Dynamic Multidetector-row Computed Tomography Research Articles

Impact of baseline feature tracking multi-detector row computed tomography-derived left ventricular global longitudinal strain on left ventricular functional recovery in TAVI patients

Abstract Background Advances in left ventricular (LV) analysis with dynamic multi-detector row computed tomography (MDCT) permit measurement of LV global longitudinal strain (GLS) and have shown their impact on risk stratification of patients with aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). Purpose To evaluate the influence of baseline feature tracking (FT) MDCT- derived LV GLS on LV functional recovery in severe AS patients undergoing TAVI. Methods A total of 194 patients with severe AS (50% male, 80±7 years) with dynamic MDCT data allowing LV GLS measurement with a novel FT algorithm and having complete echocardiography evaluation at baseline, at 3–6 months and at 1 year follow-up were evaluated. FT MDCT-derived LV GLS was measured at baseline and the study population was divided according to a cut-off value of MDCT LV GLS −14% (≤−14% [more preserved LV systolic function] vs. >−14% [more impaired LV systolic function]). Results Transthoracic echocardiography (TTE)-derived Left ventricular ejection fraction (LVEF) increased over time in both groups: in patients with preserved and reduced MDCT LV GLS, and reached a higher value in patients with preserved MDCT LV GLS (52±7% at baseline, 55±7% at 3–6 months, 58±7% at 1 year follow-up vs. 43±10% at baseline, 49±10% at 3–6 months, 53±11% at 1 year follow-up; p=0.016) (Figure 1). TTE-derived LV GLS also showed greater improvement for patients with preserved MDCT LV GLS (−17±3% at baseline, −18±3% at 3–6 months, −20±3% at 1 year follow-up vs. −12±3% at baseline, −15±3% at 3–6 months, −16±3% at 1 year follow-up; p=0.027) (Figure 1). Conclusions In severe AS patients treated with TAVI, LV function improves significantly at 3–6 and at 12 months' follow-up and shows superior recovery in patients with more preserved baseline MDCT LV GLS, suggesting that MDCT-derived LV GLS has an important impact on LV functional recovery after TAVI. Funding Acknowledgement Type of funding source: None

Prognostic Influence of Feature Tracking Multidetector Row Computed Tomography-Derived Left Ventricular Global Longitudinal Strain in Patients with Aortic Stenosis Treated With Transcatheter Aortic Valve Implantation

Computed tomography plays a central role in the evaluation of patients with severe aortic stenosis who underwent transcatheter aortic valve implantation (TAVI). Advances in left ventricular (LV) analysis with multidetector row computed tomography (MDCT) permit measurement of LV global longitudinal strain (GLS). The present study aimed at evaluating the association between feature tracking (FT) MDCT derived LV GLS and all-cause mortality in patients treated with TAVI. A total of 214 patients with severe aortic stenosis (51% male, 80 ± 7 years) who underwent TAVI and with dynamic MDCT data allowing LV GLS measurement with novel FT algorithm were included. LV GLS was measured at baseline and were divided according to a previously published cut-off value of LV GLS associated with all-cause mortality (≤-14% [more preserved LV systolic function] vs >-14% [more impaired LV systolic function]). Patients were followed for the occurrence of all-cause mortality. Mean FT MDCT-derived LV GLS was -12.5 ± 4%. During a median follow-up of 45 months (interquartile range: 29 to 62 months), 67 (31%) patients died. The cumulative rate of all-cause mortality for the patients with FT MDCT-derived LV GLS ≤-14% was 15% versus28% for the patients with FT MDCT-derived LV GLS >-14%, Log rank p = 0.001). FT MDCT-derived LV GLS was independently associated with all-cause mortality (hazard ratio: 0.851; 95% confidence interval: 0.772 to 0.937; p = 0.001). In conclusion, impaired FT MDCT-derived LV GLS is independently associated with all-cause mortality in patients treated with TAVI. Besides aortic valve area and calcification, FT MDCT-derived LV GLS is an important prognostic marker.

