Role of gadoxetic acid-enhanced liver magnetic resonance imaging in the evaluation of hepatocellular carcinoma after locoregional treatment.

Locoregional treatments, as alternatives to surgery, play a key role in the management of hepatocellular carcinoma (HCC). Liver magnetic resonance imaging (MRI) enables a multiparametric assessment, going beyond the traditional dynamic computed tomography approach. Moreover, the use of hepatobiliary agents can improve diagnostic accuracy and are becoming important in the diagnosis and follow-up of HCC. However, the main challenge is to quickly identify classical responses to loco-regional treatments in order to determine the most suitable management strategy for each patient. The aim of this review is to provide a summary of the most common and uncommon liver MRI findings in patients who underwent loco-regional treatments for HCC, with a special focus on ablative therapies (radiofrequency, microwaves and cryoablation), trans-arterial chemoembolization, trans-arterial radio-embolization and stereotactic ablative radiotherapy techniques, considering the usefulness of gadoxetate disodium (Gd-EOB-DTPA) contrast agent.

Benign focal liver lesions: The role of magnetic resonance imaging.

Liver lesions are common findings in radiologists' daily routine. They are a complex category of pathology that range from solitary benign lesions to primary liver cancer and liver metastases. Benign focal liver lesions can arise from different liver cell types: Epithelial (hepatocytes and biliary cells) and nonepithelial (mesenchymal cells). Liver magnetic resonance imaging (MRI) is a fundamental radiological method in these patients as it allows with its multiparametric approach optimal non-invasive tissue characterization. Furthermore, advanced liver MRI techniques such as diffusion-weighted imaging and hepatobiliary contrast agents have improved the detection of focal liver lesions and can be highly effective in differentiating pseudotumor from tumors, as well as benign from malignant lesions, and can also be used for differential diagnosis. Although histological examination can be useful in making a definitive diagnosis, MRI is an important modality in the diagnosis of liver lesions with a significant impact on patient care. This aim of this review is to provide a comprehensive overview of benign liver lesions on MRI.

Diagnostic accuracy of coronary computed tomography angiography for the evaluation of obstructive coronary artery disease in patients referred for transcatheter aortic valve implantation: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the diagnostic accuracy of coronary computed tomography angiography (CCTA) for the evaluation of obstructive coronary artery disease (CAD) in patients referred for transcatheter aortic valve implantation (TAVI). METHODS: EMBASE, PubMed/MEDLINE, and CENTRAL were searched for studies reporting accuracy of CCTA for the evaluation of obstructive CAD compared with invasive coronary angiography (ICA) as the reference standard. QUADAS-2 tool was used to assess the risk of bias. A bivariate random effects model was used to analyze, pool, and plot the diagnostic performance measurements across studies. Pooled sensitivity, specificity, positive ( + LR) and negative (-LR) likelihood ratio, diagnostic odds ratio (DOR), and hierarchical summary ROC curve (HSROC) were evaluated. Prospero registration number: CRD42021252527. RESULTS: Fourteen studies (2533 patients) were included. In the intention-to-diagnose patient-level analysis, sensitivity and specificity for CCTA were 97% (95% CI: 94-98%) and 68% (95% CI: 56-68%), respectively, and + LR and -LR were 3.0 (95% CI: 2.1-4.3) and 0.05 (95% CI: 0.03 - 0.09), with DOR equal to 60 (95% CI: 30-121). The area under the HSROC curve was 0.96 (95% CI: 0.94-0.98). No significant difference in sensitivity was found between single-heartbeat and other CT scanners (96% (95% CI: 90 - 99%) vs. 97% (95% CI: 94-98%) respectively; p = 0.37), whereas the specificity of single-heartbeat scanners was higher (82% (95% CI: 66-92%) vs. 60% (95% CI: 46 - 72%) respectively; p < 0.0001). Routine CCTA in the pre-TAVI workup could save 41% (95% CI: 34 - 47%) of ICAs if a disease prevalence of 40% is assumed. CONCLUSIONS: CCTA proved an excellent diagnostic accuracy for assessing obstructive CAD in patients referred for TAVI; the use of single-heartbeat CT scanners can further improve these findings. KEY POINTS: • CCTA proved to have an excellent diagnostic accuracy for assessing obstructive CAD in patients referred for TAVI. • Routine CCTA in the pre-TAVI workup could save more than 40% of ICAs. • Single-heartbeat CT scanners had higher specificity than others in the assessment of obstructive CAD in patients referred for TAVI.

