Indeterminate pulmonary nodules in non-rhabdomyosarcoma soft tissue sarcoma: A study of the European paediatric Soft Tissue Sarcoma Study Group

BACKGROUND

The aim of this study was to assess the clinical impact of indeterminate pulmonary nodules (no more than four pulmonary nodules of less than 5 mm or one nodule measuring between 5 and less than 10 mm by computed tomography [CT]) in children and adolescents with adult-type non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) at diagnosis.

METHODS

Patients with NRSTS treated in 11 centers as part of the European paediatric Soft Tissue Sarcoma Study Group (EpSSG) were retrospectively assessed. Local radiologists, blinded to clinical information except for patients' age and tumor histotype, reviewed the chest CT at diagnosis and filled out a case report form. Because patients with or without indeterminate nodules in the EpSSG NRSTS 2005 study received the same type of treatment, event-free survival (EFS) and overall survival (OS) between groups by log-rank test were compared.

RESULTS

Overall, 206 patients were examined: 109 (52.9%) were without any nodules, 78 (38%) had at least one indeterminate nodule, and 19 (9.2%) had nodules meeting the definition of metastases, which were then considered to be misclassified and were excluded from further analyses. Five-year EFS was 78.5% (95% CI, 69.4%-85.1%) for patients without nodules and 69.6% (95% CI, 57.9%-78.7%) for patients with indeterminate nodules (p = .135); 5-year OS was 87.4% (95% CI, 79.3%-92.5%) and 79.0% (95% CI, 67.5%-86.8%), respectively (p = .086).

CONCLUSIONS

This study suggests that survival does not differ in otherwise nonmetastatic patients with indeterminate pulmonary nodules compared to nonmetastatic patients without pulmonary nodules.

PLAIN LANGUAGE SUMMARY

Radiologists should be aware of the classification of indeterminate pulmonary nodules in non-rhabdomyosarcoma soft tissue sarcomas and use it in their reports. More than a third of patients with non-rhabdomyosarcoma soft tissue sarcoma can be affected by indeterminate pulmonary nodules. Indeterminate pulmonary nodules do not significantly affect the overall survival of pediatric patients with non-rhabdomyosarcoma soft tissue sarcoma.

Corrigendum: Diagnostic and therapeutic management of the thoracic outlet syndrome. Review of the literature and report of an Italian experience

[This corrects the article DOI: 10.3389/fcvm.2022.802183.].

Radiomics of spinal muscles: toward a radiological biomarker for allograft rejection in lung transplant

PURPOSE

To assess the role of muscle composition and radiomics in predicting allograft rejection in lung transplant.

MATERIAL AND METHODS

The last available HRCT before surgery of lung transplant candidates referring to our tertiary center from January 2010 to February 2020 was retrospectively examined. Only scans with B30 kernel reconstructions and 1 mm slice thickness were included. One radiologist segmented the spinal muscles of each patient at the level of the 11th dorsal vertebra by an open-source software. The same software was used to extract Hu values and 72 radiomic features of first and second order. Factor analysis was applied to select highly correlating features and then their prognostic value for allograft rejection was investigated by logistic regression analysis (level of significance p < 0.05). In case of significant results, the diagnostic value of the model was computed by ROC curves.

RESULTS

Overall 200 patients had a HRCT prior to the transplant but only 97 matched the inclusion criteria (29 women; mean age 50.4 ± 13 years old). Twenty-one patients showed allograft rejection. The following features were selected by the factor analysis: cluster prominence, Imc2, gray level non-uniformity normalized, median, kurtosis, gray level non-uniformity, and inverse variance. The radiomic-based model including also Hu demonstrated that only the feature Imc2 acts as a predictor of allograft rejection (p = 0.021). The model showed 76.6% accuracy and the Imc2 value of 0.19 demonstrated 81% sensitivity and 64.5% specificity in predicting lung transplant rejection.

CONCLUSION

The radiomic feature Imc2 demonstrated to be a predictor of allograft rejection in lung transplant.

Muscle magnetic resonance characterization of STIM1 tubular aggregate myopathy using unsupervised learning

PURPOSE

Congenital myopathies are a heterogeneous group of diseases affecting the skeletal muscles and characterized by high clinical, genetic, and histological variability. Magnetic Resonance (MR) is a valuable tool for the assessment of involved muscles (i.e., fatty replacement and oedema) and disease progression. Machine Learning is becoming increasingly applied for diagnostic purposes, but to our knowledge, Self-Organizing Maps (SOMs) have never been used for the identification of the patterns in these diseases. The aim of this study is to evaluate if SOMs may discriminate between muscles with fatty replacement (S), oedema (E) or neither (N).

METHODS

MR studies of a family affected by tubular aggregates myopathy (TAM) with the histologically proven autosomal dominant mutation of the STIM1 gene, were examined: for each patient, in two MR assessments (i.e., t0 and t1, the latter after 5 years), fifty-three muscles were evaluated for muscular fatty replacement on the T1w images, and for oedema on the STIR images, for reference. Sixty radiomic features were collected from each muscle at t0 and t1 MR assessment using 3DSlicer software, in order to obtain data from images. A SOM was created to analyze all datasets using three clusters (i.e., 0, 1 and 2) and results were compared with radiological evaluation.

RESULTS

Six patients with TAM STIM1-mutation were included. At t0 MR assessments, all patients showed widespread fatty replacement that intensifies at t1, while oedema mainly affected the muscles of the legs and appears stable at follow-up. All muscles with oedema showed fatty replacement, too. At t0 SOM grid clustering shows almost all N muscles in Cluster 0 and most of the E muscles in Cluster 1; at t1 almost all E muscles appear in Cluster 1.

CONCLUSION

Our unsupervised learning model appears to be able to recognize muscles altered by the presence of edema and fatty replacement.

Tumor cellularity beyond the visible in soft tissue sarcomas: Results of an ADC-based, single center, and preliminary radiomics study

Purpose

Soft tissue sarcomas represent approximately 1% of all malignancies, and diagnostic radiology plays a significant role in the overall management of this rare group of tumors. Recently, quantitative imaging and, in particular, radiomics demonstrated to provide significant novel information, for instance, in terms of prognosis and grading. The aim of this study was to evaluate the prognostic role of radiomic variables extracted from apparent diffusion coefficient (ADC) maps collected at diagnosis in patients with soft tissue sarcomas in terms of overall survival and metastatic spread as well as to assess the relationship between radiomics and the tumor grade.

Methods

Patients with histologically proven soft tissue sarcomas treated in our tertiary center from 2016 to 2019 who underwent an Magnetic Resonance (MR) scan at diagnosis including diffusion-weighted imaging were included in this retrospective institution review board–approved study. Each primary lesion was segmented using the b50 images; the volumetric region of interest was then applied on the ADC map. A total of 33 radiomic features were extracted, and highly correlating features were selected by factor analysis. In the case of feature/s showing statistically significant results, the diagnostic accuracy was computed. The Spearman correlation coefficient was used to evaluate the relationship between the tumor grade and radiomic features selected by factor analysis. All analyses were performed applying p&lt;0.05 as a significant level.

