Typical Enhancement Pattern Research Articles

Diagnostic MRI characteristics of pediatric clear cell sarcoma of the kidney and rhabdoid tumor of the kidney: A retrospective multi-center SIOP-RTSG Radiology panel study

IntroductionClear cell sarcoma of the kidney (CCSK) and rhabdoid tumor of the kidney (RTK) are rare malignant pediatric renal tumors, both accounting for 1–5% of diagnoses. Within the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG) protocols diagnostic invasive procedures to determine histology are discouraged. MRI has become the preferred imaging modality, however, non-invasive discrimination of CCSK and RTK remains challenging. Therefore, this study aims to identify diagnostic MRI-characteristics of CCSK and RTK, in the largest series of patients to date. Material and methodsFive SIOP-RTSG national review radiologists identified national diagnostic MRIs of histologically proven CCSKs and RTKs. Scan-protocols were based on MRI-guidelines following SIOP-RTSG protocols. Radiologists assessed their national cases using a validated case report form (CRF). ResultsRetrospectively, 59 patients were identified (n = 38 CCSK, n = 21 RTK). CCSKs showed a high median volume (576 cm3, range 54–4414), which was lower for RTKs (290 cm3, range 20–761) (p = 0.006 *10-3). Fifty-two percent (11/21) of RTK-patients showed disease at other locations, predominantly the lungs and brain, compared to 8% of CCSK-patients (3/38). RTKs showed ill-defined margins (12/21, 57%) and infiltrative growth pattern (13/21, 62%). CCSKs appeared hyper-intense on T2-weighted imaging (27/38, 71%) with a characteristics band-like enhancement (13/38, 34%), whereas RTK cases often showed T2-weighted hypo-intensity (11/21, 52%). The overall mean ADC-value for CCSK was 1.11 * 10-3 mm2/s (range 0.57–2.07 *10-3 mm2/s), and 0.72 * 10-3 mm2/s (range 0.53–0.90 *10-3 mm2/s) for RTK. ConclusionsThis retrospective study suggests a small size, T2-weighted hypo-intensity and an aggressive growth pattern may be characteristic for RTK. CCSK often showed a typical band-like enhancement pattern with relatively high ADC-values. Identified MRI-characteristics may be used in future studies focusing on validation and discrimination from especially WT, aiming for an early non-invasive diagnosis.

P354 REMOVAL OF CARDIAC AL–AMYLOID LEADS TO CARDIOMYOCYTE POSITIVE REMODELING AND RESTRICTIVE PATTERN REVERSAL

Abstract Background Properly treated AL cardiac amyloidosis can have a long survival. However, the mechanism involved in arresting or reversing cardiomyopathy, such as toxic suppression of the light chain or removal of the amyloid substance, is still unclear. We describe the case of a patient with AL amyloidosis treated with chemotherapy in whom serial endomyocardial biopsies were performed at diagnosis and after 17 years. Clinical case A 71–year–old lady onset with a hypertrophic phenotype cardiomyopathy (maximum thickness LV 18.2 mm, diastolic dysfunction with E/A ratio 2.45. preserved contractility (EF 55%) and NYHA class 3) received a diagnosis in 2004 of AL amyloidosis and underwent several cycles of chemotherapy. At clinical onset, cardiac amyloidosis was documented by endomyocardial biopsy. After 17 years, in 2021, the patient was hospitalized for palpitations and chest pain and documented intermittent phases of atrial fibrillation. The patient was reevaluated with immunoelectrophoresis, echocardiogram, cardiac magnetic resonance, coronary angiography, and left ventricular endomyocardial biopsy. Serum monoclonal chain AL–K was reduced from initial 233 mg/L to 18.2 mg/L, vn<19.4 mg/L. The echocardiogram showed reduction of the heart walls with reduction of the thickness to 14 mm, with regression of the restrictive pattern (E/A ratio from 2.45 to 0.5). Serum NT–proBNP decreased from 3188 pg/mL to 480 pg/mL (n.v.<334 pg/mL). Cardiac MRI revealed normal myocardial wall thickness, with preserved systolic function, in the absence of the typical late gadolinium enhancement pattern. Histology and electron microscopy showed no more hypo/atrophic cardiomyocytes and the interstitium was almost completely devoid of amyloid fibrils, which were distant from the cardiac cell allowing an improvement in oxygenation and trophism. Conclusions Remission of monoclonal gammopathy is associated with a removal of cardiac amyloid deposits and with a regression of cardiac hypertrophy and restrictive pattern. Histologically, the degradation of amyloid fibrils determines a better trophism of cardiomyocytes.

