Short-term effects of particulate air pollution on respiratory morbidity in asthmatic children

OBJECTIVE: The aim of this study was to quantify the effect of mandibular angulation, position, and shape of an edentulous mandible on the distortion of its image in panoramic radiographs. STUDY DESIGN: Five edentulous dry mandibles varying in size from small to wide and equipped with metal bars in and on top of the mandible were used. The mandibles were radiographed at nine different positions by tilting the mandible posteriorly around a transversal axis, using an orthopantomograph. RESULTS: The length of the images of the bars on top of the mandible increased significantly by tilting the mandibles from +20 degrees to -20 degrees. The magnification factor of the images of the intrabony bars in the mandible was the largest at 0 degrees and decreased significantly by both decreasing or increasing the inclination. The size of the mandible was not related to the magnification factor. CONCLUSION: For both diagnostic and evaluation purposes of the edentulous mandible, the panoramic radiograph is not a reliable radiographic technique unless meticulous precautions are taken for reproducible positioning of the patient in the apparatus.     

Digital radiology in dentistry: experience with direct intraoral techniques (radiovideography)

The aim of this paper was to discuss the techniques for intraoral digital radiography (radiovisiography) and to compare their accuracy in dental radiographical diagnosis. Emphasis was given to their potential applications in oral radiology. Radiovisiography was compared with intraoral films and electronic magnifications from digital panoramic radiographs in 38 patients, for a total amount of 36 caries, 27 periapical conditions and 58 metal implants. Moreover, the accuracy of the measurements made with the three techniques was assessed on a specimen of mandibular and maxillary arches containing 28 extracted teeth with endodontic files of known length. Radiovisiography was as effective as intraoral films and more effective than digital panoramic radiographs in the diagnosis of caries and periapical lesions. Nevertheless, it produced a significant magnification and yielded unreliable measurements of root canals and metal implants. Radiovisiography is very easy to use and does not require dark room procedures nor chemicals of any kind. In addition, it reduces patient's X-ray exposure by over 50% with respect to film studies. For these reasons, this technique seems to be worthy of widespread use in dental radiography, with the exception of the conditions requiring an exact measurement of working length.     

Differences in Epstein-Barr virus expression between primary and secondary cutaneous angiocentric lymphomas. French Study Group of Cutaneous Lymphomas

OBJECTIVE: The aim of this investigation was to report on the radiographic interpretation of the hard palate and nasal fossa floor in panoramic radiographs by studying different skulls, x-ray machines, and head positions in relationship to the Frankfort plane before and after ostectomy. STUDY DESIGN: Twenty dry human skulls were radiographed with three different panoramic x-ray machines in three different positions. Three of the skulls were submitted to different ostectomies. RESULTS: Multiple images of the hard palate and nasal fossa floor were present in 96.12% of the radiographs. Single images (3.88%) occurred only in the "chin up" position. CONCLUSIONS: The lower image represents the nasal fossa floor, especially its lateral and anterior limits. The upper images are double real images mainly formed by the junction of the nasal septum with the nasal fossa floor and possibly by posterior parts of the hard palate and nasal fossa floor. All images overlap in the "chin up" position becoming a single image. The most common shape of the anatomic landmark was wide angle "W" (58.33%). Other shapes present in positions "chin up" and "chin down" indicate patient positioning errors. The x-ray machines did not influence the results.     

Hypodontia and nail dysplasia syndrome. Report of a case

The role of radiography and bone scintigraphy in the diagnostic management of suspected scaphoid fracture is controversial. Two strategies were compared for patients with initial negative radiographs: repeated radiography versus selective bone scintigraphy. Using the known positive predictive value of scintigraphy, the sensitivity and specificity of both diagnostic strategies were evaluated in a series of 78 consecutive patients. The kappa value for initial radiographs was 0.76 but decreased to 0.5 for follow-up radiographs. Similarly, sensitivity decreased from 64% to 30% in follow-up radiographs. Specificity of the bone scan was 98%. The best diagnostic strategy in the management of clinically suspected scaphoid fractures consists of initial radiography followed by bone scintigraphy in patients with negative radiographs.     

