Contrast-enhanced computed tomography scanning of the postoperative spine

A prospective study of contrast-enhanced computed tomography (CT) scanning was undertaken for 17 levels previously operated upon in the lumbosacral spine in 14 patients. All levels with prior operations were scanned before and after the administration of intravenous contrast medium. A standardized technique for contrast enhancement using high doses of intravenous contrast medium was employed and a specialized technique for measuring enhancement with corrections for scan artifacts was used. Results indicated that measurable contrast enhancement occurred in 16 of 17 postoperative scars up to 12 years after surgery. Enhanced scans provided more accurate delineation of the size and margins of postoperative scarring than precontrast scans. No instances of enhancement of normal disk or recurrent herniated disk were observed. In six instances recurrent herniated disks were predicted on the basis of contrast-enhanced CT scans and subsequently confirmed at reoperation. Contrast-enhanced CT scans meticulously performed appear to permit differentiation between scarring and disk herniation in patients with recurring symptoms after operations for lumbosacral disk disease.     

The height of the cricothyroid membrane on computed tomography scans in trauma patients

Emergency cricothyrotomy is a common feature in all difficult airway algorithms. It is the final step following a ‘can't intubate, can't oxygenate’ scenario. It is rarely performed and has a significant failure rate. There is variation in the reported size of the cricothyroid membrane, especially across population groups. Procedural failure may result from attempting to pass a device with too large an external diameter through the cricothyroid membrane. We aimed to determine the maximum height of the cricothyroid membrane in a UK trauma population. Electronic callipers were used to measure the maximum height of the cricothyroid membrane on 482 reformatted trauma computed tomography scans, 377 (78.2%) of which were in male patients. The mean (SD) height of the cricothyroid membrane, as independently measured by two radiologists, was 7.89 (2.21) mm and 7.88 (2.22) mm in male patients, and 6.00 (1.76) mm and 5.92 (1.71) mm in female patients. The presence of concurrent tracheal intubation or cervical spine immobilisation was found not to have a significant effect on cricothyroid membrane height. The cricothyroid membrane height in the study population was much smaller than that previously reported. Practitioners encountering patients who may require an emergency surgical airway should be aware of these data. Rescue airway equipment with variety of external diameters should be immediately available.     

Helical computed tomography alone compared with plain radiographs with adjunct computed tomography to evaluate the cervical spine after high-energy trauma

BACKGROUND: Current literature supports the use of the three-view plain-radiograph series supplemented, when necessary, with helical computed tomography to evaluate the cervical spine in patients who have sustained trauma injury. The purpose of this study was to determine if helical computed tomography alone can be used to evaluate the cervical spine for acute osseous injury following high-energy trauma, thus eliminating the need to make radiographs. METHODS: Patients were prospectively evaluated with helical computed tomography scanning of the cervical spine and standard three-view plain radiography. At a later date, the plain radiographs and computed tomography scans were independently reviewed by two radiologists who were blinded to both the initial interpretation and the interpretation of the corresponding study. The radiologists documented whether the plain radiographs were adequate and whether they showed an acute process. The findings in the study were compared with the initial findings and, when necessary, with the discharge summaries to determine if an injury had been identified. The accuracy of the plain radiographs, of the plain radiographs that had been deemed adequate, and of helical computed tomography used alone was ascertained. RESULTS: Plain radiographs and helical computed tomography scans were made for 407 patients, and traumatic injuries were identified in fifty-eight of them. Plain radiographs alone were adequate for 194 (48%) of the 407 patients. Plain radiographs had a sensitivity of 45%, a specificity of 97%, a positive predictive value of 74%, and a negative predictive value of 91%. Adequate plain radiographs had a sensitivity of 52%, a specificity of 98%, a positive predictive value of 81%, and a negative predictive value of 93%. Helical computed tomography had a sensitivity and specificity of 98%, a positive predictive value of 89%, and a negative predictive value of >99%. The sensitivity, positive predictive value, and negative predictive value of adequate plain radiographs differed significantly from those of helical computed tomography alone (p < 0.001). Twelve (48%) of twenty-five adequate plain radiographs of patients in whom an injury had been identified on computed tomography missed that injury. Helical computed tomography alone missed one (2%) of the fifty-eight injuries. CONCLUSIONS: Although helical computed tomography has a limited ability to detect pure ligamentous injury, it can be safely used without plain radiographs to evaluate the cervical spine for osseous abnormalities such as fractures and dislocations after high-energy trauma.     

