The Role of an MRI-Based Radiomic Signature in Predicting Malignancy of Parotid Gland Tumors.

The aim of this study was to assess the ability of MRI radiomic features to differentiate between benign parotid gland tumors (BPGT) and malignant parotid gland tumors (MPGT). This retrospective study included 93 patients who underwent MRI examinations of the head and neck region (78 patients presenting unique PGT, while 15 patients presented double PGT). A total of 108 PGT with histological confirmation were eligible for the radiomic analysis and were assigned to a training group (n = 83; 58 BPGT; 25 MPGT) and a testing group (n = 25; 16 BPGT; 9 MPGT). The radiomic features were extracted from 3D segmentations of the PGT on the T2-weighted and fat-saturated, contrast-enhanced T1-weighted images. Following feature reduction techniques, including LASSO regression analysis, a radiomic signature (RS) was built with five radiomic features. The RS presented a good diagnostic performance in differentiating between PGT, achieving an area under the curve (AUC) of 0.852 (p < 0.001) in the training set and 0.786 (p = 0.017) in the testing set. In both datasets, the RS proved to have lower values in the BPGT group as compared to MPGT group (p < 0.001 and p = 0.023, respectively). The multivariate analysis revealed that RS was independently associated with PGT malignancy, together with the ill-defined margin pattern (p = 0.031, p = 0.001, respectively). The complex model, using clinical data, MRI features and the RS, presented a higher diagnostic performance (AUC of 0.976) in comparison to the RS alone. MRI-based radiomic features could be considered potential additional imaging biomarkers able to discriminate between benign and malignant parotid gland tumors.

Radiomic Features Associated with Lymphoma Development in the Parotid Glands of Patients with Primary Sjögren's Syndrome.

Non-Hodgkin Lymphoma (NHL) represents a severe complication and the main cause of morbidity in patients with primary Sjögren's syndrome (pSS). This study aimed to assess the role of textural analysis (TA) in revealing lymphoma-associated imaging parameters in the parotid gland (PG) parenchyma of patients with pSS. This retrospective study included a total of 36 patients (54.93 ± 13.34 years old; 91.6% females) diagnosed with pSS according to the American College of Rheumatology and the European League Against Rheumatism criteria (24 subjects with pSS and no lymphomatous proliferation; 12 subjects with pSS and NHL development in the PG, confirmed by the histopathological analysis). All subjects underwent MR scanning between January 2018 and October 2022. The coronal STIR PROPELLER sequence was employed to segment PG and perform TA using the MaZda5 software. A total of 65 PGs underwent segmentation and texture feature extraction (48 PGs were included in the pSS control group, and 17 PGs were included in the pSS NHL group). Following parameter reduction techniques, univariate analysis, multivariate regression, and receiver operating characteristics (ROC) analysis, the following TA parameters proved to be independently associated with NHL development in pSS: CH4S6_Sum_Variance and CV4S6_Inverse_Difference_Moment, with an area under ROC of 0.800 and 0.875, respectively. The radiomic model (resulting by combining the two previously independent TA features), presented 94.12% sensitivity and 85.42% specificity in differentiating between the two studied groups, reaching the highest area under ROC of 0.931 for the chosen cutoff value of 1.556. This study suggests the potential role of radiomics in revealing new imaging biomarkers that might serve as useful predictors for lymphoma development in patients with pSS. Further research on multicentric cohorts is warranted to confirm the obtained results and the added benefit of TA in risk stratification for patients with pSS.

The Diagnostic Value of MRI-Based Radiomic Analysis of Lacrimal Glands in Patients with Sjögren's Syndrome.

This study aimed to assess the effectiveness of MRI-based texture features of the lacrimal glands (LG) in augmenting the imaging differentiation between primary Sjögren's Syndrome (pSS) affected LG and healthy LG, as well as to emphasize the possible importance of radiomics in pSS early-imaging diagnosis. The MRI examinations of 23 patients diagnosed with pSS and 23 healthy controls were retrospectively included. Texture features of both LG were extracted from a coronal post-contrast T1-weighted sequence, using a dedicated software. The ability of texture features to discriminate between healthy and pSS lacrimal glands was performed through univariate, multivariate, and receiver operating characteristics analysis. Two quantitative textural analysis features, RunLengthNonUniformityNormalized (RLNonUN) and Maximum2DDiameterColumn (Max2DDC), were independent predictors of pSS-affected glands (p < 0.001). Their combined ability was able to identify pSS LG with 91.67% sensitivity and 83.33% specificity. MRI-based texture features have the potential to function as quantitative additional criteria that could increase the diagnostic accuracy of pSS-affected LG.

Differentiation of Endometriomas from Hemorrhagic Cysts at Magnetic Resonance: The Role of Quantitative Signal Intensity Measurements.

