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Bladder cancer
Published in Anju Sahdev, Sarah J. Vinnicombe, Husband & Reznek's Imaging in Oncology, 2020
Intravenous contrast medium is now advocated for MRI staging of bladder cancer by most authors. However, only a few studies have been reported comparing unenhanced MRI with dynamic contrast-enhanced studies. Barentsz et al. showed improved staging from 67% to 84% when IV contrast medium was used in a fast dynamic scanning mode (60). Kim et al. also showed an improved accuracy of 9% when dynamic contrast-enhanced MRI were compared with unenhanced images (61). In such studies, the extent of invasion of the bladder wall was better demonstrated in contrast-enhanced T1WI compared with conventional images, and the inclusion of contrast-enhanced sequences was the major factor in improving results. Furthermore, Hayashi et al. (59) have also shown that contrast-enhanced MRI can distinguish T1 from T2 tumours. A drawback of this study, however, was the need to use an endorectal coil to obtain high-resolution images. However, from a clinical point of view, the distinction of early tumours confined to the bladder is less important than the distinction of tumour spread beyond the bladder from that confined to the bladder wall. Therefore, the differences in accuracy of tumour staging with CT and MR for early disease are not central to patient management.
Breast imaging
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
MRI of the breast is becoming increasingly important for the assessment of indeterminate abnormalities, offering an alternative imaging test with high contrast resolution and sensitivity. Dynamic contrast-enhanced MRI shows the rate and pattern of enhancement, which can help characterise lesions as benign or malignant, and most accurately defines the extent of any malignant disease. MRI is now commonly used prior to surgery for invasive lobular cancers to assess the extent of the tumour and to detect multifocal disease. Where additional lesions are found these will require biopsy prior to surgery to determine their significance. Initially a ‘second look ultrasound’ will be performed by an experienced operator who will often, with knowledge of the location of the suspect MRI lesion, be able to locate and biopsy it. If this is not successful MRI-guided biopsy may be performed, though this is a more complex procedure. MRI with water and silicone suppression sequences is also a good means of assessing the integrity of breast implants and is more accurate than ultrasound.
Antiangiogenic Therapy for Lung Cancer: Antibodies and Other Novel Agents
Published in Kishan J. Pandya, Julie R. Brahmer, Manuel Hidalgo, Lung Cancer, 2016
VEGF trap is a fusion protein consisting of human VEGFR-1, VEGFR-2, and IgG constant domains. It has a high affinity for binding to VEGF and thus prevents binding of VEGF to VEGFR. A phase I study of this agent was conducted in patients with refractory solid tumors. The preliminary results indicate that drug-related grade 3 adverse events were uncommon and included fatigue, arthralgia, and voice disturbance (13). Dynamic contrast-enhanced, MRI-based evaluation is included in this study. No HACA antibodies were seen. One patient with renal-cell carcinoma developed stable disease for more than six months. Other ongoing phase I studies will evaluate the safety of this agent in combination with chemotherapy regimens.
Current methods and new approaches to assess aqueous humor dynamics
Published in Expert Review of Ophthalmology, 2021
Carol B. Toris, Meghal Gagrani, Deepta Ghate
In the near future, imaging techniques such as ultrasound biomicroscopy (UBM) [53], ocular coherence tomography (OCT) [54,55], or magnetic resonance imaging (MRI) [56] could be used to record the rate and pattern of movement of a tracer that had been delivered to the posterior chamber. The feasibility of this idea is supported by a recent paper using dynamic contrast enhanced MRI [57] in mice given intravenous injections of a contract agent. With this method, differences were found in fluid movement with regard to age and pigmentary glaucoma. In the future, this method could evolve into one that measures the rate of entry of a tracer from the ciliary processes into the posterior chamber (aqueous production, Fp), the rate of entry of tracer into the anterior chamber (aqueous flow, Fa) and rate of entry of tracer into the vitreous body (posterior flow, Fpost). Stimulating Fpost may become a new means to lower IOP or to deliver drugs to the retina.
How reliable are imaging techniques in aging males with bladder cancer?
Published in The Aging Male, 2020
Musab Ali Kutluhan, Emrah Özsoy, Fulya Başkak, Ahmet Ürkmez, Ramazan Topaktaş, Orhan Koca
Contrast-enhanced abdominopelvic MRI is another imaging tool used in detection of clinical lymph node positivity in bladder cancer. It shows pelvic anatomy in more detail and soft tissue contrast resolution is better than CT. Also, diffusion-weighted MRI (DW-MRI) and dynamic contrast-enhanced MRI (DCE-MRI) can provide functional information. In a retrospective study involving 45 patients, van der Pol et al. [19] reported that sensitivity and specificity of T2-weighted imaging (T2WI) + Diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) + DCE-MRI sequence in lymph node detection were 45% and 90%, respectively. In a prospective study including 122 patients by Daneshmand et al. [20], the sensitivity and specificity of DCE imaging MRI sequence in clinical lymph node detection were 41% and 92%, respectively. In our study, there was no statistically significant difference between the clinical lymph node positivity and pathological lymph node positivity (p > 0.05) and the sensitivity was 50.00%, specificity was 100%, PPV was 100%, NPV was 76.92%, and accuracy was 81.25%. In our study, the sensitivity and specificity of contrast-enhanced thoraco- abdominal MRI is consistent with the literature; however, we believe that the reason for relatively high sensitivity and specificity is due to the low number of patients with MRI in our study.
The role of imaging in juvenile idiopathic arthritis
Published in Expert Review of Clinical Immunology, 2018
Clara Malattia, Mariangela Rinaldi, Alberto Martini
Likewise, MRI can detect inflammation below the clinical threshold [81]. In a recent dynamic contrast-enhanced MRI study involving 32 JIA patients with clinically inactive disease, dynamic parameters (namely, the maximum rate of enhancement) were promising predictor of disease flare [85]. As already mentioned, it is widely accepted that normal joints may occasionally have a small degree of synovial enhancement [37]. Discriminating the normal enhancing synovial membrane from the pathological is thus a high priority in order to use MRI for the assessment of remission state. An interesting approach has been proposed by Gandjbakhch et al. who, by analyzing MRI data from several RA clinical trial cohorts [86], have proposed a ‘safe level’ of MRI inflammation below which damage progression does not occur.