This week I am presenting images of a 49-year-old woman with abdominal pain and moderate distension. Examine the images below, leave your thoughts in the comments section, and come back on Friday for the answer.
What would be your diagnosis?
2. Subpulmonary fluid
3. Diaphragmatic eventration
4. None of the above
B-0118 Determination of the vascular input function using magnitude or phase-based MRI: influence on dynamic contrast-enhanced MRI model parameters in carotid plaques
R.H.M. van Hoof, M.T.B. Truijman, E. Hermeling, R.J. van Oostenbrugge, R.J. van der Geest, M.J.A.P. Daemen, J.E. Wildberger, W.H. Backes, M.E. Kooi | Thursday, March 7, 10:30 – 12:00 / Room N/O
Purpose: A reliable vascular input function (VIF) is important for quantitative analysis of atherosclerotic carotid plaque microvasculature using dynamic contrast-enhanced (DCE) MRI. In tumour imaging and brain perfusion studies, it has been demonstrated that a phase-based VIF (ph-VIF) is less sensitive to flow artefacts compared to magnitude-based VIF (m-VIF). The purpose is (1) to compare m-VIF and ph-VIF and (2) to investigate the influence of different VIFs on DCE MRI model parameters in carotid plaques.
Methods and Materials: 21 patients with 30-99% carotid stenosis underwent 3 T DCE MRI. Data from four patients, scanned with a high temporal resolution were used to construct group-averaged m-VIF and ph-VIF of the jugular vein. The other 17 patients were used for calculating Ktrans (measure of plaque microvasculature) using m-VIF and ph-VIF. The effect of neglecting flow on the m-VIF was estimated using the Bloch equations.
Results: Peak concentrations of m-VIFs were on average 4-fold lower than for ph-VIFs (p<0.001). Despite these differences, strong and significant correlation between Ktrans determined using group averaged m-VIF and ph-VIF was found (Pearson’s correlation 0.91, p<0.001). Taking into account a theoretical flow of 8 cm/sec, the discrepancy in peak concentration of m-VIF and ph-VIF disappeared.
Conclusion: Our data suggest a strong influence of flow when calculating m-VIF of the jugular vein. Despite this, strong correlation between Ktransparameters determined using m-VIF and ph-VIF was found. It is expected that a phase-based VIF results in a quantitative more realistic value of Ktrans.
A-285 The Spanish radiographer’s role in advanced MRI research
E. Alfayate Sáez | Saturday, March 9, 14:00 – 15:30 / Room B
A Radiographer, as part of a MRI research team, is more than just a professional obtaining patient´s images for either the investigational studies or clinical trials. Being part of the team means participating and understanding the project as a whole. It means one must know the study’s objectives, collaborate in the protocol design and optimization, and inform the patient about the exam and steps to follow in order to maximize his cooperation. Personal data protection and individual privacy must be guaranteed through all the process; a written informed consent should be signed by the patient as well. Taking care of all these particular aspects is very important for a successful completion of each study/trial. Due to rapid technological advances, and the necessity to deal permanently with state-of-the-art scientific areas, Continuous Professional Development (CPD) for a Radiographer working in a research team is critical. The radiographer is part of a multidisciplinary team, where each professional performs a very specialized task, combining efforts is crucial in order to produce a work of excellence that can be shared with the scientific community. Thanks to the continuous investment in new technology, we have the opportunity, in our site, to conduct research in diverse areas, such as cardiology, traumatology, gynaecology, obstetrics and neurology. Through this presentation we will share some of the research we are working on, as well as the importance of the Radiographer role in a research centre.
Muppet and I just returned from the RSNA meeting in Chicago (Muppet very happy after spending the week with Miss Piggy!). This week we’re presenting a straightforward case to make you happy as well. Images belong to a 63-year-old man with vague chest complaints.
Where is the abnormality and what do you think it is? Leave yout thoughts and diagnosis in the comments section and come back on Friday for the answer.
A-451 Coronary artery imaging from a chest CT examination: when and how
R. Marano | Sunday, March 10, 14:00 – 15:30 / Room G/H
The continuous technological evolution of multi-detector CT scanner characterized by larger detector array with increased anatomical coverage per rotation, faster rotation and table speed, and shorter acquisition time have made reliable to perform chest imaging with reduced cardiac motion artifacts, improving the assessment of heart and contiguous structures in the course of routine thorax CT. Further, the larger anatomic coverage of detectors and the availability of scan protocols with lower radiation dose have also made reliable to apply ECG-synchronization to chest CT study, and therefore to couple cardiac/coronary imaging with chest imaging. Different clinical queries requiring a chest CT imaging may underlie cardiac or coronary source that is not clinically evident; similarly, patients scheduled for thoracic surgery, staging or studied in emergency setting may present unexpected heart or coronary artery findings that can be detected in the course of pre-operative CT or may change the treatment and prognosis. Therefore, the capability to perform the assessment of both the heart and chest by a single diagnostic tool is becoming progressively significant because the evaluation of the heart often can provide clinically relevant information in the course of routine or emergency chest CT that is not otherwise easily available.
