Demographic and clinical differences between ankylosing spondylitis and non-radiographic axial spondyloarthritis: results from a multicentre retrospective study in the Lazio region of Italy.

OBJECTIVES: Axial spondyloarthritides (axSpA) are a group of disorders that share similar pathogenetic mechanisms and clinical picture. The aim of this retrospective multicentric study was to evaluate demographic and clinical differences between ankylosing spondylitis (AS) and non-radiographic axSpA (nr-axSpA) patients. METHODS: Patients from 7 rheumatological centres in the Lazio region of Italy were included from January 1st, 2010 to April 1st, 2018, if they had undergone pelvic and/or spine radiographs or magnetic resonance imaging (MRI). Images were evaluated by one experienced radiologist in each centre who already had the clinical suspicion of axSpA. Clinical and therapeutic data were collected at the last observation visit. Categorical variables were presented with percentages and analysed by Chi squared test. Continuous variables were expressed as mean ± standard deviation and compared using the parametric unpaired t-test or the non-parametric Mann-Whitney U-test, when appropriate. p-values <0.05 were considered significant. RESULTS: 210 axSpA patients were included: 65.2% with AS and 34.7% with nr-axSpA. When comparing the two groups, AS patients had longer disease duration, were older, were more frequently males, had a greater diagnostic delay and a higher body mass index than the nr-axSpA patients (p<0.0001, p<0.0001, p=0.003 p=0.007, and p=0.04, respectively). The peripheral joints of the nr-axSpA patients were more frequently involved, had higher frequency of inflammatory bowel disease, higher C-reactive protein levels and lower frequency of HLA-B27 positivity (p=0.005, p=0.007, p=0.01, and p=0.01, respectively). TNF inhibitors were used in 87.8% patients with AS and 78.3% with nr-axSpA (p=0.04). More fat metaplasia was observed on MRI in the nr-axSpA group than in the AS group at sacroiliac joints (p=0.003), and more backfills were detected in the AS group on spine-MRI (p=0.003). Spine-bone marrow oedema was more prevalent in AS than in nr-axSpA (p=0.04), and more sclerosis and backfill were found in AS (p=0.003 and p=0.01, respectively). CONCLUSIONS: In clinical practice, distinctive features in AS and nr-axSpA patients emerged. Imaging is crucial in guiding the choice of treatment in order to control disease activity and inflammation.

Carotid artery imaging: The study of intra-plaque vascularization and hemorrhage in the era of the "vulnerable" plaque.

Intraplaque hemorrhage (IPH) is one of the main factors involved in atherosclerotic plaque (AP) instability. Its recognition is crucial for the correct staging and management of patients with carotid artery plaques to limit ischemic stroke. Imaging plays a crucial role in identifying IPH, even if the great variability of intraplaque vascularization and the limitations of our current imaging technologies make it difficult. The intent of this review is to give a general overview of the main features of intraplaque vascularization and IPH on Ultrasound (US), Computed Tomography (CT), Magnetic Resonance (MR) and Nuclear Medicine, and a brief description on the future prospectives.

Magnetic-resonance-guided focused ultrasound treatment of non-spinal osteoid osteoma in children: multicentre experience.

BACKGROUND: Osteoid osteoma is a benign and painful musculoskeletal tumour that usually affects children. Current standard treatment is CT-guided radiofrequency ablation, a minimally invasive percutaneous procedure, with clinical success rates ranging between 85% and 98%. Though minimally invasive, however, this type of procedure is not free from complications. OBJECTIVE: To investigate the efficacy and safety of magnetic resonance (MR)-guided focused ultrasound (MRgFUS), a needleless procedure of thermal ablation employed in the treatment of non-spinal osteoid osteoma in paediatric patients. MATERIALS AND METHODS: We report the results of 33 procedures of ablation of osteoid osteoma performed with MRgFUS in three university hospitals. To ablate a lesion on the bone surface, MRgFUS employs the ultrasound energy transduced along the soft tissue. The follow-up studies lasted 24 months and were performed combining clinical and imaging data. RESULTS: Mean age of the children was 13.8 years. The clinical outcome showed a primary success of 97%. One case alone was submitted to repeat treatment because the first one failed (secondary success). No major or minor complications were recorded. During the investigation time, no relapse of symptomatology or delayed complications were observed. CONCLUSION: Although our study is preliminary and limited by a low number of patients, our data show that MRgFUS is effective. This suggests that it might be useful as the first-line treatment in paediatric patients with osteoid osteoma.