Non-invasive diagnosis of transthyretin cardiac amyloidosis utilizing typical late gadolinium enhancement pattern on cardiac magnetic resonance and light chains.

While cardiac magnetic resonance (CMR) is often obtained early in the evaluation of suspected cardiac amyloidosis (CA), it currently cannot be utilized to differentiate immunoglobulin (AL) and transthyretin (ATTR) CA. We aimed to determine whether a novel CMR and light-chain biomarker-based algorithm could accurately diagnose ATTR-CA. Patients with confirmed AL or ATTR-CA with typical late gadolinium enhancement (LGE) and Look-Locker pattern for CA on CMR were retrospectively identified at three academic medical centres. Comprehensive light-chain analysis including free light chains, serum, and urine electrophoresis/immunofixation was performed. The diagnostic accuracy of the typical CMR pattern for CA in combination with negative light chains for the diagnosis of ATTR-CA was determined both in the entire cohort and in the subset of patients with invasive tissue biopsy as the gold standard. A total of 147 patients (age 70 ± 11, 76% male, 51% black) were identified: 89 ATTR-CA and 58 AL-CA. Light-chain biomarkers were abnormal in 81 (55%) patients. Within the entire cohort, the sensitivity and specificity of a typical LGE and Look-Locker CMR pattern and negative light chains for ATTR-CA was 73 and 98%, respectively. Within the subset with biopsy-confirmed subtype, the CMR and light-chain algorithm were 69% sensitive and 98% specific. The combination of a typical LGE and Look-Locker pattern on CMR with negative light chains is highly specific for ATTR-CA. The successful non-invasive diagnosis of ATTR-CA using CMR has the potential to reduce diagnostic and therapeutic delays and healthcare costs for many patients.

Prediction Model and Nomogram of Early Recurrence of Hepatocellular Carcinoma after Radiofrequency Ablation Based on Logistic Regression Analysis.

The purpose of this study was to screen for high-risk factors leading to the early recurrence of hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA) and to construct a prediction model and nomogram. This retrospective study included 108 patients with primary HCC who underwent RFA treatment at the Harbin Medical University Cancer Hospital between January 2018 and June 2019. Four risk factors were screened for using univariate and multivariate logistic regression analyses: number of tumors (hazard ratio [HR]=14.684, 95% confidence interval [CI]: 1.099-196.215, p=0.042), neutrophil-to-lymphocyte ratio (NLR) (HR=2.178, 95% CI: 1.003-4.730, p=0.049), contrast-enhanced ultrasound (CEUS) performance (HR=6.482, 95% CI: 1.161-36.184, p=0.033) and α-fetoprotein (AFP) level (HR=1.001, 95% CI: 1.000-1.003, p=0.040). We established a prediction model: Logit(p)=-3.096+2.827×(number of tumors >1=1)+1.851×(CEUS revealing rapid enhancement of blood flow signal in the arterial phase and clearance in the portal phase=1)+1.941×(NLR >1.55=1)+0.257×(AFP >32.545=1). Through clinical decision curve analysis, the model's threshold was 0.043-0.873, indicating a high clinical value. Patients with a high AFP level, typical CEUS enhancement pattern, multiple tumors and elevated NLR are more likely to relapse early.

Gelatin-Agar Liver Phantom to Simulate Typical Enhancement Patterns of Hepatocellular Carcinoma for MRI

Background: Hepatocellular carcinoma (HCC) is one of the most common cause of cancer-related deaths worldwide. The objective of this study is to detect the various stages of HCC through the utilization of a dynamic liver phantom with MRI. Methods: Three liver phantoms composed of different gelatin concentrations (2.5%wt, 4.0%wt, and 5.0%wt) and fixed agar concentrations were used. The HCC samples consisted of agarose and glycerol and were of varying sizes (0.5,1.0, and 2.0cm). The chemical, mechanical, electrical, and imaging properties of the phantoms were examined. The consistency of T1 and T2 signal intensities over a six-week period was studied. In addition, dynamic contrast-enhanced MRI was used to detect the HCC samples through the Dixon sequence. Results: The gelatin concentration of 5%wt was the most stable in regard to density, exhibited the lowest average compressive strength of 0.22MPa, and had the lowest electrical conductivity over the course of a six-week period. During this time, an increase in the T1 signal intensity was observed as the gelatin concentration in the sample increased. On the contrary, the least change in T1 and T2 was noted in the first sample with the 2.5% wt of gelatin. The HCC samples simulated the typical appearance of HCC, with the minimum sample size the body coil could detect being 1cm. Conclusion: Typical Enhancement patterns of HCC were simulated under MRI.

