CT angiography for the assessment of EVAR complications: a pictorial review.

Endovascular aneurysm repair (EVAR) is a minimally invasive treatment proposed as an alternative to open repair in patients with abdominal aortic aneurysms. EVAR consists in a stent-graft placement within the aorta in order to exclude the aneurysm from arterial circulation and reduce the risk of rupture. Knowledge of the various types of devices is mandatory because some stents/grafts are more frequently associated with complications. CT angiography is the gold standard diagnostic technique for preprocedural planning and postprocedural surveillance. EVAR needs long-term follow-up due to the high rate of complications. Complications can be divided in endograft device-related and systemic complications. The purpose of this article is to review the CT imaging findings of EVAR complications and the key features for the diagnosis.

Updated diagnostic & prognostic paradigm for CAD: a narrative review.

Cardiovascular diseases are the first cause of death globally; early detection of coronary artery disease (CAD) is a challenge for clinicians and radiologists. Over the past 2 decades there have been several improvements in the methods for the assessment of diagnosis and prognosis in patients with suspected CAD; most of these methods are imaging methods and they operate with high-end technologies. Cardiac computed tomography (CCT) as we know it today was introduced in 1998 and has ever progressed with constant pace. The first decade was the technical validation phase of the method while the second decade was the clinical validation phase. CCT has developed an excellent diagnostic and prognostic value; technological development together with radiation dose reduction, contributed to the widening of its clinical indications. The diagnostic value of CCT is particularly important as a first line in symptomatic patients with suspected obstructive CAD and low-to-intermediate cardiovascular risk. It is a test that should come, whenever possible, in front of functional evaluation because of its very high sensitivity and negative predictive value. The prognostic value of CCt is still investigational, even though it is becoming quite evident that the atherosclerotic phenotype plays a major role in the determination of prognosis, and as consequence, in the individualization of optimal pharmacological therapy, especially in the cohort without significant obstructive CAD. Recently, scientific and practical guidelines have been updated taking into account the role of CCT, which is able to provide a reliable and fast diagnosis with an additional resources optimization. Multiple registries and trials have been developed and will be summarized in this review. Recent guidelines highlighted the role of CCT in diagnosing suspected CAD.

Technical development in cardiac CT: current standards and future improvements-a narrative review.

Non-invasive depiction of coronary arteries has been a great challenge for imaging specialists since the introduction of computed tomography (CT). Technological development together with improvements in spatial, temporal, and contrast resolution, progressively allowed implementation of the current clinical role of the CT assessment of coronary arteries. Several technological evolutions including hardware and software solutions of CT scanners have been developed to improve spatial and temporal resolution. The main challenges of cardiac computed tomography (CCT) are currently plaque characterization, functional assessment of stenosis and radiation dose reduction. In this review, we will discuss current standards and future improvements in CCT.

Impact of structured report on the quality of preoperative CT staging of pancreatic ductal adenocarcinoma: assessment of intra- and inter-reader variability.

PURPOSE: To evaluate whether a structured radiology report improves the completeness of preoperative CT staging of pancreatic ductal adenocarcinoma (PDA) compared to conventional free-text reports. METHODS: We retrospectively included 27 patients (mean age, 64 ± 11.1 years) referred for pancreatic preoperative CT scan for staging of PDA between 2015 and 2018 and in whom a diagnosis of pancreatic adenocarcinoma was ultimately confirmed. Four readers independently reported CT scans with both conventional free-text and structured reports. Differences in reported morphologic and vascular features with the two reports were assessed through McNemar Test. Intra-reader and inter-reader were calculated. RESULTS: A total of 216 reports were completed by four different readers including 108 free-text and 108 structured reports. Overall, 139 of 540 morphologic characteristics of PDA and 869 of 1188 vascular key features were only described in structured reports. Encasement of left gastric artery, gastroduodenal artery and splenic artery was described in up to 14.8% using free-text reports and in up to 29.6% using structured report, resulting in low-intra-reader agreement (k = 0.033-0.216). Inter-reader agreement improved with structured report compared to free-text one for left gastric artery (ICC = 0.844 vs. ICC = 0.493, respectively), gastroduodenal artery (ICC = 0.730 vs. ICC = 0.449, respectively), portal vein (ICC = 0.847 vs. ICC = 0.638, respectively), portal confluence (ICC = 0.848 vs. ICC = 0.422, respectively) superior mesenteric vein (ICC = 0.765 vs. ICC = 0.695, respectively), and splenic vein (ICC = 0.921 vs. ICC = 0.841, respectively). CONCLUSION: Structured reports for PDA staging significantly reduces the number of missing morphological and vascular features of PDA and improves the inter-reader agreement compared to free-text reports.

