Cervical spine injury: accuracy of helical CT used as a screening technique

Objective: The study objective was to determine the sensitivity and specificity of a helical CT technique to screen for cervical spine injury in a high-risk trauma population. Materials and methods: The helical CT reports for a consecutive series of 601 high-risk adult blunt trauma victims were reviewed. Findings were confirmed using an independent reference standard, which consisted of additional cervical spine imaging (CT, MRI, or radiography), operative findings, autopsy results or clinical outcome. Results: Sensitivity and specificity of helical CT for injury were 77/81 (95 %; 95 % confidence limits: 90–100 %) and 484/520 (93 %; 95 % confidence limits 91–95 %) respectively. Four false negative cases were comprised of three missed ligamentous injuries and one missed fracture. False positive cases (n = 36) were mostly attributed to possible facet fracture (n = 6), possible ligamentous injury (n = 8) or technically inadequate scan (n = 6).The overall accuracy of the helical CT protocol for cervical spine injury in this population was 561/601 (93 %; 95 % confidence limits 91–95 %). Conclusion: Helical CT has high accuracy for cervical spine injury. We believe that helical CT should be the preferred imaging strategy in high-risk blunt trauma patients.     

Evaluation of various methods of intravenous contrast enhancement for thoraco-abdominal spiral CT scanning in trauma patients

The purpose of this study was to determine the optimal contrast concentration, volume, and injection rate for helical CT imaging of trauma patients requiring evaluation of the chest, abdomen, and pelvis. Two hundred forty patients were randomized into six different regimen groups for administration of iohexol nonionic intravenous contrast medium, each regimen containing 36 g iodine, with various injection rates, volumes, and concentrations of intravenous contrast enhancement. Parenchymal and vascular enhancement was objectively measured by obtaining pre- and post-contrast attenuation values of the thoracic and abdominal aorta, liver, and spleen, as well as post-contrast attenuation values of vascular enhancement of the portal vein and iliac artery. The contrast-enhanced images were subjectively reviewed by four radiologists blinded to the contrast administration techniques and objective evaluation results. It was found that while our ability to evaluate the abdominal organs was essentially equivalent with all six contrast administration regimens, our ability to evaluate the thoracic aorta was significantly better using 150 ml iohexol (Omnipaque 240) at 3 ml/s than with the other methods. Therefore, we recommend the use of 150 ml iohexol (Omnipaque 240) at 3 ml/s for combined chest and abdominal studies in patients with blunt trauma.     

Can chest and abdominal trauma CT eliminate the need for plain films of the spine? – Experience with 329 multiple trauma patients

Purpose: To compare the accuracy of spine plain films with chest and abdominal trauma CT in detection of spine fractures. Methods: The study prospectively enrolled 329 multiple trauma patients. Of these, 38 patients had both chest CT for trauma and thoracic spine plain films, and 87 patients had both abdominal CT for trauma and lumbar spine plain films. Results: Of the fractures visible at either chest trauma CT or thoracic spine plain film examination, all were diagnosed on CT and 62 % on plain films. Of fractures visible at either abdominal trauma CT or lumbar spine plain films, 94 % were diagnosed on CT and 67 % on plain films. The one false negative CT involved an articular process fracture, which was visible but not mentioned, in a patient with a sacral fracture. Conclusion: Evaluation of the digital scout images and bone windows when a patient has chest and abdominal trauma CT appears to be as accurate as thoracic and lumbar spine plain films in the evaluation of spinal trauma.     

CT scanning of children with blunt abdominal trauma – is oral contrast useful?