Can unenhanced MRI of the breast replace contrast-enhanced MRI in assessing response to neoadjuvant chemotherapy?

BACKGROUND: The goals of neoadjuvant chemotherapy (NAC) are to reduce tumor volume and to offer a prognostic indicator in assessing treatment response. Contrast-enhanced magnetic resonance imaging (CE-MRI) is an established method for evaluating response to NAC in patients with breast cancer. PURPOSE: To validate the role of unenhanced MRI (ue-MRI) compared to CE-MRI for assessing response to NAC in women with breast cancer. MATERIAL AND METHODS: Seventy-one patients with ongoing NAC for breast cancer underwent MRI before, during, and at the end of NAC. Ue-MRI was performed with T2-weighted sequences with iterative decomposition of water and fat and diffusion-weighted sequences. CE-MRI was performed using three-dimensional T1-weighted sequences before and after administration of gadobenate dimeglumine. Two blinded observers rated ue-MRI and CE-MRI for the evaluation of tumor response. Statistical analysis was performed to compare lesion size and ADC values changes during therapy, as well as inter-observer agreement. RESULTS: There were no statistically significant differences between ue-MRI and CE-MRI sequences for evaluation of lesion size at baseline and after every cycle of treatment ( P > 0.05). The mean tumor ADC values at baseline and across the cycles of NAC were significantly different for the responder group. CONCLUSION: Ue-MRI can achieve similar results to CE-MRI for the assessment of tumor response to NAC. ADC values can differentiate responders from non-responders.

Radiologist-rheumatologist multidisciplinary approach in the management of axial spondyloarthritis: a Delphi consensus statement.

OBJECTIVES: The aim of this study was to develop a Delphi consensus statement between rheumatologists and radiologists for the diagnosis and monitoring of axial spondyloarthritis (axial-SpA). METHODS: Following an extensive literature search to identify unmet needs and potential goals for a multidisciplinary approach, a scientific board comprising 28 Italian hospital-based rheumatologists (n=19) and radiologists (n=9) identified 8 "starting points", resulting in the development of 23 consensus statements covering issues from current practice guidelines to specific MRI protocols for the assessment of axial-SpA. Each participant anonymously expressed a level of agreement for each statement using a 5-point Likert scale (1="strongly disagree"; 5="strongly agree") via an online Delphi method.Total cumulative agreement (TCA) was defined as the sum of the percentage of response to items 4 ("agree") and 5 ("absolutely agree"). Consensus was defined as ≥80% total cumulative agreement for each statement. RESULTS: After the first round of voting (28 participants), positive consensus was reached for 28/31 (90.3%) statements. Statements without consensus (n=3) were discussed in a face-to-face plenary session prior to the second vote (28 participants). After the second round voting, positive consensus was attained for all 31 statements, with mean final TCA of 95.5% (range 82.1-100%). CONCLUSIONS: This Delphi consensus statement provides an aid to rheumatologists and radiologists for the diagnosis and monitoring of axial-SpA.

HIFU for Bone Metastases and other Musculoskeletal Applications.

High-intensity focused ultrasound (HIFU) is a totally noninvasive procedure that has shown promising results in the management of numerous malignant and nonmalignant conditions. Under magnetic resonance or ultrasound guidance, high-intensity ultrasound waves are focused on a small, well-defined target region, inducing biologic tissue heating and coagulative necrosis, thus resulting in a precise and localized ablation. This treatment has shown both great safety and efficacy profiles, and may offer a multimodal approach to different diseases, providing pain palliation, potential local tumor control, and, in some cases, remineralization of trabecular bone. In musculoskeletal field, HIFU received FDA approval for treating bone metastasis, but its application has also been extended to other conditions, such as osteoid osteoma, desmoid tumor, low-flow vascular malformation, and facet joint osteoarthritis. This article illustrates the basic principles of HIFU and its main effects on biologic tissues with particular attention on bone, provides a step-by-step description of the HIFU procedure, and discusses the commonly treated conditions, in particular bone metastases.