Feature tracking computed tomography-derived left ventricular global longitudinal strain in patients with aortic stenosis: a comparative analysis with echocardiographic measurements

BackgroundLeft ventricular (LV) systolic function is a prognostic factor in patients with severe aortic stenosis (AS). Multi-detector row computed tomography (MDCT) data are key in the evaluation of patients undergoing transcatheter aortic valve implantation (TAVI) and when acquired retrospectively, LV systolic function can be assessed. Novel software permits assessment of LV global longitudinal strain (GLS) from MDCT data. ObjectivesThe present study investigated the feasibility of feature tracking MDCT-derived LV GLS and its agreement with echocardiographic LV GLS in patients treated with TAVI. MethodsLV GLS was measured on transthoracic echocardiography using speckle tracking analysis and on dynamic MDCT using feature tracking technology. Agreement between the measurements of two different modalities was assessed using Bland-Altman analysis. ResultsA total of 214 patients (51% male, mean age: 80 ± 7 years) were analysed. Mean LV GLS on echocardiography was −13.91 ± 4.32%, whereas mean feature tracking MDCT-derived GLS was −12.46 ± 3.97%. Correlation of measurements between feature tracking MDCT-derived LV GLS and echocardiographic LV GLS demonstrated a large effect size (r = 0.791, p < 0.001). On Bland-Altman analysis, feature tracking MDCT-derived strain analysis underestimated LV GLS compared to echocardiography with a mean difference of 1.44% (95% limits of agreement −3.85% - 6.73%). ConclusionsAssessment of LV GLS on dynamic feature tracking MDCT data is feasible in TAVI patients. Compared to speckle tracking echocardiography, feature tracking MDCT underestimates the value of LV GLS.

P3377MDCT-derived left ventricular global longitudinal strain and left ventricular ejection fraction in patients with aortic stenosis: a comparative analysis with echocardiographic measurements

Abstract Introduction Known predictors of poor outcome in aortic valve stenosis patients include older age, significant valvular calcification, rapid hemodynamic progression and impaired left ventricular (LV) systolic function. LV global longitudinal strain (GLS) quantifies myocardial deformation and LV function and is associated with prognosis in patients with severe aortic stenosis (AS). Multi-detector row computed tomography (MDCT) data are key in the evaluation of patients undergoing transcatheter aortic valve implantation (TAVI) and when acquired throughout the entire cardiac cycle, LV systolic function can be assessed. Novel software can assess LV GLS from MDCT-data. Purpose The present study aimed at assessing the feasibility of determining novel MDCT-derived LV GLS as well as MDCT-derived LV ejection fraction (EF) and their agreement with echocardiographic LV GLS and LVEF in patients treated with TAVI. Methods LVEF and LV GLS were measured on echocardiography and dynamic MDCT using novel CT-software. Agreement between the measurements of two different modalities was assessed using Bland-Altman analysis. Results A total 214 patients (51% male, mean age: 80±7 years) were analysed retrospectively. Mean value of LV GLS on echocardiography was −14±4% whereas mean MDCT-derived GLS was −12.5±4%. Mean value of LVEF on echocardiography was 47±10% and mean MDCT-derived LVEF was 39±11%. On Bland-Altman analysis, MDCT-derived strain analysis underestimated LV GLS compared to echocardiography with a mean difference of 1.44% (95% limits of agreement −3.8 to 6.7%). LVEF was also underestimated on CT with a mean difference of 7.68% (95% limits of agreement −11.5% to −26%). Correlation of measurements between MDCT-derived LV GLS and echocardiographic LV GLS was significant (r=0.791, p&lt;0.001), as well as the correlation between MDCT-derived LVEF and echocardiographic LVEF (r=0.590, p&lt;0.001) (Figure). Conclusions Assessment of LV GLS and LVEF on dynamic MDCT data provides similar values to those obtained with echocardiography and could be used in the risk-stratification of severe AS patients undergoing TAVI.