Cardiovascular magnetic resonance of cardiac tumors and masses.

Cardiac masses diagnosis and treatment are a true challenge, although they are infrequently encountered in clinical practice. They encompass a broad set of lesions that include neoplastic (primary and secondary), non-neoplastic masses and pseudomasses. The clinical presentation of cardiac tumors is highly variable and depends on several factors such as size, location, relation with other structures and mobility. The presumptive diagnosis is made based on a preliminary non-invasive diagnostic work-up due to technical difficulties and risks associated with biopsy, which is still the diagnostic gold standard. The findings should always be interpreted in the clinical context to avoid misdiagnosis, particularly in specific conditions (e.g., infective endocarditis or thrombi). The modern multi-modality imaging techniques has a key role not only for the initial assessment and differential diagnosis but also for management and surveillance of the cardiac masses. Cardiovascular magnetic resonance (CMR) allows an optimal non-invasive localization of the lesion, providing multiplanar information on its relation to surrounding structures. Moreover, with the additional feature of tissue characterization, CMR can be highly effective to distinguish pseudomasses from masses, as well as benign from malignant lesions, with further differential diagnosis of the latter. Although histopathological assessment is important to make a definitive diagnosis, CMR plays a key role in the diagnosis of suspected cardiac masses with a great impact on patient management. This literature review aims to provide a comprehensive overview of cardiac masses, from clinical and imaging protocol to pathological findings.

Advanced cardiac imaging in athlete's heart: unravelling the grey zone between physiologic adaptation and pathology.

Over the last decades, interest toward athlete's heart has progressively increased, leading to improve the knowledge on exercise-induced heart modifications. Sport may act as a trigger for life-threatening arrhythmias in patients with structural or electrical abnormalities, hence requiring to improve the diagnostic capability to differentiate physiological from pathological remodeling. Pathological alterations are often subtle at the initial stages; therefore, the challenge is to promptly identify athletes at risk of sudden cardiac death during the pre-participation screening protocols. Advanced imaging modalities such as coronary computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR) can non-invasively depict coronary vessels and provide a deep morpho-functional and structural characterization of the myocardium, in order to rule out pathological life threatening alterations, which may overlap with athletes' heart remodeling. The purpose of the present narrative review is to provide an overview of most frequent diagnostic challenges, defining the boundaries between athlete's heart remodeling and pathological structural alteration with a focus on the role and importance of CCTA and CMR.

Dynamic changes of mitral valve annulus geometry at preprocedural CT: relationship with functional classes of regurgitation.

BACKGROUND: We investigated mitral valve annular geometry changes during the cardiac cycle in patients with severe mitral regurgitation (MR) who underwent cardiac computed tomography angiography (CCTA) prior to percutaneous mitral valve replacement or annuloplasty. METHODS: Fifty-one patients with severe MR and high surgical risk (Carpentier classification: 3 type I, 16 type II, 16 type IIIa, 16 type IIIb) underwent multiphase electrocardiographically gated (0-90%) CCTA, using a second generation dual-source CT scanner, as pre-procedural planning. Twenty-one patients without MR served as controls. The mitral valve annulus was segmented every 10% step of the R-R interval, according to the D-shaped segmentation model, and differences among groups were analysed by t-test or ANOVA. RESULTS: Mitral annular area and diameters were larger in MR patients compared to controls, particularly in type II. Mitral annular area varied in MR patients throughout the cardiac cycle (mean ± standard deviation of maximum and minimum area 15.6 ± 3.9 cm2 versus 13.0 ± 3.5 cm2, respectively; p = 0.001), with greater difference between annular areas versus controls (2.59 ± 1.61 cm2 and 1.98 ± 0.6 cm2, p < 0.001). The largest dimension was found in systolic phases (20-40%) in most of MR patients (n = 27, 53%), independent of Carpentier type (I: n = 1, 33%; II: n = 10, 63%; IIIa: n = 8, 50%; IIIb: n = 8, 50%), and in protodiastolic phases (n = 14, 67%) for the control group. CONCLUSIONS: In severe MR, mitral annular area varied significantly throughout the cardiac cycle, with a tendency towards larger dimensions in systole.