BACKGROUND: Endometriomas and functional hemorrhagic cysts (FHCs) are a common gynecological encounter. OBJECTIVE: This study aimed to assess the diagnostic efficiency of magnetic resonance imaging (MRI) using signal intensity measurements in differentiating endometriomas from FHCs. METHODS: Forty-six patients who underwent pelvic MRI examinations (endometriomas, n=28; FHCs, n=18) were retrospectively included. The "T2 shading" sign was evaluated subjectively and quantitatively by measuring the T1-T2 signal intensity difference and calculating the percentage of signal decrease between T1 and T2-weighted sequences. The resulted values, along with the measurement of the Apparent Diffusion Coefficient (ADC) and the signal intensity on three diffusion- weighted sequences (DWI) (b50, b400, and b800), were compared between groups by using the Mann-Whitney U test. Also, the receiver operating characteristic analysis was performed for the statistically significant results (P<0.016), and the area under the curve (AUC) was also calculated. RESULTS: The two quantitative assessment methods showed similar efficiency in detecting endometriomas (P<0.001; sensitivity, 100%; specificity, 81.82%; AUC>0.86), outperforming the classic subjective evaluation of the "T2 shading" sign (sensitivity, 92.86%; specificity, 66.67%). ADC (P=0.52) and DWI measurements (P=0.49, P=0.74, and P=0.78) failed to distinguish between the two entities. CONCLUSION: The quantitative analysis and interpretation of the "T2 shading" sign can significantly improve the differential diagnosis between endometriomas and FHCs.

Cross-sectional imaging and cytologic investigations in the preoperative diagnosis of parotid gland tumors - An updated literature review.

An accurate preoperative diagnosis of parotid tumors is essential for the selection and planning of surgical treatment. Various modern cross-sectional imaging and cytologic investigations can support the differential diagnosis of parotid tumors. The aim of this study was to achieve a comprehensive and updated review of modern imaging and cytologic investigations used in parotid tumor diagnosis, based on the latest literature data. This literature review could serve as a guide for clinicians in selecting different types of investigations for the preoperative differential diagnosis of parotid tumors. Magnetic resonance imaging (MRI) with its dynamic and advanced sequences is the first-line imaging investigation used in differentiating parotid tumors. Computed tomography (CT) and positron emission tomography (PET)-CT provide limited indications in differentiating parotid tumors. Fine needle aspiration biopsy and core needle biopsy can contribute with satisfactory results to the cytological diagnosis of parotid tumors. Dynamic MRI with its dynamic contrast-enhanced and diffusion-weighted sequences provides the best accuracy for the preoperative differential diagnosis of parotid tumors. CT allows the best evaluation of bone invasion, being useful when MRI cannot be performed, and PET-CT has value in the follow-up of cancer patients. The dual cytological and imaging approach is the safest method for an accurate differential diagnosis of parotid tumors.

Ultrasound and magnetic resonance imaging evaluation of the femoral and sciatic nerves. A study of healthy volunteers.

BACKGROUND AND AIMS: The study describes the femoral (FN) and sciatic nerves (SN), explored using ultrasound (US) and magnetic resonance imaging (MRI). The aims of the study are: to establish US/MRI correlations and define reference values: for the anteroposterior (AP) and mediolateral (ML) diameters and cross-sectional area (CSA) of the two nerves respectively, in well-defined anatomical measuring sites; to analyze the intraobserver variation; to define the value with least variability; to determine differences between the right-left and male-female reference values. METHODS: A prospective study was carried out on 24 healthy volunteers (11 men and 13 women). MRI scans were performed using a 1.5T system. To visualize both nerves (FN and SN), a single 3D T2 weighted acquisition was performed, in the coronal plane, with a wide FOV. For ultrasonographic examinations, a Hitachi EUB-8500 ultrasound machine, equipped with a 13 MHz linear transducer was used. The measurements were performed at well-defined anatomical locations. The mean reference values of the AP, ML diameters and CSA were calculated for femoral and sciatic nerves, both on MRI and US. The correlations between the values determined by the two techniques were analyzed. The intra-observer variation was calculated by measuring the nerves at the same anatomical location at two separate time points. RESULTS: Wilcoxon matched-pairs signed rank test indicated a non-significant difference (p> 0.05) for the femoral and sciatic nerves, on both sides, except the femoral nerve ML diameter on MRI (p=0.014). The mean MRI and US reference values for the femoral nerve were calculated between the psoas and iliac muscles: FNAPMRI 4.533 ± 0.486, FNAPUS 4.800 ± 1.237, FNMLMRI 6.172 ± 1.203, FNMLUS 7.685 ± 3.338, FNCSAMRI 24.811 ± 3.394, FNCSAUS 26.285 ± 17.608. The mean MRI and US measurements for the sciatic nerve were determined under the buttock, at the level of the ischial tuberosity: SNAPMRI 5.500 ± 1.201, SNAPUS 5.975 ± 1.312, SNMLMRI 10.375 ± 2.272, SNMLUS 13.500 ± 1.661, SNCSAMRI 50.625 ± 15.373, SNCSAUS 53.631 ± 15.847. The MRI and US differences between right and left sides, both for the femoral and sciatic nerves were insignificant. In selected cases, Wilcoxon paired test indicated differences between subjects, according to their gender, both on MRI and US. CONCLUSION: Reference values for the femoral and sciatic nerves at specific anatomical sites were identified. Side to side variation and gender related differences add to current knowledge on nerve size in young Caucasian population.

