MSc Magnetic Resonance Imaging
Signal intensity artifacts are often encountered during magnetic resonance MR imaging. Occasionally, these artifacts are severe enough to degrade image quality and interfere with interpretation. Signal intensity artifacts inherent in local coil imaging include intensity gradients and local intensity shift artifact. Overall, there is quite substantial evidence that ADC has potential value as an imaging biomarker of response, but standardization and large-scale validation are both steps that need to be undertaken before ADC can move forward as a clinical imaging marker. As such, quantification of ADC is currently not recommended in clinical routine [ 2 ].
U.S. Food and Drug Administration
Methods of DWI response evaluation. At histopathology, a small ypT2 tumor remnant with predominant fibrosis Mandard tumor regression grade of 2 was found. By measuring the inflow of intravenously injected contrast agents into vessels and the leakage of contrast into the extracellular space, DCE-MRI can extract quantitative and semi-quantitative parameters related to tissue perfusion and microvascularity, which have shown significant correlations with response [ 65 , 66 , 67 ].
Although already routinely applied in prostate and breast imaging, in rectal cancer, DCE-MRI has so far mainly been applied in research settings and its use is not yet advised for clinical routine [ 2 ]. More advanced methods of DWI acquisition such as intravoxel incoherent motion IVIM imaging and diffusion kurtosis imaging have also recently been introduced. These methods are to date still in premature stages of research and not yet ready to be adopted in clinics. Since the focus of this pictorial review is on clinical MR methods to assess response, to provide a complete overview of these quantitative approaches would be beyond the scope of the current paper.
Recent developments in rectal treatment urge the need for an accurate radiological response evaluation. Reduction in volume and fibrotic transformation are the two main signs of response that can be appreciated on morphological T2-weighted MRI and used to help guide the treatment strategy after CRT. Morphological MRI is mainly hampered by its inability to discriminate between sterilized fibrosis and fibrosis still containing viable tumor.
This limits the performance of MRI to identify complete responders, which is an increasingly important clinical issue given the recent paradigm shift in rectal cancer treatment toward organ-preserving treatments. Addition of diffusion-weighted imaging to the MR protocol improves the performance to discriminate between tumor and fibrosis, but certain pitfalls need to be taken into account.
Knowledge on specific patterns of morphology and diffusion signal can help to further optimize diagnostic performance. Image quantification methods are promising and may provide valuable imaging biomarkers to assess response, but to date these methods are still in the research phase and not yet ready to be adopted into clinics.
Eur J Cancer Eur Radiol — Maas M, Nelemans PJ, Valentini V et al Long-term outcome in patients with a pathological complete response after chemoradiation for rectal cancer: a pooled analysis of individual patient data. Lancet Oncol — J Natl Cancer Inst Lancet — Eur J Radiol — Slater A, Halligan S, Taylor SA, Marshall M Distance between the rectal wall and mesorectal fascia measured by MRI: effect of rectal distension and implications for preoperative prediction of a tumour-free circumferential resection margin.
Clin Radiol — Br J Surg — West MA, Dimitrov BD, Moyses HE et al Timing of surgery following neoadjuvant chemoradiotherapy in locally advanced rectal cancer—a comparison of magnetic resonance imaging at two time points and histopathological responses. Eur J Surg Oncol — Radiographics — Open Pathol J — Martens MH, van Heeswijk MM, van den Broek JJ et al Prospective, multicenter validation study of magnetic resonance volumetry for response assessment after preoperative chemoradiation in rectal cancer: can the results in the literature be reproduced?
Clinicopathologic correlations. Cancer — Br J Cancer — Patel UB, Brown G, Rutten H et al Comparison of magnetic resonance imaging and histopathological response to chemoradiotherapy in locally advanced rectal cancer. Ann Surg Oncol — J Clin Oncol — Siddiqui MR, Bhoday J, Battersby NJ et al Defining response to radiotherapy in rectal cancer using magnetic resonance imaging and histopathological scales. World J Gastroeneterol — Trials Radiology — Lambregts D, Delli Pizzi A, Lahaye M et al A pattern-based approach combining tumor morphology on MRI with distinct signal patterns on diffusion-weighted imaging to assess response of rectal tumors after chemoradiotherapy.