Typical and Atypical Imaging Findings of Hepatocellular Carcinoma on Multiphasic MDCT Scan in Histologically Proved Cases

Abstract Objective The purpose of this study was to find out the incidence of typical and atypical radiological imaging findings of hepatocellular carcinoma (HCC) on multiphase multidetector computed tomography (MDCT) scans in histologically proven cases. Materials and Methods A multiphase computed tomography study of 73 patients with histologically proven HCC was evaluated by a radiologist. Our multiphasic protocol was composed of precontrast, arterial, portal, and delayed venous phases. The reviewers analyzed the CT images for tumor size, enhancement patterns of HCC in different phases, relative timing of washout, internal cystic changes, and presence of dysmorphic intratumoral vessel aneurysms or arteriovenous shunt. Results Most of the cases (95.9%) showed typical enhancement patterns in MDCT, i.e., enhancements in the arterial phase with the portal or delayed venous phase contrast washout. Three cases (4.9%) out of 73 HCC showed enhancements in the portal phase and washout in the delayed venous phase. Seven cases out of total 73 HCC (9.5%) patients showed heterogeneous enhancements in both arterial and portal phases and contrast washout in the delayed venous phase. Venous thrombosis was noted in about 44 cases (60%) out of total 73 patients, in which portal vein thrombosis was more common than hepatic veins/inferior vena cava. Conclusion Most of the HCC show typical enhancement patterns, i.e., heterogeneous enhancements in the arterial phase and washout in the portal venous phase when we use MDCT. These findings are higher than those described previously. However, in our study, the main difference with MDCT was lower frequency of intratumoral pseudoaneurysm and bile duct invasion, and intratumoral fat and calcification (atypical character of HCC) were not found which were rare findings in previous study.

Prevalence and prognostic significance of ischemic late gadolinium enhancement pattern in non-ischemic dilated cardiomyopathy

Typical late gadolinium enhancement (LGE) patterns in dilated cardiomyopathy (DCM) include intramyocardial and subepicardial distribution. However, the ischemic pattern of LGE (subendocardial and transmural) has also been reported in DCM without coronary artery disease (CAD), but its correlates and prognostic significance are still not known. On these bases, this study sought to describe the prevalence and prognostic significance of the ischemic LGE pattern in DCM. A total of 611 DCM patients with available cardiac magnetic resonance were retrospectively analyzed. A composite of all-cause-death, major ventricular arrhythmias (MVAs), heart transplantation (HTx) or ventricular assist device (VAD) implantation was the primary outcome of the study. Secondary outcomes were a composite of sudden cardiac death or MVAs and a composite of death for refractory heart failure, HTx or VAD implantation. Ischemic LGE was found in 7% of DCM patients without significant CAD or history of myocardial infarction, most commonly inferior/inferolateral/anterolateral. Compared to patients with non-ischemic LGE, those with ischemic LGE had higher prevalence of hypertension and atrial fibrillation or flutter. Ischemic LGE was associated with worse long-term outcomes compared to non-ischemic LGE (36% vs 23% risk of primary outcome events at 5 years respectively, P=.006), and remained an independent predictor of primary outcome after adjustment for clinically and statistically significant variables (adjusted hazard ratio 2.059 [1.055-4.015], P=.034 with respect to non-ischemic LGE). The ischemic pattern of LGE is not uncommon among DCM patients without CAD and is independently associated with worse long-term outcomes.

Agarose and Wax Tissue-Mimicking Phantom for Dynamic Magnetic Resonance Imaging of the Liver

Objectives: Polymer phantoms can be used to simulate the properties of tissues or organs such as the liver during magnetic resonance imaging (MRI). Although there are reports of simulated liver phantoms with hepatocellular carcinoma (HCC); no studies have documented the simulating of the typical dynamic pattern. Aim: The present study aimed to investigate properties of developed phantoms with respect to the stability, including chemical, mechanical, electrical, as well as MRI properties (T1- and T2- signal intensities), in addition to simulating HCC in a dynamic way. Methods: In this study, liver parenchyma of size 23 ×18 ×13 cm was simulated using three different agarose-wax samples (agarose at concentrations of 2.5 wt%, 4.5 wt%, and 6.0 wt%) mixed with a fixed wax concentration of 2.6 wt%.. HCC samples were fabricated using polyurethane and glycerol of various diameters (0.5, 1.0, and 2.0 cm). Results: The results showed that the agarose-wax sample with a concentration of 2.5 wt% was the most stable sample among the other samples (P-value, 0.468) in mechanical and T1 and T2 intensities. It was also noted that the sample at the concentration of 4.5 wt% had the closest density value to human liver with a difference of 7.88%. Moreover, the agarose-wax sample at a concentration of 2.5 wt% had the closest compressibility and conductivity values, and T1-relaxation time compared to the human liver. However, the largest changes in relaxation times were observed in the fifth week of all samples (P-value = 0.047). The typical enhancement pattern for a simulated HCC of a minimum size, which can be measured with MRI, was 1.0 cm, using a body coil, and 0.5 cm using a head coil. Conclusions: The chemical, electrical density, compressive strength, density, and MR imaging properties of the phantom were measured and compared to those of the human body.