Volumetric Distribution of the White Matter Hyper-Intensities in Subject with Mild to Severe Carotid Artery Stenosis: Does the Side Play a Role?

PURPOSE: The purpose of this paper was to assess the difference in the distribution of white matter hyperintensities (WMHs) on left and right sides of the brain hemispheres of subjects with mild to severe carotid artery stenosis. MATERIAL AND METHODS: Eighty consecutive patients (mean age 71 ± 6 years, males 66) with carotid artery stenosis were prospectively recruited. FLAIR-WMH lesion volume was performed using a semiautomated segmentation technique (Jim, Xinapse System, Leicester, UK). The Wilcoxon test was applied to verify the differences in the volume of WMHs between the right and left hemispheres. RESULTS: A statistically significant difference was found in the middle cerebral artery (MCA) territory for the volume of the lesions (median volume of WMHs of the left side = 889.5 mm3; median volume of WMHs on the right side = 580.5 mm3; P = .0416); no statistically significant difference was found on the other territories by taking into considerations the lesions. By analyzing the degree of stenosis, we found a higher degree of stenosis of the left side (67.9%; 95% confidence interval [CI], 64.8%-70.9%) compared with the right side (65.7%; 95% CI, 62.4%-68.9%), but the Mann-Whitney test did not show a statistically significant difference (P = .3235). CONCLUSIONS: Results of our study suggest that there is a difference in the distribution of WMHs in the brain hemispheres according to the left/right side on the MCA territories and for the periventricular white matter in subjects with mild to severe carotid artery stenosis.

High-Intensity Focused Ultrasound for Pain Management in Patients with Cancer.

Cancer-related pain affects up to 80% of patients with malignancies. Pain is an important distressing symptom that diminishes the quality of life and negatively affects the survival of patients. Opioid analgesics are generally the primary therapy for cancer-related pain, with surgery, radiation therapy, chemotherapy, and other interventions used in cases of treatment-resistant pain. These treatments, which can be associated with substantial side effects and systemic toxicity, may not be effective. High-intensity focused ultrasound is an entirely noninvasive technique that is approved for treatment of uterine fibroids, bone metastases, and essential tremors. With magnetic resonance imaging or ultrasonographic guidance, high-intensity ultrasound waves are focused on a small well-demarcated region to result in precise localized ablation. This treatment may represent a multimodality approach to treating patients with malignant diseases-facilitating pain palliation, enhanced local drug delivery and radiation therapy effects, and stimulation of anticancer specific immune responses, and potentially facilitating local tumor control. Focused ultrasound can be used to achieve pain palliation by producing several effects, including tissue denervation, tumor mass reduction, and neuromodulation, that can influence different pathways at the origin of the pain. This technology has several key advantages compared with other analgesic therapies: It is completely noninvasive, might be used to achieve rapid pain control, can be safely repeated, and can be used in combination with chemotherapy and radiation therapy to enhance their effects. Online supplemental material is available for this article. ©RSNA, 2018.

Vena cava anomalies in thoracic surgery.

BACKGROUND: Vena cava anomalies are a rare group of anatomical variations due to an incorrect development of the superior or inferior vena cava during fetal life. They generally show no clinical relevance and the diagnosis is done due to the association with congenital heart diseases in most of cases. However, preoperative identification of these anomalies is mandatory for surgeons to proper surgical planning. If not recognized, lethal complications may occur, as already reported in literature. CASE PRESENTATION: We report a case series of three different unidentified vena cava anomalies in patients undergoing lung resection. These unrecognized anomalies led to minor complications in two cases and required an accurate intraoperative evaluation in another. A careful retrospective evaluation of preoperative radiological images showed the anomalies. CONCLUSIONS: A careful evaluation of the vena cava anatomy at pre-operative imaging is mandatory for thoracic surgeons to properly plan the surgery and avoid complications.

Analysis of CT features and quantitative texture analysis in patients with thymic tumors: correlation with grading and staging.

