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.

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.

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.

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.

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.

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.

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.

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.

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.

Longitudinal assessment of carotid atherosclerosis after Radiation Therapy using Computed Tomography: A case control Study.

OBJECTIVES: To study the carotid artery plaque composition and its volume changes in a group of patients at baseline and 2 years after head and neck radiation therapy treatment (HNXRT). METHODS: In this retrospective study, 62 patients (41 males; mean age 63 years; range 52-81) who underwent HNXRT and 40 patients (24 males; mean age 65) who underwent surgical resection of neoplasm and did not undergo HNXRT were assessed, with 2-year follow-up. The carotid artery plaque volumes, as well as the volume of the sub-components (fatty-mixed-calcified), were semiautomatically quantified. Mann-Whitney and Wilcoxon tests were used to test the hypothesis. RESULTS: In the HNXRT group, there was a statistically significant increase in the total volume of the carotid artery plaques (from 533 to 746 mm(3); p = 0.001), in the fatty plaques (103 vs. 202 mm(3); p = 0.001) and mixed plaque component volume (328 vs. 419 mm(3); p = 0.034). A statistically significant variation (from 21.8 % to 27.6 %) in the percentage of the fatty tissue was found. CONCLUSIONS: Results of this preliminary study suggest that HNXRT promotes increased carotid artery plaque volume, particularly the fatty plaque component. KEY POINTS: HNXRT increases carotid plaque volume. Plaque volume increase is mainly due to increase.in fatty plaque component. Patients who undergo HNXRT have a progression of carotid artery disease.

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.

Preliminary clinical experience with a dedicated interventional robotic system for CT-guided biopsies of lung lesions: a comparison with the conventional manual technique.

OBJECTIVE: Evaluate the performance of a robotic system for CT-guided lung biopsy in comparison to the conventional manual technique. MATERIALS AND METHODS: One hundred patients referred for CT-guided lung biopsy were randomly assigned to group A (robot-assisted procedure) or group B (conventional procedure). Size, distance from entry point and position in lung of target lesions were evaluated to assess homogeneity differences between the two groups. Procedure duration, dose length product (DLP), precision of needle positioning, diagnostic performance of the biopsy and rate of complications were evaluated to assess the clinical performance of the robotic system as compared to the conventional technique. RESULTS: All biopsies were successfully performed. The size (p = 0.41), distance from entry point (p = 0.86) and position in lung (p = 0.32) of target lesions were similar in both groups (p = 0.05). Procedure duration and radiation dose were significantly reduced in group A as compared to group B (p = 0.001). Precision of needle positioning, diagnostic performance of the biopsy and rate of complications were similar in both groups (p = 0.05). CONCLUSION: Robot-assisted CT-guided lung biopsy can be performed safely and with high diagnostic accuracy, reducing procedure duration and radiation dose in comparison to the conventional manual technique. KEY POINTS: • CT-guided biopsy is the main procedure to obtain diagnosis in lung tumours. • The robotic device facilitates percutaneous needle placement under CT guidance. • Robot-assisted CT-guided lung biopsy reduces procedure duration and radiation dose.

Automatic lung segmentation using control feedback system: morphology and texture paradigm.