Diagnosis of infra-alveolar bony lesions in the dentate alveolar process with high-resolution computed tomography. Experimental results

RATIONALE AND OBJECTIVES: Conventional intraoral radiography was compared with axial computed tomography (CT) scans for identification and classification of bony pockets in dentate jaw segments. METHODS: Fifty-five artificial bone defects were produced in six dentate jaw segments. The jaws were examined radiographically using a dental x-ray unit and by contiguous axial CT scans. Identification, classification, and vertical depth of the bony defects were compared among the specimens, radiographs, and CT scans. RESULTS: On the intraoral radiographs, 38 (69%) bony lesions were identified, and the vertical depth was underestimated by a mean of 2.2 mm, compared with the objective measurements on the jaws. In contrast, all artificial bony lesions (100%) were identified and classified on the axial CT scans and the vertical depth was underestimated by a mean of 0.5 mm. CONCLUSIONS: High-resolution CT improves the identification and metric assessment of the vertical dimension of infra-alveolar bony lesions compared with conventional intraoral x-ray films and allows these defects to be classified according to the number of existing walls into one-walled, two-walled, and three-walled bony pockets. In patients with apically extended metallic restorations, the image quality could be limited by artifacts.     

Gastric accommodation in functional dyspepsia

PURPOSE: We investigated the capabilities of chest radiography in the elderly considering that the examination must meet the main clinical indications of this population and that it is necessary in the elderly because the correct clinical assessment is often difficult or impossible. MATERIALS AND METHODS: We reviewed the chest radiographs of 756 consecutive elderly patients admitted to our hospital from September 1 to October 31, 1996. If possible, chest radiographs were performed with the AMBER technique (156 patients, 20.7%); 240 patients (31.7%) underwent conventional radiography and the others frontal projections only (360 patients, 47.6%). T-MAT G RA Kodak high contrast films with Kodak Lanex green transmitting intensifying screens were used in all cases. The AMBER examinations of 48/156 patients with hemodynamic clinical indications were repeated with conventional frontal projections. Radiographic reports were made separately by different radiologists who considered especially the diagnostic accuracy of every examination in determining the venous overload of pulmonary circulation. RESULTS: Hemodynamic studies are the most frequent clinical indication of chest radiography in elderly patients (228/756 patients in our series, 30.2%); moreover, even if careful cardiac and pulmonary circulation studies are very important in these patients, only 52.4% of all radiographs could be made in two orthogonal projections. The blurred appearance of vascular landmarks indicating increased extravascular fluid is better depicted by conventional radiography (59.7% of cases) than by AMBER (40.3%). CONCLUSIONS: We conclude that the reduced pulmonary contrast obtained with the so-called "hard X-ray" technique poorly depicts the blurred appearance of pulmonary vessels in pulmonary venous overload. Moreover, "hard X-ray" techniques can be only sporadically used because elderly patients are often in very critical conditions, which prevents this type of examination.     

Hodgkin disease and non-Hodgkin lymphoma: plain chest radiographs and chest computed tomography of thoracic involvement in previously untreated patients

PURPOSE: To provide further information about the presentation of thoracic involvement in Hodgkin disease and non-Hodgkin lymphoma and to compare chest radiography with chest CT findings. MATERIALS AND METHODS: We reviewed the chest radiographs and the CT images of 100 Hodgkin and 100 non-Hodgkin patients, all of them untreated. Our data were compared with those of literature series: the latest study comparing the different patterns of Hodgkin and non-Hodgkin disease appeared in 1976 and it compared chest radiography with conventional tomography, not with CT. RESULTS: Intrathoracic involvement (75% vs 48%) and adenopathy (74% vs 28%) were more frequent in Hodgkin than in non-Hodgkin lymphoma. Ninety-nine per cent of the patients with intrathoracic involvement (74/75) had nodal disease. Paratracheal/prevascular nodes were most frequently involved, namely in 72/74 Hodgkin (97%) and in 27/28 non-Hodgkin patients (96%). The lung parenchyma was more often involved in non-Hodgkin (24%) than in Hodgkin (8%) patients; it was associated with mediastinal/hilar adenopathy in all Hodgkin and in 10/24 (42%) non-Hodgkin cases. Parenchymal involvement was demonstrated with chest radiography in 7/8 Hodgkin (88%) and in 13/24 non-Hodgkin patients (54%). Chest radiography showed paratracheal/prevascular adenopathy more often in Hodgkin (54/72, 75%) than in non-Hodgkin (15/27, 56%) cases. Subcarinal and internal mammary adenopathy was poorly depicted with plain films, while hilar adenopathy was generally identified with both CT and chest radiography. Chest radiography usually missed posterior mediastinal and anterior diaphragmatic adenopathy. CONCLUSIONS: The differences in the presentation of Hodgkin vs non-Hodgkin disease are not sufficiently distinctive to permit radiographic differentiation of the two conditions, but some patterns are helpful. Recognizing the frequency of thoracic involvement and that of the additional CT findings in Hodgkin and non-Hodgkin patients makes a sound basis for lymphoma imaging.     

