Virtual inverted classroom to replace in-person radiology lectures at the time of the COVID-19 pandemic - a prospective evaluation and historic comparison.

BACKGROUND: In the time of the coronavirus disease 2019 (COVID-19) pandemic, in-person lectures had to be shifted to online learning. This study aimed to evaluate students' and lecturers' perception and effectiveness of a virtual inverted classroom (VIC) concept on clinical radiology in comparison to a historic control. METHODS: In the winter semester 2020/21, 136 fourth year medical students who completed the clinical radiology VIC during the pandemic, were included in the single centre, prospective study. Results were compared with a historic control that had finished the physical inverted classroom (PIC) in the immediately preceding year. The VIC consisted of an initial phase of self-determined preparation with learning videos and a second interactive phase of clinical case studies alternating between the virtual lecture hall and virtual buzz groups. At the end of the lecture series, students rated the lecture on a scale of 1 (most positive assessment) to 6 (most negative assessment) through an online survey platform. Additionally, they reported their impressions in free-form text. Lecturers were invited to comment on the VIC in a group interview. Main outcomes were final grades and student perception of the VIC. RESULTS: Students' general impression of VIC was lower than that of PIC (median value of 3 [IQR 4, 2] and 1 [IQR 0, 0], p < 0.001), respectively, p < 0.001). The highest rating was achieved concerning use of the audience response system (median 1 [IQR 1, 0]), and the lowest concerning the buzz groups (median 4 [IQR 5, 3]). Students stated that they would have appreciated more details on reading images, greater focus on plenary case studies, and provision of exam related scripts. Lecturers would have liked better preparation by students, more activity of students, and stronger assistance for group support. Exam grades after VIC were better than after PIC (median 1 [IQR 2, 1] and 2 [IQR 2,1], respectively, p < 0.001). CONCLUSIONS: Students' overall perception of VIC was satisfactory, although worse than PIC. Final grades improved compared to PIC. Provided an adapted buzz group size and support, VIC may serve as complement in medical education once the pandemic is over.

Structured work-based learning in undergraduate clinical radiology immersion experience.

BACKGROUND: Practical courses in undergraduate medical training often lack a didactic concept. Active participation and learning success largely depend on chance. This study was initiated to evaluate a novel concept of structured work-based learning (WBL) in the course of students' half-day radiology immersion experience (IE). METHODS: This prospective, single-centre cohort study included 228 third-year students of the 2019 summer semester who underwent the obligatory radiology IE at a university hospital. The course was based on a novel structured WBL concept that applied established didactic concepts including blended learning, the FAIR principles of feedback, activity, individualization, and relevance, and Peyton's four-step approach. Outcomes of equal weight were student and supervisor satisfaction with the clinical radiology IE assessed by paper-based- and online survey, respectively. Secondary outcome was achievement of intended learning outcomes assessed by means of mini clinical evaluation exercises and personal interviews. RESULTS: Satisfaction with structured WBL was high in 99.0% of students. Students' expectations were exceeded, and they felt taken seriously at the professional level. Dissatisfaction was reasoned with quality of learning videos (0.6%), little support by supervisors (0.5%), or inadequate feedback (0.6%). Supervising resident physicians rated achievement of intended learning outcomes regarding cognitive and psychomotor competences as excellent for all students. Personal interviews revealed achievement of affective competence in some students. Twelve of 16 (75.0%) supervising physicians were satisfied with focussing on intended learning outcomes and student preparation for IE. Two of 15 (13.3%) supervisors were unsatisfied with time spent, and 4 of 16 (25%) with the approach of assessment. CONCLUSIONS: This study demonstrated that both students and supervisors were satisfied with the novel concept of structured WBL within the scope of clinical radiology IE. Achievement of intended learning outcomes was promising.

Impact of a Heutagogical, Multimedia-Based Teaching Concept to Promote Self-Determined, Cooperative Student Learning in Clinical Radiology.