The role of three-dimensional computed tomography in the management of maxillofacial trauma

Open reduction and internal fixation of facial fractures demand a detailed understanding of the three-dimensional pattern of injury. This is difficult if not impossible to obtain with present radiographic methods. The purpose of this study was to define the role of three-dimensional computerized tomography (3DCT) in surgical management of facial fractures. The two-part investigation: 1) compared the diagnostic accuracy of 3DCT with conventional CT and plain film studies; and 2) examined the clinical usefulness of 3DCT to surgeons. Twenty-four acute trauma patients suspected of having facial fractures were examined radiographically with analysis of every facial bone and specific facial regions. Particular attention was directed to the course of the fracture lines and the number, size, and displacement of fracture fragments. The surgeons were then asked to conceptualize the reported and the personally observed radiographic information and document their impressions on preprinted diagrams of the facial skeleton. They also completed questionnaires designed to indicate whether patient management would be influenced by the 3DCT. The radiographic findings were correlated with intraoperative observations. The 3DCT provided superior definition of fracture lines (especially horizontal) and the extent of comminution was better appreciated. This additional information improved the surgeons' ability to plan placement of interfragmentary wires and/or plates. Surgeons were also able to more accurately predict those patients requiring immediate bone grafting. Large, life-size 3D images of the facial skeleton made intraoperative conceptualization of the injury pattern easier. The accuracy of the 3DCT images corroborated the intraoperative findings in all cases. The following conclusions are offered: 1) The diagnosis of most mandibular fractures can be made equally well with conventional and 3DCT techniques. 2) Improved diagnosis of fracture lines and the specific patterns of comminution in midface fractures is made possible with 3DCT. 3) If open reduction and internal fixation is the mode of treatment, 3DCT is desirable because the added information makes preoperative planning more accurate and thereby facilitates surgical intervention.     

Primary computed tomography survey for major trauma

In this, the final leading article in the Journal's Trauma Series, Dr Otto Chan explains why primary survey by computed tomography should replace primary clinical survey. Copyright © 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.     

Helical computed tomography of renal lesions

Helical computed tomography is a new technique that acquires a volumetric data set of both kidneys within a single breath-hold. It has proved to be superior to conventional computed tomography. Multiphasic helical computed tomography after the administration of contrast material shows advantages concerning the detection and characterization of renal lesions and the preoperative staging of renal cell carcinomas. The proper scan protocol for a sufficient examination of the kidneys is described as well as its diagnostic value. The characteristic computed tomography morphology of benign and malignant renal lesions is reviewed and the advantages of helical computed tomography are illustrated.     

Indications for computed tomography in children with blunt abdominal trauma

This investigation was undertaken to identify clinical variables, alone or in combination, that could be used to assign children to high- and low-risk categories for intra-abdominal injury following blunt trauma. Six hundred consecutive children who were examined with computed tomography (CT) following blunt trauma were enrolled. Complete data sets were available on 375 children. Stepwise logistic regression was used to identify predictor variables for the presence of abdominal injury. There were 174 children with abdominal injury detected by CT. Of these, 95 were classified as having significant injury. Indicators associated with significantly higher risk of abdominal injury included the following: more than three clinical indications given (odds likelihood ratio [OLR] = 4.60, 95% confidence interval [95% Cl] = 2.29, 9.21, p less than 0.001); gross hematuria (OLR = 5.80, 95% Cl = 2.51, 13.4, p less than 0.001); lap belt injury (OLR = 12.2, 95% Cl = 2.22, 66.8, p less than 0.01); assault or abuse as the mechanism of injury (OLR = 5.08, 95% Cl = 1.07, 24.2, p less than 0.05); abdominal tenderness (OLR = 2.73, 95% Cl = 1.296, 5.82, p less than 0.01); and Trauma Score less than or equal to 12 (OLR = 2.27, 95% Cl = 1.006, 5.13, p less than 0.01). No child with asymptomatic hematuria (n = 56), regardless of grade or neurologic impairment in the absence of abdominal findings (n = 15), had an abnormal CT examination. These data are useful as an adjunct to clinical judgment in triage when the availability of CT equipment is limited or there are competing extra-abdominal injuries.     

