Plain Film Imaging Research Articles

Comparison of Sagittal Computed Tomography and Plain Film Radiography in a Scaphoid Fracture Model

To compare computed tomography (CT) in the sagittal plane and plain film radiography in the diagnosis of scaphoid fracture and displacement. Three groups of scaphoids (no fracture, undisplaced fractures, fractures with displacement > 1 mm) from 11 cadaver wrists were prepared. Each wrist then was imaged by using sagittal plane CT scans in the long axis of the scaphoid and plain film imaging using 6 standard scaphoid views. Eight readers from 3 specialties read each group of images. The sensitivity and specificity for the presence of fracture and fracture displacement were calculated in addition to interobserver and intraobserver reliabilities for each. Both x-ray and CT scans showed a high sensitivity and specificity in detecting the presence of a fracture with no interspecialty differences. The sensitivity for displacement greater than 1 mm was lower for both modalities with no inter-specialty differences. The specificities for x-ray and CT for detecting displacement greater than 1 mm were 84% and 89%, respectively. The poor sensitivity for detecting displacement was explained by the low sensitivity of CT in the diagnosis of radial/ulnar displacement compared with x-ray and the low sensitivity of x-ray in the diagnosis of volar/dorsal displacement compared with CT scans. When fellowship-trained hand surgeons reviewed CT scans and plain films together the sensitivity and specificity for fracture displacement increased significantly. Intraobserver and interobserver reliability for both x-ray and CT scans was excellent except for the reading of CT scans among emergency physicians and for the reading of plain x-rays among senior house staff, representing moderate agreement. Based on these results both CT scans in the sagittal plane and plain films accurately detect fractures with a high degree of interobserver and intraobserver reliability, but they fall short in detecting displacement greater than 1 mm.

An investigation into the production of intra-articular gas bubbles and increase in joint space in the zygapophyseal joints of the cervical spine in asymptomatic subjects after spinal manipulation

Objectives To analyze the size and density of cervical zygapophyseal joint spaces in asymptomatic subjects using computed tomography (CT) and plain film radiography. The joint spaces were analyzed before manipulation without traction, before manipulation with manual traction, after manipulation without traction, and after manipulation with manual traction. The data obtained before the manipulation were compared with data obtained after the manipulation to determine if significant alterations occurred. Design Twenty-two asymptomatic subjects were placed into 1 or more of 6 possible experimental groups. In all experimental groups, except for experiment 1, the subjects underwent: (step 1) a premanipulation radiograph and/or CT scan, (step 2) a premanipulation plus traction radiograph and/or CT scan, (step 3) a postmanipulation radiograph and/or CT scan, and (step 4) a postmanipulation plus traction radiograph and/or CT scan. Results Except for experiment 2, there was no significant change in the width, area, and density values of the zygapophyseal joint spaces immediately after the manipulation in either the traction or traction-free positions of the neck, and no visible radiolucent cavities were demonstrated in any view. Conclusion No evidence of gas in the joint space or obvious increase in zygapophyseal joint space width immediately after the manipulation was found. This was evident in both the traction and traction-free postmanipulation scans and plain film images. This is not consistent with the current understanding of cavitation in joints, in particular, the refractory period.

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Vertebral height restoration after kyphoplasty

