Root fracture detection: a comparison of direct digital radiography with conventional radiography

OBJECTIVES: To compare the diagnostic potential of direct digital radiography with conventional film for detecting experimental root fractures. METHODS: Two hundred and one extracted single-rooted human teeth were endodontically instrumented and divided into two groups, a control group of 100 teeth and a fractured group of 101 teeth in which root fractures were produced experimentally. Each tooth was imaged using the paralleling technique with a CCD-based digital system and D-speed film. The images were interpreted by an experienced radiologist without prior knowledge of the distribution of the root fractures. The degree of agreement in detecting root fractures with each imaging system compared with the actual condition was expressed as the kappa value. The difference between the radiographic systems was then assessed by chi(2)-test at the 95% significance level. RESULTS: There was substantial agreement between the digital system and the actual condition (kappa=0.71; 95% Confidence Interval: 0.62 to 0.80) and close agreement between the film and the actual condition (kappa=0.63; 95% Confidence Interval: 0.53 to 0.74). However, this difference was not significantly different (P=0.2). CONCLUSIONS: The performance of CCD-based digital radiography in detecting root fractures is similar to film-based radiography.     

Impact of postprocessing on the detection of simulated pulmonary nodules with digital radiography

The authors compared the impact of five postprocessing algorithms on diagnostic performance in the detection of simulated pulmonary nodules on storage phosphor-based digital chest radiographs. Tissue equivalent paraffin nodules (0.5-2.5 cm diameter) were randomly positioned over the chest of a normal volunteer. Receiver operating characteristics (ROC) analysis of a total of 2500 observations by five readers indicated that the default unenhanced image having the appearance of a conventional chest radiograph (ROC area = 0.87 +/- 0.05) was as good as an image with moderate enhancement of medium frequencies (ROC area = 0.85 +/- 0.03), an image with reversed gray scale polarity (ROC area = 0.84 +/- 0.02), an image with reversed gray scale and moderate enhancement of medium frequencies (ROC area = 0.87 +/- 0.03), and an image with a linear rather than a sigmoid gradation curve and incorporating moderate enhancement of medium frequencies (ROC area = 0.87 +/- 0.03). The authors conclude that the specific algorithms they tested had no effect on the detection of pulmonary nodules.     

Impact of clinical history on radiographic detection of fractures: a comparison of radiologists and orthopedists

Are the methods used by radiologists in interpreting imaging studies different from those of attending physicians? We evaluated the influence that knowledge of localizing clinical signs has on the accuracy of fracture detection by orthopedic surgeons and compared the results with those of an identical study of radiologists performed earlier. The orthopedists studied had the same degree of experience as the radiologists. Forty radiographs of the extremities were examined twice by seven orthopedic surgeons. In 26 cases, a subtle fracture was present; 14 cases were normal. During one interpretation of the radiographs of each case, the precise location of pain, tenderness, or swelling was provided; during the other, this information was withheld. Analysis of receiver-operating-characteristic parameters indicates that the clues regarding location of trauma facilitate detection of fractures by orthopedists (an 11% improvement in Az, the area under the ROC curve, F[1,12] = 49.67, p less than .001). This finding is similar to the results of the earlier study with radiologists (a 6% improvement in Az, F[1,12] = 14.77, p less than .005). Statistical comparison of the two experiments showed that orthopedists depend on this information much more than do radiologists, demonstrated by a statistically significant prompting-by-specialty interaction (F[1,12] = 5.13, p less than .05). Localization clues improve ability of orthopedic surgeons to detect fractures in the trauma patient even more than they improve the ability of radiologists. The accuracy of the radiologist will suffer less than that of the orthopedist when localization clues are unavailable. Nonetheless, the findings show that localizing clues are important to both orthopedists and radiologists when searching for fractures.     

Specialism in radiography – a contemporary history of diagnostic radiography

Aim and methodSpecialism is relative comparing the unusual to a norm. Origins of radiographers' perceptions of what is a specialism are identified. Semi-structured interviews were conducted with 21 practitioners and 10 leading voices whose combined practice span 1932–2001.FindingsFindings show that the exclusive nature of practice is influential on what is perceived as a specialism. Radiographers held career aspirations that included greater recognition, clinical involvement, autonomy and challenging work. Career aspirations were clinical rather than managerial and extended across modality boundaries. A key barrier to career progression was inequality of opportunity as local medical career requirements were dominant. Characteristics of specialism of diagnostic radiography are identified. Factors influencing the formation of specialism are also identified.SummarySpecialisation was dominant but not necessarily constructive to career progression or additional autonomy. Specialism relates to new areas of practice and is facilitated by service need, clear practice boundaries, visionary management, medical support, role development leading to increased autonomy and additional training and education.     

