Cervical Spine Computed Tomography Research Articles

Assessing potential spinal injury in the intubated multitrauma patient: does MRI add value?

The purpose of the study was to determine the role of magnetic resonance imaging (MRI) in intubated multitrauma patients with normal computed tomography (CT) in excluding unstable ligamentous injury to the cervical spine. A retrospective evaluation was done on those multitrauma patients admitted to the intensive care unit of a level 1 trauma centre who had normal single-slice helical CT cervical spine and underwent MRI for cervical spine clearance from 1/1/04 to 30/6/05. Fifty-five patients met the inclusion criteria. Ten of these patients had a discoligamentous injury identified on MRI; however, all these patients had injuries limited to only one of the three columns of the cervical spine. Single-slice helical CT with sagittal reformats had a negative predictive value of 82% for discoligamentous injury and 100% for unstable injury. A normal single-slice helical CT with sagittal reformats of the cervical spine in intubated trauma patients excluded unstable injuries at follow-up cervical spine MR imaging.

Computed Tomography Alone for Cervical Spine Clearance in the Unreliable Patient—Are We There Yet?

Injuries to the cervical spine (CS) occur in 2% to 6.6% of blunt trauma patients. Studies have suggested that computed tomography (CT) alone is sufficient for CS clearance in unreliable patients based on follow-up magnetic resonance (MR) imaging not altering management. We hypothesized that an admission cervical spine CT with no acute injury-using new CT technology-is not sufficient for CS clearance in an unreliable patient. The trauma registry was used to identify all patients with blunt trauma who had CS imaging with a CT and MR between August 2004 and December 2005. During this time period, a clinical guideline was in place whereby patients who had persistently unreliable examinations had MR despite a normal admission CT. Medical records were reviewed for demographics, Glasgow Coma Scale (GCS) score at time of MR, and injury specific data. Seven hundred thirty-four patients in total were identified. Two hundred three patients without obvious neurologic deficits but unreliable clinical examination, defined by a GCS score of </=14, had an initial cervical spine CT read by an attending trauma radiologist as having no acute injury. Mean age was 42.3 years (+/-20.4 years) and mean Injury Severity Score was 29.1 (+/-11.8). There were 135 (66.5%) men. Mechanism of injury included motor vehicle or motorcycle collision (48.8%), falls (25.4%), pedestrians struck (10.2%), assault (7.8%), and other (7.8%). One hundred eighty-four (90.6%) patients had a negative MR and collars were subsequently removed. After collar removal, no patient developed new neurologic deficit. Eighteen (8.9%) patients had an abnormal MR, 2 of which required operative repair and 14 required extended cervical collar use. Two patients had collars removed at the discretion of the attending surgeon. One patient had a suboptimal MR and was discharged in a collar with scheduled follow-up. Newer generation CT continues to miss CS injuries in unreliable patients. MR changed the management in 7.9% of patients having had an admission CT with no acute injury. Thus, we recommend continued use of MR for CS clearance in the unreliable patient and ongoing evaluation as the quality of CT imaging continues to evolve.

Increasing utilization of computed tomography in the pediatric emergency department, 2000–2006

The objective of this study is to characterize changes in computed tomography (CT) utilization in the pediatric emergency department (ED) over a 6-year period. CT scans ordered on pediatric (ages 0 to 17 years) ED patients from July 2000 to July 2006 were analyzed in five groups: head, cervical spine, chest, abdomen, and miscellaneous. Pediatric ED patient volume and triage acuity scores were determined. There were 6,073 CT scans performed on 4,138 pediatric patients in the ED during the study period. During this same period, 78,932 pediatric patients were evaluated in the ED. From 2000 to 2006, pediatric ED patient volume increased by 2%, while triage acuity remained stable. During this same period, head CT increased by 23%, cervical spine CT by 366%, chest CT by 435%, abdominal CT by 49%, and miscellaneous CT by 96%. Increases in CT utilization were most pronounced in adolescents ages 13 to 17 years. Increases in CT utilization in this age group met or exceeded increases seen in the adult population. In children less than 13 years of age, increases were substantially smaller. Pediatric ED CT utilization particularly in the adolescent population has increased at a rate far exceeding the growth in ED patient volume, mimicking the adult trend. This increase has occurred despite considerable discussion in the medical literature about the radiation risks of CT in the pediatric population and may reflect increased availability of CT, improvements in CT diagnostic capabilities, and increased desire on the part of physicians and patients for diagnostic certainty. Whether this increased utilization results in improved patient outcomes is uncertain and deserves further study.