A-549 A. Head and neck cancer
L. Oleaga Zufiría | Monday, March 11, 08:30 – 10:00 / Room E2
Identification of recurrent tumour in the post-therapy setting is often challenging. It is essential to have a baseline study for monitoring changes and evaluating possible recurrences. After surgery, there is distortion of the anatomy, the fat planes are lost, functional lymphadenectomy may be associated with muscle resection, resection of the jugular vein or grafting, therefore, it is essential to know this data to properly analyze the images. The immediate postoperative baseline study after surgery should be performed between 4 and 6 weeks after surgery. When radiotherapy is performed, there is loss of fat planes, significant edema in the mucosa and in subcutaneous tissue. The recommended baseline study should be obtained at 3 months after a completion of radiation therapy. The imaging methods used for the staging and follow-up of head and neck tumours varies between centres. CT is the most commonly used imaging technique, however, at some institutions MRI or PET are used to detect tumour recurrence after therapy, either surgery or chemo/radiation. Distinction between post-treatment changes and recurrent or residual tumor might be difficult to assess on imaging. A soft tissue mass present in the baseline study that decreases in size, should be considered treatment-related changes. If the mass increases in size, it is suggestive of persistent or recurrent tumor. A new onset mass in the follow-up study should be considered as recurrence. Late complications due to chemo/radiation include soft-tissue necrosis, osteochondronecrosis, carotid atherosclerosis, myelopathy, nerve paralysis secondary to fibrosis and sarcomas.
Today I’m showing a vintage case, seen thirty years ago when I was a promising young staffer. The images below belong to a 57-year-old missionary living in Africa and undergoing yearly controls at our institution for unilateral hyperlucent lung.
Leave me your thoughts and diagnosis in the comments section and come back on Friday for the solution.
1. Swyer-James/Macleod syndrome
2. Bronchial tumour
3. Pulmonary artery stenosis
4. None of the above
B-0105 The incidence of biological effects from 3.0 Tesla (T) MRI compared to 1.5 T: an observational study in 911 consecutive outpatients
F. Alghamdi, P. Bertrand, L. Barantin, M.A. Lauvin, X. Cazals, F. Domengie, R. Bibi, D. Herbreteau, J.-P. Cottier | Thursday, March 7, 10:30 – 12:00 / Room L/M
Purpose: To compare the acute biological effects of a 3.0 Tesla (T) magnetic resonance imaging (MRI) to 1.5 T MRI
Methods and Materials: After MRI examination, 911 patients (449 with 3.0 T MRI and 462 with 1.5 T MRI) were presented with a verbal rating scale questionnaire consisting of 11 symptoms related to MRI examination. Chi-square tests were used to assess the relationship between the strength of the magnetic field (MF) and the incidence of the symptoms. A P value of <.05 was considered significant.
Results: There was no statistically significant relationship between the strength of the MF and the incidence of the symptoms related to static MF exposure, such as vertigo (P = .13), nausea (P = .35), headache (P = .21), and a metallic taste (P = .64). A warm feeling induced by radiofrequency (RF) was significantly higher in the 3.0 T MRI (P <.0001) with a significant correlation between the mean specific energy absorption rate (SAR) and a warm feeling in the 3.0 T MRI (P <.0001). Numbness/tingling related to the gradient MF was significantly higher in the 3.0 T MRI (P = .027).
Conclusion: The thermal effect induced by the RF and the numbness/tingling induced by the gradient field were significantly higher in the 3.0 T MRI than in the 1.5 T MRI. There was no statistically significant difference between the symptoms related to static MF exposure from the 3.0 T MRI and 1.5 T MRI.
This week I am showing you a case provided by my good friend Dr. Jordi Andreu. The radiographs below belong to a 39-year-old woman with increased shortness of breath for the last three months. Leave your thoughts and diagnosis in the comments section and come back for the answer on Friday.
1. Bullous emphysema
2. Tension pneumothorax
3. Adenomatoid malformation
4. None of the above
B-0721 CT imaging in an emergency setting is not substantially delayed by iterative reconstruction
M.J. Willemink, A.M.R. Schilham, T. Leiner, W.P.T.M. Mali, P.A. de Jong, R.P.J. Budde | Sunday, March 10, 10:30 – 12:00 / Room N/O
Purpose: Iterative reconstruction (IR) is a promising noise reducing technique with the potential to reduce radiation-dose with preserved study interpretability or improve image-quality at similar radiation-dose. One of the major drawbacks of IR is a longer reconstruction time which may be problematic in the emergency setting. The purpose of the current study was to compare reconstruction time and speed of IR and filtered back-projection (FBP) in two commonly encountered emergency imaging scan-protocols: total body trauma CT and pulmonary CTA.
Methods and Materials: Fifteen patients underwent a total body CT after a traumatic event and twenty-five adults underwent a CTA for evaluation of pulmonary embolisms on a 256-slice CT-scanner. All data were reconstructed using FBP and two IR-levels (iDose4, Philips Healthcare). Quantification of reconstruction time and speed was done with a self-written plug-in for ImageJ (US National Institutes of Health).
Results: The mean delay in reconstruction time on total body trauma CTs was 44.4±8.1 and 44.9±7.0 seconds for iDose4-levels 1 and 6, respectively, and on pulmonary CTAs 10.1±9.6 and 12.0±11.8 seconds for iDose4-levels 2 and 4, respectively. The mean reconstruction time and speed for total body trauma CTs were 87.3±14.6, 131.7±16.7 and 132.2±17.9 seconds, and 20.1±1.6, 13.2±0.8 and 13.2±0.6 slices/s for FBP, iDose4-levels 1 and 6, respectively, and for pulmonary CTAs 25.5±7.0, 35.6±9.0 and 37.6±12.0 seconds, and 26.7±5.6, 18.7±2.3 and 18.0±2.8 slices/s for FBP, iDose4-levels 2 and 4, respectively.
Conclusion: CT image reconstruction in an emergency setting is not delayed substantially by IR. Furthermore, reconstruction time and speed did not differ substantially between different IR-levels.