Impact of clinical data on chest radiography sensitivity in detecting pulmonary abnormalities in immunocompromised patients with suspected pneumonia

Purpose

Chest radiography (CXR) of immunocompromised patients has low sensitivity in the early evaluation of pulmonary abnormalities suspected to be infectious. The purpose of the study was to evaluate whether the knowledge of clinical data improves the diagnostic sensitivity of CXR in the particular setting of immunocompromised patients after hematopoietic stem cell transplantation (HSCT).

Materials and methods

Sixty-four CXRs of immunocompromised patients with clinically suspected pneumonia were retrospectively and independently evaluated by two radiologists to assess the presence of radiological signs of pneumonia, before (first reading) and after (second reading) the knowledge of clinical data. A chest computed tomography (CT) performed within 3 days was assumed as the standard of reference. For each reading, sensitivity of both radiologists was calculated.

Results

Readers showed a sensitivity of 39% and 58.5% for the first reading, and 43.9% and 41.5% for the second reading, respectively. For both readers, these values were not significantly different from those obtained at first reading (McNemar’s test, p>0.05). Interobserver agreement at second reading was fair (Cohen test, k=0.33).

Conclusions

The sensitivity of CXR is too low to consider it a stand-alone technique for the evaluation of immunocompromised patients after HSCT with suspected pneumonia, even if the radiologist knows detailed clinical data. For these patients, an early chest CT evaluation is therefore recommended.     

Small bowel phytobezoars: detection with radiography

The authors reviewed the radiographic findings in 19 patients with phytobezoars of the small bowel. The most common predisposing causes were previous gastric outlet surgery and persimmon ingestion. Twelve patients underwent contrast material-enhanced studies of the upper gastrointestinal tract, and one patient underwent a barium enema study. These examinations revealed four gastric, two duodenal, and eight small bowel phytobezoars in 10 patients. The obstruction caused by small bowel phytobezoars frequently occurred in the jejunum or proximal ileum, more proximally than has been reported in previous series. Barium studies are useful in differentiating obstruction due to postoperative adhesions from obstruction caused by bezoars. In addition, barium studies enable the detection of residual gastric bezoars. This information has important implications in patient treatment because bezoar obstruction is unlikely to respond to conservative treatment, and concurrent gastric bezoars must be removed to prevent recurrent bowel obstruction.     

Sonography compared with radiography in revealing acute rib fracture

OBJECTIVE: This study was undertaken to compare the sensitivities of sonography and radiography for revealing acute rib fracture. SUBJECTS AND METHODS: Chest radiography and rib sonography were performed on 50 patients with suspected rib fractures. Sonography was performed with a 9- or 12-MHz linear transducer. Fractures were identified by a disruption of the anterior margin of the rib, costochondral junction, or costal cartilage. The incidence, location, and degree of displacement of fractures revealed by radiography and sonography were compared. Sonography was performed again after 3 weeks in 37 subjects. RESULTS: At presentation, radiographs revealed eight rib fractures in six (12%) of 50 patients and sonography revealed 83 rib fractures in 39 (78%) of 50 patients. Seventy-four (89%) of the 83 sonographically detected fractures were located in the rib, four (5%) were located at the costochondral junction, and five (6%) in the costal cartilage. Repeated sonography after 3 weeks showed evidence of healing in all reexamined fractures. Combining sonography at presentation and after 3 weeks, 88% of subjects had sustained a fracture. CONCLUSION: Sonography reveals more fractures than does radiography and will reveal fractures in most patients presenting with suspected rib fracture. Further scientific studies are needed to clarify the appropriate role for sonography in rib fracture detection.     

Improved chest disease detection with scanning equalization radiography

The efficacy of chest disease detection with scanning equalization radiography (SER) was evaluated in a clinical study of 95 patients: 51 normals and 44 with abnormal chest radiographs. A conventional and an SER image of each patient were interpreted independently by four radiologists. The increased numbers of true positives (3%) and true negatives (9%) when the SER images were interpreted were statistically significant. There was also a reduced number of false positives (7%) with SER. This improved disease detection was noted by each of the radiologists and led to more frequent agreement (11%) of the correct interpretation among the radiologists.     

