Variations In Imaging Protocols Research Articles

Magnetic Resonance Imaging (MRI) Insights into Brain Morphology and Connectivity Disruptions in Schizophrenia

This review explores the transformative impact of Magnetic Resonance Imaging (MRI) on understanding schizophrenia. Structural MRI has unveiled significant alterations in brain regions like the hippocampus and prefrontal cortex, offering detailed insights into anatomical irregularities. Functional MRI studies have shed light on disruptions within the default mode network, providing valuable insights into cognitive deficits associated with the disorder. Additionally, Diffusion Tensor Imaging has highlighted white matter abnormalities, underscoring compromised interregional communication within the brain. Despite persistent challenges such as population heterogeneity and variations in imaging protocols, MRI techniques have significantly advanced our understanding of schizophrenia's neurobiological aspects.

Review of diffusion-weighted imaging and dynamic contrast-enhanced MRI for multiple myeloma and its precursors (monoclonal gammopathy of undetermined significance and smouldering myeloma).

The last decades, increasing research has been conducted on dynamic contrast-enhanced and diffusion-weighted MRI techniques in multiple myeloma and its precursors. Apart from anatomical sequences which are prone to interpretation errors due to anatomical variants, other pathologies and subjective evaluation of signal intensities, dynamic contrast-enhanced and diffusion-weighted MRI provide additional information on microenvironmental changes in bone marrow and are helpful in the diagnosis, staging and follow-up of plasma cell dyscrasias. Diffusion-weighted imaging provides information on diffusion (restriction) of water molecules in bone marrow and in malignant infiltration. Qualitative evaluation by visually assessing images with different diffusion sensitising gradients and quantitative evaluation of the apparent diffusion coefficient are studied extensively. Dynamic contrast-enhanced imaging provides information on bone marrow vascularisation, perfusion, capillary resistance, vascular permeability and interstitial space, which are systematically altered in different disease stages and can be evaluated in a qualitative and a (semi-)quantitative manner. Both diffusion restriction and abnormal dynamic contrast-enhanced MRI parameters are early biomarkers of malignancy or disease progression in focal lesions or in regions with diffuse abnormal signal intensities. The added value for both techniques lies in better detection and/or characterisation of abnormal bone marrow otherwise missed or misdiagnosed on anatomical MRI sequences. Increased detection rates of focal lesions or diffuse bone marrow infiltration upstage patients to higher disease stages, provide earlier access to therapy and slower disease progression and allow closer monitoring of high-risk patients. Despite promising results, variations in imaging protocols, scanner types and post-processing methods are large, thus hampering universal applicability and reproducibility of quantitative imaging parameters. The myeloma response assessment and diagnosis system and the international myeloma working group provide a systematic multicentre approach on imaging and propose which parameters to use in multiple myeloma and its precursors in an attempt to overcome the pitfalls of dynamic contrast-enhanced and diffusion-weighted imaging.Single sentence summary statementDiffusion-weighted imaging and dynamic contrast-enhanced MRI provide important additional information to standard anatomical MRI techniques for diagnosis, staging and follow-up of patients with plasma cell dyscrasias, although some precautions should be taken on standardisation of imaging protocols to improve reproducibility and application in multiple centres.

Variations of clinical SPECT/CT operations

SummaryAim: This survey gathers information about clinical SPECT/CT operations worldwide to help guide standardization of clinical SPECT/ CT imaging. Methods: An international, webbased survey of SPECT/CT users was initiated in 12/2010 through an e-mail distribution. Users were asked 71 questions related to (A) demographics, (B) SPECT/CT operations/utilization and (C) variations in imaging protocols. Results: Collected responses originated from 117 imaging centers in the Americas (66%), Europe (20%), Asia-Pacific (11%) and the Middle-East (3%), with the majority of responding sites representing public health care institutions (69%). Most sites operate 1–2 SPECT/CT-systems (74%), typically installed in Nuclear Medicine departments (84%) with extensive prior SPECT-only experience (82%). Only 14% of SPECT/CTs are installed in Radiology departments. Clinical SPECT/CT imaging is performed either as routine (51%) or ad-hoc “add-on” procedure (49%) with a high inter-site and inter-examination variability. The main application of the integrated CT is to provide anatomical localization of the tracer uptake rather than to produce contrast enhanced or other high-quality CT images. Consequently, in only 22% of the sites a CT contrast injector is installed. Only 6% of centers use SPECT/CT devices for stand-alone CT procedures. Conclusion: An international survey among clinical SPECT/CT users revealed that SPECT/CT is a not a routine component of nuclear medicine procedures. The majority of the centers responding do not fully utilize the diagnostic potential of the CT components. Significant variations in standard imaging protocols were observed. These findings illustrate the need for training and standardization and underscore the need for revisiting the role of SPECT/CT in diagnostic imaging.

Assessment of Coronary Artery Disease by Radionuclide Cineangiography: History, Current Applications, and New Directions

In recent years, the utility of radionuclide cineangiography in prognostication has made it a mainstay of management decision making. With evolution of therapeutic modalities and concomitant alteration in management strategies, however, the technique and its application are undergoing parallel evolution to optimize response to current needs. Thus, in addition to standard planar rest and exercise assessment of left ventricular function, newer approaches are involving combined perfusion and function assessment, application of pharmacological stress to permit technically advantageous variations in imaging protocols, and application of SPECT technology in collecting blood pool data for tomographic display and analysis.