Whole-body diffusion-weighted MR and FDG-PET/CT in Hodgkin Lymphoma: Predictive role before treatment and early assessment after two courses of ABVD.

PURPOSE: To evaluate whether imaging features of pathologic lymph nodes on whole-body diffusion-weighted MR have a predictive role before treatment and may assess the response after two courses of chemotherapy in comparison to FDG-PET/CT in Hodgkin Lymphoma. MATERIALS AND METHODS: We reviewed the whole-body MR and FDG-PET/CT performed on 41 patients with Hodgkin Lymphoma before and after two Doxorubicin-Bleomycin-Vinblastine-Dacarbazine (ABVD). Responder and non-responder lesions were identified on interim-FDG-PET/CT performed after two ABVD. We used Multivariate Generalized Estimating Equations model to assess statistical association between being-responder and baseline-Maximum Standard Uptake Value (SUVmax), baseline and interim-Apparent Diffusion Coefficient (ADC) and size, ADC and size changes during chemotherapy, site of disease, bulky, and stage. RESULTS: 10/41 (24%) patients were positive on interim-FDG-PET/CT. The interim-FDG-PET/CT positivity was associated with worse cumulative survival rate at 24 months in comparison to interim-FDG-PET/CT negativity (P < .05); 3/10 patients with positive interim-FDG-PET/CT and 1/31 with negative interim-FDG-PET/CT experienced disease progression. Baseline-SUVmax was 11.18 ±â€¯5.58 (3.1-28.0) and baseline-ADC was 0.70 ±â€¯0.14 × 10-3 mm2/s (0.39-0.98). There was a significant difference between responder and non-responder lesions based on interim-ADC (1.83 ±â€¯0.34 × 10-3 mm2/s vs. 1.01 ±â€¯0.27 × 10-3 mm2/s;p <.001), interim-size (3.1 cm2 vs. 9.4 cm2;p = .009), and bulky (8.2% vs. 66.7%;p = .002). There was no significant difference between responder and non-responder lesions based on baseline-SUVmax (p = .713), baseline-ADC (p = .253), ADC changes (p = .058), size changes (p = .085), site (p = .209), stage (p = .290), baseline-size (p = .064). CONCLUSIONS: Interim-ADC is helpful for identifying non-responder lesions, while size changes are not useful. Baseline-SUVmax and ADC have no predictive role. Bulky is the most useful imaging parameter to predict suboptimal response to chemotherapy.

Assessment of brain core temperature using MR DWI-thermometry in Alzheimer disease patients compared to healthy subjects.

PURPOSE: To assess the brain core temperature of Alzheimer disease (AD) patients in comparison with healthy volunteers using diffusion-weighted thermometry. MATERIALS AND METHODS: Fourteen AD patients (3 men, 11 women; age range 60-81 years, mean age 73.8 ± 6.1 years) and 14 healthy volunteers, age and sex-matched (mean age 70.1 ± 6.9 years; range 62-84 years; 5 men, 9 women) underwent MR examination between February 2014 and March 2016. MR imaging studies were performed with a 1.5-T MR scanner. Brain core temperature (T: °C) was calculated using the following equation from the diffusion coefficient (D) in the lateral ventricular (LV) cerebrospinal fluid: T = 2256.74/ln (4.39221/D) - 273.15 using a standard DWI single-shot echo-planar pulse sequence (b value 1000 s/mm2). Statistical analysis was performed using a nonparametric Wilcoxon rank-sum test to compare the patient and control groups regarding LV temperatures. RESULTS: There was no significant difference (P = 0.1937) in LV temperature between patients (mean 37.9 ± 1.1 °C, range 35.8-39.2 °C) and control group (38.7 ± 1.4 °C, range 36.9-42.7 °C). CONCLUSIONS: Brain core temperature in AD patients showed no significant alterations compared to healthy volunteers.

