Blinded comparison of cranial CT and MR in closed head injury evaluation.

PURPOSETo compare CT and MR in the evaluation of acute head injury.METHODSOne hundred seven consecutive patients who were referred to the emergency department and underwent both MR and CT cranial examinations within 48 hours were retrospectively reviewed. The films were interpreted by two neuroradiologists blinded to all patient information.RESULTSThe sensitivity of MR was significantly higher than that of CT for the detection of contusion, shearing injury, subdural and epidural hematoma, and sinus involvement. The sensitivity of CT was significantly higher than that of MR for the evaluation of fracture. The sensitivities of MR and CT were statistically equivalent for the detection of superficial soft-tissue injury. The overall sensitivity of MR for the detection of abnormalities in acute head trauma was 96.4%, and for CT was 63.4%.CONCLUSIONSCT and MR are complementary studies in the evaluation of acute head trauma. MR is necessary to define or exclude contusions, deep shearing injury, and extraaxial fluid collections in acute head trauma.     

闭合性肾损伤的CT评价

目的:探讨闭合性肾损伤的CT表现及其临床应用价值。方法:回顾性分析经临床或手术证实的54例闭合性肾损伤的临床及CT资料。结果:肾挫伤8例,肾内血肿3例,肾撕裂伤11例,肾碎裂伤2例,肾盂输尿管连接处撕裂1例,肾被膜下血肿33例,肾周血肿15例。漏诊肾盂输尿管损伤1例。结论:CT可快速、准确地判断肾损伤的程度及范围,为临床制订治疗方案提供依据。     

CT and MR imaging of primary cerebrovascular complications in pediatric head trauma

The incidence of severe traumatic head injury in children has constantly increased over the last years. Diagnostic imaging has become an unrenounceable tool for the documentation and follow-up of intracranial lesions. The use of magnetic resonance imaging (MRI) in the early posttraumatic phase has led to a more thorough understanding of intracranial injuries. We retrospectively analyzed the cranial computed tomography (CCT) and magnetic resonance (MR)-studies of patients with traumatic head injuries for primary cerebrovascular complications. In 64 children (45 male, 19 female) with traumatic head injuries, CCT and MR examinations were available for analysis. The children's age ranged from 3 months to 15 years with a median age of 7 years. All patients had initial CCT on admission to the hospital with follow-up examinations depending on clinical state and initial imaging findings. All patients had at least one MR examination between 0 to 120 days after the trauma with a median time interval of 17 days. In five of 64 (7.8%) patients, cerebrovascular complications were found on imaging studies. Initial imaging within the first 24 h after the trauma detected a complete middle cerebral artery infarction in one patient and extensive sinus thrombosis after a complex skull fracture in another. In two patients, thrombosis of the transverse sinus appeared on MRI 4 to 6 days after the trauma. In another patient with open-skull injury, a posttraumatic aneurysm of the pericallosal artery was diagnosed on MRI 30 days after the trauma. Our study shows that, although primary cerebrovascular lesions after traumatic head injuries in children are rare, the radiologist should be aware of the characteristic injury patterns and the time appearance of imaging findings on CT and MRI.     

闭合性肾损伤的CT诊断

<正>随着工业、交通事业的迅速发展,肾损伤的发生率呈上升趋势。肾损伤的及时诊断和正确处理,对预后极为重要。CT在肾损伤的诊断过程中发挥着重要作用。现对我院收治的52例闭合性肾损伤患者的CT表现进行回顾性分析,以期进一步提高对本病的认识。     

MR imaging in the evaluation of trauma

Although computed tomography (CT) and radiographs are primary modalities in the evaluation of patients undergoing trauma, the indications for magnetic resonance (MR) imaging in trauma have grown. MR has been most useful in patients with central nervous system or musculoskeletal trauma. In head trauma, MRI is most useful in the evaluation of patients with neurologic deficit greater than that expected from CT findings. MRI is useful in such situations because of its improved sensitivity to nonhemorrhagic and microhemorrhagic lesions as well as posterior fossa pathology. In the spine, MRI provides detailed assessment of the disc space, spinal cord, and ligamentous structures; guiding therapeutic decisions; and offering prognostic information. In the musculoskeletal system, MRI offers a noninvasive means of imaging injuries to the muscles, tendons, ligaments, and cartilage of the knee, shoulder, ankle, and elbow. Additionally, MRI may define a subset of radiographically occult bony injuries.     