4935Prognostic influence of MDCT-derived global left ventricular longitudinal strain in patients with aortic stenosis treated with transcatheter aortic valve implantation

Abstract Introduction Transcatheter aortic valve implantation (TAVI) is an effective treatment for patients with severe aortic stenosis (AS), It can lead to an improvement in symptoms and quality of life but there is also an increasing recognition that some patients simply fail to derive a functional, morbidity, or mortality benefit post-TAVI. Left ventricular (LV) ejection fraction is the LV systolic function parameter to risk stratify patients with severe AS. However, LV global longitudinal strain (GLS) provides incremental prognostic value to LVEF. Computed tomography plays an essential role in the evaluation of TAVI candidates. Novel software permits analysis of LV GLS from dynamic Multi-detector row computed tomography (MDCT) data. Purpose The present study aimed at investigating the prognostic value of MDCT-derived LV GLS in patients undergoing TAVI. Methods LV GLS was measured on dynamic MDCT using novel CT-software (Figure, panel A) at baseline. Patients were followed up for all-cause mortality and cumulative event rates were analyzed with Kaplan-Meier method. Results A total 214 patients (51% male, 80±7 years) were analysed retrospectively. Mean value of MDCT-derived LV GLS was −12.5±4%. During a median follow-up of 1378 days (interquartile range: 881–1895 days), 67 (31%) patients died. The Kaplan-Meier curve shows, that TAVI recipients with MDCT-derived LV GL S&gt;−14% experienced higher cumulative rates of all-cause mortality, compared to patients with MDCT-derived LV GLS ≤−14% (Chi-square 10.549; Log rank p=0.001) (Figure, panel B). On uni- and multivariate Cox-regression models, MDCT-derived LV GLS demonstrated significant association with all-cause mortality (hazard ratio [HR]: 0.851; 95% confidence interval [CI]: 0.772–0.937; p=0.001). MDCT LV GLS and survival Conclusions MDCT-derived LV GLS is independently associated with all-cause mortality in patients treated with TAVI.

Clinical utility of imaging for evaluation of hepatocellular carcinoma.

The hemodynamics of a hepatocellular nodule is the most important imaging parameter used to characterize various hepatocellular nodules in liver cirrhosis, because sequential changes occur in the feeding vessels and hemodynamic status during hepatocarcinogenesis. Therefore, the imaging criteria for hepatocellular carcinoma (HCC) are also usually based on vascular findings, eg, early arterial uptake followed by washout in the portal venous and equilibrium phases. Contrast-enhanced ultrasonography, dynamic multidetector-row computed tomography (MDCT), and dynamic magnetic resonance (MR) imaging with gadopentetate dimeglumine (Gd-DTPA) are useful for detecting hypervascular HCC on the basis of vascular criteria but are not as useful for hypovascular HCC. Contrast-enhanced MR imaging with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA), a hepatocyte-specific MR contrast agent, is superior to dynamic MDCT and dynamic MR imaging with Gd-DTPA in detecting both hypervascular and hypovascular HCC. Moreover, Gd-EOB-DTPA-enhanced MR imaging can display each histologically differentiated HCC as hypointense relative to the liver parenchyma. 18F-fluorodeoxyglucose positron emission tomography imaging might not be suitable for the screening and detection of HCC, given its lower diagnostic performance. However, this technique plays an important role in determining whether HCC has spread beyond the liver.

Autoimmune pancreatitis: multidetector-row computed tomography (MDCT) and magnetic resonance (MR) findings in the Italian experience

Multidetector-row computed tomography (MDCT) and magnetic resonance (MR) imaging are currently the most frequently performed imaging modalities for the study of pancreatic disease. In cases of suspected autoimmune pancreatitis (AIP), a dynamic quadriphasic (precontrast, contrast-enhanced pancreatic, venous and late phases) study is recommended in both techniques. In the diffuse form of autoimmune pancreatitis (DAIP), the pancreatic parenchyma shows diffuse enlargement and appears, during the MDCT and MR contrast-enhanced pancreatic phase, diffusely hypodense and hypointense, respectively, compared to the spleen because of lymphoplasmacytic infiltration and pancreatic fibrosis. During the venous phase of MDCT and MR imaging, the parenchyma appears hyperdense and hyperintense, respectively, in comparison to the pancreatic phase. In the delayed phase of both imaging modalities, it shows retention of contrast media. A "capsule-like rim" may be recognised as a peripancreatic MDCT hyperdense and MR hypointense halo in the T2-weighted images, compared to the parenchyma. DAIP must be differentiated from non-necrotizing acute pancreatitis (NNAP) and lymphoma since both diseases show diffuse enlargement of the pancreatic parenchyma. The differential diagnosis is clinically difficult, and dynamic contrast-enhanced MDCT has an important role. In the focal form of autoimmune pancreatitis (FAIP), the parenchyma shows segmental enlargement involving the head, the body-tail or the tail, with the same contrast pattern as the diffuse form on both modalities. FAIP needs to be differentiated from pancreatic adenocarcinoma to avoid unnecessary surgical procedures, since both diseases have similar clinical and imaging presentation. The differential diagnosis is clinically difficult, and dynamic contrast-enhanced MDCT and MR imaging both have an important role. MR cholangiopancreatography helps in the differential diagnosis. Furthermore, MDCT and MR imaging can identify the extrapancreatic manifestations of AIP, most commonly biliary, renal and retroperitoneal. Finally, in all cases of uncertain diagnosis, MDCT and/or MR follow-up after short-term treatment (2-3 weeks) with high-dose steroids can identify a significant reduction in size of the pancreatic parenchyma and, in FAIP, normalisation of the calibre of the upstream main pancreatic duct.