Ultrasound lymphatic imaging for the diagnosis of metastatic central lymph nodes in papillary thyroid cancer.

Up to 40% of papillary thyroid cancer (PTC) patients have lymph node metastasis, a condition that implies persistent, recurrent, or progressive disease. However, the American Joint Committee on Cancer Manual states that there is no reliable examination for adequate lymph node staging. Therefore, our aim is to develop a lymphatic imaging technique using ultrasonography to address this challenge. We consecutively enrolled PTC patients who underwent ultrasound (US) lymphatic imaging via the peritumoral injection of contrast media. Identification of the sentinel lymph nodes and the targeted sentinel lymph nodes was separately based on the lymphatic drainage pathway and the enhancement patterns. Every identified targeted node was assigned a score, according to the features on conventional US and enhancement patterns, and was referred for ultrasound-guided fine-needle aspiration. Cytological and histopathologic results represented the statuses of the targeted lymph nodes and overall central lymph nodes, respectively, which were applied to evaluate the diagnostic performance of US lymphatic imaging. In total, 100 PTC patients were included. On the basis of the cytological results, the sensitivity (97.1%, 95% confidence interval [CI]: 84.7-99.9%) of detecting positive targeted nodes by US lymphatic imaging significantly increased by 45.5% at a threshold of 4 or higher (p = 0.0001), without loss of specificity (p = 1.0000). The surgical results showed that the metastatic degree was positively correlated with an increase in the score (τ: 0.671, p < 0.001). Ultrasound lymphatic imaging has a high diagnostic performance, and its corresponding scoring system facilitates grading of the nodal burden in the central compartment. • Ultrasound neck lymphatic imaging is an effective contrast-enhanced ultrasound (CEUS) technique (applied after the peritumoral injection of contrast media) for identifying sentinel lymph nodes in the central compartment by tracing the imaged afferent lymphatic vessel. • Lack of enhancement or perfusion defects is the typical enhancement pattern for recognizing the involved central lymph nodes. • Ultrasound lymphatic imaging for identification of positive central lymph nodes before surgery may effectively avoid complications associated with the surgical sentinel node procedure.

Machine Learning-Based Ultrasomics Improves the Diagnostic Performance in Differentiating Focal Nodular Hyperplasia and Atypical Hepatocellular Carcinoma.

BackgroundThe typical enhancement patterns of hepatocellular carcinoma (HCC) on contrast-enhanced ultrasound (CEUS) are hyper-enhanced in the arterial phase and washed out during the portal venous and late phases. However, atypical variations make a differential diagnosis both challenging and crucial. We aimed to investigate whether machine learning-based ultrasonic signatures derived from CEUS images could improve the diagnostic performance in differentiating focal nodular hyperplasia (FNH) and atypical hepatocellular carcinoma (aHCC).Patients and MethodsA total of 226 focal liver lesions, including 107 aHCC and 119 FNH lesions, examined by CEUS were reviewed retrospectively. For machine learning-based ultrasomics, 3,132 features were extracted from the images of the baseline, arterial, and portal phases. An ultrasomics signature was generated by a machine learning model. The predictive model was constructed using the support vector machine method trained with the following groups: ultrasomics features, radiologist’s score, and combination of ultrasomics features and radiologist’s score. The diagnostic performance was explored using the area under the receiver operating characteristic curve (AUC).ResultsA total of 14 ultrasomics features were chosen to build an ultrasomics model, and they presented good performance in differentiating FNH and aHCC with an AUC of 0.86 (95% confidence interval [CI]: 0.80, 0.89), a sensitivity of 76.6% (95% CI: 67.5%, 84.3%), and a specificity of 80.5% (95% CI: 70.6%, 85.9%). The model trained with a combination of ultrasomics features and the radiologist’s score achieved a significantly higher AUC (0.93, 95% CI: 0.89, 0.96) than that trained with the radiologist’s score (AUC: 0.84, 95% CI: 0.79, 0.89, P < 0.001). For the sub-group of HCC with normal AFP value, the model trained with a combination of ultrasomics features, and the radiologist’s score remain achieved the highest AUC of 0.92 (95% CI: 0.87, 0.96) compared to that with the ultrasomics features (AUC: 0.86, 95% CI: 0.74, 0.89, P < 0.001) and radiologist’s score (AUC: 0.86, 95% CI: 0.79, 0.91, P < 0.001).ConclusionsMachine learning-based ultrasomics performs as well as the staff radiologist in predicting the differential diagnosis of FNH and aHCC. Incorporating an ultrasomics signature into the radiologist’s score improves the diagnostic performance in differentiating FNH and aHCC.