Must radiation dose for CT of the maxilla and mandible be higher than that for conventional panoramic radiography?

We evaluated the feasibility of performing preoperative spiral CT of the maxilla and mandible with a radiation dose similar to that used for conventional panoramic radiography. The skin entrance doses of radiation used for spiral CT (collimation, 1 mm; pitch, 2; tube voltage, 80 kV; tube current, 40 mA) and for panoramic radiography (75 kV, 8 mA, 15 seconds) were measured in one patient by using thermoluminescent dosimeter chips. Results were 0.56 +/- 0.06 mGy for CT and 0.59 +/- 0.04 mGy for radiography. Image quality was adequate for preoperative implant planning. Spiral CT of the mandible and maxilla may therefore be feasible with a radiation dose of similar magnitude as that used for conventional panoramic radiography.     

Carcinoma of the endometrium: do the nuclear grade and DNA ploidy provide more prognostic information than do the FIGO and WHO classifications?

Panoramic and computed tomographic images of 20 patients with antral malignancy were viewed separately and compared to determine the extent of bony destruction of the sinus walls seen in each film type. This study showed that panoramic radiographs can demonstrate antral malignancy at the time of diagnosis in 90% of cases. Panoramic radiographs possess the potential for identifying the need for further diagnostic procedures in evaluating the maxillary antrum. Health care workers should be aware of the value of panoramic radiographs in examining this region.     

Computed radiography of the chest in patients with paraesophageal varices: diagnostic accuracy and characteristic findings

OBJECTIVE: The purpose of our study was to determine the diagnostic accuracy of computed radiography of the chest in the detection of paraesophageal varices and to describe the characteristic radiographic findings. SUBJECTS AND METHODS: From June 1995 through May 1997, in 100 consecutive patients, portal hypertension was diagnosed through both clinical and radiologic evidence. Computed radiographs of the chest and hepatic helical CT scans of these 100 patients with portal hypertension and 20 control subjects were analyzed by two chest radiologists and one abdominal radiologist, who were not aware of the results of the other study. RESULTS: On CT, paraesophageal varices were seen in 38 (38%) of 100 patients with portal hypertension. Overall, the sensitivity, specificity, and accuracy of chest computed radiography in the detection of paraesophageal varices were 53% (20/38), 90% (74/82), and 78% (94/120), respectively. In the patients with paraesophageal varices, splenomegaly (29/38, 76%), lateral displacement or obliteration of the inferior portion of the azygoesophageal interface (18/38, 47%), obliteration or nodularity of the inferior portion of the descending thoracic aorta interface (9/38, 24%), lateral displacement of the right inferior paraspinal interface (6/38, 16%), lateral displacement of the left inferior paraspinal interface (4/38, 11%), and varices in the left inferior pulmonary ligament (1/38, 3%) were seen on chest computed radiographs. Paraesophageal varices smaller than the diameter of the descending thoracic aorta (usually <2.5 cm) were not detected. CONCLUSION: Although chest computed radiography is only moderately sensitive for paraesophageal varices, the findings are characteristic when well developed, with a limited differential diagnosis. Splenomegaly, whether detected clinically or radiographically, eliminates most other diagnostic possibilities.     