Hepatic Artery Reconstruction in Living Donor Liver Transplantation: Risk Factor Analysis of Complication and a Role of MDCT Scan for Detecting Anastomotic Stricture

In partial liver transplantation, reconstruction of the hepatic artery is technically highly demanding and the incidence of arterial complications is high. We attempted to identify the risk factors for anastomotic complications after hepatic artery reconstruction and examined the role of multidetector-row computed tomography (MDCT) in the evaluation of the reconstructed hepatic artery in liver transplant recipients. A total of 109 adult-to-adult living donor liver transplantations (LDLT) were performed at our institute between 1999 and July 2011. Hepatic artery reconstruction was performed under a surgical microscope (MS group, n = 84), until we began to adopt surgical loupes (4.5×) for arterial reconstructions in all cases after January 2009 (SL group, n = 25). A dynamic MDCT study was prospectively carried out on postoperative days 7, 14, and 28, and at postoperative month 3, 6, and 12 after April 2005 (n = 60). There were no cases of hepatic artery thrombosis and six cases (5.5 %) of interventional radiology-confirmed hepatic artery stenosis (HAS). Risk factor analysis for HAS showed that ABO-incompatible LDLT was associated with HAS. Use of surgical loupes provided superior results as compared to anastomosis under a surgical microscope, and it also provided the advantage of reduced operative time. The MDCT procedure was useful for detecting HAS; however, the false positive rate was relatively high until 3 months after the LDLT (100 % sensitivity and 72.8 % specificity at 3 months). Hepatic arterial anastomosis using surgical loupes tended to be time-saving and to yield similar or better results than traditional microscope-anastomosis. The use of MDCT aided the diagnosis of HAS, although the substantial false positive rate should be borne in mind in clinical practice.

Assessment of Gd-EOB-DTPA-enhanced MRI for HCC and dysplastic nodules and comparison of detection sensitivity versus MDCT

We aimed to evaluate gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for the detection of hepatocellular carcinomas (HCCs) and dysplastic nodules (DNs) compared with dynamic multi-detector row computed tomography (MDCT), and to discriminate between HCCs and DNs. Eighty-six nodules diagnosed as HCC or DNs were retrospectively investigated. Gd-EOB-DTPA-enhanced MRI and dynamic MDCT were compared with respect to their diagnostic ability for hypervascular HCCs and detection sensitivity for hypovascular tumors. The ability of hepatobiliary images of Gd-EOB-DTPA-enhanced MRI to discriminate between these nodules was assessed. We also calculated the EOB enhancement ratio of the tumors. For hypervascular HCCs, the diagnostic ability of Gd-EOB-DTPA-enhanced MRI was significantly higher than that of MDCT for tumors less than 2 cm (p = 0.048). There was no difference in the detection of hypervascular HCCs between hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI (43/45: 96%) and dynamic MDCT (40/45: 89%), whereas the detection sensitivity of hypovascular tumors by Gd-EOB-DTPA-enhanced MRI was significantly higher than that by dynamic MDCT (39/41: 95% vs. 25/41: 61%, p = 0.001). EOB enhancement ratios were decreased in parallel with the degree of differentiation in DNs and HCCs, although there was no difference between DNs and hypovascular well-differentiated HCCs. The diagnostic ability of Gd-EOB-DTPA-enhanced MRI for hypervascular HCCs less than 2 cm was significantly higher than that of MDCT. For hypovascular tumors, the detection sensitivity of hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI was significantly higher than that of dynamic Gd-EOB-DTPA-enhanced MRI and dynamic MDCT. It was difficult to distinguish between DNs and hypovascular well-differentiated HCCs based on the EOB enhancement ratio.

