Evaluation of an abbreviated screening MRI protocol for patients at risk for hepatocellular carcinoma.

PURPOSE: In this study, we compare an abbreviated screening MRI protocol (aMRI), utilizing only dynamic contrast-enhanced images, to a conventional liver MRI (cMRI) for the characterization of observations in at-risk patients. MATERIALS AND METHODS: 164 consecutive HCC screening MRIs were retrospectively analyzed. Two sets of de-identified image sets were created: one with all acquired sequences including T2- and diffusion-weighted sequences (cMRI), and one with only T1-weighted precontrast and dynamic post-contrast images utilizing an extracellular gadolinium contrast agent (aMRI). Three readers assigned a LI-RADS score based on the lesion with the highest LI-RADS category using the aMRI and cMRI datasets during separate reads. RESULTS: There was no change between the aMRI and cMRI LI-RADS categorization in 93%, 96%, and 96% of cases for readers 1, 2, and 3, respectively. In the majority of the discrepant cases, the score increased from LI-RADS 3 to LI-RADS 4 due to the presence of ancillary features on T2 and DWI. Kappa values for interobserver variability demonstrated fair-to-moderate LI-RADS agreement among the 3 readers. CONCLUSION: There was strong agreement between the abbreviated T1-only MRI protocol and a full liver MRI, with only 5% of cases changing LI-RADS categorization due to the inclusion of T2 and DWI. The estimated time to run this abbreviated MRI is approximately 7-10 min, possibly allowing for a more cost-effective screening MRI than our cMRIs.

Application of 3-Dimensional Printing in a Case of Osteogenesis Imperfecta for Patient Education, Anatomic Understanding, Preoperative Planning, and Intraoperative Evaluation.

BACKGROUND: The techniques and applications of 3-dimensional (3D) printing have progressed at a fast pace. In the last 10 years, there has been significant progress in applying this technology to medical applications. We present a case of osteogenesis imperfecta in which treatment was aided by prospectively using patient-specific, anatomically accurate 3D prints of the calvaria. The patient-specific, anatomically accurate 3D prints were used in the clinic and in the operating room to augment patient education, improve surgical decision making, and enhance preoperative planning. CASE DESCRIPTION: A 41-year-old woman with osteogenesis imperfecta and an extensive neurosurgical history presented for cranioplasty revision. Computed tomography (CT) data obtained as part of routine preoperative imaging were processed into a 3D model. The 3D patient-specific models were used in the clinic for patient education and in the operating room for preoperative visualization, planning, and intraoperative evaluation of anatomy. The patient reported the 3D models improved her understanding and comfort with the planned surgery when compared with discussing the procedure with the neurosurgeon or viewing the CT images with a neuroradiologist. The neurosurgeon reported an improved understanding of the patient's anatomy and potential cause of patient symptoms as well as improved preoperative planning compared with viewing the CT imaging alone. The neurosurgeon also reported an improvement in the planned surgical approach with a better intraoperative visualization and confirmation of the regions of planned calvarial resection. CONCLUSIONS: The use of patient-specific, anatomically accurate 3D prints may improve patient education, surgeon understanding and visualization, preoperative decision making, and intraoperative management.

Advances in PET Imaging of Degenerative, Cerebrovascular, and Traumatic Causes of Dementia.

In this review we present the most recent advances in nuclear medicine imaging as a diagnostic and management tool for dementia. The clinical diagnosis of dementia syndromes can be challenging for physicians, particularly in the early stages of disease. Given the growing number of individuals affected by dementia, early and accurate diagnosis can lead to improved clinical management of patients. Although tests are available for exclusion of certain causes of cognitive impairment, the results rarely allow the clinician to make a definitive diagnosis. For this reason, information obtained from imaging ("imaging biomarkers") is playing an increasingly important role in the workup of patients with suspected dementia. Imaging biomarkers also provide indispensable tools for clinical and preclinical studies of dementing illnesses to elucidate their pathophysiology and to develop better therapies. A wide range of imaging has been used to diagnose and investigate neurodegenerative disorders including structural, cerebral perfusion, glucose metabolism, neurochemical, and molecular imaging. In the first section, we discuss the imaging methods used in clinical practice to diagnose dementia as well as explore additional experimental modalities that are currently used as research tools. In the second section, a comprehensive review covering the myriad aspects of vascular disease as a cause of dementia is presented and illustrated with MRI- and PET-focused case examples. In the third section, advances in imaging Alzheimer disease pathology are emphasized by reviewing current approaches for PET imaging with ß-amyloid imaging agents. We provide an outline for the appropriate use criteria for ß-amyloid imaging agents in dementia. In addition, the recognition of the importance of neocortical neurofibrillary tangles as related to Alzheimer disease progression has led to the development of promising tau imaging agents such as [(18)F]T807. The last section provides a history brain trauma as a cause of chronic traumatic encephalopathy. Although the recognition of cognitive deficits from brain trauma dates back to the early part of last century, recent advances in our understanding of the neurobiology has led to the hope of developing molecular imaging methods for earlier diagnoses and treatment. This has become increasingly important given the raised public and physician awareness of the high incidence of this pathology in military conflicts and sports-related injuries. Overall advancements in nuclear medicine imaging have led to an improvement in the detection and accurate identification of dementia and its underlying causes. With both primary and secondary causes of dementia demonstrating often overlapping presentations, nuclear medicine imaging can play a key role not only in the diagnosis but the understanding of dementia. With earlier diagnosis and better understanding comes the hope of improved treatments or possibly someday a cure.