Patient-centered radiology: a roadmap for outpatient imaging.

Creating a patient-centered experience is becoming increasingly important for radiology departments around the world. The goal of patient-centered radiology is to ensure that radiology services are sensitive to patients' needs and desires. This article provides a framework for addressing the patient's experience by dividing their imaging journey into three distinct time periods: pre-exam, day of exam, and post-exam. Each time period has aspects that can contribute to patient anxiety. Although there are components of the patient journey that are common in all regions of the world, there are also unique features that vary by location. This paper highlights innovative solutions from different parts of the world that have been introduced in each of these time periods to create a more patient-centered experience. CLINICAL RELEVANCE STATEMENT: Adopting innovative solutions that help patients understand their imaging journey and decrease their anxiety about undergoing an imaging examination are important steps in creating a patient centered imaging experience. KEY POINTS: • Patients often experience anxiety during their imaging journey and decreasing this anxiety is an important component of patient centered imaging. • The patient imaging journey can be divided into three distinct time periods: pre-exam, day of exam, and post-exam. • Although components of the imaging journey are common, there are local differences in different regions of the world that need to be considered when constructing a patient centered experience.

Introduction of a breast apparent diffusion coefficient category system (ADC-B) derived from a large multicenter MRI database.

OBJECTIVES: To develop an intuitive and generally applicable system for the reporting, assessment, and documentation of ADC to complement standard BI-RADS criteria. METHODS: This was a multicentric, retrospective analysis of 11 independently conducted institutional review board-approved studies from seven institutions performed between 2007 and 2019. Breast Apparent Diffusion coefficient (ADC-B) categories comprised ADC-B0 (ADC non-diagnostic), ADC-B1 (no enhancing lesion), and ADC-B2-5. The latter was defined by plotting ADC versus cumulative malignancy rates. Statistics comprised ANOVA with post hoc testing and ROC analysis. p values ≤ 0.05 were considered statistically significant. RESULTS: A total of 1625 patients (age: 55.9 years (± 13.8)) with 1736 pathologically verified breast lesions were included. The mean ADC (× 10-3 mm2/s) differed significantly between benign (1.45, SD .40) and malignant lesions (.95, SD .39), and between invasive (.92, SD .22) and in situ carcinomas (1.18, SD .30) (p < .001). The following ADC-B categories were identified: ADC-B0-ADC cannot be assessed; ADC-B1-no contrast-enhancing lesion; ADC-B2-ADC ≥ 1.9 (cumulative malignancy rate < 0.1%); ADC-B3-ADC 1.5 to < 1.9 (0.1-1.7%); ADC-B4-ADC 1.0 to < 1.5 (10-24.5%); and ADC-B5-ADC < 1.0 (> 24.5%). At the latter threshold, a positive predictive value of 95.8% (95% CI 0.94-0.97) for invasive versus non-invasive breast carcinomas was reached. CONCLUSIONS: The breast apparent diffusion coefficient system (ADC-B) provides a simple and widely applicable categorization scheme for assessment, documentation, and reporting of apparent diffusion coefficient values in contrast-enhancing breast lesions on MRI. CLINICAL RELEVANCE STATEMENT: The ADC-B system, based on diverse MRI examinations, is clinically relevant for stratifying breast cancer risk via apparent diffusion coefficient measurements, and complements BI-RADS for improved clinical decision-making and patient outcomes. KEY POINTS: • The breast apparent diffusion coefficient category system (ADC-B) is a simple tool for the assessment, documentation, and reporting of ADC values in contrast-enhancing breast lesions on MRI. • The categories comprise ADC-B0 for non-diagnostic examinations, ADC-B1 for examinations without an enhancing lesion, and ADC-B2-5 for enhancing lesions with an increasing malignancy rate. • The breast apparent diffusion coefficient category system may be used to complement BI-RADS in clinical decision-making.

Bone Remodeling in Osteoarthritis-Biological and Radiological Aspects.

Among available papers published on the given subject over the last century, various terms have been used as synonyms for one, now generally accepted-osteoarthritis, in some countries called "wear and tear" or "overload arthritis". The opsolent terms-hypertrophic arthritis, degenerative arthritis, arthritis deformans and osteoarthrosis-sought to highlight the dominant clinical signs of this ubiquitous, polymorph disease of the whole osteochondral unit, which by incidence and prevalence represents one of the leading chronic conditions that cause long-term pain and incapacity for work. Numerous in vitro and in vivo research resulted in broadened acknowledgments about osteoarthritis pathophysiology and pathology on both histological and cellular levels. However, the cause of osteoarthritis is still unknown and is currently the subject of a hypothesis. In this paper, we provide a review of recent findings on biological phenomena taking place in bone tissue during osteoarthritis to the extent useful for clinical practice. Choosing a proper radiological approach is a conditio sine qua non to the early diagnosis of this entity.