CT versus MR Imaging of Hepatocellular Carcinoma: Toward Improved Treatment Decisions

Detection, characterization, staging, and treatment monitoring are major roles of diagnostic imaging of liver cancers. Developments in multidetector-row computed tomography (MDCT) technology have increased the spatial and temporal resolution of CT to allow more precise evaluation of the hemodynamics of liver tumors and improve the diagnostic accuracy of dynamic MDCT. The high spatial and temporal resolutions of dynamic MDCT enable us to reconstruct 3-dimensional (3D) images that are very useful for pretreatment evaluation. Dynamic MR imaging with fast 3D T(1)-weighted gradient echo imaging sequence using nonspecific contrast medium can be highly sensitive for detecting hypervascular HCC. However, the use of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA), a contrast medium specific to hepatic tissue, offers greater diagnostic ability and, so, has become essential to liver imaging. MR imaging with Gd-EOB-DTPA may replace CT during hepatic arteriography and CT during arterioportography.

Small (≤3 cm) hepatocellular carcinoma in cirrhosis: the role of double contrast agents in MR imaging vs. multidetector-row CT

We prospectively compared gadoliniumenhanced magnetic resonance imaging (dynamic MRI), superparamagnetic iron oxide (SPIO) (ferucarbotran) MRI and multidetector-row computed tomography (MDCT) and the combination of dynamic MRI plus MDCT vs. dynamic MRI plus SPIO-MRI (double-contrast MRI: DC-MRI) for the detection of small (<or=3 cm) hepatocellular carcinomas (HCCs). Sixty-three patients with liver cirrhosis and suspicious nodules detected during ultrasound (US) surveillance underwent DC-MRI in the same imaging session and MDCT within 15 days. The final diagnosis was established at pathology on the explanted liver (n=10), resection (n=6) and biopsy (n=38) specimens or at 2-years' follow-up (n=9). One hundred and twenty-three nodules were detected: 87 were confirmed HCCs in 54 patients. The accuracy of SPIO-MRI and dynamic MRI were similar, both being superior to MDCT. Dynamic MRI demonstrated the highest sensitivity (83.9%; p<0.001). especially for lesions <1 cm (90.6%) - coupled with a lower specificity (36.1%) than SPIO-MRI, particularly in subcentimeter lesions (28.6%). SPIO-MRI demonstrated the highest sensitivity for nodules >1 cm and the highest specificity (83.3%) superior to dynamic MRI (p<0.0001). In the per-lesion analysis, SPIO-MRI demonstrated a positive predictive value higher than dynamic MRI (p=0.0059) and than both the combinations dynamic MRI/MDCT and DC-MRI (p=0.0021 and p=0.0087, respectively). DC-MRI showed the highest sensitivity (97.7%) and accuracy (78.9%), detecting hypovascular and atypical HCCs >1 cm. Furthermore its per-patient negative predictive value was the highest (100%), and significantly higher than all the other methods. DC-MRI is the most sensitive and accurate method and can be confidently used as a single-step procedure for the detection of small HCCs, with the exception of lesions <1 cm.

Dynamic MRI, dynamic multidetector‐row computed tomography (MDCT), and coregistered 2‐[fluorine‐18]‐fluoro‐2‐deoxy‐D‐glucose–positron emission tomography (FDG‐PET)/CT: Comparative study of capability for management of pulmonary nodules