Aortopulmonary window lesions: detection with chest radiography

A retrospective morphologic study of 80 cases was undertaken to determine factors affecting detectability of computed tomographically (CT) proved aortopulmonary (AP) window lesions on conventional posteroanterior (PA) and lateral chest radiographs. Criteria used for determining abnormality were: solitary lymph node enlargement over 1.5 cm or three or more 1-cm nodes and obvious large masses or vascular anomalies. CT scans and corresponding PA and lateral radiographs were analyzed for lesion detectability, size, and location. In 49% of cases there was no detectable lesion in the AP window on radiographs; a definite AP window lesion was seen in 41%, and 10% were equivocal. Major contributing factors to low detectability of AP window lesions on radiographs include size and, more important, location of the lesion. An additional 45 cases of CT-proved normal AP windows were retrospectively reviewed to determine the false-positive rate of PA and lateral radiographs in detection of AP window lesions: 43 (96%) were classified as negative, the remaining two (4%) as equivocal. Although the AP window is a small space, it is the site of many pathologic conditions; the study results indicate that CT may be an essential procedure for its evaluation.     

Improved pulmonary nodule detection with scanning equalization radiography

The potential for improved pulmonary nodule detection with scanning equalization radiography (SER) was evaluated by means of observer performance testing during the interpretation of posteroanterior conventional radiographs and SER images of an anthropomorphic chest phantom with simulated nodules. A test set of 200 conventional and 200 SER radiographs of phantoms containing either one nodule or none was interpreted by four radiologists attempting to detect a nodule and indicate a confidence value. Their ability to detect nodules positioned over the lung was slightly improved with SER compared with conventional radiography (sensitivity, .56 vs .70); for nodules over the mediastinum or diaphragmatic areas, it was much improved (sensitivity, .29 vs .64). The results were also analyzed with receiver-operating characteristic methods, which revealed a significant improvement in lesion detect-ability over the thicker body parts with SER images. The capability of equalized chest radiographs to provide improved lesion detectability suggests that SER may set a new standard for film-based chest radiography and have a large clinical application.     

Haemorrhage in intracerebral arteriovenous malformations: detection with MRI and comparison with clinical history

Fifty-one patients with 59 angiographically proven cerebral arteriovenous malformations (AVMs) were examinded by high-field MRI to detect blood breakdown products. Results were correlated with the history of intracranial bleeding. Evidence of previous episodes of haemorrhage was seen in 10 of 12 patients (83.3%) with verified bleeding, in 4 of 9 patients (44.4%) with symptoms which could suggest bleeding and in 6 of 30 patients (20%) with negative histories. Because of the known rebleeding rate and the increased risk of associated complications, identification of the subgroup who had had haemorrhage and should therefore be considered for surgery may be beneficial. MRI can make a contribution to management by demonstrating prior haemorrhage in patients with an inadequate clinical history.     

High clinical utility of computed tomography compared to radiography in elderly patients with occult hip fracture after low-energy trauma

To evaluate the clinical utility of computed tomography (CT) compared to radiography in evaluating suspect or missed hip fractures in elderly after low-energy trauma. One hundred ninety-three hip CT examinations performed in two trauma centers during 3 years of evaluation of clinically suspect or occult hip fracture within 24 h of negative or suspect radiography were retrospectively reviewed. Consensus CT diagnosis by three observers was compared to clinical outcome and in some cases also further imaging. All patients were elderly and had sustained a low-energy trauma. Eighty-four examinations revealed no fracture. Follow-up was uneventful but for two patients who had been operated. Thirty-nine of 41 cervical hip fractures were surgically or otherwise confirmed, two cases were not operated due to week-old trauma and moderate symptoms. Twenty-nine of 68 trochanteric fractures or avulsions were confirmed surgically. Computed tomography has a high clinical utility as it can detect nearly all clinically suspect but radiographically negative cervical hip fractures as well as most trochanteric fractures and avulsions. A negative CT is near-perfect in ruling out a hip fracture requiring surgery.     

The history of humanism in the radiography essentials

The need to emphasize humanism in medical and allied health curricula has become an issue in recent years because of the tremendous increase in technology. This article investigates the history of humanism in the radiography curriculum by reviewing the historical progression of the Essentials and Guidelines of an Accredited Program for the Radiographer.     