PURPOSE: To date, didactic lecturing is a common method of university medical training. However, higher levels of competence to solve complex issues are hardly to be achieved with a largely passive learning style. We established and evaluated a heutagogical blended learning concept to investigate self-determined learning with a multimedia-based, interactive approach in the lecture room to teach clinical radiology. MATERIALS AND METHODS: In the 2019/2020 winter semester, we included 266 medical students in their fourth academic year in our prospective, observational study. Students participated in a series of 11 radiological lectures given by 10 lecturers. They were requested to prepare for lectures by watching learning videos. During the lecture, students had to answer key-feature questions (KFQ) in small groups and to jointly submit their answers by means of an audience response system (ARS). After each lecture and the exam, we conducted surveys and compared results with a historical control group. A focus group interview with lecturers was performed after conclusion of the lecture series. RESULTS: The students' overall impression of the "flipped classroom" concept and their examination grades were superior to historical controls (overall impression: 1.5 [95 % CI 1.4-1.6] vs. 2.7 [95 % CI 2.5-2.9] rated on a scale from 1 to 6, p < 0.001; examination grades: 1.8 [95 % CI 1.7-1.9] vs. 2.0 [95 % CI 1.9-2.0] rated on a scale from 1 to 5, p < 0.001). Most students agreed that learning videos (76.6 %), ARS (88.5 %), KFQ (76.5 %), and solution-oriented small group discussions (83.7 %) were useful. Lecturers stated an improved convergence of demands on learning and clinical competence. However, they also emphasized an increased initial effort for implementation. CONCLUSION: Students rated the overall benefit from the heutagogical "flipped classroom" concept as high. Examination grades improved. According to lecturers, the "flipped classroom" concept better matched later professional demands than traditional lectures. KEY POINTS: · The benefit of the "flipped classroom" concept for radiological lectures was rated high by students.. · Most students were satisfied with the multimedia and interactive elements of lectures.. · Lecturers considered heutagogical learning demands as appropriate for later clinical requirements.. CITATION FORMAT: · Teichgräber U, Ingwersen M, Mentzel H et al. Impact of a Heutagogical, Multimedia-Based Teaching Concept to Promote Self-Determined, Cooperative Student Learning in Clinical Radiology. Fortschr Röntgenstr 2021; 193: 701 - 711.

Radiological imaging characteristics of intramammary hematological malignancies: results from a german multicenter study.

To assess radiological procedures and imaging characteristics in patients with intramammary hematological malignancies (IHM). Radiological imaging studies of histopathological proven IHM cases from ten German University affiliated breast imaging centers from 1997-2012 were retrospectively evaluated. Imaging modalities included ultrasound (US), mammography and magnetic resonance imaging (MRI). Two radiologists blinded to the histopathological diagnoses independently assessed all imaging studies. Imaging studies of 101 patients with 204 intramammary lesions were included. Most patients were women (95%) with a median age of 64 years. IHM were classified as Non Hodgkin lymphoma (77.2%), plasmacytoma (11.9%), leukemia (9.9%), and Hodgkin lymphoma (1%). The mean lesion size was 15.8 ± 10.1 mm. Most IHM presented in mammography as lesions with comparable density to the surrounding tissue, and a round or irregular shape with indistinct margins. On US, most lesions were of irregular shape with complex echo pattern and indistinct margins. MRI shows lesions with irregular or spiculated margins and miscellaneous enhancement patterns. Using US or MRI, IHM were more frequently classified as BI-RADS 4 or 5 than using mammography (96.2% and 89.3% versus 75.3%). IHM can present with miscellaneous radiological patterns. Sensitivity for detection of IHM lesions was higher in US and MRI than in mammography.

Imaging findings of primary breast sarcoma: Results of a first multicenter study.

PURPOSE: To investigate imaging findings in patients with primary breast sarcoma (PBS). MATERIALS AND METHODS: A retrospective search in the databases of 10 radiological departments in Germany from 2000 to 2011 was performed. Only histologically proven cases of PBS were included into the study. Mammography was available in 31 patients (33 lesions), ultrasound images in 24 patients (24 lesions), and for 10 patients (14 lesions) magnetic resonance imaging (MRI) of the breast was performed. The breast findings were classified according to the American College of Radiology Breast Imaging Reporting and Data Systems (BI-RADS) 5th edition categories. Collected data were evaluated by means of descriptive statistics. RESULTS: Forty-two female patients (mean age 62.0 years, range, 30-86 years) were included in the study. Clinically, all women had painless lumps. Irregular (53.3% [16/30]) or oval (30.0% [9/30]) mass with indistinct (73.3% [22/30]) or microlobulated (10% [3/30]) margins were common findings on mammograms. Ultrasound revealed typically an irregular (79.2% [19/24]), hypoechoic (62.5% [15/24]) mass, with indistinct margins (79.2% [19/24]), and posterior acoustic shadowing (79.2% [19/24]). MRI showed irregular masses (81.8% [9/11]) with irregular or spiculated margins, and a rapid initial signal increase with a delayed washout in kinetic analysis. CONCLUSION: Overall, PBS has no pathognomonic imaging features and can mimic those of invasive mammary carcinoma. Breast sarcoma should be taken into the differential diagnosis of breast findings described above.