Whole-body MRI, FDG-PET/CT, and bone marrow biopsy, for the assessment of bone marrow involvement in patients with newly diagnosed lymphoma.

PURPOSE: To compare whole-body MRI (WB-MRI) with diffusion-weighted imaging (DWI), FDG-PET/CT, and bone marrow biopsy (BMB), for the evaluation of bone marrow involvement (BMI) in patients with newly diagnosed lymphoma. MATERIALS AND METHODS: This retrospective study was approved by our Institutional Review Board. Two independent radiologists and one nuclear medicine specialist reviewed all WB-MRI and FDG-PET/CT scans prospectively performed on 104 patients with newly diagnosed lymphoma (53 males; 47 Hodgkin; mean age: 44 years; range, 15-86 years) between 2013 and 2015. The delay between imaging scans and BMBs was up to 10 days. The diagnostic accuracy of WB-MRI (1.5 Tesla MR scanner, with T1w, T2w-STIR, and DWI sequences) was evaluated using BMB and FDG-PET/CT as the reference standard. We applied Cohen's kappa coefficient to assess the inter-observer agreement in WB-MRI interpretation and to compare WB-MRI, FDG-PET/CT and BMB. The Student's t test was done to compare pelvic marrow ADC values of patients with positive and negative BMB. A P-value of < 0.01 was considered significant. RESULTS: Inter-observer agreement was excellent (k = 0.937). Agreement between WB-MRI and FDG-PET/CT was excellent, with a k = 0.935. Agreement between WB-MRI and BMB was moderate (k = 0.489), and fair between FDG-PET/CT and BMB (k = 0.370). WB-MRI and FDG-PET/CT were falsely negative in four indolent non-Hodgkin lymphomas with BMI < 30% of marrow cellularity. Conversely, WB-MRI and FDG-PET/CT detected all cases with a BMI>30% of marrow cellularity. Mean ADC values in patients with positive and negative BMB were not significantly different (P = 0.049). CONCLUSION: WB-MRI and FDG-PET/CT are valuable tools for the assessment of BMI. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2017;45:1082-1089.

Whole-body magnetic resonance for staging and response assessment of lymphoma in a pregnant woman treated with antenatal chemotherapy.

A 32-year-old pregnant female presented with bilateral supraclavicular swelling, diffuse itching and right shoulder pain. After lymph nodal biopsy, a diagnosis of nodular sclerosis Hodgkin's lymphoma was obtained. A multidisciplinary team decided to start chemotherapy before the delivery, and whole-body MRI was used to stage the disease and evaluate the response after antenatal chemotherapy. This case shows that whole-body MRI is an attractive procedure that avoids radiation exposure and contrast administration, and enables staging and follow-up of a pregnant patient without risk to the fetus.

Quantitative T2* magnetic resonance imaging for renal iron overload assessment: normal values by age and sex.

PURPOSE: Few studies of renal iron content have been performed with multiecho gradient-echo (ME-GRE) T2* magnetic resonance imaging (MRI). We assessed the feasibility and reproducibility of ME-GRE T2* MRI for measuring regional and global renal T2* values, and established the lower limits of normal in healthy subjects, also correlating the measured values with age and sex. METHODS: Twenty consecutive healthy subjects (13 men and 7 women, mean age 29.1 ± 7.2 years, range 19-42 years) underwent MRI examinations using a 1.5 T magnet and an ME-GRE T2* sequence. For each kidney, T2* was measured in anterior, posterolateral, and posteromedial renal parenchymal regions. The mean T2* value was calculated as the average of the two kidneys T2* values. RESULTS: For the mean kidney T2* value, the coefficients of variation for intra- and inter-operator reproducibility were 1.76% and 6.23%, respectively. The lower limit of normal for the mean kidney T2* value was 31 ms (median 51.39 ± 10.09). There was no significant difference between left and right kidney T2* values (p = 0.578). No significant correlation was found between T2* values and subjects' age or sex. CONCLUSIONS: Renal ME-GRE T2* appears to be a feasible and reproducible technique. The renal T2* values showed no dependence on sex or age.

Assessment of atrial diastolic function in patients with hypertrophic cardiomyopathy by cine magnetic resonance imaging.