Results

A total of 36 patients matched the inclusion criteria (15 women; mean age 58.9 ± 15 years old). The most frequent histotype was myxofibrosarcoma (16.6%), and most of the patients were affected by high-grade lesions (77.7%). Seven patients had pulmonary metastases, and, altogether, eight were deceased. Only the feature Imc1 turned out to be a predictor of metastatic spread (p=0.045 after Bonferroni correction) with 76.7% accuracy. The value -0.16 showed 73.3% sensitivity and 71.4% specificity, and patients with metastases showed lower values (mean Imc1 of metastatic patients -0.31). None of the examined variables was a predictor of the overall outcome (p&gt;0.05, each). A moderate statistically significant correlation emerged only between Imc1 and the tumor grade (r=0.457, p=0.005).

Conclusions

In conclusion, the radiomic feature Imc1 acts as a predictor of metastatic spread in patients with soft tissue sarcomas and correlates with the tumor grade.

Diagnostic and Therapeutic Management of the Thoracic Outlet Syndrome. Review of the Literature and Report of an Italian Experience

The Thoracic Outlet Syndrome is a clinical potentially disabling condition characterized by a group of upper extremity signs and symptoms due to the compression of the neurovascular bundle passing through the thoracic outlet region. Because of the non-specific nature of signs and symptoms, to the lack of a consensus for the objective diagnosis, and to the wide range of etiologies, the actual figure is still a matter of debate among experts. We aimed to summarize the current evidence about the pathophysiology, the diagnosis and the treatment of the thoracic outlet syndrome, and to report a retrospective analysis on 324 patients followed for 5 years at the Padua University Hospital and at the Naples Fatebenefratelli Hospital in Italy, to verify the effectiveness of a specific rehabilitation program for the syndrome and to evaluate if physical therapy could relieve symptoms in these patients.

Coronary Artery Disease and Gallbladder Inflammatory Pseudopolyps

Axial MR image demonstrating multiple small gallbladder polypoid lesions characterized by contrast enhancement in a 78-year-old male hospitalized for acute chest pain due to coronary artery disease who showed fever and emesis during hospitalization and had signs of acute acalculous cholecystitis at computed tomography. Given the overall clinical conditions and the MR features, the inflammatory origin of the polyps was considered. The patient underwent cholecystectomy and the histological diagnosis of gallbladder inflammatory pseudopolyps was confirmed. This rare entity represents 5–10% of all gallbladder polyps, and their differentiation from benign and malignant tumors might be challenging especially in acalculous patients, thus surgery is often performed.

Spontaneous portosystemic shunts in cirrhosis: Detection, implications, and clinical associations

BACKGROUND

Spontaneous portosystemic shunts (SPSS) are common in cirrhosis. Their characterization and clinical implications remain unclear.

AIMS

To devise a system of assessment of these shunts, and assess their clinical implications METHODS: We retrospectively studied patients with cirrhosis who underwent imaging in a liver transplant program. A novel index was computed to assess total SPSS -the diameter of a circle having an area equivalent to the sum of the areas of all the existing shunts. This 'SPSS equivalent diameter' was compared with the clinical variables.

RESULTS

Among 127 patients, 70% (CI_95% 62-77) had SPSS, and 57% (CI_95% 62-77) had multiple SPSS. The risk for SPSS was related to the severity of cirrhosis (Child-Pugh B/C vs. A: OR 2.4 CI_95% 1.1-5.4) and alcoholic aetiology (OR 2.9 CI_95% 1.2-7.1). The SPSS equivalent diameter was related to a history of HE, cognitive impairment (EEG/PHES) and ammonia(p<0.05). The diameter of the inferior cava vein >19.5 mm was a predictor of large SPSS (AUC 0.77, CI_95%:0.68-0.87, p ≤ 0.001).

CONCLUSIONS

The SPSS equivalent diameter, a comprehensive assessment of portosystemic shunting, was associated with severity of liver disease, hyperammonemia, and cognitive dysfunction. The diameter of the inferior vena cava was a good predictor of SPSS.

Reduced muscle mass as predictor of intensive care unit hospitalization in COVID-19 patients

Purpose

To evaluate if reduced muscle mass, assessed with Computed Tomography (CT), is a predictor of intensive care unit (ICU) hospitalization in COVID-19 patients.

Methods

In this Institution Review Board approved study, we retrospectively evaluated COVID-19 patients treated in our tertiary center from March to November 2020 who underwent an unenhanced chest CT scan within three weeks from hospitalization.We recorded the mean Hounsfield Unit (Hu) value of the right paravertebral muscle at the level of the 12^th thoracic vertebra, the hospitalization unit (ICU and COVID-19 wards), clinical symptoms, Barthel Index, and laboratory findings.Logistic regression analysis was applied to assess if muscle loss (Hu<30) is a predictor of ICU admission and outcome.Fisher’s exact and Student’s tests were applied to evaluate if differences between patients with and without muscle loss occurred (p<0.05).

Results

One-hundred-fifty patients matched the inclusion criteria (46 females; mean age±SD 61.3±15 years-old), 36 treated in ICU. Patients in ICU showed significantly lower Hu values (29±24 vs 39.4±12, p = 0.001). Muscle loss was a predictor of ICU admission (p = 0.004).Patients with muscle loss were significantly older (73.4±10 vs 56.4±14 years), had lower Barthel Index scores (54.4±33 vs 85.1±26), red blood-cell count (3.9±1 vs 4.6±1×10¹²L⁻¹), and Hb levels (11.5±2 vs 13.2±2g/l) as well as higher white blood-cell count (9.4±7 vs 7.2±4×10⁹L⁻¹), C-reactive protein (71.5±71 vs 44±48U/L), and lactate dehydrogenase levels (335±163 vs 265.8±116U/L) (p<0.05, each).

Conclusions

Muscle loss seems to be a predictor of ICU hospitalization in COVID-19 patients and radiologists reporting chest CT at admission should note this finding in their reports.

Volumetric histograms-based analysis of apparent diffusion coefficients and standard uptake values for the assessment of pediatric sarcoma at staging: preliminary results of a PET/MRI study

PURPOSE

To assess the relationship between apparent diffusion coefficients (ADC) and standard uptake values (SUV) of pediatric sarcomas at staging by using volumetric histograms analyses.

METHODS

Children with histologically proven sarcoma, referring to our tertiary center for a whole-body ¹⁸F-FDG PET/MRI for staging and including diffusion weighted imaging in the MRI protocol were investigated. Firstly, turbo inversion recovery magnitude (TIRM) and PET images were resliced and resampled according to the ADC maps. Regions of interests were drawn along tumor margins on TIRM images and then copied on PET and ADC datasets. Pixel-based SUVs and ADCs were collected from the entire volume of each lesion. Mean, median, skewness, and kurtosis of SUVs and ADCs values were computed, and the Pearson correlation coefficient was then applied (for the entire population and for histological subgroups with more than five patients).