Purpose: To determine the usefulness of oral contrast in CT scanning of children with blunt abdominal trauma by comparing scans performed with and without oral contrast. Methods: CT scans of 273 children with abdominal trauma and 40 without trauma were reviewed. Results: Of the trauma patients, 116 (43 %) were scanned with oral contrast, 157 (57 %) without. Among the children who underwent laparotomy, CT scanning identified 6 of 6 organ injuries in those scanned with oral contrast and 11 of 12 in those scanned without. CT scanning identified all bowel injuries. The pancreatic body and tail were significantly better visualized in scans with oral contrast. Detection of pancreatic or liver injury was not, however, significantly different in the two groups. Opacification of the bowel by contrast was significantly better in elective than in trauma patients. Conclusion: There was no difference in detection of injuries between children scanned with and without oral contrast.     

Penetrating trauma to the abdominal aorta: CT demonstration of active bleeding

Contrast-enhanced helical computed tomography (CT) is the imaging study of choice for evaluating the abdomen in hemodynamically stable patients following blunt trauma. Surviving victims of penetrating trauma, in contrast, are often hemodynamically unstable and may require urgent celiotomy with or without diagnostic peritoneal lavage (DPL) or ultrasonography. Abdominal CT is not routinely performed in this patient population, but may be done if the patient with penetrating abdominal trauma is stable on admission or becomes so with resuscitation. CT in this context can address questions regarding the location and extent of injury and help decide appropriate management. We present a case of a stabilized blunt and penetrating trauma patient with negative DPL and active retroperitoneal aortic extravasation demonstrated by CT. To our knowledge, penetrating injury to the aorta with active bleeding has not been previously seen on CT.     

Blunt trauma in patients with pre-existing intra-abdominal lesions: CT diagnosis

This pictorial essay illustrates a variety of unsuspected diseases detected in blunt trauma patients who underwent helical CT for suspected abdominal injuries. Representative cases of benign and malignant diseases, congenital abnormalities, and other miscellaneous expansive intra-abdominal lesions were selected from the CT registry of a level I trauma center. The recognition of underlying disease is important for the management of trauma patients.     

The role of spiral CT vs plain films in acute cervical spine trauma: a comparative study

Purpose: To compare the diagnostic yield of conventional radiographs versus helical computed tomography (CT) in screening acute trauma patients. Methods: We reviewed 604 trauma patients who presented to our level I trauma emergency room and underwent both conventional radiography and spiral CT of the cervical spine of. Results: Of the 604 patients, 30 (5.13 %) had fractures seen on helical CT, only 10 of which were diagnosed on conventional radiography. Conclusion: In the screening of acute trauma patients, conventional radiography is less sensitive in detecting fractures than helical CT. CT should therefore be considered as a standard modality choice in such cases.     

Tracheal rupture caused by blunt chest trauma: radiological and clinical features

The aim of this study was to assess radiomorphologic and clinical features of tracheal rupture due to blunt chest trauma. From 1992 until 1998 the radiomorphologic and clinical key findings of all consecutive tracheal ruptures were retrospectively analyzed. The study included ten patients (7 men and 3 women; mean age 35 years); all had pneumothoraces which were persistent despite suction drainage. Seven patients developed a pneumomediastinum as well as a subcutaneous emphysema on conventional chest X-rays. In five patients, one major hint leading to the diagnosis was a cervical emphysema, discovered on the lateral cervical spine view. Contrast-media-enhanced thoracic CT was obtained in all ten cases and showed additional injuries (atelectasis n = 5; lung contusion n = 4; lung laceration n = 2; hematothorax n = 2 and hematomediastinum n = 4). The definite diagnosis of tracheal rupture was made by bronchoscopy, which was obtained in all patients. Tracheal rupture due to blunt chest trauma occurs rarely. Key findings were all provided by conventional chest X-ray. Tracheal rupture is suspected in front of a pneumothorax, a pneumomediastinum, or a subcutaneous emphysema on lateral cervical spine and chest films. Routine thoracic CT could also demonstrate these findings but could not confirm the definite diagnosis of an tracheal rupture except in one case; in the other 9 cases this was done by bronchoscopy. Thus, bronchoscopy should be mandatory in all suspicious cases of tracheal rupture and remains the gold standard. Received: 22 February 1999; Revision received: 29 June 1999; Accepted: 1 July 1999     

US in blunt abdominal trauma: need to be there 24 hours a day!