Focal amyloidosis of the head and neck: evaluation with CT and MR imaging

Localized amyloidosis of the head and neck was found retrospectively in the nasopharynx (n = 3) and orbit (n = 1) of four female patients (mean age, 32 years), three of whom had a prior history of antigenic stimulation. In all patients, computed tomography revealed a slightly high absorption and a relatively homogeneous, partially calcified mass. In the one patient who underwent magnetic resonance (MR) imaging, a distinctive loss of signal intensity was seen on the long repetition time/echo time sequence. This enhanced T2 relaxation may be due to (a) static or slowly fluctuating internal magnetic fields arising from adjacent amyloid protons held in relatively fixed positions within the beta-pleated sheet, resulting in quick phase dispersion; (b) chemical exchange and spin-spin interaction with adjacent water protons; and (c) diffusion through differences in diamagnetic susceptibility. This unusual appearance at MR imaging may improve the ability of radiologists to distinguish focal amyloidosis from many other diseases that affect the head and neck.     

Computed tomographic scan findings in closed head trauma

One hundred fifty closed head trauma patients are analyzed in relationship to clinical findings. Little additional data was supplied in patients with milder clinical presentations in more severe trauma, good correlation was generally obtained and computed tomographc (CT) scan eas extremely useful, ususlly eliminating the need for additional studies in the acutely traumatizes patient.     

CT and acute head trauma.

The value of CT in the management of 500 patients with head trauma is described. In these cases CT defined the effect of edema, contusion, subdural or epidural hematoma, or hydrocephalus.     

CT in the evaluation of spine trauma

Fifteen patients admitted for spine trauma in an 8 month period were studied with computed tomography (CT). All the patients had initial routine plain film screening, and 10 of 15 were also examined with conventional tomography. Five patients sustained vertical fall, axial-load injuries in the thoracolumbar junction region; two others suffered missile injury to the spine. CT provided more information than plain films in all these patients due to its superior imaging of bony detail and its ability to assess soft-tissue damage. In four of these patients, conventional tomography was done but contributed no additional information. Eight other patients sustained complex fractures of the cervical spine. In all but one, the combination of plain films and CT allowed complete evaluation of the injury. In one patient, conventional tomography showed an additional linear fracture one vertebral level below the main region of injury. Plain films and CT allow complete, safe, rapid, easily interpretable evaluation of spine trauma patients in the acute setting. Conventional tomography yields no additional clinically vital information in the acute evaluation of spine trauma, when plain films are abnormal. Its current ability to show finer bony detail than CT can be reserved for evaluating equivocal plain film and CT findings or more complete evaluation (if indicated) after the patient is clinically stable.     

Diffusion tensor MR imaging in pediatric head trauma

PURPOSE: We propose to investigate the fractional anisotropy (FA) values in pediatric patients with closed head trauma and correlate them with the initial Glasgow Coma Scale (GCS). MATERIALS AND METHODS: A retrospective evaluation of 24 pediatric patients (15 men, 9 women; mean age, 13 years; range, 2-18 years) who underwent both unenhanced head computed tomography and cerebral magnetic resonance imaging (MRI), including the tensor diffusion sequence, within 30 days of the incident. Twenty-two atraumatic control patients (9 men, 13 women; mean age, 9 years; range, 4-17 years) were randomly selected from the records of the radiology department within the same period. Fractional anisotropy measurements were taken from each of 6 major white matter volumes. Data extracted from the record of each subject included GCS, initial head computed tomographic results, and length of hospital stay. Kruskal-Wallis and t tests were used for statistical evaluation. RESULTS: The mean acute score on the GCS was 9.7 +/- 5. Mean duration of hospitalization days was 8.7 +/- 10. Statistically significant differences in mean FA values between trauma and control subjects were noted in corpus callosum. Trauma patients with positive findings on MRI and with GCS less than 10 also had lower FA values than patients with GCS greater than 10 and patients who had normal MRI findings. There was a negative correlation between time to discharge and FA values. CONCLUSIONS: In pediatric head trauma, MRI diffusion FA measurements can show abnormalities despite normal-appearing brain MRI findings. Larger investigations are required to verify the stability of correlations.     