Second-Look Ultrasound Using Shear-Wave Elastography in MRI-Suspected Locoregional Recurrence of Breast Carcinoma.

PURPOSE: To investigate if second-look US using shear-wave elastography (SWE) can help to differentiate between benign and malignant changes in the postoperative breast after surgical treatment of breast carcinoma. MATERIALS AND METHODS: SWE and related sonographic features were reviewed in 90 female patients with a history of surgical treatment of breast carcinoma and a suspicious lesion detected on a follow-up MRI scan. A single experienced radiologist performed all second-look US exams with SWE measurements placing a circular region of interest measuring 2 mm in diameter over the stiffest part of the lesion. Tissue samples for histopathological analysis were obtained during the same US examination via core-needle biopsy. RESULTS: Out of 90 lesions, 39 were proven malignant on histopathological analysis. 50 % of malignant lesions had Elmax values ranging from 128 to 199 kPa, and 50 % of benign lesions had Elmax values ranging from 65 to 169 kPa. The cut-off value of 171.2 kPa for Elmax shows a sensitivity of 59 % and specificity of 78.4 % for carcinoma recurrence, area under the curve 0.706 (CI95 % 0.6-0.81), P = 0.001. In univariate logistic models, restricted diffusion and stiffness on SWE, Elmax > 171.2 kPa, were shown as significant recurrence predictors. In the multivariate model, restricted diffusion remains significant independent recurrence predictor. With a recurrence prevalence of 43 %, the test sensitivity is 95 % (CI95 % 81-99 %) and the specificity is 75 % (CI95 % 60-85 %). CONCLUSION: Stiffer lesions should be considered suspicious on second-look US in the postoperative breast and SWE can be a helpful tool in identifying malignant lesions, especially if this is related to restricted diffusion on MRI exam. Lesion stiffness, however, should not be considered as an independent predictor of lesion malignancy in the postoperative breast, because of benign changes that can appear stiff on SWE, as well as carcinoma recurrences that may appear soft.

Results of the National Breast Cancer Screening Program in Croatia (2006-2016).

AIM: To assess the uptake of the Croatian National Breast Cancer Screening Program from 2006 to 2016. METHODS: The Croatian National Breast Cancer Screening Program, a biennial program targeting women aged 50-69, started in October 2006. From 2006 to 2016, four cycles were completed. One cycle lasted two years, with the exception of the first cycle, which lasted three years. To determine the number of detected cancers in each cycle, the screening program data were merged with the data of the Croatian National Cancer Registry. Our results were compared with the reference values from the European guidelines for quality assurance in breast cancer screening and diagnosis. RESULTS: Around 150 000 mammography exams were performed every year. The response rates for cycle 1, cycle 2, cycle 3, and cycle 4 were 63%, 57%, 60%, and 59%, respectively. Further assessment rate was 6.5%. Breast cancer was identified in 5583 women, with 4.8 cancers detected per 1000 mammography exams. CONCLUSION: The National Breast Cancer Screening Program in Croatia reached a substantial proportion of the target group. Yet, additional efforts are needed to reach at least 70% of the target population.

FORAMEN OVALE AND FORAMEN ROTUNDUM: CHARACTERIZATION OF POSTNATAL DEVELOPMENT.

The sphenoid bone development occurs in both prenatal and postnatal periods. Sphenoid bone openings are used as surgical landmarks and are of great importance for neurosurgeons in everyday practice. The aim of this study was to identify morphological characteristics, postnatal development and remodeling, as well as clinical aspect of the sphenoid bone openings and to investigate their relationship and difference in size. The macerated sphenoid bones analyzed in this study were scanned by micro-computed tomography. Areas and distance in-between foramen ovale and foramen rotundum were measured. In addition, different shapes of foramen ovale were described. The most common shape of foramen ovale on both sides was oval, followed by the round, almond and elongated shapes. Modest to strong positive correlations between all foramina and age for the whole sample and both subsamples were presented, except for the right foramen rotundum area in the male subsample, which did not show significant correlation with age. Our study revealed changes in postnatal development and anatomy of foramen ovale and foramen rotundum, primarily in the aspects of size and shape, and should contribute to reducing the risk of damage to neurovascular structures during surgical procedures.