Purpose of study: Previous kyphoplasty studies have shown good results in acute and subacute fractures, with regard to restoration of height and pain relief. The purpose of our study was to evaluate the effectiveness of kyphoplasty in older fractures compared with recent fractures, specifically as regard to height restoration.Methods used: Kyphoplasty was performed in 131 fractured vertebra in 85 patients. Indications for surgery were painful pathologic compression fractures. All surgeries were performed by the primary author. Seventy-nine patients had general anesthesia, and six had local. The patients were evaluated preoperatively with plain film, computed tomography or magnetic resonance imaging and evaluated postoperatively with plain film. Vertebral body height was measured preoperatively by obtaining a ratio of the fractured vertebra to the next available intact vertebra. This ratio was then recalculated postoperatively, and any height increase was measured and expressed as a percentage. The patients were divided in four groups, those with acute fractures (less than 1 month), subacute (1 to 3 months), established (3 to 6 months) or chronic (greater than 6 months). Clinical results were evaluated by monitoring of pain medication usage and visual analog scale pain ratings by the patients.of findings: A total of 131 fractured vertebra were treated in 85 patients. The average age was 72 years. Seventy-nine patients had a diagnosis of primary or secondary osteoporosis, four had multiple myeloma and two had metastatic cancer. Twenty fractures were acute, 32 were subacute, 18 were established and 51 were chronic. One patient has postoperative pneumonia. Thirteen patients had asymptomatic extravasation of methylmethacrylate. The 20 acute fractures had average increase in height of 39%, the subacute group had an increase of 35.4%, the established group had an increase of 54.7% and the chronic group had an increase of 30.8%. Only the established group's increase was found to be statistically significant compared with the others. Ten patients preoperatively required high-dose narcotics (morphine). Eight of these were completely off pain medication after the surgery, and two others required low-level narcotics (propoxyphene). Seventy-five patients went from an average of seven pain pills a day to less than one a day. No differences were found in results among the four groups. Pain was related as an average of 9.1 before the surgery and decreased to an average of 1.2 after the surgery. No differences were found among the four groups with regard to pain relief.Relationship between findings and existing knowledge: Previous studies have found kyphoplasty to be a safe and effective procedure for both pain relief and height restoration, especially for fractures less than 3 months in duration. We have compared results in patients with acute (less than 1 month), subacute (1 to 3 months), established (3 to 6 months) and chronic (greater than 6 months) fractures. Our evaluation has shown that not only can pain relief occur in older fractures, but that height restoration is possible in older fractures as well.Overall significance of findings: Kyphoplasty is effective for pain relief and height restoration in even older fractures. These findings suggest age of a fracture alone is not a contraindication to kyphoplasty. Quality of the bone and healing status are parameters involved in height restoration that are independent of time. Kyphoplasty of older fractures should be considered if, based on the physical examination, they are symptomatic.Disclosures: Device or drug: Kyphon balloon. Status: approved. Device or drug: methylmethacrylate. Status: not approved.Conflict of interest: Vivek Kushwaha, speaker's bureau.

Clearing the Cervical Spine in Victims of Blunt Trauma

Cervical spine injuries occur in 2.3% to 6.4% of victims of blunt trauma. The difficulty of identifying the minority of patients with cervical spine injuries continues to challenge those who triage and treat the acutely injured. We retrospectively reviewed our practice for cervical spine clearance, which consists of three-view plain radiographs supplemented by focused further studies, such as computed or plain film tomography and flexion/extension views, as needed. Fifty-four patients with cervical spine injuries were identified during a 39-month period, which represented approximately 1% of the patients evaluated. Eighty cervical spine injuries were found, of which nine were missed. Review of the six patients in whom the nine cervical spine injuries were missed demonstrated error in the interpretation of radiographic studies in five patients, only two of whom were felt to have technically adequate films in hindsight. We conclude that a protocol based on three-view plain film radiographs supplemented by focused additional studies will allow the visualization of virtually all cervical spine injuries and that the main cause of missed injuries is errors of interpretation.

Clearing the Cervical Spine in Victims of Blunt Trauma

Cervical spine injuries occur in 2.3% to 6.4% of victims of blunt trauma. The difficulty of identifying the minority of patients with cervical spine injuries continues to challenge those who triage and treat the acutely injured. We retrospectively reviewed our practice for cervical spine clearance, which consists of three-view plain radiographs supplemented by focused further studies, such as computed or plain film tomography and flexion/extension views, as needed. Fifty-four patients with cervical spine injuries were identified during a 39-month period, which represented approximately 1% of the patients evaluated. Eighty cervical spine injuries were found, of which nine were missed. Review of the six patients in whom the nine cervical spine injuries were missed demonstrated error in the interpretation of radiographic studies in five patients, only two of whom were felt to have technically adequate films in hindsight. We conclude that a protocol based on three-view plain film radiographs supplemented by focused additional studies will allow the visualization of virtually all cervical spine injuries and that the main cause of missed injuries is errors of interpretation.

MR Findings of Ossifying Fibroma with Pathologic Correlation

Purpose: To compare the MR imaging findings of ossifying fibroma with the histopathologic findings. Materials and Methods: In eight patients (M:F=1:7; age range, 1-25 years) with pathologically proven ossifying fibroma, plain film and MR images were retrospectively analyzed in terms of signal intensity, homogeneity and patterns of contrast enhancement. The MR imaging findings and histopathology were correlated. Using 1.0-T and 1.5-T MR machines, axial T1 and T2 images and gadolinium-enhanced axial and sagittal T1 images were obtained. Results: In all cases, iso-signal intensity to muscle was observed on T1-weighted images, and high signal intensity on T2-weighted images. After intravenous injection of gadolinium-DTPA in seven cases, intense contrast enhancement was seen in all lesions, which were homogenous on T1, T2, and enhanced MR images. Moderate cellularity of fibrous tissue, with even distribution of osteoid and an absence of secondary changes such as hemorrhage or cystic change were revealed by pathologic examination. Conclusion: Ossifying fibroma shows strong enhancement and homogenous signal intensity on MR images.The homogeneity of the MR signal depends on the even distribution of osteoid and an absence of secondary changes such as hemorrhage or cystic change.