Effects of different levels of CT iterative reconstruction on low-contrast detectability and radiation dose in patients of different sizes: an anthropomorphic phantom study.

PURPOSE: The purpose of this study was to verify the maintenance of low-contrast detectability at different CT dose reduction levels, in patients of different sizes, as a consequence of the application of iterative reconstruction at different strengths combined with tube current modulation. METHODS: Anthropomorphic abdominal phantoms of two sizes (small and large) were imaged at a fixed noise with iterative algorithm ASIR-V percentages in the range between 0 and 70% and corresponding dose reductions in the range of 0-83%. A total of 1400 images with and without liver low-contrast simulated lesions were evaluated by five radiologists, using the receiver operating characteristics (ROC) paradigm and evaluating the area under the ROC curve (AUC). The human observer results were then compared with AUC obtained with a channelized Hotelling observer (CHO). CNR values were also calculated. RESULTS: For the small phantom, the AUC values lie between 0.90 and 0.93 for human evaluations of images acquired without iterative reconstruction, with 30% ASIR-V and with 50% ASIR-V. The AUC decreased significantly to 0.81 (p = 0.0001) at 70% ASIR-V. The CHO results were in coherence with human observer scores. Also, similar results were observed for the large size phantom. CNR values were stable for the different ASIR-V percentages. CONCLUSIONS: The iterative algorithm maintained the low-contrast detectability up to a dose reduction of about 70%, following application of a 50% ASIR-V combined with automatic tube current modulation, regardless of the phantom size. At further dose reductions using greater iterative percentages, a significant decrease in detectability was observed.

Cardiovascular magnetic resonance in myocardial infarction with non-obstructive coronary arteries patients: A review.

The diagnosis of myocardial infarction with non-obstructive coronary arteries (MINOCA) necessitates documentation of an acute myocardial infarction (AMI), non-obstructive coronary arteries, using invasive coronary angiography or coronary computed tomography angiography and no clinically overt cause for AMI. Historically patients with MINOCA represent a clinical dilemma with subsequent uncertain clinical management. Differential diagnosis is crucial to choose the best therapeutic option for ischemic and non-ischemic MINOCA patients. Cardiovascular magnetic resonance (CMR) is able to analyze cardiac structure and function simultaneously and provides tissue characterization. Moreover, CMR could identify the cause of MINOCA in nearly two-third of patients providing valuable information for clinical decision making. Finally, it allows stratification of patients with worse outcomes which resulted in therapeutic changes in almost half of the patients. In this review we discuss the features of CMR in MINOCA; from exam protocols to imaging findings.

Characterization of the arterial enhancement pattern of focal liver lesions by multiple arterial phase magnetic resonance imaging: comparison between hepatocellular carcinoma and focal nodular hyperplasia.

PURPOSE: To evaluate the features of arterial enhancement pattern of focal nodular hyperplasia (FNH) and hepatocellular carcinoma (HCC) by triple-phase arterial magnetic resonance imaging (MRI). METHODS: Data were retrospectively collected from 52 consecutive patients who underwent triple-phase arterial MRI using hepatocyte-specific contrast agents (Gd-EOB-DTPA) from January 2017 to October 2017, with a MR imaging diagnosis of HCC or FNH. The images were independently assessed by two blinded readers. Contrast enhancement ratio (CER) and liver-to-lesion contrast ratio (LLCR) were calculated. The lesions were classified visually and also based on the peak of LLCR into the following groups: (1) early arterial, (2) middle arterial and (3) late arterial. Data were eventually analysed using nonparametric tests. RESULTS: The CER analysis showed no significant difference between HCC and FNH patients (p > 0.05). LLCRFNH were significantly higher than LLCRHCC in the early arterial (p = 0.01), but not in the middle and late arterial phases (p = 0.20 and p = 0.82, respectively). LLCRHCC presented a meaningful increase from early to middle arterial phase (p = 0.009), whereas LLCRFNH showed a decrease from middle to late arterial phase (p = 0.004). Based on the peak of LLCR, 17 (55%) FNHs were classified into early, 11 (35%) in middle and only 3 (10%) in late arterial phase groups. Similarly, 14 (34%) HCCs were categorized into early, 13 (32%) in middle and 14 (33%) in late arterial phase groups. There was a good agreement between qualitative analysis and LLCR in 85% of cases. CONCLUSION: The optimal visualization of FNH has been detected in early and middle arterial phases while HCC has been best observed during middle and late arterial phases.