PURPOSE: This study was conducted to assess the role of atrial function by cardiac magnetic resonance (CMR) for the evaluation of diastolic physiology in patients with hypertrophic cardiomyopathy (HCM) compared to healthy controls. MATERIALS AND METHODS: We enrolled 23 consecutive patients affected by HCM and 43 healthy subjects as age-matched control cases (CC). CMR was performed through acquisition of cine steady-state free precession sequences using a 1.5-T scanner. Image postprocessing was carried out using Tracking Tool software. RESULTS: Atrial volumes were significantly higher in patients with HCM compared to CC: maximum atrial volume (p = 0.007) and minimum atrial volume (p = 0.01). A statistically significant difference was also observed in atrial ejection fraction in patients with HCM (p < 0.0001). The atrial volume curves defined as cavity volume over time (dV/t) showed significant differences: early atrial peak emptying rate (PERE) (maximum rate of emptying independent of atrial contraction) in HCM was -146 ± 53 ml/s versus -227 ± 86 ml/s in CC (p < 0.0001); active atrial peak emptying rate (PERA) (maximum rate of emptying secondary to atrial contraction) in HCM was -256 ± 80 ml/s versus -216 ± 104 ml/s in CC (p = 0.05); the atrial PER E/A ratio in HCM was 0.6 ± 0.2 versus 1.05 ± 0.5 in CC (p < 0.0001). CONCLUSIONS: This study demonstrated that in HCM patients with early diastolic dysfunction the parameters of left atrial function assessed by CMR are impaired before the ventricular diastolic indexes such as the early peak filling rate and the active peak filling rate.

Hepatocellular carcinoma enhancement on contrast-enhanced CT and MR imaging: response assessment after treatment with sorafenib: preliminary results.

PURPOSE: This study was undertaken to compare response evaluation criteria in solid tumours (RECIST) 1.1 and modified RECIST (mRECIST) in patients with unresectable hepatocellular carcinoma (HCC) on sorafenib, and to describe HCC enhancement changes before and after sorafenib treatment. METHODS AND MATERIALS: Seventeen patients (12 men, 5 women; mean age 69 years; age range 58-79 years) were included. Tumour response was assessed according to RECIST and mRECIST. Two readers placed a region of interest (ROI) within each target lesion, on the portion showing enhancement during the arterial phase. The lesion attenuation values measured within the ROIs on computed tomography or the signal intensity measured on magnetic resonance imaging, during the unenhanced phase, hepatic arterial phase and venous phase were recorded. Changes in arterial and venous contrast enhancement before and after treatment were compared among the mRECIST groups using Mann-Whitney U test. RESULTS: Agreement between mRECIST and RECIST was good (Cohen's k coefficient, 0.791). Patients with partial response had a greater decrease in arterial enhancement (-79.8%) than did patients with stable disease (SD) (-24.8%; p = 0.011) or progressive disease (PD) (-32.9%; p = 0.034). No statistically significant difference in arterial enhancement variation was found among patients with SD and PD. No statistically significant difference in venous enhancement was found among the mRECIST groups. CONCLUSIONS: mRECIST showed a more favourable response compared to RECIST 1.1 in patients with unresectable HCC receiving sorafenib.

[Morpho-volumetric assessment of the right ventricle: a comparison between three-dimensional echocardiography and cardiac magnetic resonance]. / Valutazione morfo-funzionale del ventricolo destro: confronto tra ecocardiografia e risonanza magnetica cardiaca.

The morpho-volumetric assessment of the right ventricle (RV) is useful in the diagnosis and prognosis of many congenital and acquired cardiovascular diseases. The complexity of the right ventricular shape does not allow an adequate and satisfactory evaluation of the RV. Two-dimensional (2D) echocardiography is the most used tool for the assessment of RV function, as it is a noninvasive, reproducible and widespread technique, but the geometric assumptions required for measurement of RV volumes reduce its accuracy. At present, cardiac magnetic resonance is the gold standard for the evaluation of RV volumes because it does not need any assumption and is reproducible, though not always available. This imaging tool allows to follow-up patients and to monitor drug therapy. On the other hand, three-dimensional (3D) echocardiography overcomes several limitations of 2D echocardiography, in that it provides an estimation of RV volumes obtained through a real 3D data set, obtaining sections which cannot be technically achieved with 2D echocardiography. It is therefore useful to compare data on RV volumes and function obtained with 3D echocardiography versus cardiac magnetic resonance, mainly considering the lower costs and higher portability and availability of echocardiography.