Purpose: To evaluate the utility of routine abdominal ultrasound (US) as first diagnostic imaging method 24 h a day in a series of patients admitted with blunt abdominal trauma to our level II trauma center. Methods: Two thousand four hundred and eleven consecutive patients admitted after blunt abdominal trauma over 12 months were prospectively evaluated using abdominal US. The examinations were performed within 25 min after admission. An experienced senior radiologist was available on site 24 h a day (including holidays) to perform all the US examinations. The US examination included a full abdominal exploration. The US results were compared to findings at computed tomography (n = 115), clinical follow-up (n = 2244), or surgery (n = 47). Results: Overall, 2411 US abdominal studies were performed. In 5/2411 (0.2 %) patients, the US examinations were incomplete or indeterminate because of patient obesity and were therefore excluded from the study. Of the remaining 2406 US studies, 265 (11 %) were performed between 0 and 6 a.m., 770 (32 %) were performed between 6 a.m. and 12 midday, 673 (28 %) were performed between 12 midday. and 6 p.m., and the remaining 698 (29 %) were performed between 6 and 12 p.m. At US, the following post-traumatic injuries were correctly detected: 67 splenic lesions, 62 liver injuries, 13 renal contusions, 2 bowel lacerations, and 1 pancreatic injury. Nineteen patients had a sonogram with negative findings followed by CT with positive findings, while 18 patients had a sonogram with positive findings followed by CT with negative findings. The following rates were calculated for the US studies: true negative = 2224; true positive = 145; false positive = 18; false negative = 19; sensitivity = 88.4 %; specificity = 99.2 %; diagnostic accuracy = 98.2 %; positive predictive index = 88.9 %; negative predictive index = 99.1 %. Conclusion: Abdominal US provides a highly accurate, noninvasive imaging evaluation in patients who have sustained blunt abdominal trauma. This can be obtained particularly if a team of senior radiologists can perform the examination to provide high quality sonograms and be on site 24 h a day.     

Multidetector CT of blunt traumatic venous injuries in the chest, abdomen, and pelvis

Venous injuries as a result of blunt trauma are rare. Even though current protocols for multidetector computed tomography (CT) of patients with trauma are designed to evaluate primarily the solid organs and arteries, blunt venous injuries may nevertheless be identified, or at least suspected, on the basis of the multidetector CT findings. Venous injuries are associated with high morbidity and mortality rates. Diagnosis of a possible venous injury is crucial because the physical findings of a venous injury are nonspecific and may be absent. This article aims to make the radiologist aware of various venous injuries caused by blunt trauma and to provide helpful hints to aid in the identification of venous injuries. Multidetector CT technology, in combination with interactive manipulation of the raw dataset, can be useful in the creation of multiplanar reconstructed images and in the identification of a venous injury caused by blunt trauma. Familiarity with direct and indirect signs of venous injuries, as well as with examples of blunt traumatic venous injuries in the chest, abdomen, and pelvis, will help in the diagnosis of these injuries.     

Occult and secondary injuries missed by plain radiography of the cervical spine in blunt trauma patients