OBJECTIVES: To evaluate potential relationship between qualitative CT features, quantitative texture analysis (QTA), histology, WHO staging, Masaoka classification and myasthenic syndrome in patients with thymic tumors. MATERIALS AND METHODS: Sixteen patients affected by histologically proven thymic tumors were retrospectively included in the study population. Clinical information, with special regard to myasthenic syndrome and serological positivity of anti-AchR antibodies, were recorded. Qualitative CT evaluation included the following parameters: (a) location; (b) tumor edges; (c) necrosis; (d) pleural effusion; (e) metastases; (f) chest wall infiltration; (g) tumor margins. QTA included evaluation of "Mean" (M), "Standard Deviation" (SD), "Kurtosis" (K), "Skewness" (S), "Entropy" (E), "Shape from Texture" (TX_sigma) and "average of positive pixels" (MPP). Pearson-Rho test was used to evaluate the relationship of continuous non-dichotomic parameters, whereas Mann-Whitney test was used for dichotomic parameters. RESULTS: Histological evaluation demonstrated thymoma in 12 cases and thymic carcinoma in 4 cases. Tumor necrosis was significantly correlated with QTA Mean (p = 0.0253), MPP (p = 0.0417), S (p = 0.0488) and K (p = 0.0178). WHO staging was correlated with Mean (p = 0.0193), SD (p = 0.0191) and MPP (p = 0.0195). Masaoka classification was correlated with Mean (p = 0.0322), MPP (p = 0.0315), skewness (p = 0.0433) and Kurtosis (p = 0.0083). Myasthenic syndrome was significantly associated with Mean (p = 0.0211) and MPP (p = 0.0261), whereas tumor size was correlated with Mean (p = 0.0241), entropy (p = 0.0177), MPP (p = 0.0468), skewness (p = 0.009) and Kurtosis (p = 0.006). CONCLUSION: Our study demonstrates significant relationship between radiomics parameters, histology, grading and clinical manifestations of thymic tumors.

Clinical neuroimaging markers of response to treatment in mood disorders.

Mood disorders (MD) are important and frequent psychiatric illness. The management of patients affected by these conditions represents an important factor of disability as well as a significant social and economic burden. The "in-vivo" studies can help researchers to understand the first developmental events of the pathology and to identify the molecular and non-molecular targets of therapies. However, they have strong limitations due to the fact that human brain circuitry can not be reproduced in animal models. In addition, these neural pathways are difficult to be selectively studied with the modern imaging (such as Magnetic Resonance and Positron Emitted Tomography/Computed Tomography) and non-imaging (such as electroencephalography, magnetoencephalography, transcranial magnetic stimulation and evoked potentials) methods. In comparison with other methods, the "in-vivo" imaging investigations have higher temporal and spatial resolution compared to the "in-vivo" non-imaging techniques. All these factors make difficult to fully understand the aetiology and pathophysiology of these disorders, and consequently hinder the analysis of the effects of pharmacological and non-pharmacological therapies, which have been demonstrated effective in clinical settings. In this review, we will focus our attention on the current state of the art of imaging in the assessment of treatment efficacy in MD. We will analyse briefly the actual classification of MD; then we will focus on the "in vivo" imaging methods used in research and clinical activity, the current knowledge about the neural models at the base of MD. Finally the last part of the review will focus on the analysis of the main markers of response to treatment.

Radiation dose and image quality of computed tomography of the supra-aortic arteries: A comparison between single-source and dual-source CT Scanners.

PURPOSE: The purpose of this work was to compare the image quality and radiation dose delivered to patients during computed tomography (CT) angiography (CTA) of the supra-aortic arteries using two single-source (SS) and two dual-energy (DE) CT scanners. MATERIAL AND METHODS: In this retrospective study, 120 patients who underwent CTA of supra-aortic arteries were studied using four different types of CT scanners: a sixteen and forty-detector-row SS and two DE CT scanners. Seventy milliters of contrast medium were injected at a flow rate of 4mL/s using a power injector. For each patient the dose-length product (DLP), the volume computed tomography dose index (CDTIvol), the length of the scan and the effective dose (ED) were calculated. Qualitative and quantitative [image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR)] image quality assessment was performed. RESULTS: A statistically significant lower value of the DE compared to the SS technology (P<0.0001) for the CDTI, DLP and ED was found, whereas we did not find any statistically significant difference between the four scanners for the measurements of the image noise, SNR and CNR. CONCLUSION: DS CT scanners allow performing CTAs with a reduced dose compared to SS CT scanner with comparable image quality.