The use of imaging in COVID-19-results of a global survey by the International Society of Radiology.

OBJECTIVES: This survey conducted by the International Society of Radiology and supported by the European Society of Radiology aimed to collect information regarding radiology departments' current practices in the management of patients with COVID-19. METHODS: Responses from 50 radiology departments involved in the management of COVID-19 patients representing 33 countries across all continents were analyzed. The analysis revealed important variations in imaging practices related to COVID-19 across the world for different disease severity and various clinical scenarios. RESULTS: Imaging is usually not performed in asymptomatic patients (69% of institutions do not image) but is used at the end of confinement (in 60% of institutions). In the majority of institutions, chest imaging is used in suspected or confirmed patients with COVID-19 (89% and 94%). All imaging departments involved in this survey reported the use of imaging in COVID-19 patients showing severe symptoms or who were critically ill. However, there is a wide variation in imaging modality type used for each clinical scenario. The use of imaging is applied in line with existing guidelines and recommendations in 98% of institutions with structured reporting recorded in 58% of institutions. The vast majority of institutions reported a significant impact of the COVID-19 pandemic on the imaging department's routine activity (83%). CONCLUSION: We believe that the results of this survey will help to understand current heterogeneities in radiology practice and to identify needs and gaps in the organization and function of radiology departments worldwide in relation to the COVID-19 pandemic. The results of this survey may inform the development of an overall strategy for radiology department organization and imaging protocols in pandemic conditions. KEY POINTS: • The results of this survey, which included responses from 50 radiology departments representing 33 countries, showed important variations in imaging practices related to COVID-19 across the world. • While imaging is usually not performed in asymptomatic patients (69% of institutions), it is used in suspected or confirmed patients with COVID-19, in COVID-19 patients showing severe symptoms or who were critically ill, and at the end of confinement (89%, 94%, 100%, 100%, 60% of institutions, respectively). However, there is a wide variation in imaging modality type used for each clinical scenario. • In 98% of institutions, the use of imaging is applied in line with existing guidelines and recommendations, with structured reporting recorded in 58% of institutions. COVID-19 pandemic made a significant impact on the imaging department's routine activity in 83% of institutions.

Consensus on technical procedures in radiology to include in simulation-based training for residents: a European-wide needs assessment.

OBJECTIVES: To identify and prioritize technical procedures for simulation-based training that should be part of the education of residents in radiology. METHODS: This European-wide needs assessment study used a modified Delphi technique to gather consensus from different key education stakeholders in the field. The first round was a brainstorming phase to identify all procedures that a newly specialized radiologist should potentially be able to do. In the second round, each procedure was explored for the need for simulation training; the participants determined frequency, number of radiologists performing the procedure, impact on patient comfort and safety, and feasibility of simulation. The result of this round was sent back to the participants for final evaluation and prioritization. RESULTS: Seventy-one key education stakeholders from 27 European countries agreed to participate and were actively involved in the Delphi process: response rates were 72% and 82% in the second and third round, respectively. From 831 suggested procedures in the first round, these were grouped and categorized into 34 procedures that were pre-prioritized in the second round according to the need for simulation-based training. In the third round, 8 procedures were eliminated resulting in final inclusion of 26 procedures. Ultrasound procedures were highly ranked including basic skills such as probe handling; abdominal ultrasound; and ultrasound of kidneys, retroperitoneum, intestines, and scrotum. CONCLUSION: The prioritized list of procedures represents a consensus document decided upon by educational stakeholders in radiology across Europe. These procedures are suitable for simulation and should be an integral part of the education of radiologists. KEY POINTS: • The 26 identified procedures are listed according to priority and should be included as an integral part of simulation-based training curricula of radiologists across Europe. • This needs assessment is only the first step towards developing standardized simulation-based training programs that support the harmonization of education and training across Europe.

Importance of shear-wave elastography in prediction of Achilles tendon rupture.