Intraoperative evaluation of aneurysmal architecture: comparative study with transluminal images of 3D MR and CT angiograms

BACKGROUND AND PURPOSE: When exposure and visual access in aneurysmal microsurgery are limited, exact intraoperative information must be obtained regarding the whole shape of the aneurysm, property of the aneurysmal wall, vessels hidden behind the aneurysmal sac, and surrounding bony structures of the skull base. We developed a transluminal imaging technique that uses 3D MR and CT angiograms and applied it for intraoperative transparent evaluation of the angioarchitecture of cerebral aneurysms. METHODS: Transluminal images were reconstructed from a perspective volume-rendering algorithm by selecting information on the luminal margin from the whole volume data sets of MR and CT angiograms. The images show the vessel and aneurysmal walls as a series of rings and provide direct visualization of the underlying objects through the spaces between the rings. By connecting a graphic workstation to the operative microscope, data were reconstructed intraoperatively and adjusted to coincide with the operative views by manipulating the projection and visual angle. The aneurysmal angioarchitecture could then be evaluated transparently on the reconstructed transluminal images through the operative approach. RESULTS: Transluminal images provided direct transparent visualization of the aneurysmal architecture, including orifices at the neck, dome, and bleb and the parent arteries though the vessel and aneurysmal walls. The angioarchitecture of the neck complex was evaluated intraoperatively with transluminal 3D MR and CT angiograms through the operative approach before actual aneurysmal neck clipping. CONCLUSIONS: Intraoperative exact evaluation of aneurysmal angioarchitecture with transluminal images would be a feasible and useful adjunct for aneurysmal microsurgery. Merging of data across modalities including 3D MR and CT angiography may improve preoperative or intraoperative evaluation of the angioarchitecture of cerebral aneurysms.     

Longitudinal stress fractures of the tibia: comparative study of CT and MR imaging

The aim of this study was to compare the performance of CT and MRI in the diagnosis of longitudinal stress fracture of the tibia (LSFT). A retrospective study of imaging findings was performed in 15 patients with LSFT. The CT and MR images were compared for detection of fracture line, callus, bone marrow edema, and soft tissues changes. The CT and MRI techniques allowed the detection of the fracture line in 82 and 73 % of cases, respectively. The callus was always visualized with CT or MRI. The MRI technique had a markedly higher sensitivity than CT in the detection of bone marrow edema (73 vs 18 %) and soft tissue lesions (87 vs 9 %). This may cause a misleading aggressive appearance on MRI. Computed tomography remains the best imaging modality for diagnosis of LSFT. However, MRI findings should be known to obviate the performance of CT or bone biopsy. Received 26 May 1997; Revision received 1 October 1997; Accepted 13 November 1997     

MR imaging of brain contusions: a comparative study with CT

Ninety-eight brain contusions in 17 patients served as a data base for a comparative study of MR and CT for defining brain contusions. MR was the more sensitive technique, detecting 98% of the brain contusions compared with only 56% by CT. CT was slightly better for showing hemorrhagic components, documenting 77% of hemorrhages compared with 71% for MR. The appearance of the contusions on MR was variable, depending on the T1- and T2-weighting of the images and the constituents of the contusions, such as edema, hemorrhage, and encephalomalacia. On MR, hemorrhagic components appeared as high signal on T1-weighted images and as either low or high signal on T2-weighted images, depending on the age of the hemorrhage. The approximate ages of hemorrhagic contusions were often suggested by their appearance on T1- and T2-weighted images. CT is very effective for evaluating acute head trauma, but MR is recommended for documenting brain contusions during the subacute and chronic stages of head injuries.     

CT detection of occult pneumothorax in head trauma

A prospective evaluation for occult pneumothorax was performed in 25 consecutive patients with serious head trauma by combining a limited chest CT examination with the emergency head CT examination. Of 21 pneumothoraces present in 15 patients, 11 (52%) were found only by chest CT and were not identified clinically or by supine chest radiograph. Because of pending therapeutic measures, chest tubes were placed in nine of the 11 occult pneumothoraces, regardless of the volume. Chest CT proved itself as the most sensitive method for detection of occult pneumothorax, permitting early chest tube placement to prevent transition to a tension pneumothorax during subsequent mechanical ventilation or emergency surgery under general anesthesia.     