Background: Plain radiography does not visualize every cervical spine injury sustained by blunt trauma victims. The purpose of this study was to examine the prevalence and types of injuries missed by plain radiographs of the cervical spine and determine how frequently such radiography fails to detect any cervical spine injury. Methods: Images from all radiographic studies performed on blunt trauma victims presenting to 21 participating institutions were reviewed to compile an exhaustive list of all CSIs sustained by each individual. These injuries were then compared with the injuries detected by plain radiography alone. Patients were classified as having a “sentinel” injury if one or more of their injuries were visible on plain radiographs. Patients were classified as having a radiographically “occult” injury if none of their injuries were visible on plain radiographs. The number and types of injuries missed on plain radiographs were then separately tabulated for the sentinel and occult injury groups. Results: Plain radiographs were completed in 570 of 818 victims of acute cervical spine injury and revealed 702 of 1,056 injuries. Plain films failed to detect 98 occult injuries present in 60 patients (10.5 %), and failed to detect 256 secondary injuries in 510 patients (89.5 %) who had a sentinel injury identified. Plain radiographs failed to reveal 79 of 136 (58.1 %) lateral mass injuries and 67 of 105 (63.8 %) lamina injuries, making these the most frequent sites of missed injury. Conclusions: Plain radiographs frequently fail to reveal injuries to the cervical spine, particularly those involving the lamina and lateral mass. The majority of the missed injuries represent secondary injuries in patients with a sentinel injury identified on these films. However, plain films fail to detect any injury in a minority of injured patients.     

Imaging of blunt chest trauma

In western European countries most blunt chest traumas are associated with motor vehicle and sport-related accidents. In Switzerland, 39 of 10,000 inhabitants were involved and severely injured in road accidents in 1998. Fifty two percent of them suffered from blunt chest trauma. According to the Swiss Federal Office of Statistics, traumas represented in men the fourth major cause of death (4 %) after cardiovascular disease (38 %), cancer (28 %), and respiratory disease (7 %) in 1998. The outcome of chest trauma patients is determined mainly by the severity of the lesions, the prompt appropriate treatment delivered on the scene of the accident, the time needed to transport the patient to a trauma center, and the immediate recognition of the lesions by a trained emergency team. Other determining factors include age as well as coexisting cardiac, pulmonary, and renal diseases. Our purpose was to review the wide spectrum of pathologies related to blunt chest trauma involving the chest wall, pleura, lungs, trachea and bronchi, aorta, aortic arch vessels, and diaphragm. A particular focus on the diagnostic impact of CT is demonstrated. Received: 29 November 1999; Accepted: 28 January 2000     

Value of multidetector computed tomography in assessing blunt multitrauma patients

PURPOSE: To find out if multidetector computed tomography (MDCT), using a dedicated trauma protocol, provides sufficient diagnostic information of the injuries of blunt multitrauma patients to enable the planning of treatment for all body compartments. MATERIAL AND METHODS: One-hundred-and-thirty-three patients exposed to high-energy trauma were referred and scanned with the standardized MDCT multitrauma protocol. The imaging protocol consisted of axial scanning of the head and helical scanning of the facial bones, cervical spine, thorax, abdomen, and pelvis. The scanning times were 12 s for the head, 19-21 s for the facial bones and cervical spine (1 mm collimation), and 32-50 s for the thorax, abdomen, and pelvis (2 mm collimation). One-hundred-and-forty milliliters of non-iodinated contrast material (300 mg I/ml) was administered intravenously at 3 ml/s. RESULTS: Ninety-nine of the patients (74%) had at least one finding consistent with trauma. The most frequent findings were in the thorax in 58 patients (44%). Nineteen false-negative findings and two false-positive findings were made. The overall sensitivity of MDCT was 94%, specificity 100%, and accuracy 97%. CONCLUSION: MDCT is accurate in the assessment of blunt multitrauma patients. The decision to treat the patient can be made on the basis of MDCT with a reasonable level of certainty.     

Screening for cervical spine trauma with helical CT: experience with 676 cases

Purpose: CT scanners with helical capability are commonplace. Evaluation of multiple trauma patients using this technique is fast, and easily performed as part of the radiological evaluation. Our purpose was to ascertain the clinical effectiveness of cervical spine screening with helical CT in a large sample population of multitrauma patients. Materials and methods: A retrospective review was carried out using screening helical CT scans from multitrauma patients referred to the Massachusetts General Hospital emergency department. The radiographic diagnosis was evaluated and tallied along with the clinical diagnosis and outcome for each patient included in the study. Results: Six hundred seventy-six patients conformed to the inclusion criteria. In this series, 59 true-positive, 616 true-negative, 1 false-negative, and no false-positive findings were encountered. These data result in a sensitivity of 98.3 %, a specificity of 100 %, and an accuracy of 99.9 %. Conclusions: Screening helical CT in the evaluation of trauma patients has a high diagnostic accuracy, and is sensitive and specific in diagnosing clinically relevant fractures of the cervical spine.     