PURPOSE: It was demonstrated that about 6% of patients with a ruptured Achilles tendon experience the rupture of contralateral tendon in the future; the aim of this study was to estimate the risk for rupture of contralateral tendon in patients who underwent surgical reconstruction of ruptured Achilles tendon by using subjective questionnaires and shear-wave elastography. METHODS: Twenty-four patients who underwent surgical repair of the ruptured Achilles tendon and twelve age-matched healthy controls were examined with ultrasound SWE. Functional outcomes were assessed with American Orthopedic Foot and Ankle Society (AOFAS) scoring system and subjective rating system which we introduced and validated. RESULTS: The elasticity of injured tendon was markedly decreased (by 42%) compared to the contralateral tendon of the patient, as expected. Both AOFAS score and our novel subjective assessment scale positively correlate with ultrasound SWE values in ruptured Achilles tendons. The elasticity of contralateral Achilles tendons in patients was 23% lower than among healthy individuals. CONCLUSION: Irrespective of the lack of difference in the subjective feeling assessed by AOFAS, the contralateral tendon in the patients with reconstructed Achilles tendon has significantly lower stiffness than healthy individuals. Therefore, contralateral tendons in patients who suffered from rupture are more prone to future ruptures.

Comparison of sonoelastographic values of breast tissue with mammographically and ultrasonically assessed density: a cross-sectional study.

AIM: To determine the relationship between breast stiffness assessed with sonoelastography (elasticity) and breast tissue density assessed with mammography (MG) and ultrasound (US). METHODS: This cross-sectional study involved 100 women who underwent MG, gray-scale US, and shear-wave sonoelastography during 2013. Mammographic density was categorized into four groups and sonographic density into three groups according to Breast Imaging-Reporting and Data System criteria. The stiffness of breast parenchymal and adipose tissue in all breast quadrants was quantified by shear-wave sonoelastography. Mean elastographic estimates were compared with MG- and US-derived density estimates. RESULTS: Parenchymal and adipose tissue elasticity positively correlated with MG- and US-derived breast density (for parenchyma: for MG Kendall's tau b 0.522; Jonckheere-Terpstra test P<0.001 and for US Kendall's tau b 0.533; Jonckheere-Terpstra test P<0.001); the higher was the breast density on MG and US, the higher was the elastographic stiffness. CONCLUSION: Sonoelastographic breast stiffness strongly positively correlated with breast density. Thus, sonoelastography may have a potential for estimating the breast cancer risk, which allows a novel application of this technique in routine clinical practice.

The importance of introducing artificial intelligence to the medical curriculum - assessing practitioners' perspectives.

AIM: To assess the attitude about the importance of introducing education on artificial intelligence (AI) in medical schools' curricula among physicians whose everyday job is significantly impacted by AI. METHODS: An anonymous questionnaire was distributed at the national level in Croatia among radiologists and radiology residents practicing in primary, secondary, and tertiary health care institutions, both in the private and the public sectors. The overall response rate was 45% (144 of 321). RESULTS: A large majority of participants - 89.6% (95% Agresti-Coull confidence interval 0.83-0.94) agreed on the need for education on AI to be included in medical curricula. Answers revealed a very high support across age groups and regardless of subspecialty area. A slightly higher support was present among physicians working in university hospitals compared with those in primary care centers, and among radiology residents compared with radiologists - but these estimated differences are uncertain, and the support levels were clearly high across the considered variables. CONCLUSION: Since medical students have previously been shown to support introducing education on AI, a growing literature argues the same for reasons here reviewed, and physicians practicing a highly relevant area (radiology) overwhelmingly agree, we conclude that medical schools should indeed take steps to keep pace with technological progress in medicine by including education on AI in their curricula, be it as part of existing or new courses.

Evaluation of Breast Cancer Morphology Using Diffusion-Weighted and Dynamic Contrast-Enhanced MRI: Intermethod and Interobserver Agreement.

BACKGROUND: The capability of diffusion-weighted imaging (DWI) for morphological analysis of breast lesions is underexplored. PURPOSE: To evaluate the utility of DWI for assessment of morphological features of breast cancer by comparing DWI and dynamic contrast-enhanced (DCE) MRI findings to determine intermethod and interobserver agreement. STUDY TYPE: Retrospective. POPULATION: Seventy-eight women with pathohistologically proven breast cancer. FIELD STRENGTH/SEQUENCE: 1.5T. DWI and DCE images. ASSESSMENT: Diffusion-weighted and DCE images were placed in two separate case sets. Three radiologists, blinded to all other information, independently evaluated each case set on two separate occasions. Lesions were interpreted according to the fifth edition of the ACR BI-RADS lexicon. STATISTICAL ANALYSIS: Kappa (κ) statistics were calculated in order to assess intermethod and interobserver agreement. RESULTS: For values that attained statistical significance (P < 0.05), intermethod agreement ranged from fair (κ = 0.22) for nonmass internal patterns to significant (κ = 0.8) for lesion type. On DWI, interobserver agreement varied from fair (κ = 0.34) for mass shape to significant (κ = 0.75) for lesion type. On DCE MRI, interobserver agreement varied from fair (κ = 0.27) for irregular vs. spiculated mass margin to perfect (κ = 1) for circumscribed vs. noncircumscribed mass margin. DATA CONCLUSION: On the whole, there was moderate intermethod agreement. The values of interobserver agreement were mostly similar between DWI and DCE MRI. This suggests that DWI is applicable for morphological assessment of breast cancer, notwithstanding substantially inferior spatial resolution compared to DCE MRI. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;49:1381-1390.