Interstitial Lung Disease (ILD) encompasses a wide array of diseases that share some common radiologic characteristics. When diagnosing such diseases, radiologists can be affected by heavy workload and fatigue thus decreasing diagnostic accuracy. Automatic segmentation is the first step in implementing a Computer Aided Diagnosis (CAD) that will help radiologists to improve diagnostic accuracy thereby reducing manual interpretation. Automatic segmentation proposed uses an initial thresholding and morphology based segmentation coupled with feedback that detects large deviations with a corrective segmentation. This feedback is analogous to a control system which allows detection of abnormal or severe lung disease and provides a feedback to an online segmentation improving the overall performance of the system. This feedback system encompasses a texture paradigm. In this study we studied 48 males and 48 female patients consisting of 15 normal and 81 abnormal patients. A senior radiologist chose the five levels needed for ILD diagnosis. The results of segmentation were displayed by showing the comparison of the automated and ground truth boundaries (courtesy of ImgTracer™ 1.0, AtheroPoint™ LLC, Roseville, CA, USA). The left lung's performance of segmentation was 96.52% for Jaccard Index and 98.21% for Dice Similarity, 0.61 mm for Polyline Distance Metric (PDM), -1.15% for Relative Area Error and 4.09% Area Overlap Error. The right lung's performance of segmentation was 97.24% for Jaccard Index, 98.58% for Dice Similarity, 0.61 mm for PDM, -0.03% for Relative Area Error and 3.53% for Area Overlap Error. The segmentation overall has an overall similarity of 98.4%. The segmentation proposed is an accurate and fully automated system.

Osteoid osteoma: MR-guided focused ultrasound for entirely noninvasive treatment.

PURPOSE: To determine the preliminary feasibility, safety, and clinical efficacy of magnetic resonance (MR)-guided focused ultrasound for the treatment of painful osteoid osteoma. MATERIALS AND METHODS: This prospective institutional review board-approved study involved six consecutive patients (five males and one female; mean age, 21 years) with a diagnosis of osteoid osteoma based on clinical and imaging findings. All patients underwent MR-guided focused ultrasound ablation after providing informed consent. Lesions located in the vertebral body were excluded. The number of sonications and the energy deposition were recorded. Treatment success was determined at 1, 3, and 6 months after treatment. A visual analog scale (VAS) score for pain was used to assess changes in symptoms. MR imaging features of osteoid osteoma (edema, hyperemia, and nidus vascularization) were considered at baseline and at imaging follow-up. RESULTS: Treatment was performed with a mean of 4 sonications ± 1.8 (standard deviation), with a mean energy deposition of 866 J ± 211. No treatment- or anesthesia-related complications occurred. The pre- and posttreatment mean VAS scores significantly differed (7.9 ± 1.4 and 0.0 ± 0.0, respectively). At imaging, the edema and hyperemia associated with osteoid osteoma gradually disappeared in all lesions. However, nidus vascularization still persisted after treatment in four of six patients. CONCLUSION: This limited series demonstrated that MR-guided focused ultrasound treatment of osteoid osteoma can be performed safely with a high rate of success and without apparent treatment-related morbidity.

Differences in plaque morphology and correlation of stenosis at the carotid artery bifurcation and the carotid siphon.

OBJECTIVE: The purpose of this study was to compare the type of plaque and the degree of stenosis in the carotid artery bifurcation and the carotid siphon to explore potential correlations between these parameters. MATERIALS AND METHODS: A total of 119 patients (87 men, 32 women; mean age, 69 years) were retrospectively studied using MDCT angiography. Component types of the carotid artery bifurcation and the carotid siphon plaque were defined according to attenuation values, and the volumes of each plaque component were calculated. The degree of stenosis was calculated according to the North American Symptomatic Endarterectomy Trial method. Data were compared using the Wilcoxon signed-rank test, Spearman correlation analysis, and receiver operating characteristic (ROC) analysis. RESULTS: The results of the Wilcoxon test showed a statistically significant difference (p = 0.0001) between the degree of stenosis at the carotid artery bifurcation and that at the carotid siphon. We observed a statistically significant difference (p = 0.0001) between the total volumes of the carotid artery bifurcation (mean value, 748 mm(3)) and the carotid siphon (mean value, 54 mm(3)) plaque. Moreover, the respective mean percentages of calcified, mixed, and lipid components of plaque were 17%, 56%, and 27% in the carotid artery bifurcation and 73%, 19%, and 8% in the carotid siphon, showing a statistically significant difference (p = 0.001). ROC analysis did not show association between carotid siphon plaque volume and previous cerebrovascular events (Az = 0.562; p = 0.149), whereas the total volume of the carotid artery bifurcation plaque--and, in particular, the volume of the lipid components--showed a statistically significant association (Az = 0.691, and Az = 0.758; p < 0.001). CONCLUSION: No significant association was found between presence of mixed and fatty components of plaque in the carotid artery bifurcation and presence of similar components in the carotid siphon. The carotid artery bifurcation total plaque volume (and, in particular, carotid artery bifurcation lipid volume) was associated with previous cerebrovascular events, whereas no association with the volume of carotid siphon plaque (and its subcomponents) was found.