RESULTS

Thirteen patients met the inclusion criteria (six females; mean age 8.31 ± 6.03 years). Histology revealed nine rhabdomyosarcomas, three Ewing sarcomas, and one chondroblastic osteosarcoma. A significant negative correlation between ADCs' and SUVs' mean (r_mean = - 0.501, P < 0.001), median (r_median = - 0.519, P < 0,001), and skewness (r_skewness = - 0.550, P < 0.001) emerged for the entire population and for rhabdomyosarcomas (r_mean = - 0.541, P = 0.001, r_median = - 0.597, P < 0.001, r_skewness = - 0.568, P < 0.001), whereas a significant positive correlation was found for kurtosis (r_kurtosis = 0.346, P < 0.001, and r_kurtosis = 0.348, P < 0.001 for the entire population and for rhabdomyosarcomas, respectively).

CONCLUSION

Our preliminary results demonstrate that, using volumetric histograms, simultaneously collected SUVs and ADCs are dependent biomarkers in pediatric FDG-avid sarcomas. Further studies, on a larger population, are necessary to confirm this evidence and assess its clinical implications.

Sternal transplant using cadaveric allograft: quantitative and qualitative assessment of bone healing by computed tomography

Background

Sternal transplant using cadaveric allograft (STCA) is a complex and rarely performed surgical procedure usually applied for massive bone tissue loss, sternotomy complications, or neoplastic resections. Although radiological imaging and especially computed tomography (CT) is routinely applied for the post-surgical assessment, up to now, a standardized approach evaluating the outcome of STCAs is missing. Therefore, aim of this study was to qualitatively and quantitatively evaluate, by CT, bone healing after STCA.

Methods

The first and the last available postsurgical CT of patients who underwent STCA in two tertiary centers between 2009 and 2017 were collected. Standardized regions of interest were applied on the cancellous bone along the transplanted sternum, and, as reference, on the fourth thoracic vertebra, at both time points, collecting the density values. The areas nearby the fixation devices were assessed by a four-points qualitative score. To evaluate the mineralization, the analysis of the variance (ANOVA) with post-hoc Bonferroni correction was applied for the quantitative measurements while the Wilcoxon test was used for the qualitative score (P<0.05). To evaluate the intra-rater reliability of the qualitative and the quantitative analyses, the same rater repeated the measurements after two months and the Cohen's kappa (k) and the intraclass correlation coefficient (ICC) were computed.

Results

Fourteen patients (11 females, 61±12.8 years) were examined. The first control CTs were performed 32±40.26 days after the STCA and the last CT were acquired after 729±745 days. The quantitative and the qualitative score significantly increased between the two intervals (P<0.05, each). The density of the transplanted sternum was lower than that of the vertebral reference at the first CT (P=0.006) while no differences occurred at the last control (P=0.361). The assessments showed high intra-rater reliability and agreement (ICC ≥0.890, k≥0.906).

Conclusions

The hereby-proposed qualitative and quantitative methods demonstrated to be good tools for assessing bone healing after STCA.

[18F]FDG PET/MRI versus contrast-enhanced MRI in detecting regional HNSCC metastases

OBJECTIVE

To compare the accuracy of contrast-enhanced MRI using established dimensional and morphological criteria versus integrated [¹⁸F]FDG PET/MRI in identifying regional lymph node metastases in patients with newly diagnosed head and neck squamous cell carcinoma (HNSCC). For this purpose, we compare MRI and PET/MRI using the histopathological findings in dissected lymph nodes as the gold standard.

METHODS

We retrospectively reviewed 26 patients with histologically proven HNSCC who underwent gadolinium-enhanced [¹⁸F]FDG PET/MRI as part of their staging. All neck lymph nodes were classified on MRI using dimensional and/or morphological criteria. Then, they were jointly assessed by a nuclear medicine physician and a radiologist using integrated [¹⁸F]PET/MR images. ROC curves were obtained to compare the techniques. Lymph node histopathology was considered as the reference standard.

RESULTS

Out of 865 lymph nodes, 35 were malignant at histopathology (3 with micro-metastases). Sensitivity and specificity were 48.6% and 99.5% for MRI using dimensional criteria; 60.0% and 99.6% for MRI using morphological criteria; 60.0% and 99.4% for MRI using both; and 74.3% and 97.6% for PET using MR as anatomic localization. The area under the ROC curve was higher for PET and MRI localization (0.859) than for MRI using dimensional (0.740; p < 0.05), or morphological (0.798; p < 0.05), or both criteria (0.797; p < 0.05). PET/MR using a PET SUVmax cutoff of 5.7 combined with MRI using dimensional and/or morphological criteria reached high values for accuracy (98.2%), NPV (98.2%), and PPV (95.2%).

CONCLUSIONS

Compared with traditional contrast-enhanced MRI or PET alone, integrated PET/MRI could improve diagnostic accuracy in detecting metastatic lymph nodes in patients with HNSCC.

Validation of a composed COVID-19 chest radiography score: the CARE project

OBJECTIVES

The aim of this study was to validate a composed coronavirus disease 2019 (COVID-19) chest radiography score (CARE) based on the extension of ground-glass opacity (GG) and consolidations (Co), separately assessed, and to investigate its prognostic performance.

METHODS

COVID-19-positive patients referring to our tertiary centre during the first month of the outbreak in our area and with a known outcome were retrospectively evaluated. Each lung was subdivided into three areas and a three-grade score assessing the extension of GG and Co was used. The CARE was derived from the sum of the subscores. A mixed-model ANOVA with post hoc Bonferroni correction was used to evaluate whether differences related to the referring unit (emergency room, COVID-19 wards and intensive care unit (ICU)) occurred. Logistic regression analyses were used to investigate the impact of CARE, patients' age and sex on the outcome. To evaluate the prognostic performance of CARE, receiver operating characteristic curves were computed for the entire stay and at admission only.

RESULTS

A total of 1203 chest radiographs of 175 patients (120 males; mean age 67.81±15.5 years old) were examined. On average, each patient underwent 6.8±10.3 radiographs. Patients in ICU as well as deceased patients showed higher CARE scores (p<0.05, each). Age, Co and CARE significantly influenced the outcome (p<0.05 each). The CARE demonstrated good accuracy (area under the curve (AUC)=0.736) using longitudinal data as well as at admission only (AUC=0.740). A CARE score of 17.5 during hospitalisation showed 75% sensitivity and 69.9% specificity.

CONCLUSIONS

The CARE was demonstrated to be a reliable tool to assess the severity of pulmonary involvement at chest radiography with a good prognostic performance.