Usefulness of panoramic radiography in the diagnosis of postmenopausal osteoporosis in women. Width and morphology of inferior cortex of the mandible

OBJECTIVES: To evaluate the usefulness of width and morphology of the inferior cortex of the mandible on panoramic radiographs in the diagnosis of postmenopausal osteoporosis. METHODS: The width and morphology of the mandibular inferior cortex on panoramic radiographs were compared with trabecular bone mineral density (TBMD) of the 3rd lumbar vertebrae (L3) measured by dual energy quantitative computed tomography in 29 premenopausal and 95 postmenopausal women. RESULTS: There was a significant negative correlation between the width (Kendall's tau = -0.36, p < 0.001) and morphology (Kendall's tau = -0.49, p < 0.001) of the mandibular inferior cortex and the L3 TBMD. Regression analysis showed that significant linear relationships were observed between the L3 TBMD and age (p < 0.001), cortical width (p < 0.05), morphology (p < 0.05), controlling body mass index, number of teeth present and menopausal status (R2 = 0.42). CONCLUSION: Our results suggest that panoramic radiography could be reliable in screening for osteoporosis.     

Radiographic modalities for diagnosis and treatment planning in implant dentistry

Early in the development of implant technology it became apparent that conventional dental imaging techniques were limited for evaluating patients for implant surgery. During the treatment planning phase, the recipient bed is routinely assessed by visual examination and palpation, as well as by periapical and panoramic radiology. These two imaging modalities provide a two-dimensional image of mesial-distal and occlusal-apical dimensions of the edentulous regions where implants might be placed. When adequate occlusal-apical bone height is available for endosteal implants, the buccal-lingual width and angulation of the available bone are the most important criteria for implant selection and success. However, neither buccal-lingual width nor angulation can be visualized on most traditional radiographs. Although clinical examination and traditional radiographs may be adequate for patients with wide residual ridges that exhibit sufficient bone crestal to the mandibular nerve and maxillary sinus, these methods do not allow for precise measurement of the buccolingual dimension of the bone or assessment of the location of unanticipated undercuts. For these concerns, it is necessary to view the recipient site in a plane perpendicular to a curved plane through the arch of the maxilla or mandible in the region of the proposed implants. Implant dentists soon recognized that, for optimum placement of implants, cross-sectional views of the maxilla and mandible were the ideal means of providing necessary pre-operative information. Today, the two most often employed and most applicable radiographic studies for implant treatment planning are the panoramic radiograph and tomography. Although distortion can be a major problem with panoramic radiographs, when performed properly they can provide valuable information, and are both readily accessible and cost efficient. To help localize potential implant sites and assist in obtaining accurate measurements, it is recommended that surgical stents be used with panoramic radiographs. In simple cases, where a limited number of implants are to be placed, panoramic radiography and/or tomography may be used to obtain a view of the arch of the jaw in the area of interest. For complex, cases, where multiple implants are required, the CT scan imaging procedure is recommended. Because of its ability to reconstruct a fully three dimensional model of the maxilla and mandible, CT provides a highly sophisticated format for precisely defining the jaw structure and locating critical anatomic structures. The use of CT scans in conjunction with software that renders immediate "treatment plans" using the most real and accurate information provides the most effective radiographic modality currently available for the evaluation of patients for oral implants. To follow patients after implant surgery, DSR can be helpful by addressing the limitations of other radiographic modalities in detecting postoperative changes. By eliminating unchanged information, DSR allows the clinician's eye to focus on actual changes that have occurred between the recordings of two images.     

Nodular sarcoidosis of the liver and spleen: analysis of 32 cases

PURPOSE: To describe the computed tomographic (CT) appearance of nodular hepatosplenic sarcoidosis and its association with stage with chest radiography and clinical status. MATERIALS AND METHODS: Thirty-two patients (21 women, 11 men; aged 25-68 years) with nodular hepatosplenic sarcoidosis were evaluated. CT findings were described along with chest radiographic stage, clinical status, and level of angiotensin-converting enzyme (ACE). RESULTS: Nodules were small, multiple, and of low attenuation. Organomegaly was common. Abdominal adenopathy was present in 76% of the patients. Chest radiographs were normal in 25%; 61% had stage 1 or 2 radiographs. Abdominal or systemic symptoms were present in 66%. ACE level was elevated in 10 (91%) of 11 patients tested. No change in chest radiographic stage was noted in 74% of patients with follow-up radiographs. CONCLUSION: Nodular hepatosplenic sarcoidosis is associated with organomegaly, adenopathy, and symptoms. Nodules were not associated with advanced lung disease and did not herald a change in chest radiographic stage. An elevated ACE level may be helpful in diagnosis.     