Choroidal thickness and the retinal ganglion cell complex in chronic Leber's hereditary optic neuropathy: a prospective study using swept-source optical coherence tomography.

BACKGROUND/OBJECTIVES: Choroidal thinning has been suggested in Leber's hereditary optic neuropathy (LHON). No study has been conducted of the choroid in relation to the retinal ganglion cell-inner plexiform layer (RGC-IPL). We sought to measure choroidal thickness in chronic LHON and to correlate thickness changes with the RGC-IPL. SUBJECTS/METHODS: Chronic LHON, 11778 mitochondrial DNA (mtDNA) mutation, patients (26 eyes; mean age: 35.1 ± 16.1 years) were prospectively recruited at Doheny Eye Center, University of California Los Angeles from March 2016 to July 2017. Age-matched healthy controls (27 eyes; mean age: 32.4 ± 11.1 years) were enroled for comparison. Swept-source optical coherence tomography (SS-OCT) imaging was performed in chronic LHON patients and compared with age-matched healthy controls. RESULTS: The macular choroid was significantly thinner in chronic LHON (250.5 ± 62.2 µm) compared with controls (313.9 ± 60.2 µm; p < 0.0001). The peripapillary choroid was also significantly thinner in chronic LHON (135.7 ± 51.4 µm) compared with controls (183.0 ± 61.8 µm, p < 0.001). Choroidal thickness strongly correlated with retinal nerve fibre layer (RNFL) thickness in both the macular (R2 = 0.72; 95% CI, 0.57-0.84) and peripapillary regions (R2 = 0.53; 95% CI, 0.31-0.70). Choroidal thickness was also significantly correlated with macular RGC-IPL thickness (R2 = 0.51; 95% CI, 0.26-0.73). CONCLUSIONS: Choroidal thinning in chronic LHON correlated strongly with both RNFL and RGC-IPL thicknesses. These findings may suggest a pathophysiological mechanism involving vascular pathology of the choroid in relation to the retinal ganglion cell complex in LHON.

Magnetic resonance enterography.

Crohn's disease is a condition of chronic inflammation that may involve any part of the gastrointestinal tract, although it more frequently affects the terminal ileum. Longstanding inflammation may lead to several bowel complications including obstruction, stricture, fistula and abscesses which often necessitate surgery. Cross-sectional imaging methods such as computed tomography and magnetic resonance imaging are being utilized more frequently to assess mural and extramural inflammatory bowel disease manifestations. Magnetic resonance enterography (MRE) for assessment of small bowel is optimal because of absence of ionizing radiation, better soft tissue contrast, development of motion-free sequences and high resolution images. A typical protocol includes pre and postcontrast sequences utilizing an enteric contrast agent for adequate bowel distention and an antiperistaltic agent. Overall, MRE allows the evaluation of disease activity, extraenteric complication and response to therapy with a great impact on patient management. In this review we discuss the features of MRE from patient's preparation and exam protocol to pathological findings.

Retinal vessel calibre measurements by optical coherence tomography angiography.