Retrospective Analysis of a Modified Organizational Model to Guarantee CT Workflow during the COVID-19 Outbreak in the Tertiary Hospital of Padova, Italy

At the beginning of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) outbreak in Italy, the cluster of Vò Euganeo was managed by the University Hospital of Padova. The Department of Diagnostic Imaging (DDI) conceived an organizational approach based on three different pathways for low-risk, high-risk, and confirmed Coronavirus Disease 19 (COVID-19) patients to accomplish three main targets: guarantee a safe pathway for non-COVID-19 patients, ensure health personnel safety, and maintain an efficient workload. Thus, an additional pathway was created with the aid of a trailer-mounted Computed Tomography (CT) scanner devoted to positive patients. We evaluated the performance of our approach from February 21 through April 12 in terms of workload (e.g., number of CT examinations) and safety (COVID-19-positive healthcare workers). There was an average of 72.2 and 17.8 COVID-19 patients per day in wards and the Intensive Care Unit (ICU), respectively. A total of 176 high-risk and positive patients were examined. High Resolution Computed Tomography (HRCT) was one of the most common exams, and 24 pulmonary embolism scans were performed. No in-hospital transmission occurred in the DDI neither among patients nor among health personnel. The weekly number of in-patient CT examinations decreased by 27.4%, and the surgical procedures decreased by 29.5%. Patient screening and dedicated diagnostic pathways allowed the maintenance of high standards of care while working in safety.

Recurrent retroperitoneal sarcomas: Clinical outcomes of surgical treatment and prognostic factors

BACKGROUND AND PURPOSE

Locoregional recurrence after resection of primary retroperitoneal sarcoma (RPS) is a challenging therapeutic issue. The objective of this study was to identify clinicopathological factors predictive of overall survival (OS) and disease specific survival (DSS) after reoperation for recurrent RPS.

PATIENTS AND METHODS

We retrospectively collected data from the medical records of 800 patients who underwent resection for sarcoma at our Institution, from 1983 to 2015. Among these patients, 120 were treated for retroperitoneal sarcoma and 55 had a locoregional recurrence (LR). Four of them did not undergo surgery and thus were excluded from this study leaving 51 cases available for data analysis. Univariate and multivariate survival analyses were performed to identify prognostic factors.

RESULTS

Median overall survival was 33 months. The 1-year, 3-year and 5-year OS rates were 75.5%, 47.1% and 31.6% respectively. Multivariate Cox regression analysis suggested that extension of surgery (P = 0.026), surgical margin status (P = 0.015) and histological grade of recurrent tumor (P = 0.047) were independent prognostic factors for OS. Median DSS was 48 months. The 1-year, 3-year and 5-year DSS rates were 79.2%, 53.1% and 40.9%, respectively. At multivariate analysis, predictors of DSS were extension of surgery (P = 0.004), margin status (P = 0.011), histological grade of recurrent tumor (P = 0.008), and disease free interval (DFI) (P = 0.020). As regards histological subtype of recurrent RPS, at univariate analysis, well-differentiated liposarcoma (WDLS) was associated with better OS and DSS (P = 0.052 and P = 0.016 respectively) compared to dedifferentiated liposarcoma (DDLS).

CONCLUSIONS

According to our findings, surgery is more beneficial in patients with low-grade sarcoma, WDLS and long DFI. The achievement of clear resection margins, rather than performing a multivisceral resection, appears to be a key factor to improve OS and DSS.

Transjugular intrahepatic portosystemic shunt in non-cirrhotic portal hypertension related to cystic fibrosis in a lung transplant patient

Liver involvement is not uncommon in patients with cystic fibrosis (CF). Even if serious complications as non-cirrhotic portal hypertension, cirrhosis and liver failure rarely occur, they are associated with impaired survival and reduced quality of life. Herein, we have reported the first case of a patient with CF and non-cirrhotic portal hypertension who underwent transjugular intrahepatic portosystemic shunt placement for recurrent variceal bleeding after bilateral lung transplantation, and we have reviewed the available literature pertaining to this field.

Accuracy of mammography dosimetry in the era of the European Directive 2013/59/Euratom transposition

PURPOSE

To evaluate the impact of increasing levels of accuracy for mean glandular dose (MGD) evaluation in the era of the European Directive 2013/59/Euratom transposition.

METHOD

4028 women who had a mammography examination by one of five mammography units using different detector technologies were included in this study. 16,006 images were processed by a software algorithm that determines breast glandularity quantitatively and uses this to estimate patient-specific MGD (psMGD). Entrance dose (ED) values and half value layers (HVLs) measured for each mammography system were collected to evaluate the effect of equipment calibration in psMGD calculation. The psMGD values adjusted for system calibration were compared with organ dose (OD) provided by manufacturers as image metadata.

RESULTS

Overall median relative difference between calibrated psMGD and organ dose was below 3%, with larger differences for individual systems. The psMGD adjustment for system calibration was particularly useful for one system for which ED had an evident miscalibration issue. The mean difference between psMGD with calibration and organ dose provided by manufacturers was 4.1 %, ranging from -16.3 % to +24.5 %. The proportion of images for which organ dose was more than 10 % 'inaccurate' compared to psMGD was between 11 % and 46 %, depending on the mammography system.

CONCLUSION

Patient-specific mean glandular dose, possibly adjusted for system calibration, allows more accurate individual breast dosimetry than what would be performed using organ dose provided by manufacturers. Conversely, definition of diagnostic reference levels could be achieved using either psMGD or organ dose.

Sarcopenia in juvenile localized scleroderma: new insights on deep involvement

OBJECTIVES

Juvenile localized scleroderma (JLS) is a rare chronic autoimmune disease which can also affect bones and muscles. Nevertheless, muscle loss was not previously investigated in patients with JLS. Thus, the aim of this study was to retrospectively evaluate deep involvement and assess and quantify sarcopenia in JLS patients using magnetic resonance imaging (MRI).

METHODS

Fourteen children with JLS (nine females, mean age ± SD, 7.1 ± 3.6 years) referring to our tertiary center from January 2012 to January 2018 who underwent at least one MRI examination including axial T1-weighted and short tau inversion recovery images were included. Two readers assessed in consensus superficial and deep involvement. Muscle edema, muscle fatty infiltration, and sarcopenia were independently scored (absent, moderate, or severe) and the Cohen's kappa coefficient computed. Skin perimeter, subcutaneous area, muscle area, and muscle volume were independently measured using the contralateral unaffected extremity as reference (paired Student's t test, p < 0.05). The intraclass correlation coefficient (ICC) was used to investigate the reliability of the measurements.

RESULTS

All patients showed superficial involvement with subcutaneous fat atrophy being the most common finding (13 patients). Bone marrow edema occurred in five patients. Muscle edema affected ten children (moderate in seven, severe in three; k = 0.89), muscle fatty replacement occurred in one case (severe; k = 1.00), and sarcopenia was detected in eight patients (severe in two; k = 0.78). All quantitative parameters were lower on the affected side than on the unaffected contralateral limb (p < 0.05, each) and all measurements showed a high reliability (ICC > 0.750, each).

CONCLUSION

Patients with JLS can be affected by sarcopenia and quantitative analyses allow a robust characterization of such finding.