Dis Colon Rectum — Foti PV, Privitera G, Piana S et al Locally advanced rectal cancer: qualitative and quantitative evaluation of diffusion-weighted MR imaging in the response assessment after neoadjuvant chemo-radiotherapy. Eur J Radiol Open — Br J Radiol — Sassen S, de Booij M, Sosef M et al Locally advanced rectal cancer: is diffusion weighted MRI helpful for the identification of complete responders ypT0N0 after neoadjuvant chemoradiation therapy?
Insights Imaging 8 Suppl 1 :S conference proceeding. Barbaro B, Fiorucci C, Tebala C et al Locally advanced rectal cancer: MR imaging in prediction of response after preoperative chemotherapy and radiation therapy. MERCURY Study Group Diagnostic accuracy of preoperative magnetic resonance imaging in predicting curative resection of rectal cancer: prospective observational study. BMJ Vliegen RF, Beets GL, Lammering G et al Mesorectal fascia invasion after neoadjuvant chemotherapy and radiation therapy for locally advanced rectal cancer: accuracy of MR imaging for prediction.
Tech Coloproctol — Yu SK, Chand M, Tait DM, Brown G Magnetic resonance imaging defined mucinous rectal carcinoma is an independent imaging biomarker for poor prognosis and poor response to preoperative chemoradiotherapy. Eur J Cancer — Ann Oncol — Cancer Imaging — Magn Reson Imaging — Kyriazi S, Blackledge M, Collins DJ, Desouza NM Optimising diffusion-weighted imaging in the abdomen and pelvis: comparison of image quality between monopolar and bipolar single-shot spin-echo echo-planar sequences.
Santiago I, Barata MJ, Figueiredo N, Pares O, Matos C The tram track sign: a new, highly specific and reliable sign for the detection of complete response after neoadjuvant therapy in rectal cancer. Insights Imaging 9 Suppl 2 conference proceeding. Part II. What are the criteria to predict involved lymph nodes? Int J Colorectal Dis — J Med Imaging Radiat Oncol — Ryu KH, Kim SH, Yoon JH et al Diffusion-weighted imaging for evaluating lymph node eradication after neoadjuvant chemoradiation therapy in locally advanced rectal cancer.
Acta Radiol — Abdom Imaging — Barbaro B, Vitale R, Valentini V et al Diffusion-weighted magnetic resonance imaging in monitoring rectal cancer response to neoadjuvant chemoradiotherapy. Nougaret S, Vargas HA, Lakhman Y et al Intravoxel incoherent motion-derived histogram metrics for assessment of response after combined chemotherapy and radiation therapy in rectal cancer: initial experience and comparison between single-section and volumetric analyses. Strahlenther Onkol — J Magn Reson Imaging — Sun YS, Zhang XP, Tang L et al Locally advanced rectal carcinoma treated with preoperative chemotherapy and radiation therapy: preliminary analysis of diffusion-weighted MR imaging for early detection of tumor histopathologic downstaging.
Kremser C, Judmaier W, Hein P, Griebel J, Lukas P, de Vries A Preliminary results on the influence of chemoradiation on apparent diffusion coefficients of primary rectal carcinoma measured by magnetic resonance imaging. Curvo-Semedo L, Lambregts DM, Maas M et al Rectal cancer: assessment of complete response to preoperative combined radiation therapy with chemotherapy—conventional MR volumetry versus diffusion-weighted MR imaging.
Lambregts DM, Rao SX, Sassen S et al MRI and diffusion-weighted MRI volumetry for identification of complete tumor responders after preoperative chemoradiotherapy in patients with rectal cancer: a bi-institutional validation study. Ann Surg — Acta Oncol — Biomed Res Int. Radiother Oncol — Download references. All authors read and approved the final manuscript. Correspondence to Doenja M. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Reprints and Permissions. Search all SpringerOpen articles Search. Lambregts 1 , Thierry N. Abstract In recent years, neoadjuvant chemoradiotherapy CRT has become the standard of care for patients with locally advanced rectal cancer. Keypoints Response evaluation with MR imaging can serve as a surgical roadmap and help identify near- complete responders for organ-preserving treatments Diffusion-weighted MRI improves the performance of MRI to discriminate between tumor and fibrosis, but certain pitfalls need to be taken into account Knowledge on specific patterns of morphology and diffusion signal can be helpful to improve response evaluation with MRI.
