Seminars in ultrasound, CT, and MR
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Semin. Ultrasound CT MR · Feb 2003
Randomized Controlled Trial Multicenter Study Clinical TrialCT screening for lung cancer.
The Early Lung Cancer Action Project (ELCAP) recently demonstrated that earlier diagnosis of lung cancer can be achieved with CT, and these results have led to considerable demand for CT screening. The advisability of screening seems obvious, as screening has been shown to provide for lung cancer treatment at a relatively early stage, leading to a better chance to avert death from lung cancer than when treatment is prompted by symptoms and/or signs. There are, however, countervailing ideas that CT lung cancer screening has not yet been demonstrated to 'save lives.' Further, it has been stated that CT screening has a notable problem of "overdiagnosis," meaning that screening finds lesions that are not life threatening, leading to unnecessary surgery. ⋯ We feel that randomization is not necessary for evaluating a diagnostic test and may generate misleading results. Rather, we feel that the desired information is how often and how early is the disease diagnosed using that test. The purpose of this article is to raise the general level of concern about the underpinnings of such randomized 'screening' trials, and to convey some of the evidence that led to our pessimism about the NLST.
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Semin. Ultrasound CT MR · Dec 2002
ReviewClinical evaluation of postoperative sinonasal surgical patients.
Rhinosinusitis is a very common upper respiratory illness. Functional endoscopic sinus surgery has been successfully utilized in the surgical treatment of medically refractory rhinosinusitis. The endoscopic approach has also been extended to various skull base lesion and sinonasal neoplasms. ⋯ Judicious use of nasal endoscopy and importance of CT imaging of the sinuses are discussed. Emphasis is placed on establishing communication between the sinus surgeon and radiologist to facilitate evaluation of the sinonasal surgical patients. liming and specific types of imaging studies before any revision sinus surgery are discussed. Major complications associated with endoscopic sinus surgery are reviewed.
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Fluoroscopically guided diagnostic and interventional procedures have become much more commonplace over the last decade. Current fluoroscopes are easily capable of producing dose rates in the range of 0.2 Gy (20 rads) per minute. The dose rate often changes dramatically with patient positioning and size. ⋯ In some cases skin doses have been in excess of 60 Gy (6000 rads). In many instances the procedures have been performed by physicians with little training in radiation effects, little appreciation of the radiation injuries that are possible or the strategies that could have been used to reduce both patient and staff doses. Almost all of the severe injuries that have occurred were avoidable.
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Semin. Ultrasound CT MR · Jun 2002
ReviewImaging of the glossopharyngeal, vagus, and accessory nerves.
The origination and course of the glossopharyngeal, vagus and accessory cranial nerves explains their function and localizes pathology. Abnormalities of these lower cranial nerves may be intrinsic or extrinsic and is due to a multiplicity of disease processes. The clinical presentation of the involved cranial nerve helps to guide imaging evaluation. Magnetic resonance imaging without and with contrast is the mainstay of imaging of cranial nerves IX, X and XI pathology, but computed tomography provides substantial information as well.
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Semin. Ultrasound CT MR · Aug 2001
ReviewClearance of the cervical spine in multitrauma patients: the role of advanced imaging.
The cervical spine is injured in 3% of major trauma patients. Radiographic clearance for injury must be provided efficiently and accurately. There are numerous choices for clearance that are now in clinical practice: lateral radiograph only, 3-view or 5-view cervical-spine (c-spine) series, flexion-extension radiographs, computed tomography (CT) with multiplanar reformations, and magnetic resonance imaging (MRI). ⋯ MRI is also much less sensitive than CT to fractures of the posterior elements of the spine, and to injuries of the craniocervical junction. The causes of missed cervical spine injury and delayed instability are discussed and shown in this article. An algorithm for the use of advanced imaging is proposed.