Use of plain radiography to screen for cervical spine injuries

Study Objective: Standard radiographic screening may fail to reveal any evidence of injury in some patients with spinal injury. The purposes of this investigation were to document the efficacy of standard radiographic views and to categorize the frequencies and types of injuries missed on plain radiographic screening of the cervical spine. Methods: All patients with blunt trauma selected for radiographic cervical spine imaging at 21 participating institutions underwent a standard 3-view series (cross-table lateral, anteroposterior, and odontoid views), as well as any other imaging deemed necessary by their physicians. Injuries detected with screening radiography were then compared with final injury status for each patient, as determined by review of all radiographic studies. Results: The study enrolled 34,069 patients with blunt trauma, including 818 patients (2.40% of all patients; 95% confidence interval [CI] 2.40% to 2.40%) having a total of 1,496 distinct cervical spine injuries. Plain radiographs revealed 932 injuries in 498 patients (1.46% of all patients; 95% CI 1.46% to 1.46%) but missed 564 injuries in 320 patients (0.94% of all patients; 95% CI 0.94% to 0.94%). The majority of missed injuries (436 injuries in 237 patients [representing 0.80% of all patients]; 95% CI 0.80% to 0.80%) occurred in cases in which plain radiographs were interpreted as abnormal (but not diagnostic of injury) or inadequate. However, 23 patients (0.07% of all patients; 95% CI 0.05% to 0.09%) had 35 injuries (including 3 potentially unstable injuries) that were not visualized on adequate plain film imaging. These patients represent 2.81% (95% CI 1.89% to 3.63%) of all injured patients with blunt trauma undergoing radiographic evaluation. Conclusion: Standard 3-view imaging provides reliable screening for most patients with blunt trauma. However, on rare occasions, such imaging may fail to detect significant unstable injuries. In addition, it is difficult to obtain adequate plain radiographic imaging in a substantial minority of patients. [Mower WR, Hoffman JR, Pollack CV Jr, Zucker MI, Browne BJ, Wolfson AB, for the NEXUS Group. Ann Emerg Med. July 2001;38:1-7.]

MR Imaging Findings of Intraosseous Lipoma

Purpose: To evaluate the MR imaging findings of intraosseous lipoma. Materials and Methods: The MR imaging findings of 12 cases of intraosseous lipoma were retrospectively analyzed with regard to internal signal intensity, enhancement patterns, the presence of calcification and the status of the margin. The findings relating to these last two features were compared with those of plain films and CT. Results: Six tumors were located in the calcaneus, three in the tibia, two in the ilium, and one in the carpal lunate. A fat component was clearly identified in all cases, but no lesion was purely fatty. Cyst formation was noted in four cases, and hyperintense portions different from the cystic area were seen on T2WI in ten. Contrast enhancement was observed in four patients, and although plain film and CT images revealed, in all cases, the presence of calcification, in two cases this was not demonstrated by MRI. In all cases, however, MRI showed well-defined tumoral margins. Conclusion: MRI clearly depicts fat and other components related to the involutional changes occurring in cases of intraosseous lipoma. The information these images provide is useful for the diagnosis and histologic classification of intraosseous lipoma.

Primary Non-Hodgkin's Bone Lymphoma in a Child: A Case Report

Non-Hodgkin’s bone lymphoma is rare, accounting for only 3-4% of all primary malignant bone tumors. The femur, tibia and humerus are most frequently affected. Most lesions are located in the medul-lary cavity of the diaphysis, or in the metaphysis adjacent to the diaphysis and the majority of patients are between 20 and 40 years old. Intermittent localized pain, dull and aching, and not relieved by rest, is present in almost all patients. Classically, the lesion begins in the bone marrow as a permeative or moth-eaten lytic process. The treat-ment of choice for primary non-Hodgkin ’s bone lymphoma is radiation therapy and adjuvant chemotherapy. The prognosis for this tumor is better than that for the majority of other primary malignant bone tumors, and the five-year survival rate is approximately 48%. We report a case of primary non-Hodgkin ’s bone lymphoma in a 9-year-old boy, describing the MR and plain film imaging findings.