PURPOSE: To compare the vessel calibre measurements between optical coherence tomography angiography (OCTA) and colour fundus photography. METHODS: In this retrospective comparative study, OCTA and colour fundus images of healthy eyes and eyes with optic atrophy were evaluated. The colour fundus image was registered manually using Image J software to the OCTA image of the optic disc. Two independent graders measured the vessel calibre of the widest vein and artery in each peripapillary quadrant on a 3.4 mm diameter circle centred on the optic disc in the same location on both images. The difference in vessel calibre between the two techniques was assessed. RESULTS: A total of 312 vessels from 29 healthy eyes and 20 eyes with atrophic optic discs were included. There was a high level of agreement between graders for measurement of vessel calibre in both colour fundus (intraclass correlation coefficient=0.93, coefficient of variation=0.07) and OCTA images (intraclass correlation coefficient=0.94, coefficient of variation=0.05). The mean vessel calibre in colour fundus images (94.5±23.2 µm) and OCT images (112.2±26.1 µm) was correlated (r=0.8, p<0.001), but the difference was statistically significant (mean difference: 17.6±1.5 µm, p<0.001). This difference was evident for both arteries (mean difference: 18.2±16.3 µm, p<0.001) and veins (mean difference: 15.1±16.2 µm, p<0.001) individually, with a similar magnitude of difference for both vessel types (p=0.08). In addition, the magnitude of difference between imaging modalities was similar in atrophic and healthy discs (17.1±15.9 vs 18.4±15.2 µm, respectively, p=0.4). The difference, however, was significantly higher in vessels with a calibre of ≤94.5 compared with larger vessels (19.3±16.3 vs 15.6±14.4 µm, respectively, p=0.02). CONCLUSIONS: Vessel calibre measurements were significantly larger in OCTA images compared with colour fundus photographs, particularly for smaller vessels. These differences may need to be accounted for when using OCTA-derived metrics.

Dynamic functionality and static changes of retinal vessels in diabetic patients treated with intravitreal ranibizumab.

AIMS: To investigate the short-term effects of intravitreal ranibizumab on retinal vessel functionality in patients with diabetic macular edema (DME) by Dynamic Vessel Analyzer (DVA). METHODS: Patients presenting with DME were enrolled in the study. All patients underwent a complete ophthalmic evaluation, including optical coherence tomography and dynamic and static vessel analysis, using the DVA before (baseline), 1 week and 1 month after administration of intravitreal ranibizumab. DME subject were compared with diabetic retinopathy (DR) without DME subjects, and with normal non diabetic subjects (controls) matched for age and sex. RESULTS: A total of 45 eyes of 45 subjects (15 eyes for each group) were included in the analysis. In DME patients, dynamic analysis showed a significant decrease in mean arterial dilation from baseline to 1 week. Mean central retinal artery equivalent (CRAE) of DR patients without DME was significantly different from baseline and week 1 of DME eyes. In healthy control subjects, CRAE was significantly different from CRAE at baseline and 1 week on DME patients, but not significantly different from DR patients without DME. CONCLUSIONS: Using DVA in patients with DME, dynamic analysis showed a significant decrease in mean arterial dilation from baseline to 1 week in DME eyes. A significant reduction in arterial vessels could be demonstrated in DME patients compared to DR patients without DME and controls.

Changes in Choroidal Thickness follow the RNFL Changes in Leber's Hereditary Optic Neuropathy.

Leber's hereditary optic neuropathy (LHON) is typically characterized by vascular alterations in the acute phase. The aim of this study was to evaluate choroidal changes occurring in asymptomatic, acute and chronic stages of LHON. We enrolled 49 patients with LHON, 19 with Dominant Optic Atrophy (DOA) and 22 healthy controls. Spectral Domain-Optical Coherence Tomography (SD-OCT) scans of macular and peripapillary regions were performed in all subjects, to evaluate macular and peripapillary choroidal thickness, and retinal nerve fiber layer (RNFL) thicknes. Macular and peripapillary choroidal thicknesses were significantly increased in the acute LHON stage. On the contrary, macular choroidal thickness was significantly reduced in the chronic stage. Furthermore, peripapillary choroidal thickness was decreased in chronic LHON and in DOA. Both RNFL and choroid had the same trend (increased thickness, followed by thinning), but RNFL changes preceded those affecting the choroid. In conclusion, our study quantitatively demonstrated the involvement of the choroid in LHON pathology. The increase in choroidal thickness is a feature of the LHON acute stage, which follows the thickening of RNFL. Conversely, thinning of the choroid is the common outcome in chronic LHON and in DOA.

Assessment of the Real-Life Usage of Intravitreal Dexamethasone Implant in the Treatment of Chronic Diabetic Macular Edema in France.

