sections and coronal multiplanar reformations (MPRs) was tested for the number, size, and location of uroliths and for the presence of alternative diagnoses. The time required for review by both observers was recorded. We found uroliths in 72 patients. There was no difference between 3-mm axial sections and coronal reformations from 1.25-mm sections with regard to the number of detected stones (n = 264 for both protocols), whereas coronal reformations from 3-mm sections revealed significantly fewer calcifications (n = 255, p = 0.016). Coronal reformations did not improve the localization of calcifications. Review time, however, was significantly shorter for coronal reformations than for axial sections (p = 0.001); however, coronal reformations were less sensitive than axial sections for the detection of additional findings suggestive of alternative diagnoses in 16 (30%) of 53 patients. Coronal reformations from MDCT do not improve urinary stone detection but may reduce evaluation time; however, there is the danger of missing additional findings. Coronal reformations reconstructed from thick (i.e., 3-5 mm) axial sections may result in reduced detection of small stones and should therefore be avoided.