Developing a clinical competency examination in radiology: Part I—Test structure

Background: There is a need for radiology educational outcome measures that evaluate clinical competency. This is the first of two articles introducing a clinical competency examination in radiology. This first article describes the evolution and structure of the examination. The second article presents the results of two administrations of the examination and evaluates possible outcome predictors. Objective: To develop a measure of clinical competency in radiology. Design: Descriptive. Methods: A test was developed to simulate the radiologic interpretive skills needed in clinical chiropractic practice. Students were timed as they responded to questions regarding the localization, categorization, management, and identification of pathologic conditions presented on plain film images of the spine and chest. Twenty-five radiographic cases were displayed at individual viewbox stations, and student responses to the 4 questions were compared with the consensus responses of 2 radiology instructors. Results: Two versions of the test, using different cases, were given to the same ninth trimester class of 210 chiropractic students in a 10-trimester program. Of the 210 students, 116 (55.2%; 86 men and 30 women) took version 1 of the examination, and 1 month later 181 (86.2%: 138 men and 43 women) took version 2 of the examination. Student comments after each examination were favorable. Conclusion: The test structure uniquely provides information related to the student's ability to localize, categorize, manage, and identify pathologic conditions on imaging studies. At present the examination is instructor time intensive; further refinement is needed before wide implementation can occur. (J Manipulative Physiol Ther 1999;22:57–62)

Scoliosis circa 2000: radiologic imaging perspective. II. Treatment and follow-up.

Plain film imaging remains important for the diagnosis and surveillance of scoliosis, as well as for the detection of complications after surgery. New means of treating scoliosis have become established and should be understood by the radiologist. To the well-known postoperative complications, including pneumothorax, pneumonia, and gastrointestinal obstruction, are added new specific potential problems with the new surgical methodology.

Scoliosis circa 2000: radiologic imaging perspective. I. Diagnosis and pretreatment evaluation.

Plain film imaging remains important for the diagnosis and surveillance of scoliosis, as well as for the detection of complications after surgery. Advances in CT and MR imaging have greatly improved the ability to detect or confirming non-idiopathic causes of scoliosis, including abnormalities within the spinal canal. Three-dimensional thinking has become more important in evaluating and understanding scoliosis.

Radiologic emergency management in multiple trauma cases

The management of multiple trauma patients has improved recently. Surgeons' education, preclinical rescue structures, initial clinical survey and therapeutic strategies, as well as diagnostic imaging, have progressed. Plain film imaging is increasingly being abandoned in favor of CT. Fast imaging techniques (spiral CT) have led to the inclusion of CT in the primary survey. To minimize the risk to the patient during prolonged diagnostic time, algorithms have to be defined concerning structures, emergency room equipment and quality. Basics, state of the art and suggestions concerning management of multiple trauma patients are presented and discussed from the radiologist's point of view.

Costs of plain-film radiography in a partially digitized radiology department. An activity-based cost analysis.

The aim of the study was to analyse the costs of computed radiography (CR) as part of a small picture archiving and communication system (mini-PACS), and to compare these costs with those of conventional analogue radiography using activity-based accounting (ABC). The study was conducted at the Central Hospital of Vaasa where in 1993 the Radiology Department acquired a mini-PACS with a CR reader, a chest CR unit, and a CT unit as digital image processing modalities. Of altogether 34140 plain-film examinations, 3/4 were made with CR and stored mostly on film, and 1/4 were made with conventional analogue radiography. The costs and activities of these two modes were analysed by means of the ABC method which identifies and allocates indirect costs in radiological procedures. The costs of CR imaging were 9% higher than those of conventional radiography. The costs of the chest CR unit were equal to those of conventional radiography. The difference was due to higher investment costs in digital image processing. The time gained from a reduction in the number of retakes did not shorten the time spent by patients in the examination room, and its effect on film costs was minimal. In planning the step-by-step transition of conventional film-based analogue radiography to fully digitized radiography, it should be noted that films are still used in the transition period and that this is associated with higher costs than in the previous system of conventional analogue plain-film imaging.