Hierarchical Temporal Attention Network for Thyroid Nodule Recognition Using Dynamic CEUS Imaging.

Contrast-enhanced ultrasound (CEUS) has emerged as a popular imaging modality in thyroid nodule diagnosis due to its ability to visualize vascular distribution in real time. Recently, a number of learning-based methods are dedicated to mine pathological-related enhancement dynamics and make prediction at one step, ignoring a native diagnostic dependency. In clinics, the differentiation of benign or malignant nodules always precedes the recognition of pathological types. In this paper, we propose a novel hierarchical temporal attention network (HiTAN) for thyroid nodule diagnosis using dynamic CEUS imaging, which unifies dynamic enhancement feature learning and hierarchical nodules classification into a deep framework. Specifically, this method decomposes the diagnosis of nodules into an ordered two-stage classification task, where diagnostic dependency is modeled by Gated Recurrent Units (GRUs). Besides, we design a local-to-global temporal aggregation (LGTA) operator to perform a comprehensive temporal fusion along the hierarchical prediction path. Particularly, local temporal information is defined as typical enhancement patterns identified with the guidance of perfusion representation learned from the differentiation level. Then, we leverage an attention mechanism to embed global enhancement dynamics into each identified salient pattern. In this study, we evaluate the proposed HiTAN method on the collected CEUS dataset of thyroid nodules. Extensive experimental results validate the efficacy of dynamic patterns learning, fusion and hierarchical diagnosis mechanism.

Role of Triple Phase Computed Tomography in the Evaluation of Liver Lesions

Introduction: Wide range of benign and malignant tumours can occur in the liver, the largest organ in our body. So far, the histopathological diagnosis was considered the gold standard with the limitation of it being invasive. However, the advances in the radiological imaging techniques would surpass this difficulty, as well helps in coming to a close, if not many times the definitive diagnosis, thus preventing these invasive diagnostic procedures. Aim: To assess the role of triple phase Computed Tomography (CT) in the evaluation of liver lesions by evaluating the enhancing characteristics and comparing the findings with ultrasound, Magnetic Resonance Imaging (MRI), Biopsy and follow-up as applicable during the study period. Materials and Methods: This is a longitudinal prospective study conducted at Kamineni Institute of Medical Sciences, Narketpally, on 60 selected subjects for a period of 12 months, during July 2017 to July 2018. Patients of age more than 20 years of both gender with clinical suspicion or inconclusively diagnosed liver lesions were selected. These patients are evaluated using standard triple phase contrast CT liver protocol on 16 slice multidetector CT scan. The different enhancing patterns were inspected and compared to USG, MRI and Biopsy as applicable. All the collected data were tabulated in Microsoft excel sheet and were analysed in SPSS Software version 21. Results: The study consisted of 60 patients with 35 male and 25 female and assessed a total of 200 individual liver lesions. Out of which, 141 were malignant and 59 benign. Metastasis being the most common (n=113), followed by Hepatocellular Carcinoma (HCA) (n=26) and intrahepatic Cholangiocarcinoma (CCA) (n=2) in malignant lesions and Haemangioma (n=26) was the commonest benign lesion followed by cysts (n=20), abscess (n=10), Focal Nodular Hyperplasia (FNH) (n=2) and adenoma (n=1). In total, there were 112 (56%) hypovascular lesions and 88 hypervascular lesions (44%), with 11 enhancement patterns which are correlated to standards of reference satisfactorily. The study shows triple phase CT is 100% sensitive in diagnosing abscess, simple cysts, FNH and intrahepatic CCA and showed varied sensitivities with other lesions like HCC (sensitivity-79%), Haemangioma (sensitivity-92.3%), Metastasis (sensitivity- 91.1%), however, it showed 100% specificity in diagnosing all the cases when there was typical enhancement pattern for the individual lesion concerned. The four benign enhancement patterns and five malignant enhancement patterns were noted along with hypo/hypo/hypo, hypo/hypo/hyper and hyper/A/A patterns which needs cautious interpretation. Conclusion: We recommend triple phase CT scan as a standard first line procedure with high sensitivity, specificity and accuracy in differentiating benign and malignant liver lesions and avoiding unnecessary biopsies. Hepatic Arterial Phase (HAP) is used in identifying small hypervascular lesions and Porto-Venous Phase (PVP) in detecting small hypovascular lesions. Particularly in HCC, triple phase CT provides additional information of vascular invasions, arterioportal shunts, capsular delineation and vascular road map for pre-surgical evaluation.