Helical CT: a useful technique in the evaluation of aortic intramural hematoma

Purpose: To investigate the diagnostic role of helical CT in aortic intramural hematoma. Material and methods: We retrospectively evaluated CT images obtained during a 6-year period, between 1994 and 2000, in 427 patients who underwent helical CT. Only 21 patients had typical findings of aortic intramural hematoma. All studies were performed with helical technique before and after a power injection of nonionic contrast material. Results: Twenty-one patients had aortic wall thickening (9 type A and 12 type B in Stanford's classification). Wall thickening was more than 4 mm in all cases, it was irregular in shape in 16/21 patients (76 %) and had a regular concentric shape in the remaining 5/21 patients (24 %). One patient with type A hematoma died soon after CT diagnosis because of arrhythmia caused by hemopericardium. Five patients (4 type B and one type A) underwent pharmacological therapy and radiological follow-up. Fifteen patients (7 type A and 8 type B) underwent prosthetic surgery and six of these died of postoperative complications. Conclusion: Helical CT represents the first step in the early diagnosis of aortic intramural hematoma before complications develop. In our experience, which agrees with the reports of other authors, helical CT is an accurate and valuable investigation for identifying the location and extent of an aortic intramural hematoma.     

CT evaluation of pediatric abdominal trauma: pitfalls and quandaries

CT of the pediatric abdomen after blunt trauma has become a widely accepted technique for evaluation of hepatic and splenic injury. However, detection of hollow viscus and pancreatic injury remains challenging and controversial. Detection of bowel rupture (extravasated oral contrast, bowel discontinuity), pancreatic injury (laceration, separation of fragments) and bladder rupture may be difficult, particularly with inadequate technique and lack of vigilance. This article reviews findings associated with several injuries which may present diagnostic pitfalls as well as technical factors relating to the administration of enteric contrast and CT cystography.     

Traumatic aortic injury: an imaging review

Traumatic aortic injury (TAI) is a major cause of fatality in high speed deceleration injuries. It accounts for 10–20% of fatalities in blunt chest trauma. These injuries are usually related to high-speed motor vehicle and motorcycle collisions, pedestrian–motor vehicle collisions, and falls. Only 10–20% of patients who suffer TAI survive the initial injury and reach the emergency department. If left untreated, 30% die within 6 h, 40–50% die within 24 h, and 90% die within 4 months. A chronic pseudoaneurysm will develop in 2–5% of patients whose injury is not diagnosed. It is imperative, therefore, that these injuries are detected promptly and accurately. Symptoms and physical examination findings are nonspecific. External evidence of chest wall injury is present in 7–90% of cases, so that in up to 30% of the cases no apparent chest injury is identified on physical examination. Chest radiographs are very sensitive in detecting mediastinal hemorrhage, but have a low positive predictive value for aortic injury. The positive predictive value for chest radiography ranges between 5% and 20% for TAI. Aortography has been considered the gold standard for many years in the evaluation of TAI, but is time-consuming, labor- and resource-intensive, and invasive. Because of the shortcomings of physical examination and these more traditional imaging examinations, computed tomography (CT) has become increasingly utilized as a screening and diagnostic tool. Recent investigations have documented its high sensitivity and specificity in the detection of TAI. This article reviews the recent investigations of imaging evaluation of TAI, with a focus on helical CT. Electronic Publication     

Acute pulmonary embolism: visualization of high attenuation clot in the pulmonary artery on noncontrast helical chest CT