CT analysis of the axis for transarticular screw fixation of rheumatoid atlantoaxial instability

To investigate the morphological characteristics of the axis of rheumatoid arthritis (RA) patients with atlantoaxial instability and to determine, by means of sagittal reconstructed computed tomography (CT), the suitability for atlantoaxial transarticular screw fixation. Twenty-seven patients, who had undergone reconstructed cervical spine CT scanning preoperatively and posterior atlantoaxial arthrodesis for atlantoaxial instability, were identified from a database for inclusion in this study. The isthmus height and internal height of the lateral mass of the axis were measured using digital imaging software. The mean isthmus height and internal height of the lateral mass of the axis in RA patients (n=14) were significantly lower than in non-RA patients (n=13) (P<0.01). A high-riding vertebral artery (VA) was present in 54% (15 joints, 9 patients) of the 28 atlantoaxial joints in the RA group and in 12% (3 joints, 2 patients) of the 26 atlantoaxial joints in the non-RA group (P<0.01). In RA patients, the axis showed more extensive thinning of the isthmus and lateral mass than in non-RA patients. A precise preoperative evaluation of screw trajectory using reconstruction CT imaging may be useful in atlantoaxial transarticular fixation, particularly for RA patients with atlantoaxial instability.

Increasing utilization of computed tomography in the adult emergency department, 2000–2005

This study aims to characterize changes in computed tomography (CT) utilization in the adult emergency department (ED) over a 5-year period. CT scans ordered on adult ED patients from July 2000 to July 2005 were analyzed in five groups: head, cervical spine, chest, abdomen, and miscellaneous. ED patient volume and triage acuity scores were determined. Triage acuity scores are used to determine the severity of a patient's illness or injury and the need for immediate evaluation and treatment. There were 46,553 CT scans performed on 27,625 adult patients in the ED during the study period. During this same period, 194,622 adult patients were evaluated in the ED. From 2000 to 2005, the adult emergency department patient volume increased by 13% while triage acuity remained stable. During this same period, head CT increased by 51%, cervical spine CT by 463%, chest CT by 226%, abdominal CT by 72%, and miscellaneous CT by 132%. Although increases were generally greater for patients over age 40, the increase in those less than 40 years was also substantial. Of the 4,320 individual patients who underwent chest CT, 83 (2%) had chest CT on three or more separate ED visits. Of 10,960 patients undergoing abdominal CT, 406 (4%) had abdominal CT on three or more separate ED visits. ED CT utilization has increased at a rate far exceeding the growth in ED patient volume. This presumably reflects the improved utility of CT in diagnosing serious pathology, its increased availability, and a desire on the part of physicians for diagnostic certainty. Whether this increase in utilization results in improved patient outcomes is at present unclear and deserves additional study.

Exclusion of unstable cervical spine injury in obtunded patients with blunt trauma: Is MR imaging needed when multi-detector row CT findings are normal?: Hogan GJ, Mirvis SE, Shanmuganathan K, et al. Radiology 2005;237:106–13

This retrospective study analyzed what additional information is gained from performing magnetic resonance (MR) imaging of the cervical spine in blunt trauma patients with unreliable examinations and normal computed tomography (CT) findings. Data were collected for 366 obtunded patients with normal cervical spine CT results who had MR studies done to exclude soft tissue injury. All abnormal MR reports were collected and the associated CT and MR images were subsequently reviewed by separate senior attending trauma radiologists.

Whole Body Imaging in Blunt Multisystem Trauma Patients Without Obvious Signs of Injury

The use of liberal whole body imaging (pan scan) in patients based on mechanism is warranted, even in evaluable patients with no obvious signs of chest or abdominal injury. Prospective observational study. Academic level I trauma center. All patients admitted following blunt multisystem trauma. Pan scan, including computed tomography (CT) of the head, cervical spine, chest, abdomen, and pelvis, with the following inclusion criteria: (1) no visible evidence of chest or abdominal injury, (2) hemodynamically stable, (3) normal abdominal examination results in a neurologically intact patient or unevaluable abdominal examination results secondary to a depressed level of consciousness, and (4) significant mechanisms of injury. Radiological findings and changes in treatment based on these findings were recorded. Any alteration in the normal treatment plan as a direct result of CT scan findings. These alterations include early hospital discharge, admission for observation, operative intervention, and additional diagnostic studies or interventions. One thousand patients underwent pan scan during the 18-month observation period, of which 592 were evaluable patients with no obvious signs of abdominal injury. Clinically significant abnormalities were found in 3.5% of head CT scans, 5.1% of cervical spine CT scans, 19.6% of chest CT scans, and 7.1% of abdominal CT scans. Overall treatment was changed in 18.9% of patients based on abnormal CT scan findings. The use of pan scan based on mechanism in awake, evaluable patients is warranted. Clinically significant abnormalities are not uncommon, resulting in a change in treatment in nearly 19% of patients.