Studying The Imaging Properties Of Liver Tumors On Magnetic Resonance Imaging With Primovist - A Hepatospecific Paramagnetic Gadolinium-Based Contrast Agent

The study was performed on 25 patients diagnosed with liver tumors, assigned magnetic resonance imaging (MRI) with Primovist - a hepatospecific paramagnetic gadolinium-based contrast agent at the International Medical Center of Hue Central Hospital. The result is as followed: 11 HCCs, 1 biliary tract malignant tumor, 1 hepatic adenoma, 6 metastates, 2 FNH, 1 hepatic AML, 3 hemangiomas. 47 lesions in total, including 9 lesions smaller than 1cm, 12 lesions 1-2 cm, 26 lesions larger than 2 cm. All 11 HCCs are hypointense on T1W, hyperintense on T2W, intratumoral high signal on DWI, 9 cases have typical enhancement pattern on Dynamic phase (arterial enhancement with washout assessed on the portal venous phase), 10 cases have no enhancement on Hepatocellular phase. Metastasis lesions have peripheral enhancement on both arterial and venous phases, no enhancement on delayed phase due to not having hepatic cells. The the biliary tract tumor is pathologically correct, with minor peripheral enhancement 30 seconds after injection, gradual centripetal enhancement after 60 and 90 seconds, no enhancement on delayed phase due to not having hepatic cells. 3 cases with hemangiomas are hyperintense on T2WI, similar to blood vessels, hypointense on T1WI, pheripherally enhanced 30 seconds after injection, fully centripetal fill-in after 90 seconds, non-enhanced on delayed phase (20 minutes) due to not having hepatic cells. 2 cases with FNH have iso- or mildly hyperintense on T1W, isointense on T2W and hypointense on DWI, isointense on hepatocellular phase due to the reservation of hepatic cells. Liver MRI with Primovist is specific for Hepatic cells, playing a critical role in detecting small lesions and differentiating benign and malignant lesions of the liver, especially those without typical enhancement pattern on Dynamic phase.

Pearls and pitfalls in magnetic resonance imaging of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common primary hepatic malignancy, which usually arises in cirrhotic liver. When the typical enhancement pattern, consisting of late arterial hyperenhancement followed by washout, is present in nodules larger than 1 cm, HCC can be confidently diagnosed without the need for tissue biopsy. Nevertheless, HCC can display an atypical enhancement pattern, either as iso or hypovascular lesion, or hypervascular lesion without washout. Not only the enhancement pattern of HCC could be atypical, but also a variety of histological types of HCC, such as steatotic, scirrhous, fibrolamellar, or combined hepatocellular-cholangiocellular carcinoma could raise diagnostic dilemmas. In addition, distinct morphological types of HCC or different growth pattern can occur. Awareness of these atypical and rare HCC presentations on magnetic resonance imaging is important for accurate differentiation from other focal liver lesions and timely diagnosis, which allows optimal treatment of patients.

MRI in the differential diagnosis between well-differentiated hepatocellular carcinomas and high-grade dysplastic nodules in cirrhotic liver

ObjectiveTo assess the diagnostic efficacy of magnetic resonance imaging (MRI) in the differential diagnosis between well-differentiated hepatocellular carcinomas (WD-HCCs) and high-grade dysplastic nodules (HGDNs) in cirrhotic liver. MethodsFrom January 2012 to April 2018, we retrospectively analyzed 91 cirrhotic nodules (HGDN, n = 31, WD-HCC, n = 60) which were confirmed by surgery or pathology. Each patient underwent gadobenate dimeglumine-enhanced hepatic MRI. The MRI characteristics and enhancement effects were calculated and analyzed. ResultsHyperintensity on diffusion-weighted imaging (DWI), the typical enhancement pattern and hypo-intensity on T1-Weighted imaging (T1WI)were showed with statistically significant difference between WD-HCCs and HGDNs in cirrhotic live (P = 0.002, 0.008, 0.002, respectively). And high signal intensity (SI) on DWI (sensitivity, 66.7%, specificity, 67.7%) was the most specific feature to differentiated WD-HCCs from HGDNs. The combination of DWI and the dynamic enhancement pattern improved the differentiation of WD-HCCs from HGDNs(specificity 83.9%). ConclusionDWI is the most specific technique to differentiate WD-HCCs from HGDNs. The combination of DWI and the typical dynamic enhancement pattern can improve the differentiation of WD-HCCs from HGDNs. Pre-enhanced T1WI, as well as a capsule, provides additional diagnostic values.