Noninvasive Therapy for Osteoid Osteoma: A Prospective Developmental Study with MR Imaging-guided High-Intensity Focused Ultrasound.

Purpose To demonstrate that magnetic resonance (MR) imaging-guided high-intensity focused ultrasound (HIFU) is a safe, effective, and durable treatment option for the management of osteoid osteoma in children and young adults. Materials and Methods This prospective study was institutional review board approved and is registered with clinicaltrials.gov (identification number NCT02302651). Written informed consent was obtained from patients or their parents. Patients who had both clinical and radiologic findings that were diagnostic for nonvertebral osteoid osteoma and no contraindications to MR imaging-guided HIFU were enrolled between June 2010 and June 2013. The feasibility, safety, and clinical effectiveness of MR imaging-guided HIFU were considered primary outcomes; tumor control at imaging was considered a secondary outcome. Analyses were conducted on a per-protocol basis. Results Forty-five of the 50 recruited patients underwent MR imaging-guided HIFU. All patients were discharged without treatment-related complications. The median visual analog scale (VAS) pain score (scale, 0-10) decreased from 8 before treatment to 0 at 1-week and 1- , 6- , 12- , 24- , and 36-month follow-up. Similarly, median VAS scores for the degree to which pain interfered with sleep and physical and daily activities decreased to 0 within the 1st month after treatment and remained stable at subsequent follow-up. Overall, 39 (87%) of the 45 patients achieved and maintained a VAS score of 0 during the 3-year observation period. Quality of life, as assessed by using Functional Assessment of Cancer Therapy-Bone Pain (FACT-BP) scores (scale, 0-60 points), improved, with the median FACT-BP score of 28 (points) before treatment increasing to a median score of 55 at 1-week follow-up and 60 at 6-month and subsequent follow-ups. At (final) 36-month follow-up, MR imaging depicted an absence of residual nidus vascularity in 32 (76%) of the 42 patients who were treated with MR imaging-guided HIFU only. Conclusion The durable clinical efficacy and safety of MR imaging-guided HIFU were demonstrated. These features are evidence of the potential of MR imaging-guided HIFU to be part of a routine strategy for the treatment of osteoid osteoma. © RSNA, 2017.

Imaging-guided chest biopsies: techniques and clinical results.

BACKGROUND: This article aims to comprehensively describe indications, contraindications, technical aspects, diagnostic accuracy and complications of percutaneous lung biopsy. METHODS: Imaging-guided biopsy currently represents one of the predominant methods for obtaining tissue specimens in patients with lung nodules; in many cases treatment protocols are based on histological information; thus, biopsy is frequently performed, when technically feasible, or in case other techniques (such as bronchoscopy with lavage) are inconclusive. RESULTS: Although a coaxial system is suitable in any case, two categories of needles can be used: fine-needle aspiration biopsy (FNAB) and core-needle biopsy (CNB), with the latter demonstrated to have a slightly higher overall sensitivity, specificity and accuracy. CONCLUSION: Percutaneous lung biopsy is a safe procedure even though a few complications are possible: pneumothorax, pulmonary haemorrhage and haemoptysis are common complications, while air embolism and seeding are rare, but potentially fatal complications. TEACHING POINTS: • Imaging-guided biopsy is one of the main methods to obtain lung nodule specimens. • CT has the highest accuracy for diagnosis as an imaging guide. • Compared to FNAB, CNB has a higher accuracy for diagnosis. • Pneumothorax and parenchymal pulmonary haemorrhage care the most frequent complications. • Several clinical and technical variables can affect diagnostic accuracy and patient safety.

Relationship between white matter hyperintensities volume and the circle of Willis configurations in patients with carotid artery pathology.