MR imaging-guided focused ultrasound for treatment of bone metastasis.

Magnetic resonance (MR) imaging-guided focused ultrasound is an alternative noninvasive method for reducing the pain in skeletal metastases. MR imaging-guided focused ultrasound ablation offers several key advantages over other noninvasive treatment modalities. This technology enables the performance of three-dimensional treatment planning with MR imaging and continuous temperature mapping of treated tissue by using MR thermometry, thereby enabling real-time monitoring of thermal damage in the target zone. The concentration of acoustic energy on the intact surface of cortical bone produces a rapid temperature increase that mediates critical thermal damage to the adjacent periosteum, the most innervated component of mature bone tissue. Such thermal ablation has been shown to be an extremely effective approach for pain management. Energy delivered during MR imaging-guided focused ultrasound ablation and accumulated inside the pathologic soft tissue of the metastases can create a variable amount of tissue necrosis. This technique has also a potential role in achieving local tumor control, allowing remineralization of trabecular bone or reduction in lesion size. The current report presents a detailed step-by-step guide for performing MR imaging-guided focused ultrasound ablation of bone metastases, including use of MR thermometry for monitoring treatment, protocol selection for simple palliation of pain or for local tumor control, and a description of imaging features of periosteal neurolysis or metastasis ablation. Two case studies are also presented: in the first, the technique provided palliation of pain in bone metastases, and in the second, the technique achieved tumor control as further proof of primary efficacy. MR imaging-guided focused ultrasound ablation is a promising method for successful palliation of bone metastasis pain and tumor control, because of the bony structure remodeling induced by thermo-related coagulative necrosis.

Semiautomated and automated algorithms for analysis of the carotid artery wall on computed tomography and sonography: a correlation study.

OBJECTIVES: The purpose of this study was to compare automated and semiautomated algorithms for analysis of carotid artery wall thickness and intima-media thickness on multidetector row computed tomographic (CT) angiography and sonography, respectively, and to study the correlation between them. METHODS: Twenty consecutive patients underwent multidetector row CT angiographic and sonographic analysis of carotid arteries (mean age, 66 years; age range, 59-79 years). The intima-media thickness of the 40 carotid arteries was measured with novel and dedicated automated software analysis and by 4 observers who manually calculated the intima-media thickness. The carotid artery wall thickness was automatically estimated by using a specific algorithm and was also semiautomatically quantified. The correlation between groups was calculated by using the Pearson ρ statistic, and scatterplots were calculated. We evaluated intermethod agreement using Bland-Altman analysis. RESULTS: By comparing automated carotid artery wall thickness, automated intima-media thickness, semiautomated carotid artery wall thickness, and semiautomated intima-media thickness analyses, a statistically significant association was found, with the highest values obtained for the association between semiautomated and automated intima-media thickness analyses(Pearson ρ = 0.9; 95% confidence interval, 0.82-0.95; P = 0.0001). The lowest values were obtained for the association between semiautomated intima-media thickness and automated carotid artery wall thickness analyses (Pearson ρ = 0.44; 95% confidence interval, 0.15-0.66; P = 0.0047). In the Bland-Altman analysis, the better results were obtained by comparing the semiautomated and automated algorithms for the study of intima-media thickness, with an interval of -16.1% to +43.6%. CONCLUSIONS: The results of this preliminary study showed that carotid artery wall thickness and intima-media thickness can be studied with automated software, although the CT analysis needs to be further improved.