PURPOSE: Intravitreal steroids, including dexamethasone implant (Ozurdex(®)), are effective for the treatment of diabetic macular edema (DME). However, the dosing regimen for Ozurdex in DME is unclear, and thus, this study was designed to evaluate the dosing regimen for dexamethasone in real-life clinical practice. METHODS: Results are presented from 3 studies based on a questionnaire that was sent out by e-mail to physicians; the monitoring of drugs dispensing over time through pharmacies; and the French Social Security database for 2011 and 2012. Data are presented as the average number of dexamethasone treatments per year and the time interval between injections. RESULTS: Study 1 involved 111 ophthalmologists and assessed DME prescriptions. The number of injections per year and the time interval between 2 successive injections were measured as 2.3 and 4.8 months, respectively. In study 2, the survey incorporated 570 prescriptions from retail pharmacies; the mean follow-up period was 13.7 months, and 2.3 injections were administered per year with a time interval between injections of 5.2 months. In study 3, relating to the reimbursements by social security, 114 patients were initially identified and, among these, 15 patients were treated with Ozurdex. Over the course of a 25-month follow-up period, an average of 2.5 Ozurdex implants were injected per year with 4.7 months between injections. CONCLUSIONS: The average number of dexamethasone implant injections was consistent between studies with an average of 2.4 injections per year and 4.9 months between treatments. This highlights the need for a study to evaluate the optimal treatment frequency in DME.

Assessment of Choroidal Topographic Changes by Swept-Source Optical Coherence Tomography After Intravitreal Ranibizumab for Exudative Age-Related Macular Degeneration.

PURPOSE: To investigate choroidal topographic changes by swept-source optical coherence tomography (Swept-OCT) in patients undergoing intravitreal injections of anti-vascular endothelial growth factor (VEGF) for exudative age-related macular degeneration (AMD). DESIGN: Prospective interventional study. METHODS: Consecutive patients with unilateral treatment-naïve exudative AMD were entered into the study over 6 months. Changes in choroidal thickness after intravitreal ranibizumab injections, overall in the macula and in neovascular and non-neovascular areas, from baseline to month 3 (loading phase) and month 6 (pro re nata phase), were investigated by means of Swept-OCT maps. RESULTS: Forty-one eyes of 41 patients (mean age: 79.4 ± 7.3 years) were analyzed. Choroidal thickness at study entry was significantly thicker in the study eyes as compared to fellow eyes (P < .05). Analysis of sectorial choroidal thickness over time in study eyes revealed a significant reduction in both neovascular and non-neovascular areas from baseline to month 3 and month 6 (P < .0001 for all). Central choroidal thickness revealed significant variation between treated and fellow eyes from baseline to month 3 (P = .017) and month 6 (P = .045). The visual gain was significantly higher (P = .02) in patients with a larger choroidal thickness reduction (≥29 µm, n = 11) vs the others (n = 30). CONCLUSIONS: The thinning of the macular choroid (affected or not by choroidal neovascularization), along with the significantly thicker choroid in exudative AMD eyes before treatment initiation compared to fellow eyes, allows the hypothesis that anti-VEGF treatment may favorably influence the choroidal exudation by reducing choroidal vascular hyperpermeability.

Advantage of Applying OSC to (1)H NMR-Based Metabonomic Data of Celiac Disease.

BACKGROUND: Celiac disease (CD) is a disorder associated with body reaction to gluten. After the gluten intake, an immune reaction against the protein occurs and damages villi of small intestine in celiac patients gradually. OBJECTIVES: The OSC, a filtering method for minimization of inter- and intra-spectrometer variations that influence on data acquisition, was applied to biofluid NMR data of CD patients. PATIENTS AND METHODS: In this study, metabolites of total 56 serum samples from 12 CD patients, 15 CD patients taking gluten-free diet (GFD), and 29 healthy cases were analyzed using nuclear magnetic resonance (NMR) and associated theoretical analysis. Employing ProMetab (version ProMetab_v3_3) software, data obtained from NMR spectra were reduced and orthogonal signal correction (OSC) effect on celiac disease metabonomics before and after the separation by principle component analysis (PCA) was investigated. RESULTS: The three groups were separated by OSC and findings were analyzed by partial least squares discriminant analysis (PLS-DA) method. Root mean square error of calibration (RMSEc) and correlation coefficient of calibration (Rc) for PLS-DA referred to an efficient group separation filtered by OSC. CONCLUSIONS: The applied leave-one-out cross-validation to PLS-DA method performed along with OSC confirmed validation of data analysis. Finally four metabolites are introduced as CD biomarkers.