PURPOSE: We aimed to assess if there is a difference of distribution and volume of white matter hyperintensities (WMH) in the brain according to the Circle of Willis (CoW) configuration in patients with carotid artery pathology. MATERIAL AND METHODS: One-hundred consecutive patients (79 males, 21 females; mean age 70 years; age range 46-84 years) that underwent brain MRI before carotid endarterectomy (CEA) were included. FLAIR-WMH lesion volume was performed using a semi-automated segmentation technique and the status of the circle of Willis was assessed by two neuroradiologists in consensus. RESULTS: We found a prevalence of 55% of variants in the CoW configuration; 22 cases had one variants (40%); 25 cases had two variants (45.45%) and 8 cases showed 3 variants (14.55%). The configuration that was associated with the biggest WMH volume and number of lesions was the A1+PcoA+PcoA. The PcoA variants were the most prevalent and there was no statistically significant difference in number of lesions and WMH for each vascular territory assessed and the same results were found for AcoA and A1 variants. CONCLUSION: Results of our study suggest that the more common CoW variants are not associated with the presence of an increased WMH or number of lesions whereas uncommon configurations, in particular when 2 or more segment are missing increase the WMH volume and number of lesions. The WHM volume of the MCA territory seems to be more affected by the CoW configuration.

Volumetric Analysis of Carotid Plaque Components and Cerebral Microbleeds: A Correlative Study.

PURPOSE: The purpose of this work was to explore the association between carotid plaque volume (total and the subcomponents) and cerebral microbleeds (CMBs). MATERIALS AND METHODS: Seventy-two consecutive (male 53; median age 64) patients were retrospectively analyzed. Carotid arteries were studied by using a 16-detector-row computed tomography scanner whereas brain was explored with a 1.5 Tesla system. CMBs were studied using a T2*-weighted gradient-recalled echo sequence. CMBs were classified as from absent (grade 1) to severe (grade 4). Component types of the carotid plaque were defined according to the following Hounsfield unit (HU) ranges: lipid less than 60 HU; fibrous tissue from 60 to 130 HU; calcification greater than 130 HU, and plaque volumes of each component were calculated. Each carotid artery was analyzed by 2 observers. RESULTS: The prevalence of CMBs was 35.3%. A statistically significant difference was observed between symptomatic (40%) and asymptomatic (11%) patients (P value = .001; OR = 6.07). Linear regression analysis demonstrated an association between the number of CMBs and the symptoms (P = .0018). Receiver operating characteristics curve analysis found an association between the carotid plaque subcomponents and CMBs (Az = .608, .621, and .615 for calcified, lipid, and mixed components, respectively), and Mann-Whitney test confirmed this association in particular for the lipid components (P value = .0267). CONCLUSIONS: Results of this study confirm the association between CMBs and symptoms and that there is an increased number of CMBs in symptomatic patients. Moreover, we found that an increased volume of the fatty component is associated with the presence and number of CMBs.

Clinical and radiological features driving patient selection for antiangiogenic therapy in non-small cell lung cancer (NSCLC).

BACKGROUND: The use of antiangiogenic therapy in non-small cell lung cancer (NSCLC) requires thorough evaluation of patient characteristics in order to avoid potential safety issues, particularly pulmonary haemorrhage (PH). The aim of this consensus by a panel of experts was to identify important criteria for the selection of patients with NSCLC who would benefit from antiangiogenic therapy. METHODS: Radiologists and oncologists were selected for the expert panel. The nominal group technique (NGT) and the Delphi questionnaire were used for consensus generation. The NGT consisted of four steps, the result of which was used to set the Delphi questionnaire. A final report was generated based on the opinions of the experts from the panel. RESULTS: An extremely important prerequisite for the evaluation of an antiangiogenic therapeutic approach in patients with NSCLC was thorough clinical and radiological analysis of the relationships between tumour and vascular or anatomical structures (performed in close co-operation by oncologists and radiologists). The panel identified major parameters to be considered before the use of antiangiogenic treatment, collectively agreeing on the relevance of tumour cavitation, vascular infiltration, endobronchial growth and thromboembolism for chest tumour sites, and of the presence of aneurysms, extra-thoracic bleeding, brain metastases or thrombi for extra-thoracic sites. Moreover, a structured report containing information not only on the tumour but also on the general vascular status is essential to guide the treatment choice The experts agreed that tumour localization in the absence of vessel infiltration, cavitation, and the use of antiplatelet therapy are relevant parameters to be assessed, but their presence should not necessarily exclude a patient from receiving antiangiogenic therapy. CONCLUSION: Close co-operation between oncologists and radiologists in the diagnosis, treatment selection, and assessment of response is essential for ensuring therapeutic appropriateness in the NSCLC setting. It should be noted that neither the use of antiplatelet therapy nor tumour localisation are to be considered as contraindications to antiangiogenic treatment.