Fibromyalgia associated with female urethral syndrome

The case of a patient with a false-positive fracture on the panoramic view of the mandible is presented. The patient motion produced a spurious image that perfectly mimicked a fracture without any evidence of motion. To better assess motion artifact, panoramic views of a "phantom" human skull were developed with movement during the exposure. These radiographs were analyzed with the assistance of a radiologist, and diagnostic features of motion artifact are discussed. Some radiographs were created by movement that mimicked fractures without the telltale signs of motion artifact. These "motion pseudofractures" are diagnosed clinically if the examiner knows that motion can mimic fractures, and all x-ray findings are carefully correlated with clinical findings. Diagnosis of a motion pseudofracture will avoid the additional expense and time of a specialty consultation.     

Measurement of scatter fractions in erect posteroanterior and lateral chest radiography

Scatter fractions (SFs) measured in patients undergoing erect posteroanterior (PA) and lateral chest radiography with a 12:1 antiscatter grid are reported. Modifications to the posterior beam-stop (PBS) technique allowed measurement of scatter in these patients, without altering the diagnostic image and without additional radiation exposure. The SF measurements are reported by anatomic location on 42 clinical chest images. Average SF values ranged from 0.27 to 0.90 on lateral radiographs and from 0.27 to 0.68 on PA radiographs. Scatter measurements with the 12:1 grid were found to be greater than estimates from previous PA chest phantom experiments. To the authors' knowledge, they were the first to measure radiation scatter with the PBS technique in patients undergoing PA and lateral chest radiography with the antiscatter grid.     

The utility of chest radiography in the follow-up of pneumonia

AIM: We conducted this study to determine whether chest radiography was clinically useful in the follow-up of uncomplicated pneumonia affecting children aged between 6 weeks and 15 years. METHOD: We examined the case records of all 78 paediatric admissions for pneumonia to our hospital over one year. Thirteen children were excluded on account of age or other complicating factors. RESULTS: Of the 65 study cases, the mean age was 3.5 years (range 0.4-13 years). On admission 51 (79%) had cough, 53 (82%) fever, 53 (82%) tachypnoea and 50 (77%) had abnormal chest signs. Elevation of C reactive protein was recorded in 43 (66%) cases and leukocytosis in 42 (65%). All children received initial chest radiographs which showed unilobular/lobar changes in 34 (53%), bilobar changes in 19 (29%) and diffuse abnormalities in 7 (11%). Forty-one patients were followed up both clinically and radiologically, usually (31 cases) between four and six weeks after discharge. Thirty-seven children had no abnormal symptoms or signs and had normal chest radiographs. The remaining four had symptoms and signs, their radiographs showed either slight resolution or no change from the admission films. CONCLUSION: In cases of uncomplicated pneumonia, follow-up chest radiography should be deferred until at least four weeks after discharge and is not indicated if symptoms and signs are absent.     

Prevalence and duration of postoperative pneumoperitoneum: sensitivity of CT vs left lateral decubitus radiography

OBJECTIVE: The purpose of this study was to evaluate the prevalence, location, and duration of pneumoperitoneum in postoperative patients and to compare the sensitivities of CT and left lateral decubitus radiography in the detection of postoperative pneumoperitoneum. SUBJECTS AND METHODS: Twenty-seven CT scans and 27 abdominal radiographs with the patient in the left lateral decubitus position were obtained prospectively in 17 patients after uncomplicated abdominal surgery. Fifteen patients were examined 3 days after surgery and 12 were examined 6 days after surgery. The studies were evaluated in a blinded fashion for the presence, location, and volume of free air. The presence of air on the radiographs and the presence and quantity of air on the CT scans were correlated with each subject's surgical procedure, age, sex, and body habitus. RESULTS: Pneumoperitoneum was seen on 13 (87%) of 15 CT scans and eight (53%) of 15 radiographs obtained 3 days after surgery and on six (50%) of 12 CT scans and one (8%) of 12 radiographs obtained 6 days after surgery. The calculated volume of free air seen on the CT scans ranged from 0.3 to 5.8 ml. Sixty-two percent of collections by volume were located in the midline/parahepatic space, 22% in the pelvis, and 16% in the mesentery. Radiographs showed pneumoperitoneum in only nine (47%) of 19 examinations in which the corresponding CT scans showed free air. Findings on radiographs were false-negative in seven (87%) of eight obese patients in whom pneumoperitoneum was detected on CT scans. CONCLUSION: The prevalence of pneumoperitoneum in the postoperative period based on CT findings is greater than that previously reported. Small amounts of pneumoperitoneum frequently collect along the anterior abdominal wall in two preferential spaces, the pararectus and midrectus recesses. The results of this study show that CT is significantly more sensitive than plain radiography for detecting small amounts of free intraperitoneal air in postoperative patients. Radiography is particularly insensitive for imaging obese and heavy patients.     