KEY POINTS

• Deep involvement in juvenile localized scleroderma is frequently characterized by sarcopenia. • In juvenile localized scleroderma, muscle edema and sarcopenia are mostly moderate while fatty infiltration, even if rare, can be severe. • Sarcopenia can be reliably quantified in children with juvenile localized scleroderma using MRI.

The role of radiological and hybrid imaging for muscle metastases: a systematic review

AIM OF THE STUDY

Skeletal muscle metastases (SMM) are a rare entity, mainly detected at autopsy. Nevertheless, radiological and nuclear medicine imaging can contribute to the diagnosis with a significant impact on the treatment and prognosis of neoplastic patients. This study aimed to systematically review the features of SMM at imaging considering the primary tumors and the sites of occurrence.

MATERIALS AND METHODS

We conducted a systematic search of three electronic database (i.e., PubMed, Science Direct, and Web of Science) up to May 2019, without any language or time interval restriction. Two reviewers performed the search and selection process, data extraction, and synthesis. We resolved disagreements by consensus and/or involving a third reviewer. The included studies have been classified according to the Oxford Centre for Evidence Based Medicine (CEBM) grading system.

RESULTS

Out of 8598 and 1077 articles respectively for radiological and hybrid imaging, 29 papers were included. According to CEBM, twelve were level 4. Computed tomography (CT) is mainly applied and, despite the existence of CT and magnetic resonance-based classifications, these are rarely used. Positron emission tomography/CT allowed the detection of small and subtle lesion also in the extremities. Muscles of the trunk were mostly affected and mainly respiratory tumors are associated with this type of metastatic spread.

CONCLUSION

Radiological and hybrid imaging allow a precise characterization of SMM. However, a more systematic approach, including also the application of available classification systems, may increase the diagnostic accuracy for this rare type of metastases.

KEY POINTS

• Skeletal muscle metastases have heterogeneous characteristics at imaging but mostly abscess-like features and high metabolic activity are described. • Skeletal muscle metastases mainly affect the muscles of the trunk. • Pulmonary, urological, and gastrointestinal cancers are the most frequent cause of skeletal muscle metastases.

Outcomes of patients with continuous flow left ventricular assist device undergoing emergency endovascular treatment for atraumatic bleeding

Introduction

Severe spontaneous bleeding is a significant complication in patients with continuous flow left ventricular assist devices; there is little evidence on endovascular treatment to support its use.

Materials and methods

We observed seven patients (five men, two women, age 43–67 years) with continuous flow left ventricular assist devices on antiaggregant/coagulant therapy, admitted to our hospital for uncorrectable symptomatic anemia; CT-angiography and diagnostic angiography confirmed the presence of atraumatic arterious bleeding from the gastrointestinal tract (six patients), from the intercostal artery and from the bronchial tree (one patient).

Results

All patients where successfully treated via an endovascular approach with superselective embolization of the involved arterial branches with coils and particles.

Conclusion

Spontaneous atraumatic bleeding is a frequent complication in patients with continuous flow left ventricular assist devices; endovascular treatment represents a promising alternative to the surgical approach as it is less invasive, easily repeatable and associated to a reduced procedural risk.

Radiological Assessment of Paediatric Fungal Infections: A Pictorial Review With Focus on PET/MRI

Paediatric invasive fungal infections have significantly increased over the past few decades, in particular among the immunocompromised population. Candida and Aspergillus spp. are still the most commonly isolated organisms. Image-based assessment of fungal infections can indeed be challenging especially in oncological patients where the differential diagnosis relative to other infections and neoplastic lesions cannot be often obvious. Therefore, the knowledge of the main radiological features associated with fungal infections is crucial to achieve an early correct diagnosis and address the most appropriate therapeutic approach. Thus, our aim was to review the main radiological features of paediatric fungal infections with particular focus on positron emission tomography/magnetic resonance imaging (PET/MRI), referring to the experience of our tertiary level hospital.

Fully integrated 18F-FDG PET/MR in large vessel vasculitis

BACKGROUND

To evaluate the usefulness of [18F] fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) in large vessels vasculitis (LVV) patients.

METHODS

We performed an observational retrospective study based on our records. Images were acquired on a PET/MR scanner using 18F-FDG-PET whole body imaging. For each PET scan, a qualitative analysis and a semi-quantitative measure using the maximum of the standardized uptake value (SUVMax) were performed. SUVMax measurements normalized to the liver uptake were categorized using a grading scale. Vessel's wall thickness (WT) was measured at five fixed points (inferior margin of T5, T9, T12, L3, thickest area-max WT).

RESULTS

23 LVV patients were included, 56.5% giant cells arteritis, 34.8% Takayasu's arteritis and 8.7% isolated aortitis, all Caucasian, mostly females (82%). We considered 32 PET scans for the LVV group (from min. 1 to max. 3 scans/patient) mainly during follow-up (29/32 scans), and 23 PET scans from a control group of non-metastatic malignancies patients. We found higher SUVMax compared to controls, in all sites, irrespective of clinical disease activity. Mean WT resulted higher in patients than in controls but was not correlated to SUVMax. Mean WT positively correlated with age in both cohorts, inversely correlated to disease duration, while no correlation with SUVMax was observed. The concordance between clinically active disease and PET hypermetabolism was poor (K Cohen 0.33).

CONCLUSIONS

PET/MR is a safe imaging technique capable of detecting inflammation in aortic wall. Low radiological exposure of PET/MR should be considered especially in young women receiving follow-up studies.

FGF signaling deregulation is associated with early developmental skeletal defects in animal models for mucopolysaccharidosis type II (MPSII)

Skeletal abnormalities represent a major clinical burden in patients affected by the lysosomal storage disorder mucopolysaccharidosis type II (MPSII, OMIM #309900). While extensive research has emphasized the detrimental role of stored glycosaminoglycans (GAGs) in the bone marrow (BM), a limited understanding of primary cellular mechanisms underlying bone defects in MPSII has hampered the development of bone-targeted therapeutic strategies beyond enzyme replacement therapy (ERT). We here investigated the involvement of key signaling pathways related to the loss of iduronate-2-sulfatase activity in two different MPSII animal models, D. rerio and M. musculus. We found that FGF pathway activity is impaired during early stages of bone development in IDS knockout mice and in a newly generated Ids mutant fish. In both models the FGF signaling deregulation anticipated a slow but progressive defect in bone differentiation, regardless of any extensive GAGs storage. We also show that MPSII patient fibroblasts harboring different mutations spanning the IDS gene exhibit perturbed FGF signaling-related markers expression. Our work opens a new venue to discover possible druggable novel key targets in MPSII.

Are panels of clinical, laboratory, radiological, and microbiological variables of prognostic value in deep neck infections? An analysis of 301 consecutive cases

BACKGROUND

Deep neck infections (DNIs) are often clinically challenging, and may be life-threatening.

OBJECTIVE

The present retrospective study aimed to identify panels of clinical, laboratory, radiological, and microbiological parameters that could identify patients with DNIs at higher risk of complications or long-term hospitalization.

MATERIALS AND METHODS

The investigation concerned 301 consecutive patients with DNIs treated at our institution between 2000 and 2014.