To compare the nodule management capabilities of dynamic MRI, dynamic multidetector-row computed tomography (MDCT) and coregistered positron emission tomography (PET)/CT. Dynamic MRI, dynamic MDCT, PET, microbacterial, and pathological examinations were administered to 175 consecutive patients with 202 nodules (<30 mm in diameter). The final diagnoses resulted in the classification of 202 nodules into two groups: requiring further intervention and treatment (N = 163) and no further evaluation (N = 39) groups. Maximum relative enhancement and slope of enhancement ratio were calculated as dynamic MR indices. Maximum enhancement, net enhancement, slope of enhancement, and absolute loss of enhancement were calculated as dynamic CT indices. maximum value of standard uptake value (SUV(max)) was measured on coregistered PET/CT. Receiver operating characteristics (ROC) analyses were performed to determine feasible threshold values for nodule management, and results were tested using McNemar's test. When feasibility threshold values were adopted for nodule management, the specificity (82.1%) and accuracy (93.6%) of the slope of the enhancement ratio were significantly higher than those of dynamic CT indices (P < 0.05) and SUV(max) (P < 0.05). Dynamic MRI can play a more specific and/or accurate role for nodule management as compared with dynamic MDCT and coregistered PET/CT.

Enhancement of the liver on dynamic MDCT: investigation among three groups consisting of noncirrhotic patients and cirrhotic patients with and without a large portosystemic shunt

The aim of this study was to determine any difference in hepatic enhancement values on dynamic multidetector row computed tomography (MDCT) among three groups: noncirrhotic patients and cirrhotic patients with and without a large portosystemic shunt. A group of 20 noncirrhotic patients (group A), 43 cirrhotic patients without a large shunt (group B), and 20 cirrhotic patients with a large shunt (group C) underwent dynamic MDCT of the liver using a standard concentration (300 mg I/ml) and volume (100 ml) of contrast material. The attenuation values of the liver were measured during arterial, portal, and late phases. The hepatic enhancement value during the portal phase was significantly higher in group A (56.2 +/- 13.7 HU) than in the other two groups (group B 39.8 +/- 11.9 HU, group C 41.3 +/- 8.3 HU) (P < 0.01). No significant difference was present between group B and group C. The regression line of the scattergram, which shows the relation between the hepatic enhancement value during the portal phase and the iodine dose per the patients' body weight was more gently sloping in group C than in the other two groups. In cirrhotic patients without a large shunt, injection of a larger amount of total iodine is necessary to optimize hypovascular tumor visualization. However, in cirrhotic patients with a large shunt, further investigation is needed concerning the effectiveness of administering a larger amount of total iodine.

Solitary Pulmonary Nodule: Characterization with Combined Wash-in and Washout Features at Dynamic Multi–Detector Row CT

To prospectively assess the accuracy of combined wash-in and washout characteristics at dynamic contrast material-enhanced multi-detector row computed tomography (CT) in distinguishing benign from malignant solitary pulmonary nodules. Institutional review board approval and informed consent were obtained. The study included 107 patients (62 men, 45 women; mean age, 55 years; range, 22-81 years) with a solitary pulmonary nodule. After unenhanced CT (2.5-mm collimation) scans were obtained, dynamic CT was performed by using a helical technique (series of images obtained throughout the nodule, with 2.5-mm collimation, at 30, 60, 90, and 120 seconds and 4, 5, 9, 12, and 15 minutes) after intravenous injection of contrast medium (120 mL). Tissue diagnosis was made in 70 nodules, and follow-up images showed benignancy in the remaining 37 (no change in size, n = 32; decrease in size, n = 5). CT findings were analyzed in terms of wash-in and washout of contrast medium. Sensitivity, specificity, and accuracy for malignant nodules were calculated by considering both the wash-in and washout characteristics at dynamic CT. There were 49 malignant and 58 benign nodules. When diagnostic criteria for malignancy of both wash-in of 25 HU or greater and washout of 5-31 HU were applied, sensitivity, specificity, and accuracy for malignancy were 94% (46 of 49 nodules), 90% (52 of 58 nodules), and 92% (98 of 107 nodules), respectively. Of 58 benign nodules, 27 showed less than 25 HU wash-in, 14 showed persistent contrast enhancement without washout and with wash-in of 25 HU or greater, and 11 showed washout greater than 31 HU and wash-in of 25 HU or greater. Evaluation of solitary pulmonary nodules by analyzing combined wash-in and washout characteristics at dynamic contrast-enhanced multi-detector row CT showed 92% accuracy for distinguishing benign nodules from malignant nodules.