Synovial hemangioma: imaging features in eight histologically proven cases, review of the literature, and differential diagnosis

OBJECTIVE: This study was undertaken to describe the imaging characteristics of synovial hemangioma, with the goal of improving the disappointing rate (22%) of clinical diagnosis of this condition. A review of the literature and the differential diagnosis of intra-articular lesions, including synovial osteochondromatosis and pigmented villonodular synovitis, are also presented. PATIENTS: The subjects of the study were 8 patients (4 males, 4 females; age range: 5-47 years; mean age: 19 years) with histologically confirmed synovial hemangioma involving the knee (n = 7) or wrist (n = 1). We retrospectively examined the imaging studies performed in these patients, including plain radiography (n = 8), magnetic resonance imaging (MRI; n = 4), angiography (n = 3), arthrography (n = 2), and contrast-enhanced computed tomography (CT; n = 2). RESULTS: Plain radiographs showed a soft tissue density suggesting either joint effusion or a mass in all patients. Phleboliths and bone erosions on plain films in four patients with extra-articular soft tissue involvement pointed to the correct diagnosis. Angiography, showing fine-caliber, smooth-walled vessels, contrast pooling in dilated vascular spaces, and early visualization of venous structures, was diagnostic in two patients. Neither arthrography nor CT yielded specific enough findings. MRI was consistently effective in allowing the correct diagnosis to be made preoperatively, showing an intra-articular or juxta-articular mass of intermediate signal intensity on T1-weighted images and of high signal intensity of T2- or T2*-weighted images with low-signal channels or septa within it. A fluid-fluid level was found in two patients with a cavernous-type lesion. CONCLUSION: Despite the limited nature of this study, it shows clearly that MRI is the procedure of choice whenever an intra-articular vascular lesion such as synovial hemangioma is suspected. Nonetheless, phleboliths and evidence of extra-articular extension of plain radiographs point to angiography as an effective procedure of first resort because it can be combined with embolotherapy.     

Bone mineral density in periodontally healthy and edentulous postmenopausal women

(Osteoporosis is the most common metabolic disease among postmenopausal women. Reduced masticatory function caused by tooth loss may be a contributing risk factor of osteoporosis. The present study examined the effect of dentate state on skeletal bone mineral density (BMD) in postmenopausal women. Fourteen periodontally healthy dentate subjects (group H; mean age: 64.0 + 5.5 years) and 12 edentulous subjects (group E; mean age: 67.1 + 2.9 years) were randomly selected from the clinics of the departments of Periodontology and Gerodontology, respectively. Informed consent was obtained from all participants. BMD of the lumbar spine (L2-L4) was measured by dual energy x-ray absorptiometry. In addition, occlusal force was measured in 11 group H subjects and 8 group E subjects by using an occlusal diagnostic system. Risk factors associated with osteoporosis including age, calcium intake, physical activity, and cigarette smoking and causes of tooth loss were assessed by interview and questionnaire sent to all participants. The BMD of group H was 1.07 t 0.21 g/cm2 and that of group E was 0.89 + 0.17 g/cm2, which was significantly different(P< 0.05). The occlusal force of group H and E patients was 312.4 + 148 Nand 56.3 + 36 N, respectively, which was significantly different (P< 0.05). Risk factors such as calcium intake, physical activity, and smoking did not differ significantly between the 2 groups. Thus, the periodontally healthy dentate women, who showed about 6 times higher occlusal force than edentulous women, maintained significantly higher BMD of the lumbar spine than edentulous women. Our results suggest that sufficient masticatory function with periodontally healthy dentition may inhibit or delay the progress of osteoporotic change in skeletal bone or that edentulous women may be more susceptible to osteoporosis.