Impact of sonography in gouty arthritis: comparison with conventional radiography, clinical examination, and laboratory findings

OBJECTIVE: To explore the typical sonographic features of gray-scale and Power Doppler of acute and chronic gouty arthritis in conjunction with radiographic, clinical, and laboratory findings. MATERIALS AND METHODS: All hand, finger, and toe joints of 19 patients with acute and chronic gout were examined with gray-scale and Power Doppler sonography. The number and size of bone changes detected with sonography was compared to radiographic findings. Vascularization of the synovial tissue was scored on Power Doppler (grades 0-3), and was compared with clinical appearance, including swelling, tenderness, and redness (grades 0-3). RESULTS: In acute gout, mild to moderate echogenic periarticular nodules with sonotransmission and hypervascularization of the edematous surrounding soft tissue were found. In chronic gout, tophaceous nodules completely blocked transmission of US wave, leading to strong reflexion and dorsal shadowing in a minority of cases. No significant difference in the detection of large bone changes (>2mm) was found between sonography and radiography. However, gray-scale sonography was significantly more sensitive in the detection of small bone changes (p<0.001). Power Doppler scores were statistically significantly higher than clinical examination scores (p<0.001). DISCUSSION: Sonography is superior to radiographs in evaluating small bone changes. The inflammatory process in joints can be better detected with Power Doppler sonography than with clinical examination. Typical sonographic appearance of acute and in particular of chronic gout might provide clues on gouty arthritis that adds to the information available from conventional radiography, clinical, and laboratory findings.     

Mediastinal abnormalities: detection with storage phosphor digital radiography

Conventional film radiography (FR) and six postprocessing algorithms of isodose storage phosphor digital radiography (SR) (0.2-mm X 10-bit pixel matrix) were compared in the evaluation of 40 mediastinal and 30 pulmonary lesions in 60 patients who underwent computed tomography of the chest. The six SR algorithms varied among each other in only one image parameter. One algorithm approximated conventional image characteristics. The other five algorithms were designed to optimize imaging of the mediastinum and tested the effects of gray-scale reversal, adjustment of optical density, a linear instead of a sigmoid gradation curve, and moderate edge enhancement of high and medium spatial frequencies. Performance was evaluated by calculating the average area under the receiver operating characteristic curve (Az) of 5,040 observations by six readers. Post-processing with high-frequency edge enhancement and density optimization for the mediastinum significantly improved performance of SR over FR in the detection of mediastinal lesions (Az = .80 +/- .02 vs .73 +/- .01, respectively). Gray-scale reversal significantly decreased performance (Az = .64 +/- .03). All SR algorithms that were postprocessed to optimize imaging of the mediastinum were significantly inferior to FR in the detection of pulmonary lesions.     

Efficacy of digital radiography for the detection of pneumothorax: comparison with conventional chest radiography.

As part of our continuing evaluation of the clinical applicability of digital radiography, we compared the abilities of radiologists to detect pneumothoraces on conventional chest radiographs with their performances when using three formats of digitally obtained images. Twenty-three frontal-view chest radiographs with pneumothoraces and 22 other chest radiographs, either normal or showing miscellaneous abnormalities, were interpreted by five experienced radiologists in each of four formats: conventional film-screen chest radiographs, small-format (17.8 x 21.6 cm) computed radiographs, large-format (35.6 x 43.1 cm) computed radiographs, and digital images viewed on an interactive electronic workstation. The receiver-operating-characteristic curve areas for each observer for the four types of images were compared by a z test on a critical ratio, and the mean sensitivity and specificity values were compared by the sign rank test. The mean areas under the receiver-operating-characteristic curves ranged from 0.869 for the digital workstation to 0.915 for film-screen images. The differences observed among formats were not statistically significant. Mean specificities also were not significantly different, ranging from 0.90 for large-format computed radiographs to 0.96 for the digital workstation. Mean sensitivity ranged from 0.65 for the digital workstation to 0.82 for film-screen images. Radiologists interpreting digital workstation images were significantly less sensitive in detecting pneumothoraces than with film-screen and small-format computed images (p = .06). In this study, radiologists detected pneumothoraces equally well on conventional film-screen radiographs and digital images printed on film; however, they detected pneumothoraces less well on electronic viewing consoles. This latter finding reflects an important practical difference in the working behavior of radiologists interacting with a digital workstation.