Quantitative assessment of selective in-plane shielding of tissues in computed tomography through evaluation of absorbed dose and image quality

This study aimed at assessment of efficacy of selective in-plane shielding in adults by quantitative evaluation of the achieved dose reduction and image quality. Commercially available accessories for in-plane shielding of the eye lens, thyroid and breast, and an anthropomorphic phantom were used for the evaluation of absorbed dose and image quality. Organ dose and total energy imparted were assessed by means of a Monte Carlo technique taking into account tube voltage, tube current, and scanner type. Image quality was quantified as noise in soft tissue. Application of the lens shield reduced dose to the lens by 27% and to the brain by 1%. The thyroid shield reduced thyroid dose by 26%; the breast shield reduced dose to the breasts by 30% and to the lungs by 15%. Total energy imparted (unshielded/shielded) was 88/86 mJ for computed tomography (CT) brain, 64/60 mJ for CT cervical spine, and 289/260 mJ for CT chest scanning. An increase in image noise could be observed in the ranges were bismuth shielding was applied. The observed reduction of organ dose and total energy imparted could be achieved more efficiently by a reduction of tube current. The application of in-plane selective shielding is therefore discouraged.

Lowering the thyroid dose in screening examinations of the cervical spine

The first objective of this study was to test the hypothesis that a lower-dose (14.1 mGy thyroid dose) protocol for helical computed tomography (CT) of the entire cervical spine demonstrates equivalent technical adequacy and diagnostic accuracy as the standard-dose protocol (26.0 mGy thyroid dose) used at our institution. The second objective was to estimate the excess thyroid cancer mortality for three cervical spine screening protocols. Eight patients underwent two helical CT acquisitions of the entire cervical spine (standard and lower dose); from these acquisitions, a database of 128 randomized images (64 standard dose and 64 lower dose) was constructed. Three radiologists evaluated each of the 128 images for technical adequacy and, if the image was technically adequate, diagnostic accuracy. Historical data of excess thyroid cancer mortality stratified by age and sex were used to estimate the impact of lowering the thyroid dose in cervical spine screening. Estimates used a linear extrapolation of mortality data. The lower-dose protocol for helical CT of the entire cervical spine demonstrates equivalent technical adequacy and diagnostic accuracy as the standard protocol. The excess thyroid cancer mortality is a function of patient age and sex; for 25-year-old men, the excess mortality per 100,000 patients is 96.7 (standard-dose CT), 52.4 (lower-dose CT), and 6.7 (radiographs alone, 1.8 mGy thyroid dose). The equivalent technical adequacy and diagnostic accuracy of a lower-dose protocol for helical CT of the entire cervical spine support its implementation in routine screening. The excess thyroid mortality emphasizes the need to maintain an open dialogue with our referring clinicians with respect to the mechanism of injury, clinical findings, and radiation risks.

The Inefficiency of Plain Radiography to Evaluate the Cervical Spine After Blunt Trauma

Controversy persists regarding the most efficient and effective method of cervical spine evaluation after blunt trauma. Historic guidelines for patients undergoing computed tomography (CT) of the head advocate imaging the occiput-C2 as part of that study. For the remaining cervical spine, plain cervical spine radiographs (CSR) with supplemental CT are recommended. Many patients who require head CT also undergo supplemental cervical spine CT after plain CSR, which leads to separate, discontinuous cervical spine CT scans. We sought to determine the incidence of this in our population. We hypothesized that plain CSR alone often proves inadequate to evaluate the cervical spine in patients who require head CT. The Eastern Association for the Surgery of Trauma (EAST) guidelines for cervical spine evaluation after blunt trauma were previously adopted and followed during the study period from December 1, 2002 to July 1, 2003. Our protocol included cross-table lateral and anteroposterior CSR with the occiput-C2 imaged with the head CT. We used segmental cervical spine CT to supplement those regions inadequately visualized by plain films. The electronic charts of 848 consecutive blunt trauma victims were retrospectively reviewed. The data abstracted included demographics, injury severity score, and the use and results of head CT and radiographic evaluation of the cervical spine. Of 848 consecutive blunt trauma patients, 716 (84.4%) underwent head CT. Average age was 44 years old, and average Injury Severity Score was 9. Seventy-six patients (11.6%) had clinical cervical spine examination alone, whereas 640 (89.4%) underwent plain CSR. In 178 patients (27.8%), plain two-view CSR visualized the entire cervical spine. Plain CSR were inadequate to visualize the complete cervical spine in 462 patients (72.2%). Of these patients, segmental CT was performed in 400 (87.6%). The remaining 62 (13.4%) patients did not have radiologic completion of their cervical spine evaluation before clinical examination. Nineteen patients (3.0%) had cervical spine fractures diagnosed on CT, of which only 6 (31.6%) were seen on plain CSR. The sensitivity and specificity of CSR to detect fractures was 31.6 and 99.2%, respectively. Plain CSR are inadequate to fully evaluate the cervical spine after blunt trauma, and supplemental CT is commonly required. Complete cervical spine CT is available, efficient, and accurate. Our findings support a growing body of literature that suggests that this modality should be used for blunt trauma patients who require radiographic evaluation of the cervical spine. Plain cervical spine radiographs need not be obtained. The EAST guidelines for cervical spine evaluation after blunt trauma should be updated to reflect this evolving practice pattern.