Magnetic resonance imaging findings of intramammary metastases.

The purpose of this study was to identify magnetic resonance imaging (MRI) findings of intramammary metastases (IM). We identified 8 cases with IM, which were investigated by breast MRI (1.5T). In every case, the diagnosis of IM was proven histopathologically on breast biopsy specimens. Overall, 187 IM were identified. IM had inconsistent MRI features, which cannot be clearly classify as benign or malignant. IM should be taken into consideration in the differential diagnosis of breast lesions to avoid possible misinterpretations.

The necrosis sign in magnetic resonance-mammography: diagnostic accuracy in 1,084 histologically verified breast lesions.

Necrosis sign (NS) is a new descriptor for differential diagnosis of breast lesions in magnetic resonance (MR)-mammography (MRM). This study was designed: (a) to analyze diagnostic accuracy of NS in 1,084 histologically verified breast lesions, (b) to assess performance of NS in subgroups. This study was approved by the local ethical committee. All histologically verified lesions having undergone MR-mammography at our institution over 12 years were evaluated by experienced radiologists (> 500 MRM) according to standard protocols and study design (T1w; 0.1 mmol/kg bw gadolinium diethylenetriamine penta-acetic acid; T2-turbo spin echo (TSE)). Patients with history of breast biopsy (surgically, minimal-invasive), radiation- or chemotherapy ≤ 1 year before MRM were excluded. NS was assessed on T2w-TSE sequences and was rated positive if a hyperintense center in a hypointense lesion could be visualized (chi-squared test). One thousand and eighty-four lesions were available for statistical analysis (648: malignant, 436: benign). NS was significantly associated with malignancy (p < 0.001), providing specificity and positive predictive value (PPV) of 96.1% and 78.8%. Malignant lesions > 20 mm presented significantly more often NS (p < 0.001) than neoplasias ≤ 20 mm. There was no difference regarding prevalence of NS in small versus advanced benign lesions (n.s.), leading to better performance of NS in lesions > 20 mm (PPV: 87.8%). Correlation between NS and Grading of invasive carcinomas was significant. In this study of 1,084 lesions necrosis sign was a specific and highly predictive feature for differential diagnosis in MRM (Specificity: 96.1%; PPV: 78.8%). This particularly counts for advanced lesions (PPV 87.8%). As this new descriptor correlates with Grading, it could be used as an initial estimate of patient's prognosis.

Sensitivity and specificity of unilateral edema on T2w-TSE sequences in MR-Mammography considering 974 histologically verified lesions.

The objective of this investigation was to determine the diagnostic value of unilateral edema in differentiating benign from malignant breast disease on T2w-TSE images in MR-Mammography (MRM). All patients from a 10-year period undergoing surgery in the same institution after having received MRM in our department were included in this prospective analysis of previous acquired examinations. To eliminate bias caused by prior procedures, all patients having had biopsy, operation, radiation therapy, or chemotherapy before MRM were excluded. T2w-TSE images were acquired after a dynamic contrast-enhanced series of T1-weighted images in a standardized examination protocol (1.5 T). Edema was defined as a high-signal intensity on T2w-TSE images and it was categorized as absent, perifocal, or diffuse. Examinations were rated by two experienced observers blinded to all procedures and results following MRM. In cases of disconcordance, the opinion of a third radiologist decided. Statistical testing included Pearson's Chi-squared test and Fisher's exact testing. A total of 1,010 patients with a mean age of 55 years (SD: 11.6 years, range: 16-87 years) with 1,129 histologically verified lesions were included in this investigation. After removing all patients with prior procedures from the patient collective, 974 lesions were left for statistical analysis. Perifocal edema was highly significantly (p < 0.001) associated with malignant disease, leading to a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 33.5%, 93.9%, 89.6, and 57.1%, respectively. Unilateral edema in general showed the following diagnostic parameters: sensitivity 53.0%, specificity 80.5%, PPV 80.9%, and NPV 52.3%. Edema seems to be associated with malignancy in the majority of cases. Especially, specificity and PPV were found to be high. These findings may be helpful in diagnostic decisions on otherwise equivocal cases.

The adjacent vessel sign on breast MRI: new data and a subgroup analysis for 1,084 histologically verified cases.

OBJECTIVE: The adjacent vessel sign (AVS) is a descriptor for differentiating malignant from benign breast lesions on breast MRI (bMRI). This investigation was designed to verify the previous reports on the diagnostic accuracy of AVS and to assess correlation between AVS, histopathological diagnosis, lesion size and lesion grade. MATERIALS AND METHODS: This study was approved by the local ethical committee. Experienced radiologists evaluated 1,084 lesions. The exclusion criteria were no histological verification after bMRI and breast interventions that were done up to one year before bMRI (surgery, core biopsy, chemo- or radiation therapy). The native and dynamic contrast-enhanced T1-weighted series were acquired using standardized protocols. The AVS was rated positive if a vessel leading to a lesion could be visualized. Prevalence of an AVS was correlated with the lesions' size, grade and histology using Chi-square-tests. RESULTS: The AVS was significantly associated with malignancy (p < 0.001; sensitivity: 47%, specificity: 88%, positive-predictive-value [PPV]: 85%). Malignant lesions > 2 cm more often presented with an AVS than did those malignant lesions < 2 cm (p < 0.0001; sensitivity: 65%, PPV: 90%). There was no correlation of the AVS with the tumor grade. The prevalence of an AVS didn't significantly differ between invasive lobular carcinomas versus ductal carcinomas. In situ cancers were less frequently associated with an AVS (p < 0.001). CONCLUSION: The adjacent vessel sign was significantly associated with malignancy. Thus, it can be used to accurately assess breast lesions on bMRI. In this study, the AVS was particularly associated with advanced and invasive carcinomas.

Clinical MR-mammography: are computer-assisted methods superior to visual or manual measurements for curve type analysis? A systematic approach.

RATIONALE AND OBJECTIVES: Enhancement characteristics after administration of a contrast agent are regarded as a major criterion for differential diagnosis in magnetic resonance mammography (MRM). However, no consensus exists about the best measurement method to assess contrast enhancement kinetics. This systematic investigation was performed to compare visual estimation with manual region of interest (ROI) and computer-aided diagnosis (CAD) analysis for time curve measurements in MRM. MATERIALS AND METHODS: A total of 329 patients undergoing surgery after MRM (1.5 T) were analyzed prospectively. Dynamic data were measured using visual estimation, including ROI as well as CAD methods, and classified depending on initial signal increase and delayed enhancement. RESULTS: Pathology revealed 469 lesions (279 malignant, 190 benign). Kappa agreement between the methods ranged from 0.78 to 0.81. Diagnostic accuracies of 74.4% (visual), 75.7% (ROI), and 76.6% (CAD) were found without statistical significant differences. CONCLUSIONS: According to our results, curve type measurements are useful as a diagnostic criterion in breast lesions irrespective of the method used.

Differentiation of phyllodes breast tumors from fibroadenomas on MRI.

OBJECTIVE: The purpose of our study was to evaluate the MRI appearance of phyllodes breast tumors and to differentiate them from fibroadenomas. MATERIALS AND METHODS: MR images were obtained on a 1.5-T imager. T1- and T2-weighted sequences and dynamic 2D fast-field echo T1-weighted sequences were performed. MR images of 23 patients with 24 phyllodes breast tumors (one malignant, 23 benign) were analyzed with respect to morphology and contrast enhancement. The tumors were compared with the MRI appearance of 81 fibroadenomas of 75 patients. RESULTS: Well-defined margins were seen in 87.5% of the phyllodes tumors and 70.4% of the fibroadenomas, and a round or lobulated shape in 100% and 90.1%, respectively. A heterogeneous internal structure was observed in 70.8% of phyllodes tumors and in 49.4% of fibroadenomas. Nonenhancing internal septations were found in 45.8% of phyllodes tumors and 27.2% of fibroadenomas. A significantly greater increase in signal was seen on T2-weighted images in the tissue surrounding phyllodes tumors (21%) compared with fibroadenomas (1.2%). Most of both lesions appeared with low signal intensity on T1- and T2-weighted images. After the administration of contrast material, 33.3% of phyllodes tumors and 22.2% of fibroadenomas showed a suspicious signal intensity-time course. CONCLUSION: Phyllodes breast tumors and other fibroadenomas cannot be precisely differentiated on breast MRI. Phyllodes tumors have benign morphologic features and contrast enhancement characteristics suggestive of malignancy in 33% of cases.