Introduction and clinical background Neoadjuvant therapy has become the standard of care for patients with locally advanced rectal cancer. Protocol and patient preparation The recommended MR imaging protocol for restaging is similar to that for primary staging. Full size image.
When physical examination and MRI were used together, their sensitivity for ACL and medial meniscal injuries was high and the specificity for the lateral meniscus was higher. For ACL injuries, there was concordance between the examinations. However, the best concordance was between arthroscopy and physical examination.
For the medial meniscus, the best concordance was observed between arthroscopy and MRI and for the lateral meniscus it was also between arthroscopy and MRI. MR accuracy and arthroscopic incidence of meniscal radial tears. Skeletal Radiol. Clinical value of magnetic resonance imaging of the knee. ANZ Surg.
- Pitfalls and artifacts encountered in clinical MR imaging of the spine..
- Clinical MR Imaging: A Practical Approach - Google книги.
- Oxford Centre for Clinical Magnetic Resonance Research — Radcliffe Department of Medicine!
- 700 Cake recipes!
- UCD School of Medicine & Medical Science : MSc Magnetic Resonance Imaging.
- Related Posts.
A systematic approach to magnetic resonance imaging interpretation of sports medicine injuries of the knee. Am J Sports Med. Brooks S, Morgan M. Accuracy of clinical diagnosis in the knee arthroscopy. Ann R Coll Surg Engl. The clinical significance of anterior horn meniscal tears diagnosed on magnetic resonance images. The accuracy of physical diagnostic tests for assessing meniscal lesions of the knee: a meta- analysis. J Fam Pract. The value of clinical examination versus magnetic resonance imaging in the diagnosis of meniscal tears and anterior cruciate ligament rupture.
Barry BP. General principles of arthroscopy. In: Terry SC, editor. Philadelphia: Mosby Inc; , 2. The accuracy of selective magnetic resonance imaging compared with the findings of arthroscopy of the knee. J Bone Joint Surg Am. Imaging evaluation of meniscal injury of the knee joint: a comparative MR imaging and arthroscopic study. Clin Imaging. The efficacy of magnetic resonance imaging in acute knee injuries. Clin J Sport Med. Clinical magnetic resonance imaging and arthroscopic findings in knees: a comparative prospective study of meniscus anterior cruciate ligament and cartilage lesions.
MRI preferable to diagnostic arthroscopy in knee injuries. A double- blind comparison of 47 patients.
Acta Orthop Scand. Magnetic resonance imaging of knee disorders. Clinical value and cost- effectiveness in a sports medicine practice. Rev Bras Ortop. Accuracy of magnetic resonance imaging of the kee and unjustified surgery. Clin Orthop Relat Res.
Magnetic resonance imaging of the knee: a review. Imaging Decisions. Arthroscopic evaluation of the accuracy of clinical examination versus MRI in diagnosing meniscus tears and cruciate ligament ruptures. Arch Iran Med. Predicted probability of meniscus tears: comparing history and physical examination with MRI. Swiss Med Wkly. The efficacy of magnetic resonance imagines in acute knee injuries. J Sports Med. Clinical examination, MRI or arthroscopy: wich is the gold standard in the diagnosis of significant internal derangement in the knee?
J Bone Joint Surg Br.
MR Solutions, world leader in MRI technology
Does this patient have a torn meniscus or ligament of the knee? Value of the physical examination. Clinical, MRI and arthroscopic correlation in meniscal and anterior cruciate ligament injuries. Int Orthop. History, clinical findings, magnetic resonance imaging, and arthroscopic correlation in meniscal lesions. Knee Surg Sports Traumatol Arthrosc.
- Structural Aspects in the Theory of Probability: A Primer In Probabilities On Algebraic-Topological Structures.
- Metacognition in Science Education: Trends in Current Research.
- Los Angeles & Beyond. Hollywood, Beverly Hills, Santa Monica, Burbank, Malibu, Pasadena;
Comparison of MRI and arthroscopic images for the diagnosis of knee disorders. Acta Ortop Mex. Clinical, MRI and arthroscopic correlation in internal derangement of knee. A comparison of accuracy between clinical examination and magnetic resonance imaging in the diagnosis of meniscal and anterior cruciate ligament tears.
Understanding interobserver agreement: the kappa statistic. Fam Med. E-mail: mgsleao uol. This is an open-access article distributed under the terms of the Creative Commons Attribution License.