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Inflammatory Bowel Disease
Published in Vincenzo Berghella, Maternal-Fetal Evidence Based Guidelines, 2022
When a woman presents with symptomatic colitis and relapse is suspected, it is important to rule out infectious causes including Clostridium difficile colitis. Clostridium difficile may have a more fulminant course in patients with IBD [1]. Although imaging and colonoscopy/sigmoidoscopy may be indicated in the initial diagnosis of CD, they are often not necessary for workup of a relapse. If imaging is needed, MRI and ultrasound are preferable to computed tomography to avoid fetal radiation exposure. Gadolinium should be avoided. Flexible sigmoidoscopy without sedation can be safely performed if needed [28, 30]. A full colonoscopy can be performed with anesthesia and fetal monitoring if appropriate and if it will change management [28, 30].
Bone metastases
Published in Anju Sahdev, Sarah J. Vinnicombe, Husband & Reznek's Imaging in Oncology, 2020
Rupert Berkeley, Muaaze Ahmad, Rikin Hargunani
MRI is the most accurate imaging modality in the differentiation between these two entities (Figures 30.17 and 30.18). MRI spine protocols using sagittal T1W FSE, T2W FSE, STIR, and axial T1W FSE and T2W FSE are usually sufficient. DWI sequences are useful if diagnostic uncertainty remains (30). Administration of intravenous gadolinium may be helpful.
Contrast enhancement agents and radiopharmaceuticals
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
To understand fully the physics and chemistry of contrast agents for MRI goes beyond the scope of this book. However, it is perhaps of value at this stage to consider the difference between paramagnetic and ferromagnetic compounds. Paramagnetic compounds can be defined as pertaining to the property of any substance (excluding iron and other materials that attract a magnetic field very strongly) that displays a tendency to move to the strongest part of a non-uniform magnetic field. Gadolinium, a paramagnetic compound, may be considered for use as MRI contrast. These agents are chosen for use in medical imaging because of their magnetic susceptibility, low toxicity and therefore good tolerance by patients, in addition to their relatively low cost. Gadolinium is a rare earth metal possessing high relaxivity, i.e. an ability to alter relaxation times on adjacent protons in tissue. Paramagnetic media may be considered as ‘positive’ enhancement, increasing image intensity on T1-weighted images. Gadolinium is also referred to as a T1 contrast agent, as its greatest effect is on T1 relaxation.
Admission and follow-up cardiac magnetic resonance imaging findings in BNT162b2 Vaccine-Related myocarditis in adolescents
Published in Infectious Diseases, 2023
Seval Özen, Ayşe Esin Kibar Gül, Belgin Gülhan, Nilgün Işıksalan Özbülbül, Saliha Kanık Yüksek, Harun Terin, Özlem Mustafaoğlu, Pınar Bayraktar, İbrahim Ece, İbrahim İlker Çetin, Fatih Üçkardeş, Gülsüm İclal Bayhan, Aslınur Özkaya Parlakay
The presence of late gadolinium enhancement is an indicator of cardiac injury and fibrosis, and it has been strongly associated with a poorer prognosis in conventional acute myocarditis cases. Georgiopoulos et al. [23] found the presence and extent of late gadolinium enhancement to be a significant predictor of unfavourable cardiac outcomes. Dubey et al. [24] reached similar results in a cohort of 12 paediatric patients where late gadolinium enhancement persisted despite the resolution of edoema. In a cohort of adolescents with myopericarditis associated with mRNA-based COVID-19 vaccination, the majority of the patient continued to show late gadolinium enhancement abnormalities [11]. In our study, we observed the presence of late gadolinium enhancement in both initial and follow-up MRI examinations. This increases concerns about potential long-term effects. Nevertheless, the prognostic significance of late gadolinium enhancement in vaccine-related myopericarditis needs more research. Our study had certain limitations. It was not possible to exclude all alternative aetiologies including idiopathic aetiologies and other infectious aetiologies. Cardiac biopsies were not performed on any patient because all patients were clinically stable during their hospitalisation. Because of the low number of our cases, we are unable to report the precise incidence of myocarditis and myocarditis after mRNA-based COVID-19 vaccination.
Normative lacrimal gland dimensions by magnetic resonance imaging in an Australian cohort
Published in Orbit, 2023
Khizar Rana, Valerie Juniat, Sandy Patel, Dinesh Selva
Patients were evaluated using a Magnetom 3 T Skyra scanner (Siemens, Germany) with a conventional turbo spin-echo sequence (TR/TE, 500/15; field of view, 200x200mm; matrix, 512 x 512; slice thickness 3 mm). Contrast-enhanced images were obtained after intravenous administration of standard weight-based dose of gadolinium. Axial scans were obtained parallel to the optic nerve which was standardised across all patients’ scans. Coronal scans were perpendicular to the axial plane. The lacrimal gland was visualised in the axial and coronal planes. The coronal length was measured from the most superior to inferior tip of the lacrimal gland. The coronal width was measured perpendicular to the coronal length from the medial to the lateral edge of the lacrimal gland (Figure 1a). The axial length was defined as the distance from the most posterior to anterior tip of the lacrimal gland. The axial width was the distance from the medial to lateral edge of the lacrimal gland, perpendicular to the axial width (Figure 1b). All measurements were performed on a high-resolution picture archiving and communication system (PACS).
Diagnosis of coronary artery disease: potential complications of imaging techniques
Published in Acta Cardiologica, 2022
Evangelos Sdogkos, Andrew Xanthopoulos, Grigorios Giamouzis, John Skoularigis, Filippos Triposkiadis, Ioannis Vogiatzis
Consensus statements were recently developed and endorsed by the American College of Radiology (ACR) and National Kidney Foundation to improve and standardise the care of patients with kidney disease who have an indication(s) to receive ACR-designated group II or group III intravenous gadolinium-based contrast media (GBCM). The risk of nephrogenic systemic fibrosis (NSF) from group II GBCM in patients with advanced kidney disease is thought to be extremely low. No unconfounded cases of NSF have been reported for the only available group III GBCM (gadoxetate disodium). Depending on the clinical indication, the potential harms of delaying or withholding group II or group III GBCM for a magnetic resonance imaging (MRI) in a patient with acute kidney injury or eGFR less than 30 mL min−1 1.73 m−2 should be balanced against and may outweigh the risk of NSF. Dialysis initiation or alteration is likely unnecessary based on group II or group III GBCM administration [12]. Besides, gadolinium may stay in the body for months to years and accumulate in bone, brain, and kidney tissue without necessarily pre-existing kidney disease. This is referred to as Gadolinium Deposition Disease. The Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have issued relevant announcements, while the use of gadoteridol is recommended as the default GBCM in MRI imaging [13].