The use of preoperative computed tomography scanning in total hip arthroplasty

Computed tomography (CT) scanning is a useful tool in many areas of orthopedics. This prospective study reviews the authors' experience with CT scans in 73 patients studied prior to total hip arthroplasty. The CT scan is valuable in the primary total hip arthroplasty if the radiograph suggests medial, posterior, or superior acetabular wall defects. In some instances, bone grafting or other special procedures are required for the reconstruction of these defects. In the present study, preoperative CT identified an abnormality in 18 cases with deficient acetabular walls, while plain radiographs identified only six of these difficulties. Although important information for planning revision total hip arthroplasties was noted in this series, CT scans are indicated primarily in instances of suspected acetabular wall defects.     

The role of computed tomography in blunt abdominal trauma in children

This study was performed in order to test the hypothesis that abdominal computed tomography (CT) can assist in the decision to perform laparotomy in children following blunt trauma to the abdomen. Three hundred forty children with blunt abdominal trauma underwent evaluation with CT. Abdominal injuries were detected in 84 children (25%). These included: 75 injuries to solid viscera in 60 patients (30 splenic, 29 hepatic, 13 renal, and three pancreatic); four injuries to hollow viscera (three small bowel transections, and one rupture of the urinary bladder); and 23 skeletal injuries (21 fractures of the pelvis, and two lumbar spine subluxations). Injury to solid viscera was categorized as minor in 32 (43%), moderate in 18 (24%), or severe in 25 (33%) according to an assessment of the percentage of parenchyma involved. Hemoperitoneum was detected in 42 patients, and characterized as small in 18 (43%), moderate in nine (21%), and large in 15 (36%). CT was useful in establishing the location and extent of injuries, and in detecting the presence of blood or air in the peritoneal cavity. However, the extent of injury to solid viscera detected on CT did not correlate with the need for laparotomy. Of 46 moderate to severe anatomic injuries of the liver, spleen or kidney, only five (9%) required surgical intervention because of persistent bleeding or infection. Although laparotomy occurred more frequently in the presence of a large hemoperitoneum, only 6/24 (25%) with moderate to large hemoperitoneum required surgical exploration. This analysis confirms the usefulness of CT for detection of location and extent of injury in pediatric blunt abdominal trauma.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiac echinococcosis: the diagnostic value of computed tomography scanning

The diagnosis of cardiac hydatid disease is a difficult one. Conventional and specific cardiac investigations are not pathognomonic of this disease. In this report, the diagnostic value of computed tomography (CT) scanning was prospectively investigated in seven patients. In five patients, the diagnosis was confirmed surgically. The CT-information obtained correlated accurately to the operative findings. In all the patients, CT-densities of the lesions were measured and were found to coincide with values of mean CT-densities of hydatid cysts elsewhere in the body. The capability of measuring tissue densities is unique to CT-scanning and have been emphasized in this report.     

Cerebellar abscess: the impact of computed tomographic scanning

Thirty-four cases of cerebellar abscess, diagnosed by computed tomographic (CT) scanning, were managed according to a standard protocol during a 4-year period. Triple high dosage intravenous antibiotics were used, open catheter drainage of the abscess was instituted, and external ventricular drainage was added if obvious hydrocephalus was present. Seventeen patients made a good recovery, and five remained minimally disabled. Ten patients died, and two were left severely disabled. A relationship between the level of consciousness on admission and final outcome was established. In addition, two particular CT scan features (viz. the presence of hydrocephalus and the stage of the abscess) were significant adverse prognostic factors.