Retrospective analysis of patients for development of nephrogenic systemic fibrosis following conventional angiography using gadolinium-based contrast agents

The purpose was to retrospectively review the data of 27 patients with renal insufficiency who underwent conventional angiography with gadolinium-based contrast agents (GDBCA) as alternative contrast agents and assess the occurrence of nephrogenic systemic fibrosis (NSF) together with associated potential risk factors.

Comparison of physiological triggering schemes for diffusion-weighted magnetic resonance imaging in kidneys

To determine the potential benefit of combined respiratory-cardiac triggering for diffusion-weighted imaging (DWI) of kidneys compared to respiratory triggering alone (RT).

Evaluation of renal allograft function early after transplantation with diffusion-weighted MR imaging

To determine the inter-patient variability of apparent diffusion coefficients (ADC) and concurrent micro-circulation contributions from diffusion-weighted MR imaging (DW-MRI) in renal allografts early after transplantation, and to obtain initial information on whether these measures are altered in histologically proven acute allograft rejection (AR).

Predicting and monitoring cancer treatment response with diffusion-weighted MRI

An imaging biomarker that would provide for an early quantitative metric of clinical treatment response in cancer patients would provide for a paradigm shift in cancer care. Currently, nonimage based clinical outcome metrics include morphology, clinical, and laboratory parameters, however, these are obtained relatively late following treatment. Diffusion-weighted MRI (DW-MRI) holds promise for use as a cancer treatment response biomarker as it is sensitive to macromolecular and microstructural changes which can occur at the cellular level earlier than anatomical changes during therapy. Studies have shown that successful treatment of many tumor types can be detected using DW-MRI as an early increase in the apparent diffusion coefficient (ADC) values. Additionally, low pretreatment ADC values of various tumors are often predictive of better outcome. These capabilities, once validated, could provide for an important opportunity to individualize therapy thereby minimizing unnecessary systemic toxicity associated with ineffective therapies with the additional advantage of improving overall patient health care and associated costs. In this report, we provide a brief technical overview of DW-MRI acquisition protocols, quantitative image analysis approaches and review studies which have implemented DW-MRI for the purpose of early prediction of cancer treatment response.

Do patients benefit from routine follow-up to detect recurrences after radical cystectomy and ileal orthotopic bladder substitution?

The need for and intensity of follow-up to detect disease recurrence after radical cystectomy (RC) for transitional cell carcinoma (TCC) remains a matter for debate.

Cancer of the oral cavity and oropharynx

Tumours in the oral cavity and oropharynx differ in presentation and prognosis and the detection of spread of tumour from one subsite to another is essential for the T-staging. This article reviews the anatomy and describes the pattern of spread of different cancers arising in the oral cavity and oropharynx; the imaging findings on computerized tomography and magnetic resonance imaging are also described. Brief mention is made on the role of newer imaging modalities such as [(18)F]fluorodeoxyglucose-positron emission tomography/computed tomography, perfusion studies and diffusion-weighted magnetic resonance imaging.

2010 International consensus algorithm for the diagnosis, therapy and management of hereditary angioedema

ABSTRACT:

Diffusion-weighted MR imaging of native and transplanted kidneys

Applications of diffusion-weighted (DW) magnetic resonance (MR) imaging outside the brain have gained increasing importance in recent years. Owing to technical improvements in MR imaging units and faster sequences, the need for noninvasive imaging without contrast medium administration, mainly in patients with renal insufficiency, can be met successfully by applying this technique. DW MR imaging is quantified by the apparent diffusion coefficient (ADC), which provides information on diffusion and perfusion simultaneously. By using a biexponential fitting process of the DW MR imaging data, these two entities can be separated, because this type of fitting process can serve as an estimate of both the perfusion fraction and the true diffusion coefficient. DW MR imaging can be applied for functional evaluation of the kidneys in patients with acute or chronic renal failure. Impairment of renal function is accompanied by a decreased ADC. Acute ureteral obstruction leads to perfusion and diffusion changes in the affected kidney, and renal artery stenosis results in a decreased ADC. In patients with pyelonephritis, diffuse or focal changes in signal intensity are seen on the high-b-value images, with increased signal intensity corresponding to low signal intensity on the ADC map. The feasibility and reproducibility of DW MR imaging in patients with transplanted kidneys have already been demonstrated, and initial results seem to be promising for the assessment of allograft deterioration. Overall, performance of renal DW MR imaging, presuming that measurements are of high quality, will further boost this modality, particularly for early detection of diffuse renal conditions, as well as more accurate characterization of focal renal lesions.