SONOELASTOGRAPHIC FEATURES OF HIGH-RISK BREAST LESIONS AND DUCTAL CARCINOMA IN SITU - A PILOT STUDY.

The aim of this study was to evaluate the quantitative sonoelastographic values recorded on shear-wave sonoelastography (SWE) of high-risk breast lesions and ductal carcinoma in situ (DCIS). We retrospectively analyzed histopathologic and SWE data (quantitative maximum, minimum and mean stiffness, lesion-to-fat ratio (E-ratio), lesion size) of 228 women referred to our Department for core needle breast biopsy during a four-year period. Among 230 lesions, histopathologic findings showed 34 high-risk breast lesions and 29 DCIS, which were compared with 167 ductal invasive carcinomas. High-risk lesions had lower values of all sonoelastographic features than ductal in situ and invasive carcinoma, however, only E-ratio showed a statistically significant difference in comparison to DCIS (3.7 vs. 6, p<0.001). All sonoelastographic features showed significant difference between in situ and invasive carcinoma. There was a significant correlation between lesion size and stiffness (r=0.36; p<0.001). Stiffness measured by SWE is an effective predictor of the histopathologic severity of sonographically detectable breast lesions. Elasticity values of high-risk lesions are significantly lower than those of malignant lesions. Furthermore, we showed that along with the sonographic appearance, which in most cases shows typical microcalcifications, DCIS had significantly different elasticity parameters than invasive carcinoma.

Liver elastography malignancy prediction score for noninvasive characterization of focal liver lesions.

BACKGROUND & AIMS: To analyse elastographic characteristics of focal liver lesions (FLL)s and diagnostic performance of real-time two-dimensional shear-wave elastography (RT-2D-SWE) in order to differentiate benign and malignant FLLs. METHODS: Consecutive patients diagnosed with FLL by abdominal ultrasound (US) underwent RT-2D-SWE of FLL and non-infiltrated liver by intercostal approach over the right liver lobe. The nature of FLL was determined by diagnostic work-up, including at least one contrast-enhanced imaging modality (MDCT/MRI), check-up of target organs when metastatic disease was suspected and FLL biopsy in inconclusive cases. RESULTS: We analysed 196 patients (median age 60 [range 50-68], 50.5% males) with 259 FLLs (57 hepatocellular carcinomas, 17 cholangiocarcinomas, 94 metastases, 71 haemangiomas, 20 focal nodular hyperplasia) of which 70 (27%) were in cirrhotic liver. Malignant lesions were stiffer (P < .001) with higher variability in intralesional stiffness (P = .001). The best performing cut-off of lesion stiffness was 22.3 kPa (sensitivity 83%; specificity 86%; positive predictive value [PPV] 91.5%; negative predictive value [NPV] 73%) for malignancy. Lesion stiffness <14 kPa had NPV of 96%, while values >32.5 kPa had PPV of 96% for malignancy. Lesion stiffness, lesion/liver stiffness ratio and lesion stiffness variability significantly predicted malignancy in stepwise logistic regression (P < .05), and were used to construct a new Liver Elastography Malignancy Prediction (LEMP) score with accuracy of 96.1% in validation cohort (online calculator available at http://bit.do/lemps). CONCLUSION: The comprehensive approach demonstrated in this study enables correct differentiation of benign and malignant FLL in 96% of patients by using RT-2D-SWE.

Position paper on screening for breast cancer by the European Society of Breast Imaging (EUSOBI) and 30 national breast radiology bodies from Austria, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Israel, Lithuania, Moldova, The Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Spain, Sweden, Switzerland and Turkey.