Assessment of treatment response in hepatocellular carcinoma: a review of the literature.

Hepatocellular carcinoma (HCC) has a high incidence all over the world. Even if the primary end point of treatment of HCC is survival, radiological response could be a surrogate end point of survival, and could have a key role in clinical management. Since 1950 several radiological response criteria have been applied; however, it was not until 2000 that specific criteria for HCC were introduced by the European Association for the Study of the Liver (EASL), and these were then standardized in 2010 with the development of the modified Response Evaluation Criteria for Solid Tumors (mRECIST) for HCC. The purpose of this brief review is to compare data in literature regarding the application and the performance of mRECIST in clinical practice, and to discuss unclear and open issues.

CT coronary angiography at an ultra-low radiation dose (<0.1 mSv): feasible and viable in times of constraint on healthcare costs.

Computed tomography coronary angiography (CTCA) has reached very high standards both in terms of diagnostic performance and radiation dose reduction. This commentary follows a report on CTCA using less than 0.1 mSv in selected patients. This is an extraordinary accomplishment, both for technology and for medicine. The difficult task is now to implement this tool in clinical practice so it can play the best possible role. CTCA can improve diagnostic pathways, can save money for healthcare systems and could even improve pharmacological therapy. All of this may happen, but it will require the combined effort of all the experienced operators in this field, including the referring clinicians. In times of financial constraint, CTCA may also help to restrict ineffective medical expenses.

Coronary calcium score and computed tomography coronary angiography in high-risk asymptomatic subjects: assessment of diagnostic accuracy and prevalence of non-obstructive coronary artery disease.

OBJECTIVES: The aim of the study was to compare the coronary artery calcium score (CACS) and computed tomography coronary angiography (CTCA) for the assessment of non-obstructive/obstructive coronary artery disease (CAD) in high-risk asymptomatic subjects. METHODS: Two hundred and thirteen consecutive asymptomatic subjects (113 male; mean age 53.6 +/- 12.4 years) with more than one risk factor and an inconclusive or unfeasible non-invasive stress test result underwent CACS and CTCA in an outpatient setting. All patients underwent conventional coronary angiography (CAG). Data from CACS (threshold for positive image: Agatston score 1/100/1,000) and CTCA were compared with CAG regarding the degree of CAD (non-obstructive/obstructive; or=50% lumen reduction). RESULTS: The mean calcium score was 151 +/- 403 and the prevalence of obstructive CAD was 17% (8% one-vessel and 10% two-vessel disease). Per-patient sensitivity, specificity, positive and negative predictive values of CACS were: 97%, 75%, 45%, and 100%, respectively (Agatston >or=1); 73%, 90%, 60%, and 94%, respectively (Agatston >or=100); 30%, 98%, 79%, and 87%, respectively (Agatston >or=1,000). Per-patient values for CTCA were 100%, 98%, 97%, and 100%, respectively (p < 0.05). CTCA detected 65% prevalence of all CAD (48% non-obstructive), while CACS detected 37% prevalence of all CAD (21% non-obstructive) (p < 0.05). CONCLUSION: CACS proved inadequate for the detection of obstructive and non-obstructive CAD compared with CTCA. CTCA has a high diagnostic accuracy for the detection of non-obstructive and obstructive CAD in high-risk asymptomatic patients with inconclusive or unfeasible stress test results.

Right coronary artery arising from pulmonary trunk: assessment with conventional coronary angiography and multislice computed tomography coronary angiography.

We present a case of a 59-year-old man who was admitted to the hospital because of atypical chest pain and dyspnea. Conventional coronary angiography showed an anomalous origin of the right coronary artery from the pulmonary trunk. The patient underwent multislice computed tomography in order to clarify the origin and course of the anomalous vessel. The aim of this report is to emphasize the role of multislice computed tomography as an accurate noninvasive imaging tool in the evaluation of coronary artery anomalies.

Improved T2* assessment in liver iron overload by magnetic resonance imaging.

