Seminars in ultrasound, CT, and MR
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Semin. Ultrasound CT MR · Oct 2006
ReviewMultidetector-row computed tomography imaging of splenic trauma.
The spleen is the intra-abdominal organ most often injured as a result of blunt trauma. Multidetector-row computed tomography (MDCT) plays an important role in the detection and characterization of splenic injury. ⋯ This article reviews the various appearances of the injured spleen and discusses the use of MDCT in the initial evaluation of injury. The indications for angiography and embolization are reviewed, with examples of appearances of the postembolization spleen.
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Computed tomography (CT), especially multidetector row CT (MDCT), is often the preferred imaging test used for evaluation of nontraumatic thoracic aortic abnormalities. Unenhanced images, usually followed by contrast-enhanced arterial imaging, allow for rapid detailed aortic assessment. Understanding the spectrum of acute thoracic aortic conditions which may present similarly (aortic dissection, aneurysm rupture, penetrating atherosclerotic ulcer, intramural hematoma) will ensure that patients are diagnosed and treated appropriately. Familiarity with imaging protocols and potential mimics will prevent confusion of normal anatomy and variants with aortic disease.
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Semin. Ultrasound CT MR · Aug 2005
ReviewMagnetic resonance evaluation of pregnant patients with acute abdominal pain.
Acute abdominal pain in a pregnant patient is associated with a long differential diagnosis, and diagnostic imaging is often required to guide management. Ultrasound is safe and widely available; however, maternal structures may be difficult to evaluate during pregnancy due to anatomic changes. ⋯ Magnetic resonance (MR) imaging provides excellent anatomic resolution and tissue characterization without ionizing radiation, and MR diagnosis frequently requires no contrast administration. Using an appropriate combination of sequences, MR imaging can reliably demonstrate many causes of acute abdominal pain during pregnancy.
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Semin. Ultrasound CT MR · Apr 2005
ReviewComplications of percutaneous vertebroplasty and their prevention.
Vertebroplasty is an efficient treatment of vertebral collapses of malignant or benign origin but also carries a risk of complications. Cement extravasation is a frequent occurrence in vertebroplasty. It is well tolerated in the large majority of cases but is also the main source of complications especially nerve root compression in case of cement leakage into the intervertebral foramen and pulmonary embolism of cement complicating venous cement leakage. ⋯ In addition, incidence of new vertebral fractures in adjacent vertebrae may be increased by vertebroplasty. General reactions possibly due to a reflex reaction to intramedullary bone injection and fat embolism may also occur. This article reviews the safety measures to reduce the risk of cement extravasation including high quality permanent radiological guidance enabling early detection of cement extravasation, use of conscious sedation, bilateral transpedicular approach at the thoracic and lumbar levels, careful selection of the bone penetration site in order to make a single vertebral needle path, careful needle placement to avoid the risk of cortical breakthrough, use of a well-opacified and refrigerated cement with a toothpaste consistency.
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Lumbar provocation discography is an invasive diagnostic procedure to identify pain originating from within the lumbar discs. Specific morphological changes within the disc, classified as radial fissures, can be imaged following the injection of radiopaque contrast into the nucleus pulposus. The reproduction of concordant low back and/or referred somatic pain to the lower extremity under controlled conditions and the demonstration of annular radial tears are part of a spectrum of internal disc disruption that is separate from disc degeneration. A review of the validity and technique of lumbar discography as well as recently described causes of false positive responses are presented.