Science to practice: Can diffusion-weighted MR imaging findings be used as biomarkers to monitor the progression of renal fibrosis?

In an experimental murine model of unilateral ureteral obstruction, Togao et al demonstrated that diffusion-weighted (DW) magnetic resonance (MR) imaging can depict and enable monitoring of abnormal changes in the progression of renal fibrosis; because these microstructural changes are complex and multifactorial, future studies focused on their specificity should be performed before they are applied in clinical trials.

Three-year follow-up of human transplanted kidneys by diffusion-weighted MRI and blood oxygenation level-dependent imaging

To prospectively determine the 3-year stability and potential changes of functional parameters in renal allograft recipients obtained from diffusion-weighted imaging (DWI) and blood oxygenation level-dependent (BOLD) MRI.

Monitoring and Assessment of Desertification and Land Degradation: Knowledge Management, Institutions and Economics: White Paper of the DSD Working Group 3

The White Paper is a review of leading scientific knowledge on the role of knowledge management, institutions and economics in monitoring and assessment of land degradation and desertification. It provides key recommendations for more effective policies and actions for combating desertification both withn the UNCCD and beyond. This White Paper is the result of an international collaboration and consultation led jointly by the Association of DesertNet International and the United Nations University - Institute for Water, Environment and Health (UNU-INWEH), of the Dryland Science for Development Consortium (DSD). The findings were presented at the First UNCCD Scientific Conference held during the COP-9 in Buenos Aires, 2009.

Diffusion-weighted magnetic resonance imaging detects local recurrence after radical prostatectomy: initial experience

Current conventional cross-sectional imaging techniques, such as contrast-enhanced computed tomography and magnetic resonance imaging (MRI), are largely inaccurate in detecting local recurrence after radical prostatectomy. We report on five patients with biochemical recurrence after radical retropubic prostatectomy and pelvic lymph node dissection for whom local recurrence could only be detected with diffusion-weighted (DW) MRI. Prior to DW-MRI, all patients had negative digital rectal examinations, negative or equivocal conventional cross-sectional imaging, and negative bone scans. All suspicious lesions on DW-MRI imaging were histologically proved to be local recurrences of prostate cancer after either transrectal ultrasound-guided or transurethral biopsy. These results should encourage other centres to test our findings.

Long-term renal function after urinary diversion by ileal conduit or orthotopic ileal bladder substitution

Data on long-term renal function are scarce for ileal conduit diversion (ICD) and even rarer for orthotopic ileal bladder substitution (BS).

Does quantification of USPIO uptake-related signal loss allow differentiation of benign and malignant normal-sized pelvic lymph nodes?

Ultrasmall superparamagnetic iron oxide (USPIO) particles are promising contrast media, especially for molecular and cellular imaging besides lymph node staging owing to their superior NMR efficacy, macrophage uptake and lymphotropic properties. The goal of the present prospective clinical work was to validate quantification of signal decrease on high-resolution T(2)-weighted MR sequences before and 24-36 h after USPIO administration for accurate differentiation between benign and malignant normal-sized pelvic lymph nodes. Fifty-eight patients with bladder or prostate cancer were examined on a 3 T MR unit and their respective lymph node signal intensities (SI), signal-to-noise (SNR) and contrast-to-noise (CNR) were determined on pre- and post-contrast 3D T(2)-weighted turbo spin echo (TSE) images. Based on histology and/or localization, USPIO-uptake-related SI/SNR decrease of benign vs malignant and pelvic vs inguinal lymph nodes was compared. Out of 2182 resected lymph nodes 366 were selected for MRI post-processing. Benign pelvic lymph nodes showed a significantly higher SI/SNR decrease compared with malignant nodes (p < 0.0001). Inguinal lymph nodes in comparison to pelvic lymph nodes presented a reduced SI/SNR decrease (p < 0.0001). CNR did not differ significantly between benign and malignant lymph nodes. The receiver operating curve analysis yielded an area under the curve of 0.96, and the point with optimal accuracy was found at a threshold value of 13.5% SNR decrease. Overlap of SI and SNR changes between benign and malignant lymph nodes were attributed to partial voluming, lipomatosis, histiocytosis or focal lymphoreticular hyperplasia. USPIO-enhanced MRI improves the diagnostic ability of lymph node staging in normal-sized lymph nodes, although some overlap of SI/SNR-changes remained. Quantification of USPIO-dependent SNR decrease will enable the validation of this promising technique with the final goal of improving and individualizing patient care.