RESULTS

The discriminatory power of a combination of two variables (unknown origin of the infection and the need for surgical treatment) in terms of deep neck infection complications occurrence featured an AUC (ROC) of 0.6701. The power of a panel of four variables (age, leukocyte count, need for surgical treatment, days elapsing from hospitalization to surgical procedure) to identify DNIs necessitating long-term hospitalization featured an AUC (ROC) of 0.7929.

CONCLUSION

Using the scale proposed by Hosmer and Lemeshow, the four-variable panel showed an amply acceptable, nearly excellent discriminatory power for long-term hospitalization.

SIGNIFICANCE

Although this panel achieved promising results for prognostic purposes, other parameters potentially capable of predicting the outcome of DNIs and orienting treatment decisions need to be investigated.

Muscle MRI in patients with dysferlinopathy: pattern recognition and implications for clinical trials

BACKGROUND AND OBJECTIVE

Dysferlinopathies are a group of muscle disorders caused by mutations in the DYSF gene. Previous muscle imaging studies describe a selective pattern of muscle involvement in smaller patient cohorts, but a large imaging study across the entire spectrum of the dysferlinopathies had not been performed and previous imaging findings were not correlated with functional tests.

METHODS

We present cross-sectional T1-weighted muscle MRI data from 182 patients with genetically confirmed dysferlinopathies. We have analysed the pattern of muscles involved in the disease using hierarchical analysis and presented it as heatmaps. Results of the MRI scans have been correlated with relevant functional tests for each region of the body analysed.

RESULTS

In 181 of the 182 patients scanned, we observed muscle pathology on T1-weighted images, with the gastrocnemius medialis and the soleus being the most commonly affected muscles. A similar pattern of involvement was identified in most patients regardless of their clinical presentation. Increased muscle pathology on MRI correlated positively with disease duration and functional impairment.

CONCLUSIONS

The information generated by this study is of high diagnostic value and important for clinical trial development. We have been able to describe a pattern that can be considered as characteristic of dysferlinopathy. We have defined the natural history of the disease from a radiological point of view. These results enabled the identification of the most relevant regions of interest for quantitative MRI in longitudinal studies, such as clinical trials.

CLINICAL TRIAL REGISTRATION

NCT01676077.

The clinical spectrum of CASQ1-related myopathy

OBJECTIVE

To identify and characterize patients with calsequestrin 1 (CASQ1)-related myopathy.

METHODS

Patients selected according to histopathologic features underwent CASQ1 genetic screening. CASQ1-mutated patients were clinically evaluated and underwent muscle MRI. Vacuole morphology and vacuolated fiber type were characterized.

RESULTS

Twenty-two CASQ1-mutated patients (12 families) were identified, 21 sharing the previously described founder mutation (p.Asp244Gly) and 1 with the p.Gly103Asp mutation. Patients usually presented in the sixth decade with exercise intolerance and myalgias and later developed mild to moderate, slowly progressive proximal weakness with quadriceps atrophy and scapular winging. Muscle MRI (n = 11) showed a recurrent fibrofatty substitution pattern. Three patients presented subclinical cardiac abnormalities. Muscle histopathology in patients with p.Asp244Gly showed vacuoles in type II fibers appearing empty in hematoxylin-eosin, Gomori, and nicotinamide adenine dinucleotide (NADH) tetrazolium reductase stains but strongly positive for sarcoplasmic reticulum proteins. The muscle histopathology of p.Gly103Asp mutation was different, showing also NADH-positive accumulation consistent with tubular aggregates.

CONCLUSIONS

We report the clinical and molecular details of the largest cohort of CASQ1-mutated patients. A possible heart involvement is presented, further expanding the phenotype of the disease. One mutation is common due to a founder effect, but other mutations are possible. Because of a paucity of symptoms, it is likely that CASQ1 mutations may remain undiagnosed if a muscle biopsy is not performed.

Non Lipomatous Benign Lesions Mimicking Soft-tissue Sarcomas: A Pictorial Essay

The incidental finding of soft tissue masses is a challenge for the radiologist. Benign and malignant lesions can be differentiated relying on patient history, symptoms and mostly with the help of imaging. Ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) become fundamental in order to distinguish these lesions but the radiologist needs to know the main characteristics of benign soft tissue masses and sarcomas. Herein, we present a pictorial review of lesions mimicking soft tissue sarcomas features.

Magnetic Resonance Imaging Assessment of Lipomatous Soft-tissue Tumors

AIM

To establish the accuracy of magnetic resonance imaging (MRI) in distinguishing between benign and malignant lipomatous tumors; to evaluate the reproducibility of the MRI interpretation assessing the agreement between judgments of two radiologists with the same experience in soft-tissue sarcomas; to identify an association among MRI findings (size, depth, septa, nodules, signal homogeneity) and nature of the lesion.

MATERIALS AND METHODS

A total of 54 patients (28 men and 26 women), with a mean age of 56 (range=27-84) were included years. All subjects followed-up by the Multidisciplinary Sarcoma Group. The following MRI findings were judged in a blind study by two radiologists: size, localization, septa, nodules and signal homogeneity. A diagnostic indication was then given from among lipoma, atypical lipomatous tumour (ALT) and liposarcoma. Accuracy in distinguishing between benign and malignant lesions, and between lipoma and ALT (Fisher's exact test), inter-operator agreement (Cohen's kappa), association of MRI findings and malignancy of the lesion (Fisher's exact test and odds ratio) were evaluated.

RESULTS

The inter-operator agreement was complete (100%). The agreement between diagnostic hypothesis and histological diagnosis was statistically significant (p<0.05). Among the radiological findings taken into account, only septa and signal homogeneity were significantly associated with the malignancy of the lesion (p<0.05).

CONCLUSION

MRI could be helpful in distinguishing lipomatous tumors, allowing biopsy to be avoided in some cases (negative predictive value=100%).

Bayesian Quantification of Contrast-Enhanced Ultrasound Images With Adaptive Inclusion of an Irreversible Component

Contrast Enhanced Ultrasound (CEUS) is a sensitive imaging technique to assess tissue vascularity and it can be particularly useful in early detection and grading of arthritis. In a recent study we have shown that a Gamma-variate can accurately quantify synovial perfusion and it is flexible enough to describe many heterogeneous patterns. However, in some cases the heterogeneity of the kinetics can be such that even the Gamma model does not properly describe the curve, with a high number of outliers. In this work we apply to CEUS data the single compartment recirculation model (SCR) which takes explicitly into account the trapping of the microbubbles contrast agent by adding to the single Gamma-variate model its integral. The SCR model, originally proposed for dynamic-susceptibility magnetic resonance imaging, is solved here at pixel level within a Bayesian framework using Variational Bayes (VB). We also include the automatic relevant determination (ARD) algorithm to automatically infer the model complexity (SCR vs. Gamma model) from the data. We demonstrate that the inclusion of trapping best describes the CEUS patterns in 50% of the pixels, with the other 50% best fitted by a single Gamma. Such results highlight the necessity of the use ARD, to automatically exclude the irreversible component where not supported by the data. VB with ARD returns precise estimates in the majority of the kinetics (88% of total percentage of pixels) in a limited computational time (on average, 3.6 min per subject). Moreover, the impact of the additional trapping component has been evaluated for the differentiation of rheumatoid and non-rheumatoid patients, by means of a support vector machine classifier with backward feature selection. The results show that the trapping parameter is always present in the selected feature set, and improves the classification.