EUSOBI and 30 national breast radiology bodies support mammography for population-based screening, demonstrated to reduce breast cancer (BC) mortality and treatment impact. According to the International Agency for Research on Cancer, the reduction in mortality is 40 % for women aged 50-69 years taking up the invitation while the probability of false-positive needle biopsy is <1 % per round and overdiagnosis is only 1-10 % for a 20-year screening. Mortality reduction was also observed for the age groups 40-49 years and 70-74 years, although with "limited evidence". Thus, we firstly recommend biennial screening mammography for average-risk women aged 50-69 years; extension up to 73 or 75 years, biennially, is a second priority, from 40-45 to 49 years, annually, a third priority. Screening with thermography or other optical tools as alternatives to mammography is discouraged. Preference should be given to population screening programmes on a territorial basis, with double reading. Adoption of digital mammography (not film-screen or phosphor-plate computer radiography) is a priority, which also improves sensitivity in dense breasts. Radiologists qualified as screening readers should be involved in programmes. Digital breast tomosynthesis is also set to become "routine mammography" in the screening setting in the next future. Dedicated pathways for high-risk women offering breast MRI according to national or international guidelines and recommendations are encouraged. KEY POINTS: • EUSOBI and 30 national breast radiology bodies support screening mammography. • A first priority is double-reading biennial mammography for women aged 50-69 years. • Extension to 73-75 and from 40-45 to 49 years is also encouraged. • Digital mammography (not film-screen or computer radiography) should be used. • DBT is set to become "routine mammography" in the screening setting in the next future.

Elastographic features of triple negative breast cancers.

OBJECTIVES: To evaluate shear-wave elastographic (SWE) features of triple negative breast cancers (TNBC) and determine useful discriminators from other types of invasive breast cancers. METHODS: SWE features of 26 TNBC were reviewed and compared to 32 non-TNBC. Qualitative SWE features of lesion colour appearance, shape and homogeneity were analysed. Quantitative features were measured: mean (El mean), maximum (El max) and minimum (El min) elasticity value of the stiffest portion of the mass, mean elasticity of the surrounding tissue (El mean surr) and lesion to fat elasticity ratio (E ratio). RESULTS: TNBC are more often regularly shaped (57.7 % vs. 6.2 %), while non-TNBC are more commonly red (93.7 % vs 42.3 %) and heterogeneous (68.7 % vs 42.3 %). The stiffness of TNBC is significantly lower compared to non-TNBC. The two groups could be distinguished on the basis of El max (p = 0.001), El mean (p = 0.001), El min (p = 0.001) and E ratio (p = 0.0017). Lesion to fat elasticity ratio in TNBC group was statistically significantly lower than in the non-TNBC control group (p = 0.009). CONCLUSIONS: TNBC often demonstrate benign morphological features, are softer on SWE and have a lower lesion to fat stiffness ratio compared to the other, more common types of invasive breast cancers. KEY POINTS: • TNBC often demonstrate benign morphological features on SWE. • TNBC present on elastography mostly as red, regularly shaped, heterogeneous lesions. • TNBC are less stiff compared to other invasive breast cancers. • TNBC have lower lesion to fat stiffness ratio than other breast cancers.

Shear-wave sonoelastographic features of invasive lobular breast cancers.

AIM: To evaluate shear-wave elastographic (SWE) and related gray-scale features of pure invasive lobular breast carcinoma (ILC) and compare them with invasive ductal breast cancers (IDC). METHODS: Quantitative SWE features of mean (El-mean), maximum (El-max), minimum (El-min) elasticity values of the stiffest portion of the mass, and lesion-to-fat elasticity ratio (E-ratio) were measured in 40 patients with pure ILC and compared with 75 patients with IDC. Qualitative gray-scale features of lesion size, echogenicity, orientation, and presence of distal shadowing were determined and compared between the groups. RESULTS: ILC were significantly larger than IDC (P=0.008) and exhibited significantly higher El-max (P=0.015) and higher El-mean (P=0.008) than IDC. ILC were significantly more often horizontally oriented, while IDC were significantly more often vertically oriented (P<0.001); ILC were significantly more often hyperechoic than IDC (P<0.001). Differences in stiffness between ILC and IDC determined by quantitative SWE parameters were present only in small tumors (≤1.5 cm in size), ie, small ILC had significantly higher El-max (P=0.030), El-mean (P=0.014), and El-min (P=0.045) than small IDC, while tumors larger than 1.5 cm had almost equal stiffness, without significant differences between the groups. CONCLUSION: Specific histopathologic features of ILC are translated into their qualitative sonographic and quantitative sonoelastographic appearance, with higher stiffness of small ILC compared to small IDC. Gray-scale and sonoelastographic features may help in diagnosing ILC.