Computed Tomography Versus Plain Radiography to Screen for Cervical Spine Injury: A Meta-Analysis

To compare the test performance of plain radiography and computed tomography (CT) in the detection of patients with cervical spine injuries following blunt traumatic events among those patients determined to require screening radiography. We conducted a MEDLINE search for articles published from January 1995 through June 2004, manually reviewed bibliographies, and hand searched four journals. Studies were included if they contained data on the performance of both plain radiography and CT in the detection of patients with blunt cervical spine injuries. Both authors screened titles and abstracts identified by the search and seven of the 712 articles met all inclusion criteria. Both authors independently abstracted data from these seven studies and disagreements were resolved by mutual agreement. Patient entry criteria were highly variable for each study and there were no randomized controlled trials. For identifying patients with cervical spine injury, the pooled sensitivity for cervical spine plain radiography was 52% (95% CI 47, 56%) and for CT was 98% (95% CI 96, 99%). The test for heterogeneity suggests that significant differences exist between studies in the measurement of the sensitivity for plain radiography (p = 0.07). Due to limitations of the gold standard tests in each study, a calculation of a combined specificity was not possible. Despite the absence of a randomized controlled trial, ample evidence exists that CT significantly outperforms plain radiography as a screening test for patients at very high risk of cervical spine injury and thus CT should be the initial screening test in those patients with a significantly depressed mental status. There is insufficient evidence to suggest that cervical spine CT should replace plain radiography as the initial screening test for less injured patients who are at low risk for cervical spine injury but still require a screening radiographic examination.

Fiberoptic Intracranial Pressure Monitoring during Magnetic Resonance Imaging

Fiberoptic Intracranial Pressure Monitoring during Magnetic Resonance Imaging

Overlooked metastatic lesions of the occipital condyle: a missed case treasure trove.

Radiologic images obtained in nine patients with known primary cancer and occipital or head and neck pain were retrospectively reviewed after having been initially interpreted as normal. Imaging studies included head computed tomography (CT) in five cases, brain magnetic resonance (MR) imaging in six cases, cervical spine CT and MR imaging in five cases, radiography in two cases, and scintigraphy in two cases. This reevaluation demonstrated lesions of the occipital condyles in all patients. Seven patients had unilateral occipital condyle masses, and two patients had bilateral condyle lesions. Lesions were found to either involve only the occipital condyle (n = 4), extend to the adjacent occipital bone (n = 3), or extend to the ipsilateral clivus (n = 2). Misinterpretation of radiologic examinations resulted in an average delay in diagnosis of 10 weeks from the onset of symptoms to definitive therapy (irradiation). It is important to evaluate the occipital condyles in all patients with occipital pain, especially those with cancer. Neoplastic disease involving the occipital condyles is not common; however, it is frequently missed at imaging. Careful review of unenhanced sagittal and axial T1-weighted MR images and of the inferior sections from axial head CT studies will make it possible to avoid this potential pitfall.

CT of the spine: Are plain spine radiographs necessary?

This study was designed to determine whether plain radiographs added any information of clinical significance to the information provided by CT (computed tomography) and its standard digital radiographs in 100 patients presenting for CT of the lumbar spine and 46 patients presenting for cervical spine CT. In only three (3%) of the lumbar studies and two (4.3%) of the cervical studies did the plain radiographs add diagnostic information. The added diagnostic information did not affect patient management in all cases with indications other than trauma. Good quality oblique cervical spine digital radiographs were obtained in 10 cases simply by moving the tube and detectors to the 45 degrees and 135 degrees azimuths. The evidence from this study suggests that when a CT examination of lumbar or cervical spines is planned on a high resolution CT scanner for indications other than trauma, a conventional plain radiographic examination can be omitted in the first instance.