MR and CT in the evaluation of sarcoid myopathy

Sarcoid myopathy is a relatively rare extrapulmonary complication of sarcoidosis. We evaluated the diagnostic utility of MR at 1.5 T in four patients with sarcoid myopathy of the lower extremities established by biopsy. Two of the patients were of the "atrophic type" and two of the "nodular type." The findings on MR were compared with the findings on CT, gallium scanning, and electromyography. Only MR was positive in all cases. The T2-weighted scans (spin echo 2,000/80) revealed two distinctly different patterns of abnormality (i.e., discrete foci of high signal intensity lesions in the patients with the nodular type of sarcoid myopathy and atrophic muscle of high signal intensity in the patients with the atrophic type). Due to its ability to provide objective findings of the extent and distribution of muscle involvement, MR should prove useful in the detection, diagnosis, and monitoring of sarcoid myopathy.     

CT for acute stage of closed head injury

Brain damage after head injury can be classified by its time course. Primary damage that includes acute subdural hematoma (SDH), acute epidural hematoma (EDH), and intraaxial lesions that include contusions, diffuse axonal injury (DAI), and intracranial hemorrhage (ICH), occurs at the moment of impact and is thought to be irreversible. Secondary damage that includes herniations, diffuse cerebral swelling, and secondary infarction and hemorrhage, evolves hours or days after injury as a consequence of systemic or intracranial complications. The duration and severity of secondary damage influence outcome. Head injury management is focused on preventing, detecting, and correcting such secondary damage. CT has been widely used for the neuromonitoring of head trauma. CT is the gold standard for the detection of intracranial abnormalities and is a safe method for survey. While MRI is more sensitive and accurate in diagnosing cerebral pathology, CT is considered the most critical imaging technique for the management of closed head-injured patients in the acute stage. In this article, we review the imaging findings and literature of various lesions of closed head injury in the acute stage.     

Imaging findings in diffuse axonal injury after closed head trauma

Even in patients with closed head trauma, brain parenchyma can be severely injured due to disruption of axonal fibers by shearing forces during acceleration, deceleration, and rotation of the head. In this article we review the spectrum of imaging findings in patients with diffuse axonal injuries (DAI) after closed head trauma. Knowledge of the location and imaging characteristics of DAI is important to radiologists for detection and diagnosis. Common locations of DAI include: cerebral hemispheric gray-white matter interface and subcortical white matter, body and splenium of corpus callosum, basal ganglia, dorsolateral aspect of brainstem, and cerebellum. In the acute phase, CT may show punctate hemorrhages. The true extent of brain involvement is better appreciated with MR imaging, because both hemorrhagic and non-hemorrhagic lesions (gliotic scars) can be detected. The MR appearance of DAI lesions depends on several factors, including age of injury, presence of hemorrhage or blood-breakdown products (e. g., hemosiderin), and type of sequence used. Technical aspects in MR imaging of these patients are discussed. Non-hemorrhagic lesions can be detected with fluid attenuated inversion recovery (FLAIR), proton-density-, or T2-weighted images, whereas gradient echo sequences with long TE increase the visibility of old hemorrhagic lesions. Received 17 September 1997; Revision received 2 December 1997; Accepted 15 December 1997     

CT evaluation of hip trauma

Selection of treatment for fracture dislocations about the hip is based on the stability of the joint space, congruity of fracture fragments, the presence or absence of intraarticular fragments, and the overall condition of the patient. However, the condition of the acetabulum, femoral head, and joint space is frequently difficult to evaluate on conventional radiographs of the pelvis. To provide the orthopedist with more information on which to base treatment, 13 patients had computed tomography (CT) after accidents resulting in trauma to the hip and pelvis. The CT scan was believed to have significantly influenced the treatment in four of the patients and provided useful information in several others. CT was found to be helpful especially for evaluating presence or absence of intraarticular osseous loose fragments after reduction of the dislocated hip for evaluating congruity of the joint space after fractures of the femoral head and acetabulum. CT also provided useful information concerning the adjacent soft tissues and associated pelvic fractures.