Diffusion-Weighted Magnetic Resonance Imaging as a Noninvasive Parameter for Differentiating Benign and Malignant Intraperitoneal Collections.

Background and Objective: The imaging differentiation of benign from malignant intraperitoneal collections (IPCs) relies on the tumoral morphological modifications of the peritoneum, which are not always advocating for malignancy. We aimed to assess ascitic fluid with the apparent diffusion coefficient (ADC) to determine non-invasive, stand-alone, differentiation criteria for benign and malignant intraperitoneal effusions. Materials and Methods: Sixty-one patients with known IPCs who underwent magnetic resonance examinations for reasons such as tumor staging, undetermined abdominal mass and disease follow up were retrospectively included in this study. All subjects had a final diagnosis of the fluid based on pathological examinations, which were divided into benign (n = 37) and malignant (n = 24) IPCs groups. ADC values were measured separately by two radiologists, and the average values were used for comparing the two groups by consuming the independent samples t-test. The receiver operating characteristic analysis was performed to test the ADC values' diagnostic ability to distinguish malignant from benign collections. Results: The differentiation between benign and malignant IPCs based on ADC values was statistically significant (p = 0.0034). The mean ADC values were higher for the benign (3.543 × 10-3 mm2/s) than for the malignant group (3.057 × 10-3 mm2/s). The optimum ADC cutoff point for the diagnosis of malignant ascites was <3.241 × 10-3 mm2/s, with a sensitivity of 77.78% and a specificity of 80%. Conclusions: ADC represents a noninvasive and reproducible imaging parameter that may help to assess intraperitoneal collections. Although successful in distinguishing malignant from benign IPCs, further research must be conducted in order to certify if the difference in ADC values is a consequence of the physical characteristics of the ascitic fluids or their appurtenance to a certain histopathological group.

Ultrasound appearance of peripheral nerves in the neck: vagus, hypoglossal and greater auricular.

BACKGROUND AND AIM: Information in ultrasonography about reference values of nerves, particularly of those located in the neck is limited. The aim of the study is to demonstrate the feasibility of direct visualization of the vagus, hypoglossal and greater auricular nerves, testing the method on healthy volunteers and estimate the reference values for two perpendicular diameters and cross-sectional area (CSA). METHODS: A prospective study was carried out on 21 healthy volunteers (12 women and 9 men), recording their demographic characteristics. A 13 MHz transducer was used on a Hitachi EUB-8500 machine. The vagus nerve was measured at the bifurcation of common carotid artery (CCA) and at the intersection of the internal jugular vein with omohyoid muscle. The hypoglossal nerve was identified as it crosses the posterolateral border of the mylohyoid muscle in the submandibular space. The auricular nerve was identified on the superficial surface of the sternocleidomastoid muscle at 1 cm from its posterior margin. The mean CSA on axial scans, nerve width and thickness were determined. The side-to-side and gender differences of the estimated reference values and their correlations with the weight, height, and body mass index (BMI) were evaluated. RESULTS: The mean ultrasound-estimated CSA was measured for the vagus nerve at CCA bifurcation (2.14 ± 0.79 on the left 2.86 ± 1.27 on the right), vagus nerve at the level of omohyoid muscle (2.10 ± 0.06 on the left and 2.43 ± 0.08 on the right), hypoglossal nerve (1.71 ± 0.08 on the left, 1.24 ± 0.06 on the right) and greater auricular nerve (0.90 ± 0.53 on the left and 0.79 ± 0.71 on the right). The vagus nerve was significantly larger on the right side compared to the left side. Larger hypoglossal nerve was observed in men compared to women. Significant correlations were observed between weight and CSA of the greater auricular nerve. CONCLUSION: Direct visualization of the vagus, greater auricular nerve and hypoglossal nerves is feasible. Reference values for the size of the studied nerves at specific anatomic landmarks were established. Side, gender and body weight differences of the nerves CSA were noted.