Helical CT of the thorax is frequently utilized for the evaluation of chest pain or shortness of breath affecting the emergency patient. To improve diagnostic accuracy, thoracic CT examinations are frequently tailored to address specific conditions. Although tailored protocols may enhance diagnostic accuracy, implementing the wrong protocol could result in a misdiagnosis. The proper protocol choice may particularly difficult in the emergency patient due to the nonspecific nature of many chest pain syndromes. Recently, helical CT has been used for the evaluation of suspected pulmonary embolism (PE). Demonstration of an intravascular filling defect surrounded by contrast-enhanced blood is diagnostic of PE. However, because the clinical presentation of PE is frequently nonspecific, awareness of the many potential imaging manifestations of PE is important. Therefore, we present the rare circumstance of high-attenuation clot visible within the pulmonary arteries on noncontrast helical CT; PE was confirmed after the administration of iodinated contrast medium.     

Helical computed tomography of liver injuries: A trial of dual phase imaging

This study was performed to evaluate whether consecutive arterial phase and portal venous phase scans of the upper abdomen are contributory in the evaluation of the liver in patients with blunt abdominal trauma. The purpose of the study was to determine whether such dual acquisition using helical computed tomography (HCT) provides improved definition of injuries and significant information about the dynamics of posttraumatic hemorrhage.During a 10-month period, all patients referred for evaluation of blunt abdominal trauma were scanned using a dual phase imaging technique. Two consecutive and comparable scan clusters were programmed to study the upper abdomen, with a slice collimation of 10 mm and a 11 pitch. Intravenous contrast medium was delivered at a rate of 2 ml/sec for a total of 125 ml, with scan delays of 30 and 70 seconds (arterial and venous phases of hepatic enhancement).Thirty-two patients with hepatic lacerations were encountered, and the images from both acquisitions were compared and graded according to lesion conspicuity. The presence of contrast medium extravasation associated with parenchymal injuries was also recorded.In 23 (72%) of the 32 patients, the liver injuries were better defined in the portal venous phase, and in eight (25%) patients, the lesions were equally shown in both phases. In only one case, the lesion was better demonstrated in the arterial phase. Contrast medium extravasation was noted in two patients at the site of liver laceration. In three additional cases, contrast medium extravasation was also noted in associated splenic injuries. In all of these patients, the extravasation (bleeding laceration) was seen only in the images corresponding to the portal venous phase.Dual phase HCT of the upper abdomen does not provide significant additional information in the evaluation of patients with liver injuries resulting from blunt abdominal trauma. With a single scan cluster through the upper abdomen after a 70-second injection-scan delay, lesion definition is optimal, and vascular opacification remains adequate.     

Helical computed tomography diagnosis of gastrointestinal perforation in the elderly patient

Purpose: To determine the value of helical CT in a consecutive series of elderly patients referred with clinically suspected gastrointestinal perforation. Methods: Our series comprised 34 consecutive elderly patients (mean age: 68 years) presenting with acute abdominal symptoms potentially suggestive of gastrointestinal perforation. All the patients were prospectively subjected to abdominal computed tomography (CT). On helical CT, the presence of free air was considered diagnostic of gastrointestinal perforation. Other findings such as intraperitoneal free fluid, thickening of bowel wall, streaky density within the mesentery, “dirty fat” sign, and focal collection of extraluminal fecal matter (“dirty mass”) were considered indirect findings of perforation. Results: At surgery, the following sites of perforation were found: duodenum (38.2 %), stomach (29.4 %), ileum (8.8 %), sigmoid colon (8.8 %), rectum (5.8 %), and jejunum, appendix, and transverse colon (2.9 % of cases each). CT demonstrated the presence of free air in 94.1 % of cases; intraperitoneal free fluid was present in 76.4 % of patients and thickening of bowel wall in 50 %. Streaky density within the mesentery was found in one patient. Conclusion: CT is a reliable diagnostic method by which to assess gastrointestinal perforation, because it provides excellent contrast resolution to depict the presence of even small amounts of free air in the abdomen. This is particularly helpful where elderly patients are concerned.