Radiologic Response Assessment in Pediatric Soft Tissue Sarcoma: Computed-Assisted Volume Evaluation

OBJECTIVES

To compare 3 methods of dimensional assessment, with particular attention to a new software assisted method of volume calculation, in soft tissue sarcoma, and to investigate the interobserver agreement and the intermethod agreement in chemotherapy response classification and resultant clinical repercussions.

STUDY DESIGN

We studied 34 pediatric patients with nonmetastatic soft tissue sarcoma who had undergone only diagnostic biopsy. Tumor size was measured both at diagnosis and after induction chemotherapy by 3 observers and using 3 measurement methods: maximum axis (1 diameter), estimated volume (3 diameters), and computed volume (software-assisted volume calculation). We used overall concordance correlation coefficient and Bland-Altman statistical methods to assess interobserver agreement and overall concordance correlation coefficient and the κ Cohen coefficient to assess intermethod agreement.

RESULTS

According to overall concordance correlation coefficient, the interobserver agreement was very high for each method, with a slight superiority of the software assisted method; this agreement was not confirmed in Bland-Altman plots for maximum axis and estimated volume methods. According to kappa coefficients, the intermethod agreement in chemotherapy response evaluation was poor.

CONCLUSIONS

Computed volume was the most accurate method in soft tissue sarcoma tumor size assessment. One- and 3-dimensional methods are not concordant in chemotherapy response classification. In particular, the maximum axis method underestimates chemotherapy response and can lead to switching the chemotherapy regimen erroneously.

Desmoid Fibromatosis of the Abdominal Wall: Surgical Resection and Reconstruction with Biological Matrix Egis®

Desmoid tumor is a rare monoclonal fibroblast proliferation that is regarded as benign. The clinical management of desmoid tumors is very complex and requires a multidisciplinary approach because of the unpredictable disease course. For those cases localized in the anterior abdominal wall, symptomatic and unresponsive to medical treatment, radical resection and reconstruction with a prosthetic device are indicated. We present here a case of desmoid fibromatosis of the left anterolateral abdominal wall with a marked increase of the mass that required a large excision followed by reconstruction with biological matrix. The fact that it can be incorporated in patient tissue without a fibrotic response and that it can resist future infections, together with a very competetive price, made the new collagen matrix Egis^® our first choice.

Prospective evaluation of Quasistatic Ultrasound Elastography (USE) compared with Baseline US for parotid gland lesions: preliminary results of elasticity contrast index (ECI) evaluation

AIMS

To assess the diagnostic value of elasticity contrast index (ECI) elastography, in comparison with conventional ultrasound for the differentiation of benign and malignant parotid lesions.

MATERIAL AND METHODS

Sixty-three consecutive patients with parotid gland tumors, treated surgically at a single tertiary center were enrolled. Ultrasound evaluation consisted of B-mode, color-Doppler and quasistatic ultrasound elastography (USE), conducted with the ECI technique. For each lesion the echogenicity, margins, vascularization, and capsulation were considered to determine benign or malignant lesions. Histology was considered the gold standard.

RESULTS

Using conventional parameters, the observer suggested malignant lesions in 20 cases and benign lesions in 43 cases (accuracy: 61.8%). ECI>3.5 alone was the most accurate parameter (accuracy: 90.5%), with sensitivity of 93.7% and specificity of 89.4%. However, when combined with the other US criteria, no statistically significant diagnostic accuracy improvement was achieved.

CONCLUSIONS

Our results show that USE with ECI index measurement can help to discriminate preoperatively benign from malignant lesions, with the exception of pleomorphic adenoma which is stiff. We suggest that USE can be used as an additional tool to conventional US evaluation of salivary gland lesions.

A genuine pediatric parapharyngeal abscess a year after uneventful adenotonsillectomy

Brescia G, Pedruzzi B, Stramare R, Pendolino AL, Martini A, Marioni G. A genuine pediatric parapharyngeal abscess a year after uneventful adenotonsillectomy. Turk J Pediatr 2017; 59: 715-718. It is unusual for a parapharyngeal abscess (PA) to occur late after an adenotonsillectomy. We report herein a 13-year-old female patient who developed a PA a year after an uneventful adenotonsillectomy. The patient underwent 2 surgical explorations and was given intravenous antibiotic treatment. She was discharged in good general condition after spending 7 days in hospital. The potential pathophysiological mechanisms behind PA formation late after tonsillectomy or adenotonsillectomy, and rational treatments for PA are critically discussed.

A Case of "en bloc" Excision of a Chest Wall Leiomyosarcoma and Closure of the Defect with Non-Cross-Linked Collagen Matrix (Egis®)

Sarcomas arising from the chest wall account for less than 20% of all soft tissue sarcomas, and at this site, primitive tumors are the most frequent to occur. Leiomyosarcoma is a malignant smooth muscle tumor and the best outcomes are achieved with wide surgical excision. Although advancements have been made in treatment protocols, leiomyosarcoma remains one of the more difficult soft tissue sarcoma to treat. Currently, general local control is obtained with surgical treatment with wide negative margins. We describe the case of a 50-year-old man who underwent a chest wall resection involving a wide portion of the pectoralis major and minor muscle, the serratus and part of the second, third and fourth ribs of the left side. The full-thickness chest wall defect of 10 × 8 cm was closed using a non-cross-linked acellular dermal matrix (Egis^®) placed in two layers, beneath the rib plane and over it. A successful repair was achieved with no incisional herniation and with complete tissue regeneration, allowing natural respiratory movements. No complications were observed in the postoperative course. Biological non-cross-linked matrix, derived from porcine dermis, behaves like a scaffold supporting tissue regeneration; it can be successfully used as an alternative to synthetic mesh for chest wall reconstruction.

Core needle biopsy of soft tissue tumors, CEUS vs US guided: a pilot study

PURPOSE

The purpose of this study was to evaluate the usefulness of contrast-enhanced ultrasonography (CEUS) in the bioptic sampling of soft tissue tumors (STT) compared with unenhanced ultrasonography alone.

METHODS

This is a prospective longitudinal study of 40 patients subjected to ultrasonography (US)-guided core needle biopsy (CNB) to characterize a suspected STT. Three series of bioptic samplings were carried out on each patient, respectively using unenhanced US alone and CEUS in both the areas of the tumor enhanced or not by the contrast medium. All bioptic samples underwent a histological evaluation and the results were analyzed by comparing the histology of the biopsy with the definitive diagnosis in 15 surgically excised samples.