Comparison of the Enhancement Pattern of Hepatic Hemangioma on Magnetic Resonance Imaging Performed With Gd-EOB-DTPA Versus Gd-BOPTA

PurposeTo compare magnetic resonance imaging (MRI) findings with gadoxetic acid and gadobenate dimeglumine for the diagnosis of hepatic hemangiomas. Materials and MethodsIn this retrospective study, we included 26 hemangiomas (mean size was 14 mm ± 10 mm) in 19 patients (mean age 60 ± 14 years) scanned with both gadobenate dimeglumine MRI and gadoxetic acid MRI. For each patient, we collected multiple lesion variables including location, number, size and enhancement pattern on arterial, portal venous, 3-minute and hepatobiliary phases with both gadoxetic acid and gadobenate dimeglumine. The enhancement pattern with the two contrast agents was then compared. ResultsThe typical enhancement pattern of hepatic hemangiomas was more common—though not statistically significant—with gadobenate dimeglumine compared to gadoxetic acid (57% [15 of 26] vs 42% [11 of 26], respectively; P = 0.4057 for both peripheral globular discontinuous enhancement in the arterial phase and centripetal fill-in in the portal venous phase). A significantly higher number of hemangiomas showed centripetal fill-in or hyperintensity in the 3-minute phase with gadobenate dimeglumine compared to gadoxetic acid (88% [23 of 26) vs 58% [15 of 26]; P = 0.0266). A pseudo washout sign in the 3-minute phase was detected in one of the 5 flash-filling hemangiomas with gadoxetic acid, but not gadobenate dimeglumine. All hemangiomas were hypointense in the hepatobiliary phase with both gadobenate dimeglumine and gadoxetic acid. ConclusionsThe enhancement pattern of hepatic hemangiomas may vary depending on the hepatobiliary agent, with more frequent lack of the typical pattern with gadoxetic acid compared to gadobenate dimeglumine.

The application of contrast‐enhanced ultrasound for the characterization of hepatic tumors: An assessment focusing on hepatocellular carcinoma

There are only limited applications of contrast‐enhanced ultrasound (CEUS) in Taiwan. We aimed to report our initial experience of CEUS in the diagnosis of hepatic tumors, focusing on hepatocellular carcinoma (HCC). From September 2015 to January 2017, 126 patients were recruited for CEUS using Definity at Tainan Municipal Hospital for the evaluation of hepatic tumors. Of the 126 patients with 64 pathology‐proven liver lesions, 61 were studied. The enhancement patterns of the liver nodules were evaluated according to the 2012 World Federation for Ultrasound in Medicine and Biology and European Federation of Societies for Ultrasound in Medicine and Biology (WFUMB‐EFSUMB) guidelines. The diagnostic value of CEUS was assessed using histopathological results as reference standards and was compared with those of dynamic computed tomography (CT) and magnetic resonance imaging (MRI). The sensitivity, specificity, accuracy, and positive and negative predictive values of CEUS in the HCC diagnosis were 73.6%, 90.9%, 76.6%, and 97.5% and 41.7%, respectively. In terms of diagnostic accuracy of HCC, the discordance between CEUS and dynamic CT/MRI was not statistically significant (P = 0.76). Higher body mass index (&gt;25 kg/m2) showed a significantly negative association with the typical HCC enhancement pattern on CEUS (P = 0.017). No adverse events related to the ultrasound contrast agent were found in the study. From researchers' initial experience, CEUS with Definity contrast agent can be safely and effectively applied in the diagnosis of HCC. Further investigations based on more cases of liver tumors are still warranted.