Using Tomography to Diagnose Occult Ankle Fractures

Study objectives: To determine the incidence of occult ankle fractures and to determine whether an ankle effusion identified radiographically correlated with the presence of an occult fracture. Methods: Attending physicians in the emergency department of a university hospital prospectively identified patients with acute ankle injuries that produced ecchymosis or edema over two or more major ligaments of the ankle. Plain radiographs of these patients demonstrated ankle effusions without fractures. A consecutive sample of patients with acute ankle injuries was selected. Thirty-six of 1,151 patients were eligible to enter the study; 2 of these patients subsequently were excluded from the data analysis. All eligible patients underwent plain ankle tomography at 3-mm intervals in the coronal and sagittal planes. The types and frequencies of occult ankle fractures identified on plain film tomography were noted. The distention of the ankle joint capsule of enrolled patients was measured to determine if the degree of effusion correlated with the presence of an occult fracture. Results: The minimum incidence of occult fractures in the general population with ankle injuries was 1%. Twelve of 34 patients (35%) with acute, severe injuries had occult fractures. Depending on the size, an effusion was correlated with the presence of an occult fracture in 35% to 85% of the study population. Conclusion: Plain film tomography should be used when evaluating ankle injuries if both edema or ecchymosis over two or more stabilizing ligaments and radiographic evidence of an effusion are present simultaneously. [Ho K, Connell DG, Janzen DL, Grunfeld A, Clark TIW: Using tomography to diagnose occult ankle fractures. Ann Emerg Med May 1996;27:600-605.]

Radiation exposure in paranasal sinus imaging

Plain films of the paranasal sinus were the imaging technique most frequently used before the advent of computed tomography. With improved resolution, computed tomography imaging has become the standard for evaluating patients with disease of the paranasal sinuses. With the widespread availability of computed tomography scanning, patients are likely to undergo multiple examinations during the treatment of their disease. Concern has been raised over the radiation exposure to the patient, in particular, with regard to radiation-induced cataracts. The purpose of this study is to measure the radiation dose associated with a variety of techniques for imaging the paranasal sinuses. A cadaveric specimen with thermoluminescent dosimeters placed over the orbits was used to measure radiation exposure during plain-film imaging, limited computed tomography, standard axial and coronal computed tomography, thin-cut axial computed tomography, and thin-cut coronal computed tomography. The measured dose in all these techniques is less than 4% of the acute dose associated with cataract formation. (OTOLARYNGOL HEAD NECK SURG 1995;112:248-51.)

Radiation exposure in paranasal sinus imaging

Plain films of the paranasal sinus were the imaging technique most frequently used before the advent of computed tomography. With improved resolution, computed tomography imaging has become the standard for evaluating patients with disease of the paranasal sinuses. With the widespread availability of computed tomography scanning, patients are likely to undergo multiple examinations during the treatment of their disease. Concern has been raised over the radiation exposure to the patient, in particular, with regard to radiation‐induced cataracts. The purpose of this study is to measure the radiation dose associated with a variety of techniques for imaging the paranasal sinuses. A cadaveric specimen with thermoluminescent dosimeters placed over the orbits was used to measure radiation exposure during plain‐film imaging, limited computed tomography, standard axial and coronal computed tomography, thin‐cut axial computed tomography, and thin‐cut coronal computed tomography. The measured dose in all these techniques is less than 4% of the acute dose associated with cataract formation.

Technetium-99m MDP Bone Scan and MRI Correlation in the Detection of Occult Bone Infarction

A 37-year-old female on prednisone therapy for inflammatory bowel disease had chronic focal knee pain bilaterally for several months. Plain film imaging results were normal. However, Tc-99m MDP bone scintigraphy obtained the same day revealed diffuse increased uptake of radionuclide within the distal femoral metaphases and knees bilaterally. Additional diffuse increased activity was seen in the left tibial plateau, with a second small focal area of activity within the proximal tibial diaphysis

Digital skeletal radiography.

Skeletal radiography accounts for a large proportion of the plain film images generated in most radiology departments, yet it has been underemphasized in the investigation of digital imaging technologies. Unique features of skeletal radiography provide a challenge in the evaluation and investigation of digital skeletal imaging. This review summarizes the results of ongoing research in digital skeletal radiography. Elementary concepts of digital imaging are reviewed to provide a foundation for discussion of nominal contrast and resolution requirements for clinically useful digital skeletal radiography. Methods of acquiring digital skeletal images are reviewed, and digital image display, image compression, and basic image processing techniques are discussed with emphasis on specific skeletal applications.