In the clinical MRI practice, it is common to assess liver iron overload by T2* multi-echo gradient-echo images. However, there is no full consensus about the best image analysis approach for the T2* measurements. The currently used methods involve manual drawing of a region of interest (ROI) within MR images of the liver. Evaluation of a representative liver T2* value is done by fitting an appropriate model to the signal decay within the ROIs vs. the echo time. The resulting T2* value may depend on both ROI placement and choice of the signal decay model. The aim of this study was to understand how the choice of the analysis methodology may affect the accuracy of T2* measurements. A software model of the iron overloaded liver was inferred from MR images acquired from 40 thalassemia major patients. Different image analysis methods were compared exploiting the developed software model. Moreover, a method for global semiautomatic T2* measurement involving the whole liver was developed. The global method included automatic segmentation of parenchyma by an adaptive fuzzy-clustering algorithm able to compensate for signal inhomogeneities. Global liver T2* value was evaluated using a pixel-wise technique and an optimized signal decay model. The global approach was compared with the ROI-based approach used in the clinical practice. For the ROI-based approach, the intra-observer and inter-observer coefficients of variation (CoVs) were 3.7% and 5.6%, respectively. For the global analysis, the CoVs for intra-observers and inter-observers reproducibility were 0.85% and 2.87%, respectively. The variability shown by the ROI-based approach was acceptable for use in the clinical practice; however, the developed global method increased the accuracy in T2* assessment and significantly reduced the operator dependence and sampling errors. This global approach could be useful in the clinical arena for patients with borderline liver iron overload and/or requiring follow-up studies.

[Anomalous origin of the circumflex artery from the right aortic sinus: assessment with conventional coronary angiography and multislice computed tomography]. / Origine anomala dell'arteria circonflessa dal seno di Valsalva destro: valutazione mediante tomografia computerizzata multistrato ed angiografia coronarica convenzionale.

Anomalous origin of the circumflex coronary artery from the right sinus of Valsalva is the most common coronary anomaly. This anomaly is thought to be of little clinical significance without the presence of severe narrowing of the vessel. A 43-year-old woman was referred to our institution for evaluation of atypical chest pain and equivocal results of the exercise stress test. We decided to perform multislice computed tomography coronary angiography before any other invasive studies. The scan was performed with a 16-row scanner (Aquilion 16 CFX, Toshiba Medical Systems, Tokyo, Japan) after intravenous administration of non-ionic contrast material. Scans revealed that the circumflex coronary artery originated from the right sinus of Valsalva; the initial course was retro-aortic until it reached its target in the atrioventricular groove; peripheral distribution of the circumflex coronary artery was then normal. The anomalous vessel presented a significant stenosis in its proximal tract. Coronary angiography confirmed that the origin of the circumflex coronary artery was from the right aortic sinus and the significant stenosis of the proximal portion of this vessel. This case confirms the full capability and accuracy of multislice computed tomography with the aid of post-processing techniques in the identification and evaluation of the ectopic origin of the left circumflex coronary artery from the right sinus of Valsalva, displaying accurately the origin, size, course, and relationship of the anomalous vessel with respect to surrounding structures.

Image assessment with multislice CT coronary angiography.

AIM: To investigate the diagnostic accuracy of two different protocols for image evaluation used in multislice computed tomography coronary angiography (MSCT-CA). MATERIALS AND METHODS: Sixty patients with suspected coronary artery disease undergoing conventional coronary angiography (CA) were enrolled for MSCT-CA. All patients underwent 16-row MSCT (Sensation 16, Siemens, Germany) with the following parameters: detector rows 16, collimation 0.75 mm, gantry rotation time 375 ms. Two independent observers assessed the images for significant stenosis using a a protocol with standard projections and a three-dimensional protocol. The diagnostic accuracy for both methods was calculated using quantitative CA as a reference standard. RESULTS: The sensitivity, specificity, negative predictive value and positive predictive value obtained with the conventional projection protocol and with three-dimensional protocol were: 54% and 93%, 97% and 97%, 76% and 86%, 92% and 99%, respectively. CONCLUSIONS: Conventional projections in the assessment of MSCT-CA provide insufficient diagnostic accuracy compared with three-dimensional processing.