CEUS in malignant liver lesion - abdominal contrast

The diagnosis of malignant focal liver lesions is based on the association of clinical findings and ultrasound findings (both B-mode and in the vascularization pattern of these lesions). The main questions to be answered are: this finding is incidental in a healthy patient or the focal lesion is part of a broader framework Regarding to clinical features, the main issues are: the injury is incidental in a healthy patient or the FLL is part of the one clinical presentation, as monitoring cancer treatment, infectious or if the patient has a chronic liver disease, in follow up of hepatocellular carcinoma (HCC). What symptoms are present: fever, consuptivo context, etc. Concerning previous treatments: must also be searched. Presentation of typical pattern and enhancement patterns of various histologic types of malignant FLL on B-mode and Contrast Enhanced Ultrasound (CEUS), respectively. Explanation of their hemodynamic behaviour post contrast injection based on their histology and recognition of atypical patterns of contrast enhancement. The main malignant FLLs will be presented (cases of the HCC and metastases). Since the FLL is present, how to describe the main findings of the lesions is essential. The FLL should be characterized as the location (segment), number of lesions (if 3 or more nodules), size (at least 2 axes), echotexture, echogenicity, presence of necrosis / calcification / perinodular halo. Margin: regularity/ definition. Besides these findigns, it is very important characterize if there is vascular infiltration / thrombosis (portal vein, hepatic veins, ICV). If there is thrombosis of the portal system: staging it is helpful (give affected segments, extension). Another point is trying to define the thrombosis origin (hematogenous or tumoral). Presence of dilatation of the bile ducts must be reported, and ascites as well. The pattern of liver parenchyma must be reported: chronic liver disease or not / volume redistribution and other signs of cirrhosis.

Assessment of small hepatocellular carcinoma: perfusion quantification and time-concentration curve evaluation using color-coded and quantitative digital subtraction angiography.

To explore the role of quantitative digital subtraction angiography (QDSA) in the diagnosis of small hepatocellular carcinoma (HCC).Between November 2015 and November 2017, all patients who underwent chemoembolization for HCC were retrospectively reviewed. Patients with tumors measuring more than 5 cm or evident post-processing imaging artifacts were excluded. Images were post-processed using the QDSA technique. Regions of interest were manually drawn on proper hepatic artery (as a reference), target HCC and peritumoral liver. Time-concentration curves and flow parameters of the peak ratio, subtracted time-to-peak (TTP), and area under the curve (AUC) ratio was obtained and analyzed.A total of 146 HCCs (mean diameter, 1.6 cm) of 71 cirrhotic patients (54 men, 17 women; mean age, 67.7 years) were enrolled. Compared with liver parenchyma, HCCs showed an increased and more rapid flow (peak ratio, AUC ratio, subtracted TTP, and wash-in slope; all P <.001). Compared with untreated HCCs, chemoembolized HCCs showed a slower flow (subtracted TTP and wash-in slope, P = .004 and .002, respectively). HCCs with a typical enhancement pattern on computed tomography (CT) or magnetic resonance imaging (MRI) had a trend toward Type III (washout pattern) time-concentration curves (P <.001). Chemoembolized HCCs had a trend toward Type II (plateau pattern) time-concentration curves (P = .005).QDSA technology can be used to quantify perfusion measurements of HCC and hepatic parenchyma and to assess perfusion changes after HCC chemoembolization.

Role of cardiovascular magnetic resonance in suspected cardiac amyloidosis: late gadolinium enhancement pattern as mortality predictor.

BackgroundCardiac magnetic resonance (CMR) has gained a central role in the diagnosis of cardiac amyloidosis (CA). While the diagnostic role of a typical late gadolinium enhancement (LGE) pattern (global subendocardial enhancement coupled with accelerated contrast washout) has been identified, evidence is still conflicting regarding the prognostic role of such examination.Methods and resultsWe retrospectively analysed all patients referring for CMR at Niguarda Hospital (Milan, Italy) from January 2006 to January 2015 for suspected CA. Primary outcome was all-cause mortality. We identified 42 patients and divided them into 2 groups, according to the presence (Group A) or absence (Group B) of a typical amyloidosis LGE pattern. At the end of the follow-up (median 37 months, interquartile range 10–50 months), 31 patients (74%) had died. The hazard ratio for all-cause death was 3.2 (95% confidence interval [CI] 1.5–6.4, p < 0.01) for Group A versus Group B. Median survival time was 17 months (95% CI 7–42 months) for Group A and 70 months (95% CI 49–94 months) for Group B (p < 0.01). Multivariate analysis did not find any adjunctive predictive role for biventricular volumes and ejection fraction, indexed left ventricular mass, transmitral E/e’ at echocardiography, age at diagnosis or serum creatinine.ConclusionIn our population, a typical LGE pattern was significantly associated with higher mortality. Moreover, patients with a typical LGE pattern showed a globally worse prognosis. Our data suggest that the LGE pattern may play a central role in prognostic stratification of patients with suspected CA, thus prompting further diagnostic and therapeutic measures.