Ultrasonographic and Imaging Appearance of Peripheral Intraneural Vascular Anomalies: Report of Two Cases and Review of the Literature.

The purpose of the paper is to present the ultrasonographic and imaging appearance of two cases of peripheral nerve intraneural vascular anomalies and provide a comprehensive review of the publications on this subject.The clinical presentation, ultrasonographic appearance, corresponding imaging and outcome of a case of ulnar nerve venous malformation and a case of median nerve arteriovenous malformation are presented.Literature search revealed 35 papers presenting 52 cases of vascular anomalies involving the peripheral nerves. The ultrasonographic appearance was described only in ten cases. Our review suggests that peripheral intraneural vascular anomalies are twice more frequent in women. About three quarters of them are located in the upper limb, with the median nerve involved in one third and the ulnar nerved involved in a quarter of all cases. Most of the cases are hemangiomas. Peripheral neural compartment syndromes in patients with coexisting vascular anomalies may prompt for vascular neural involvement, requiring diagnostic imaging studies. Gray-scale and Doppler ultrasound are the methods of first choice, as they provide not only direct visual proof of neural involvement but also contribute to the differential diagnosis between hemangiomas and vascular malformations.

The Added Value of Color Parameters in Analyzing Elastographic Images of Ultrasound Detected Breast Focal Lesions.

AIMS: The purpose of the study was to determine if the color quantitative analysis obtained on elastographic images of breast lesions could improve the benign-malignant differentiation, and also to identify some of the circumstances which would benefit most from such an analysis. PATIENTS AND METHODS: The study design was a longitudinal prospective one, all data being acquired between May 2007 and September 2008. The US device used: Hitachi 8500 EUB machine with elastography option. For suspicious breast lesions histopathology was obtained by means of percutaneous biopsy or post-surgery. Studied color parameters (numeric values): average color (red, green, blue), color dispersion, average intensity, average hue, hue dispersion. Calculus modality: Image Processing Version 1.3, a program developed in collaboration with the Technical University of Cluj Napoca. RESULTS: Seventy-one (71) women were selected for the study. A hundred and six circumscribed breast lesions were detected by means of ultrasound in the studied group. Five color parameters were independently associated with the histological diagnosis (AvgBlue, AvgGreen and AvgRed; DispRed and DispIntensity) with AvgBlue parameter making the most important contribution (p<0.0001); the greater the values of AvgBlue (more than 92), the higher the chances of malignancy and the greater the values of AvgGreen (more than 88), the higher the chances for a benign lesion. CONCLUSION: High numeric values for Avg Blue (more than 92) would increase the probability of malignancy and thus recommend a more aggressive diagnostic management (biopsy), while high numeric values for AvgGreen (more than 88) would reassure the examiner to proceed conservatively with short interval or routine follow-ups.

Breast Diagnosis: Concordance Analysis Between the BI-RADS Classification and Tsukuba Sonoelastography Score.

AIMS: To establish the correlations between the ultrasound (US) BI-RADS classification and Tsukuba elastography score when assessing breast lesions. To determine which type of breast lesion (BI-RADS category) would benefit most from an elastographic assessment. PATIENTS AND METHODS: The investigated sample of imaging comprised a number of 129 images belonging to 92 subjects examined with a Hitachi 8500 US device. Each lesion was assessed according to the BI-RADS and Tsukuba elastography score. Histopathology was obtained by means of percutaneous biopsy or post-surgery. Fibroadenoma-like lesions unchanged over a period of 3 years were considered benign. RESULTS: The 1, 2 and BGR Tsukuba scores mostly correlated with BI-RADS II and III lesions such as cysts, hamartomas, lipomas, hematomas, non-palpable fibroadenomas. Palpable fibroadenomas initially included in BI-RADS IVa/b category, usually received benign elasticity scores (1 or 2), the exception being represented by a minority of cases of old, fibrotic or calcified lesions (elastic score 3 or 4). Non-specific BI-RADS IVa/b lesions, such as mastopathic nodules demonstrated rather soft, elastic properties on elastogram (score 1 or 2). The 4 and 5 Ueno-Itoh scores were predominantly correlated with BI-RADS IVc and V categories represented by high risk lesions (radial scar, papillomas, atypical epithelial ductal hyperplasia) and in situ or invasive carcinomas. CONCLUSIONS: Generally the BI-RADS classification correlates well with the Tsukuba elasticity score, the main exception being represented by fibrotic, calcified lesions which falsely appear more suspicious post-elastography. BI-RADS III and IV lesions would benefit most from an elastographic assessment, a low Tsukuba score allowing a less invasive approach, while a high score imposes histopathological evaluation.