RESULTS

27 (67.5 %) of the 40 patients completed the entire study procedure; in 19 cases (70.3 %) the three bioptic samplings gave unanimous results, also when compared to the surgical specimen; in seven cases (25.9 %) use of CEUS allowed to obtain additional or more accurate information about the mass in question, compared to simple US guidance without contrast; in one patient (3.7 %) sampling obtained using unenhanced ultrasonography guidance and in the areas enhanced by the contrast agent had precisely the same results of the surgical specimen.

CONCLUSIONS

CEUS, due to its ability to evaluate microvascular areas, has proven to be a promising method in guiding bioptic sampling of soft tissue tumor, directing the needle to the most significant areas of the tumor. Given the small number of patients evaluated in our study, to achieve statistically significant results, it would be appropriate to obtain a larger sample size, since the very first results seem to be encouraging and to justify the increase of the population.

Clinical and molecular study in a long-surviving patient with MLASA syndrome due to novel PUS1 mutations

Myopathy-lactic acidosis-sideroblastic anemia (MLASA) syndrome is a rare autosomal recessive disease. We studied a 43-year-old female presenting since childhood with mild cognitive impairment and sideroblastic anemia. She later developed hepatopathy, cardiomyopathy, and insulin-dependent diabetes. Muscle weakness appeared in adolescence and, at age 43, she was unable to walk. Two novel different mutations in the PUS1 gene were identified: c.487delA (p.I163Lfs*4) and c.884 G>A (p.R295Q). Quantitative analysis of DNA from skeletal muscle biopsies showed a significant increase in mitochondrial DNA (mtDNA) content in the patient compared to controls. Clinical and molecular findings of this patient widen the genotype-phenotype spectrum in MLASA syndrome.

Pixel-based approach to assess contrast-enhanced ultrasound kinetics parameters for differential diagnosis of rheumatoid arthritis

Inflammatory rheumatic diseases are the leading causes of disability and constitute a frequent medical disorder, leading to inability to work, high comorbidity, and increased mortality. The standard for diagnosing and differentiating arthritis is based on clinical examination, laboratory exams, and imaging findings, such as synovitis, bone edema, or joint erosions. Contrast-enhanced ultrasound (CEUS) examination of the small joints is emerging as a sensitive tool for assessing vascularization and disease activity. Quantitative assessment is mostly performed at the region of interest level, where the mean intensity curve is fitted with an exponential function. We showed that using a more physiologically motivated perfusion curve, and by estimating the kinetic parameters separately pixel by pixel, the quantitative information gathered is able to more effectively characterize the different perfusion patterns. In particular, we demonstrated that a random forest classifier based on pixelwise quantification of the kinetic contrast agent perfusion features can discriminate rheumatoid arthritis from different arthritis forms (psoriatic arthritis, spondyloarthritis, and arthritis in connective tissue disease) with an average accuracy of 97%. On the contrary, clinical evaluation (DAS28), semiquantitative CEUS assessment, serological markers, or region-based parameters do not allow such a high diagnostic accuracy.

Role of Radiologic Imaging in Genetic and Acquired Neuromuscular Disorders

Great technologic and clinical progress have been made in the last two decades in identifying genetic defects of several neuromuscular diseases, as Spinal Muscular Atrophy, genetic muscular dystrophies and other genetic myopathies. The diagnosis is usually challenging, due to great variability in genetic abnormalities and clinical phenotypes and the poor specificity of complementary analyses, i.e., serum creatine kinase (CK) and electrophysiology. Muscle biopsy represents the gold standard for the diagnosis of genetic neuromuscular diseases, but clinical imaging of muscle tissue is an important diagnostic tool to identify and quantifyies muscle damage. Radiologic imaging is, indeed, increasingly used as a diagnostic tool to describe patterns and the extent of muscle involvement, thanks to modern techniques that enable to definethe definition of degrees of muscle atrophy and changes in connective tissue. They usually grade the severity of the disease process with greater accuracy than clinical scores. Clinical imaging is more than complementary to perform muscle biopsy, especially as ultrasound scans are often mandatory to identify the muscle to be biopsied. We will here detail and provideWe will herein provide detailed examples of the radiologic methods that can be used in genetic and acquired neuromuscular disorders, stressing pros and cons.

KEY WORDS

Muscle Imaging, MRI, CT, genetic muscle disorders, myopathies, dystrophies.

Persistent Muscle Fiber Regeneration in Long Term Denervation. Past, Present, Future

Despite the ravages of long term denervation there is structural and ultrastructural evidence for survival of muscle fibers in mammals, with some fibers surviving at least ten months in rodents and 3-6 years in humans. Further, in rodents there is evidence that muscle fibers may regenerate even after repeated damage in the absence of the nerve, and that this potential is maintained for several months after denervation. While in animal models permanently denervated muscle sooner or later loses the ability to contract, the muscles may maintain their size and ability to function if electrically stimulated soon after denervation. Whether in mammals, humans included, this is a result of persistent de novo formation of muscle fibers is an open issue we would like to explore in this review. During the past decade, we have studied muscle biopsies from the quadriceps muscle of Spinal Cord Injury (SCI) patients suffering with Conus and Cauda Equina syndrome, a condition that fully and irreversibly disconnects skeletal muscle fibers from their damaged innervating motor neurons. We have demonstrated that human denervated muscle fibers survive years of denervation and can be rescued from severe atrophy by home-based Functional Electrical Stimulation (h-bFES). Using immunohistochemistry with both non-stimulated and the h-bFES stimulated human muscle biopsies, we have observed the persistent presence of muscle fibers which are positive to labeling by an antibody which specifically recognizes the embryonic myosin heavy chain (MHCemb). Relative to the total number of fibers present, only a small percentage of these MHCemb positive fibers are detected, suggesting that they are regenerating muscle fibers and not pre-existing myofibers re-expressing embryonic isoforms. Although embryonic isoforms of acetylcholine receptors are known to be re-expressed and to spread from the end-plate to the sarcolemma of muscle fibers in early phases of muscle denervation, we suggest that the MHCemb positive muscle fibers we observe result from the activation, proliferation and fusion of satellite cells, the myogenic precursors present under the basal lamina of the muscle fibers. Using morphological features and molecular biomarkers, we show that severely atrophic muscle fibers, with a peculiar cluster reorganization of myonuclei, are present in rodent muscle seven-months after neurectomy and in human muscles 30-months after complete Conus-Cauda Equina Syndrome and that these are structurally distinct from early myotubes. Beyond reviewing evidence from rodent and human studies, we add some ultrastructural evidence of muscle fiber regeneration in long-term denervated human muscles and discuss the options to substantially increase the regenerative potential of severely denervated human muscles not having been treated with h-bFES. Some of the mandatory procedures, are ready to be translated from animal experiments to clinical studies to meet the needs of persons with long-term irreversible muscle denervation. An European Project, the trial Rise4EU (Rise for You, a personalized treatment for recovery of function of denervated muscle in long-term stable SCI) will hopefully follow.