Qualitative analysis of small (≤2 cm) regenerative nodules, dysplastic nodules and well-differentiated HCCs with gadoxetic acid MRI.

BACKGROUND: The characterization of small lesions in cirrhotic patients is extremely difficult due to the overlap of imaging features among different entities in the step-way of the hepatocarcinogenesis. The aim of our study was to evaluate the role of gadoxetic-acid MRI in the differentiation of small (≤2 cm) well-differentiated hepatocellular carcinomas from regenerative and dysplastic nodules. METHODS: Seventy-three cirrhotic patients, with 118 focal liver lesions (≤2 cm) were prospectively recruited. MRI examination was performed with a 3T magnet and the study protocol included T1 - and T2-weighted pre-contrast sequences and T1 -weighted gadoxetic-acid enhanced post-contrast sequences obtained during the arterial, venous, late dynamic and hepatobiliary phases. All lesions were pathologically confirmed. Two radiologists blinded to clinical and pathological information evaluated two imaging datasets; another radiologist analysed the signal intensity characteristics of each lesion. Sensitivity, specificity and diagnostic accuracy were considered for statistical analysis. RESULTS: Good agreement was reported between the two readers (κ 0.70). Both readers reported a significantly improved sensitivity (57.7 and 66.2 vs 74.6 and 83.1) and diagnostic accuracy (0.717 and 0.778 vs 0.843 and 0.901) with the adjunction of the hepatobiliary phase 57.7 vs 74.6 and 66.2 vs 83.1 (p ≤ 0.04). CONCLUSIONS: Gadoxetic-acid MRI is a reliable tool for the characterization of HCC and lesions at high risk to further develop.

Magnetic resonance-guided focused ultrasound for the treatment of painful bone metastases: role of apparent diffusion coefficient (ADC) and dynamic contrast enhanced (DCE) MRI in the assessment of clinical outcome.

PURPOSE: To assess the correlation between functional MRI, including ADC values obtained from DWI and DCE, and clinical outcome in patients with bone metastases treated with MRgFUS. METHODS AND MATERIALS: Twenty-three patients with symptomatic bone metastases underwent MRgFUS treatment (ExAblate 2100 system InSightec) for pain palliation. All patients underwent clinical and imaging follow-up examinations at 1, 3 and 6 months after treatment. Visual Analog Scale (VAS) score was used to evaluate treatment efficacy in terms of pain palliation while ADC maps obtained by DWI sequences, and DCE data were used for quantitative assessment of treatment response at imaging. Spearman Correlation Coefficient Test was calculated to assess the correlation between VAS, ADC and DCE data. RESULTS: All treatments were performed successfully without adverse events. On the basis of VAS score, 16 (69.6 %) patients were classified as complete clinical responders, 6 (26.1 %) as partial responders and only one (4.3 %) was classified as a non-responder. The mean VAS score decreased from 7.09 ± 1.8 at baseline to 2.65 ± 1.36 at 1 month, 1.04 ± 1.91 at 3 months and 1.09 ± 1.99 at 6 months (p < 0.001). Baseline mean ADC value of treated lesions was 1.05 ± 0.15 mm2/s, increasing along follow-up period (1.57 ± 0.27 mm2/s 1st month; 1.49 ± 0.3 mm2/s 3rd month; 1.45 ± 0.32 mm2/s 6th month, p < 0.001). Non perfused volume (NPV) was 46.4 at 1 month, 45.2 at 3 months and 43.8 at 6 months. Spearman Coefficient demonstrated a statistically significant negative correlation between VAS and ADC values (ρ = -0.684; p = 0.03), but no significant correlation between VAS and NPV (ρ = 0.02216, p = 0.9305). Among other DCE data, Ktrans significantly changed in complete responders (3 months Ktrans = 2.14/min; -ΔKt = 52.65 % p < 0.01) and was not significantly different in partial responders (3 months Ktrans 0.042/min; ΔKt = 11.39 % p > 0.01). CONCLUSION: In patients with painful bone metastases treated with MRgFUS, ADC and Ktrans variation observed in the ablated lesions correlate with VAS values and may play a role as objective imaging marker of treatment response.

Imaging follow-up after liver transplantation.

Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures.