A pilot study to evaluate the use of virtual lectures for undergraduate radiology teaching

Purpose

To demonstrate that virtual lectures can substitute conventional lectures in radiology education for medical students.

Methods and materials

During the course 2005–2006, 89 out from 191 (46.6%) third year students of a subject entitled “General Radiology”, participated voluntarily in a pilot study including 22 virtual lectures (Flash presentations translated from the same PowerPoint presentations of conventional lectures, adding recorded narration and navigation tools). Participants (P) studied by means of virtual lectures, while non-participants (NP) assisted to conventional lectures.The results of the final oral exam classified from 0 to 3, and a 60-questions evaluation on image interpretation were used to compare both groups after training. Finally, 34 students from the group P (38.2%) fulfilled a 10-points scale quality survey about the project.

Results

Final exam qualifications were significantly higher for P than for NP (2.11 ± 0.85 versus 1.73 ± 1.04) as well as the number of correct answers of the evaluation on image interpretation (24.2 ± 6.2 versus 21.2 ± 5.4), but differences could obey to different attitudes between both groups. The usefulness of virtual lectures to learn General Radiology obtained the highest global scoring (8.82 ± 1.00). Contents were generally better evaluated than the design of the presentations.

Conclusion

Virtual lectures can substitute conventional lectures in radiology education for medical students with no detriment to students’ learning. Their potential advantage is that magisterial lectures can be used to discuss contents with students in a more participative way if virtual lectures are provided before.     

Integration of interactive three-dimensional image post-processing software into undergraduate radiology education effectively improves diagnostic skills and visual-spatial ability

Purpose

Integrating interactive three-dimensional post-processing software into undergraduate radiology teaching might be a promising approach to synergistically improve both visual-spatial ability and radiological skills, thereby reducing students’ deficiencies in image interpretation. The purpose of this study was to test our hypothesis that a hands-on radiology course for medical students using interactive three-dimensional image post-processing software improves radiological knowledge, diagnostic skills and visual-spatial ability.

Materials and methods

A hands-on radiology course was developed using interactive three-dimensional image post-processing software. The course consisted of seven seminars held on a weekly basis. The 25 participating fourth- and fifth-year medical students learnt to systematically analyse cross-sectional imaging data and correlated the two-dimensional images with three-dimensional reconstructions. They were instructed by experienced radiologists and collegiate tutors. The improvement in radiological knowledge, diagnostic skills and visual-spatial ability was assessed immediately before and after the course by multiple-choice tests comprising 64 questions each. Wilcoxon signed rank test for paired samples was applied.

Results

The total number of correctly answered questions improved from 36.9 ± 4.8 to 49.5 ± 5.4 (p < 0.001) which corresponded to a mean improvement of 12.6 (95% confidence interval 9.9–15.3) or 19.8%. Radiological knowledge improved by 36.0% (p < 0.001), diagnostic skills for cross-sectional imaging by 38.7% (p < 0.001), diagnostic skills for other imaging modalities – which were not included in the course – by 14.0% (p = 0.001), and visual-spatial ability by 11.3% (p < 0.001).

Conclusion

The integration of interactive three-dimensional image post-processing software into undergraduate radiology education effectively improves radiological reasoning, diagnostic skills and visual-spatial ability, and thereby even diagnostic skills for imaging modalities not included in the course.     

Radiology as seen by medical students

Purpose

To determine the impact of exposing medical students to medical imaging during the first year of the second cycle of medical school (DCEM1) on their perception of this medical specialty and the acquisition of its basic concepts.

Materials and methods

All students in the 2007-2008 graduation class entering into the first year of the second cycle of medical school were anonymously enrolled into this project that included pre-rotation and post-rotation questionnaires, theory classes followed by clinical rotations with clearly predetermined objectives.

Results

A total of 108 students were enrolled, with 70% being females. The parents of the students had a medical or paramedical profession in 46.3% of cases. Before the rotation, 61.6% of students perceived a difference between a hospital-based practice and private practice. Fifty-two percent of students had a clear idea of their professional future prior to the rotation. Five students (4.7%) believed prior to the rotation that it might have an impact on their professional future, versus 63% after the rotation (P < 0.0001). The students whose parents work in the medical or paramedical field do not have a better defined idea of their professional future; on the other hand, they have more interest for radiology (73.6% with high or very high interest versus 52.8%, P = 0.03). After the rotation, there was a significant increase in the number of students with high or very high interest for radiology (77.8% versus 66.7%, P = 0.023). A student noted that he would redirect his career to radiology. There was also a significant increase in the number of students perceiving a difference between a hospital-based practice and private practice (82.2% versus 61.6%, P = 0.003). With regards to radiology knowledge before and after the rotation, there was a significant increase of mean scores (P < 0.001). Eighty-eight percent of students were satisfied or very satisfied with the radiology rotation. Overall, the students believe that 70% of the objectives were achieved. The only criticism from the students was that the clinical instructors were overworked.

Conclusion

Early exposure of medical students to radiology increases their level of interest for the specialty and increases the perception of differences between a hospital-based practice and private practice. The overall knowledge of students about radiology was improved, but the workload of clinical instructors impaired the quality of the rotation.     

Do computers teach better? A media comparison study for case-based teaching in radiology.

A prospective study was performed to better define the role of computers in teaching radiology to medical students. Two hundred twenty-five 3rd-year students were randomly assigned to one of four groups and exposed to 10 radiology cases as well as to a voluntary weekly radiology lecture. Group A used computer-based cases with interactive elements; group B used computer-based cases without interactive elements; group C used paper-based cases with interactive elements; and group D was not exposed to the cases and served as a control group. On a multiple-choice question test, groups A, B, and C showed significant improvement (+11.2%, +15.1%, and +13.0%, respectively), whereas group D did not (+0.6%). On an image interpretation test, group A showed the most improvement (+15.7% [P <.001]), followed by group B (+15.1% [P <.01]) and group C (+10.2% [P <.05]); group D showed no significant improvement (+8.5%). No significant differences in the learning outcome were found between the two interactive groups (computer based and paper based). Computer-based teaching with case studies (with or without interactivity) improves students' problem-solving ability in radiology.     

Importance of radiology clerkships in teaching medical students life-threatening abnormalities on conventional chest radiographs

RATIONALE AND OBJECTIVES: The purpose of this study was to investigate the ability of medical students who had already completed medicine and surgery clerkships to identify life-threatening abnormalities on conventional chest radiographs. MATERIALS AND METHODS: From May 2000 to August 2001, 72 consecutive 3rd- and 4th-year medical students enrolled in the radiology clerkship at Rhode Island Hospital completed examinations before and after the radiology clerkship. During the examination, they were asked to identify acute abnormalities on five conventional chest radiographs. Only students who had already completed both medicine and surgery clerkships were included in this prospective study. RESULTS: Before the radiology clerkship, the frequency of correct diagnoses of pneumothorax, pneumoperitoneum, congestive heart failure, misplaced endotracheal tube, and misplaced feeding tube were 40%, 61%, 57%, 6%, and 6%, respectively. After the radiology clerkship, these findings were correctly identified more than 94% of the time (P < .001). CONCLUSION: Learning to identify life-threatening abnormalities on conventional chest radiographs through medicine and surgery clerkships is insufficient. The radiology clerkship provides a unique educational experience that significantly improves these abilities.     

Survey of radiology residents: breast imaging training and attitudes

PURPOSE: To investigate the training and attitudes of residents regarding breast imaging. MATERIALS AND METHODS: A telephone survey was conducted with 201 4th-year residents (postgraduate medical school year 5) and 10 3rd-year residents (postgraduate medical school year 4) at 211 accredited radiology residencies in the United States and Canada. Survey topics included organization of the breast imaging section, residents' role in the section, clinical practice protocols of the training institution, residents' personal thoughts about breast imaging, and their interest in performing breast imaging in the future. RESULTS: Of 211 programs, 203 (96%) had dedicated breast imaging rotations; 196 (93%) rotations were 8 weeks or longer; 153 (73%), 12 weeks or longer. Residents dictated reports in 199 (94%) programs. Residents performed real-time ultrasonography (US) in 186 (88%) programs, needle localization in 199 (94%), US-guided biopsy in 174 (82%), and stereotactically guided biopsy in 181 (86%). One hundred eighty-four (87%) residents rated interpretation of mammograms more stressful than they did that of other images, and 137 (65%) believed mammograms should be interpreted by subspecialists. One hundred thirty-five (64%) residents would not consider a fellowship in breast imaging if offered, and 133 (63%) would not want to spend 25% or more of their time in clinical practice on interpretation of mammograms. The most common reasons given for not considering a fellowship or interpretation of mammograms were that breast imaging was not an interesting field, that they feared lawsuits, and that it was too stressful. Fellowships were offered at 53 programs, and at 46 programs, a total of 63 fellows were recruited. CONCLUSION: Residency training in breast imaging has improved in terms of time and curriculum. However, a majority of the residents would not consider a fellowship and did not want to interpret mammograms in their future practices.     

Blended learning in radiology: is self-determined learning really more effective?

Objective To investigate whether there are differences in learning outcomes after the application of self-determined (intrinsic motivation) or mandatory (extrinsic motivation) use of e-learning units in an undergraduate radiology internship.Methods 96 medical students undergoing a one-week radiology internship were included in this study. Ten electronic cases (e-cases) were created for a blended learning approach. The e-learning environment was accessed on a self-determined (group B; n = 32) or a mandatory basis (group C; n = 32). A group without access to the e-learning environment served as control group (group A; n = 32). Usage parameters of the e-cases were recorded. Results of a pre- and post-course assessment were used to quantitatively analyze learning outcomes.Results In group B 19/32 (59%) students processed at least one e-case, while in group C all students processed at least one e-case. There was a trend towards a higher improvement in knowledge in students exposed to a blended learning approach (group B: 13.7%; group C: 15.4%) than in the control group (group A: 8.5%; p = 0.5356). Group C processed (p = 0.0093) and passed (p = 0.0078) significantly more e-cases, than with group B. There were no significant differences in the mean time per e-case and the total time on e-cases between both groups.Conclusion Extrinsic motivation results in a more extensive use of e-learning units in an undergraduate radiology internship when compared with intrinsic motivation. The choice of the teaching strategy has a bigger influence on learning outcomes than the type of motivation, highlighting the need for qualified medical teachers.     

Radiological clerkships as a critical curriculum component in radiology education

Objective

The aim of this research was to explore the perceived value of clinical clerkships in the radiology curriculum as well as the impact of radiology clerkship on students’ beliefs about the profession of radiology as a whole and as a career.

Methods

This study is a sequel to a previous survey in which student perceptions about radiology curriculum components were investigated. The present study focuses on a further analysis of a subsection in this study, based on 14 statements about radiology clerkship and two statements about radiology as a career.

Results

Perceived usefulness of the aspects of radiology clerkship as “radiology examination”, “skills development” and “diagnosis focus” were awarded the highest scores. The predict value of the subscale “radiology examination” on the level of performance was very high (adjusted R² = 0.19, p < .001).

Conclusion

Students expressed highly favorable evaluation of clerkship as a learning environment to learn to order and to interpret imaging studies as well as an unique possibility to attend various radiological examinations and to access to specific radiology software systems, as well as to get a better view on radiology and to improve image interpretation skills. This positive attitude towards clerkship is closely tied to students’ beliefs about the profession of radiology as a whole. These aspects of dedicated radiology clerkship are crucial for effective and high-quality education as well as for the choice of radiology as a career.     

Percepciones de estudiantes de Medicina sobre el impacto de la inteligencia artificial en radiología

ObjectivesTo analyze medical students’ perceptions of the impact of artificial intelligence in radiology.Material and methodsA structured questionnaire comprising 28 items organized into six sections was distributed to students of medicine in Spain in December 2019.ResultsA total of 341 students responded. Of these, 27 (7.9%) included radiology among their three main choices for specialization, and 51.9% considered that they clearly understood what artificial intelligence is. The overall rate of correct answers to the objective true-or-false questions about artificial intelligence was 70.7%. Whereas 75.9% expressed their disagreement with the hypothesis that artificial intelligence would replace radiologists, only 41.9% disagreed with the hypothesis that the demand for radiologists would decrease in the future. Only 36.7% expressed concerns about the role of artificial intelligence related to choosing radiology as a specialty. A greater proportion of students in the early years of medical school agreed with statements that radiologists accept artificial-intelligence-related technological changes and work with the industry to apply them as well as with statements about the need to include basic training about artificial intelligence in the medical school curriculum.ConclusionsThe students surveyed are aware of the impact of artificial intelligence in daily life, but not of the current debate about its potential applications in radiology. In general, they think that artificial intelligence will revolutionize radiology without having an alarming effect on the employability of radiologists. The students surveyed think that it is necessary to provide basic training about artificial intelligence in undergraduate medical school programs.     

Concentric resistance training increases muscle strength without affecting microcirculation

Purpose

While the evidence is conclusive regarding the positive effects of endurance training, there is still some controversy regarding the effects of resistance training on muscular capillarity. Thus, the purpose was to assess whether resistance strength training influences resting skeletal muscle microcirculation in vivo.

Materials and methods

Thirty-nine middle-aged subjects (15 female, 24 male; mean age, 54 ± 9 years) were trained twice a week on an isokinetic system (altogether 16 sessions lasting 50 min, intensity 75% of maximum isokinetic and isometric force of knee flexors and extensors). To evaluate success of training, cross-sectional area (CSA) of the quadriceps femoris muscle and its isokinetic and isometric force were quantified. Muscular capillarization was measured in biopsies of the vastus lateralis muscle. In vivo, muscular energy and lipid metabolites were quantified by magnetic resonance spectroscopy and parameters of muscular microcirculation, such as local blood volume, blood flow and velocity, by contrast-enhanced ultrasound analyzing replenishment kinetics.

Results

The significant (P < 0.001) increase in CSA (60 ± 16 before vs. 64 ± 15 cm² after training) and in absolute muscle strength (isometric, 146 ± 44 vs. 174 ± 50 Nm; isokinetic, 151 ± 53 vs. 174 ± 62 Nm) demonstrated successful training. Neither capillary density ex vivo (351 ± 75 vs. 326 ± 62) nor ultrasonographic parameters of resting muscle perfusion were significantly different (blood flow, 1.2 ± 1.2 vs. 1.1 ± 1.1 ml/min/100 g; blood flow velocity, 0.49 ± 0.44 vs. 0.52 ± 0.74 mm s⁻¹). Also, the intensities of high-energy phosphates phosphocreatine and β-adenosintriphosphate were not different after training within the skeletal muscle at rest (β-ATP/phosphocreatine, 0.29 ± 0.06 vs. 0.28 ± 0.04).

Conclusion

The significant increase in muscle size and strength in response to concentric isokinetic and isometric resistance training occurs without an increase in the in vivo microcirculation of the skeletal muscles at rest.     

Comparison of accuracy and time-efficiency of CT colonography between conventional and panoramic 3D interpretation methods: An anthropomorphic phantom study

Purpose

To retrospectively compare the conventional three-dimensional (3D) interpretation method with the panoramic 3D method with regard to accuracy and time-efficiency in the detection of colonic polyps, using pig colonic phantoms as the standard of reference.

Materials and methods

One-hundred and sixty-two polyps were created in 18 pig colonic phantoms. CT colonography was performed with a 64-row detector CT scanner. Two-week interval reviews for the CTC image dataset with both the conventional and the panoramic 3D interpretation method were independently performed by three radiologists. The sensitivities of both methods were compared with the McNemar test. The mean interpretation time for each interpretation method was also assessed and compared with the Wilcoxon signed-rank test.

Results

Compared with the conventional 3D method (0.96 for reader 1, 0.89 for reader 2, and 0.97 for reader 3), the panoramic method revealed comparable sensitivities (0.91 for reader 1, 0.86 for reader 2, and 0.93 for reader 3) (p > 0.05). Interpretation time was significantly shorter with the panoramic method (115.1 ± 32.7 s for reader 1, 229.7 ± 72.2 s for reader 2, and 282.6 ± 113.7 s for reader 3) than with the conventional method (218.9 ± 59.9 s for reader 1, 379.4 ± 117.0 s for reader 2, and 458.7 ± 149.4 s for reader 3) for all readers (p < 0.05).

Conclusion

Compared with the conventional 3D interpretation method, the panoramic 3D interpretation method shows improved time-efficiency and comparable sensitivity in the detection of colonic polyps.     

Medical Student Performance After a Vertically Integrated Radiology Clerkship

PurposeProper selection of imaging examinations and basic image interpretation skills are essential for all physicians, yet only approximately 25% of US medical schools require clerkships in radiology. Although there is limited time in most medical school curricula to allow the addition of a required radiology clerkship, the authors developed one that is vertically integrated over a two-year period. This clerkship includes one week of contact with radiologists distributed over the M2 and M3 years, podcasts, online modules, required readings, and presentations. A standard national examination is administered at the end of the clerkship period. This clerkship was designed to address the educational needs of students while occupying minimal time in the curriculum. The purpose of this study was to determine if students completing this clerkship perform as well on a national radiology examination as students from other medical schools, regardless of their curricula.MethodsAt the end of the M3 year, these students take a computer-based radiology examination developed by the Alliance of Medical Student Educators in Radiology and used by students at multiple medical schools nationally. The mean and median scores of these students were compared with those of students at these other institutions.ResultsThe mean and median scores of the students were 74% and 74% (standard deviation, 7.5%) compared with 74% and 50% (standard deviation, 8.4%) at other institutions.ConclusionsStudents completing this vertically integrated radiology clerkship had test scores comparable with those of students at other medical schools.     

The value of good medical student teaching: increasing the number of radiology residency applicants

RATIONALE AND OBJECTIVES: The authors attempted to define the value of good medical student teaching to the profession of radiology by examining the effect of radiology course improvements on the number of 4th-year students applying to radiology residencies. MATERIALS AND METHODS: Course evaluation and residency application data were obtained from six consecutive classes of 4th-year medical students at the study institution, and these data were compared with national data. RESULTS: Between 1995 and 2000, the number of 4th-year U.S. medical students applying to radiology increased 1.6 times. At the study institution, that number increased 4.5 times, a statistically significant difference (P = .020, chi2 test). Student survey data indicate that this increase reflects a general increase in the quality of radiology teaching in the study institution and specific changes in a required 2nd-year medical school course. CONCLUSION: These results strongly suggest that good medical student teaching pays important dividends, not only to the departments that provide it but also to the profession of radiology as a whole. Exposing students to good radiology teaching early in their medical school careers is especially important. Radiology departments that provide outstanding medical student education should be studied to help develop a model of educational best practices.     

CT Colonography: Role of a second reader CAD paradigm in the initial training of radiologists

Purpose

To evaluate the influence of CAD for the evaluation of CT colonography (CTC) datasets by inexperienced readers during the attendance of a dedicated hands-on training course.

Method and materials

Twenty-seven radiologists inexperienced in CTC (11 with no CTC training at all, 16 having previously reviewed no more than 10 CTC cases overall) attended a hands-on training course based on direct teaching on fifteen workstations (four Advantage Windows 4.4 with Colon VCAR software, GE; six CADCOLON, Im3D; five ColonScreen (Toshiba/Voxar) with ColonCAD™ API, Medicsight). During the course, readers were instructed to analyze 26 CTC cases including 38 colonic lesions obtained through low-dose MDCT acquisitions, consisting of 12 polyps sized less than 6 mm, 9 polyps sized between 6 and 10 mm, 12 polyps sized between 11 mm and 30 mm, and 5 colonic masses sized >3 cm. CTC images were reviewed by each reader both in 2D and 3D mode, respectively by direct evaluation of native axial images and MPR reconstructions, and virtual endoscopy or dissected views. Each reader had 15 min time for assessing each dataset without CAD, after which results were compared with those provided by CAD software. Global rater sensitivity for each lesion size before and after CAD usage was compared by means of two-tailed Student's t test, while sensitivity of each single reader before and after CAD usage was assessed with the McNemar test.

Results

For lesions sized <6 mm, global rater sensitivity was 0.1852 ± 0.1656 (mean ± SD) before CAD-assisted reading and 0.2345 ± 0.1761 after CAD (p = 0.0018). For lesions sized 6-9 mm, sensitivity was 0.2870 ± 0.1016 before CAD-assisted reading and 0.3117 ± 0.1099 after CAD (p = 0.0027). For lesions sized 10-30 mm, sensitivity was 0.5308 ± 0.2120 before CAD-assisted reading and 0.5637 ± 0.2133 after CAD (p = 0.0086), while for lesions sized >30 mm, sensitivity before CAD-assisted reading was 0.3556 ± 0.3105 and did not change after CAD usage (p = 1). Sensitivity of each single rater did not significantly differ before and after CAD for any lesion size category (McNemar test, p > 0.05). Specificity was not significantly different before and after CAD for any lesion size (>96% for all size categories).

Conclusion

CAD usage led to increased overall sensitivity of inexperienced readers for all polyps sizes, except for lesions >30 mm, but sensitivity of individual raters was not significantly higher compared with CAD-unassisted reading.     

Analysis of radiology education in undergraduate medical doctors training in Europe

Objectives

The purpose of the present study is to describe how undergraduate radiology teaching is organized in Europe and to identify important characteristics of undergraduate radiology curriculum.

Methods

An electronic survey on undergraduate teaching was distributed by the European Society of Radiology (ESR) to 38 national delegates of the ESR Education Committee.

Results

The “classic type” of radiology teaching method is more frequent than the “modular type”. In 38% of medical training centres the first experience with radiology is in pre-clinical years. The students enrolled in the fourth medical year experience the largest involvement in radiology education. The total number of teaching hours (mean 89 h, median 76 h) varies across the countries and differs depending on the radiological topic (mean across all topics 14.8 h, median 13). Written tests and oral exams were the most frequently used examination modes. Clerkships are reported as a key part of training.

Conclusion

This first international comparative study of undergraduate radiological curriculum in Europe identifies a large number of differences in curriculum content and teaching methods throughout Europe. More research is needed to establish the radiological educational competences resulting from these differing curricula's to improve and to standardize the teaching according to (inter)national and institutional needs.     

Prolonged local persistence of cisplatin-loaded gelatin microspheres and their chemoembolic anti-cancer effect in rabbits

Purpose

To confirm prolonged cisplatin release from drug-loaded gelatin microspheres (GMSs) and their improved chemoembolic anti-cancer effect against VX2 liver tumors in rabbits.

Materials and methods

Two groups of twelve rabbits each were treated intraarterially either with 2 mg/kg cisplatin-loaded GMSs (=0.04 mg/kg cisplatin) or 0.04 mg/kg cisplatin solution by administering them into the right renal artery. Platinum concentrations within the renal parenchyma were analyzed immediately following infusion (day 0) and on days 1, 3, and 7 using the atomic absorption method. In a second experiment four groups of five rabbits each with implanted VX2 liver tumors were treated intraarterially through the hepatic artery with the following drugs: 2 mg/kg cisplatin-loaded GMSs (=0.04 mg/kg cisplatin) (group I), 2 mg/kg GMSs without any drug (group II), 1.5 mg/kg cisplatin solution (group III) and saline (group IV). Tumor volumes were analyzed pre-injection and 7 days after with MRI allowing calculating the relative tumor growth rate (%). Degree of liver cell necrosis was assessed on the histopathological specimens.

Results

The renal parenchymal platinum concentrations (μg/ml) with 4.51 ± 2.25 (day 0), 1.59 ± 0.70 (day 1), 0.72 ± 0.10 (day 3) and 0.20 ± 0.06 (day 7) were significantly more pronounced after cisplatin-loaded GMS on days one and three compared to cisplatin with 1.99 ± 0.55, 0.08 ± 0.03, 0.18 ± 0.01 and 0.10 ± 0.07, respectively. Relative tumor growth rates resulted in 84.5% ± 26.4 (group I); 241.4% ± 145.1 (II); 331.9% ± 72.2 (III), and 413.6% ± 103.6 (IV) with statistical significant differences between groups I and III, and groups I and IV. Similar degrees of necrosis were observed in both GMSs treated groups, while ballooning of hepatocytes was highest in cisplatin-loaded GMSs.

Conclusions

With cisplatin-loaded GMSs more pronounced and prolonged local parenchymal cisplatin concentrations may be achieved offering the advantage of an increased and prolonged anti-cancer effect compared to cisplatin alone or controls. Moreover this proves indirectly the breakdown and release of cisplatin from the GMSs which is of primary importance for drug delivery systems.     

Effect of diagnostic predictions combined with clinical information on avoiding perceptual errors of computed tomography

Purpose

We hypothesized that even with appropriate clinical information, abnormal CT findings can still be missed if correct diagnostic predictions are not made.

Materials and methods

Of 388 total students (97 5th-year medical students × 4), students who detected abnormalities without clinical information were eliminated. The remaining students (hereafter, subjects) obtained clinical information, made diagnostic predictions, and reevaluated images. The proportion of failures in detecting abnormalities was compared between the correct prediction group and the incorrect prediction group. In the correct prediction group, the relationship between failures of detection and the ranking of the correct diagnosis was also examined.

Results

A total of 341 subjects were assessed. The proportion of subjects who failed to detect abnormalities in the correct prediction group (47.7 %, 93/195) was significantly lower (P < 0.001) than in the incorrect prediction group (85.6 %, 125/146). In the correct prediction group, the proportion of subjects who failed to detect abnormalities was significantly lower (P = 0.004) when the correct diagnosis was ranked first (38.5 %, 42/109) compared with lower rankings (59.3 %, 51/86).

Conclusion

Making appropriate diagnostic predictions and estimating the possibility of them based on clinical information is important to avoid missing abnormal CT findings.     

Facilitating cartilage volume measurement using MRI

Purpose

To compare quantitative cartilage volume measurement (CVM) using different slice thicknesses.

Materials and methods

Ten knees were scanned with a 1.5 T MRI (Sonata, Siemens, Erlangen, Germany) using a 3D gradient echo sequence (FLASH, fast low-angle shot). Cartilage volume of the medial and lateral tibial plateau was measured by two independent readers in 1.5 mm, 3.0 mm and 5.0 mm slices using the Argus^® software application. Accuracy and time effectiveness served as control parameters.

Results

Determining cartilage volume, time for calculation diminished for the lateral tibial plateau from 384.6 ± 127.7 s and 379.1 ± 117.6 s to 214.9 ± 109.9 s and 213.9 ± 102.2 s to 122.1 ± 60.1 s and 126.8 ± 56.2 s and for the medial tibial plateau from 465.0 ± 147.7 s and 461.8 ± 142.7 s to 214.0 ± 67.9 s and 208.9 ± 66.2 s to 132.6 ± 41.5 s and 130.6 ± 42.0 s measuring 1.5 mm, 3 mm and 5 mm slices, respectively. No statistically significant difference between cartilage volume measurements was observed (p > 0.05) while very good inter-reader correlation was evaluated.

Conclusion

CVM using 1.5 mm slices provides no higher accuracy than cartilage volume measurement in 5 mm slices while an overall time saving up to 70% is possible.     

MR fetography using heavily T2-weighted sequences: comparison of thin- and thick-slab acquisitions

Purpose

To evaluate the use of MR-fetography sequences in identifying the major fetal structures and to compare thick- and thin-slab acquisitions for their diagnostic value.

Materials and methods

Twenty-one consecutive, pregnant women with suspected fetal pathology underwent fetal magnetic resonance imaging (MRI) using a 1.5 T MRI unit. Heavily T2-weighted, single-shot fast spin-echo (SSFSE) sequences with a long echo train (MR-fetography) were acquired in a thick- and thin-slab modus. Thick- and thin-slab acquisitions were reviewed by two experienced radiologists with regard to the overall image quality and landmark anatomical structures (spinal canal, spinal cord, posterior fossa, cerebellum, brainstem, basal cisterns, stomach, urinary bladder and umbilical cord according to a three-scale grading system (good, moderate and poor). Visibility scores were calculated and compared between both sequences.

Results

Overall image quality was graded good in 76.2%, moderate in 19.0% and poor in 4.8% for thick-slab images and good in 81%, moderate in 14.3% and poor in 4.8% for thin-slab images. The visibility scores of the thick/thin-slab images for evaluation of the main fetal structures were as follows: for the spinal canal 2.8 ± 0.4/2.9 ± 0.54 (p > 0.05), spinal cord 2.4 ± 0.75/2.7 ± 0.66 (p > 0.05), posterior fossa components (cerebellum, brainstem and basal cisterns) 2.4 ± 0.68/2.8 ± 0.54; 2.4 ± 0.67/2.7 ± 0.66; 2.5 ± 0.51/2.7 ± 0.56 (p < 0.05), stomach 2.8 ± 0.44/2.9 ± 0.48 (p > 0.05), urinary bladder 2.8 ± 0.51/2.8 ± 0.54 (p > 0.05) and umbilical cord 2.9 ± 0.30/2.6 ± 0.60 (p < 0.05).

Conclusion

Heavily T2-weighted MR-fetography renders a quick overview of fetal contours, fetal position, amount of amniotic fluid and integrity and presence of several major fluid containing structures. Thick- and thin-slab acquisitions render complementary information. Thick-slab images display the entire fetus in one projection while thin-slab images provide more detailed anatomical information. The short imaging time usually allows measuring both thick- and thin-slab images. MR-fetography is as a helpful addition to conventional fetal MRI. MR-fetography should not be viewed as a single, stand alone sequence but as a supporting fast MR sequence in a well-designed multisequence fetal MRI protocol. Future studies evaluating larger patient groups are mandatory.