PURPOSE: To evaluate the diagnostic accuracy of chest x-ray interpretation of diffuse calcification of pulmonary nodules. MATERIALS AND METHODS: On plain chest radiograph and CT, 152 pulmonary nodules with diffuse calcification in 98 patients were selected. The nodules were of various diameters : 44 were of 0.5 - 1cm (Group1), 58 were of 1 - 2cm (Group 2), and 50 were of 2 - 3cm (Group 3). On plain chest radiograph, diffuse calcification was considered to be present when the density of pulmonary nodules of 0.5 - 1cm and 1 - 2cm indiameter was greater than that of the overlapping area of the second and fifth ribs. The density of nodules 2-3cmin diameter was compared with that of the mid-claviclar cortex; calcification was considered to be present when the density of the former was greater than that of the latter. Diffuse calcification of a pulmonary nodule on CT image was considered to be present when more than 10% of the area of the nodule showed a higher attenuation than the surrounding rib cortex. RESULTS: The overall diagnostic accuracy of chest radiographs in the detection of diffuse calcification was as follows : sensitivity 77.6%, specifity 89%, PPV (positive predictive value) 82.3%, NPV(negative predictive value) 86.9%. In group 1, sensivity was 96%, specifity 89.5%, PPV 91.6%, and NPV 94.9%. In group 2 nodules, sensitivity was 77.8%, specifity 91%, PPV 89%, and NPV 81.4%. In group 3, sensitivity was 56%,specifity 88% PPV 56% and NPV 83.9%. CONCLUSION: Chest radiographs showed relatively high accuracy in the diagnosis of diffuse calcificatio of pulmonary nodules, particulary when the nodule was less than 2cm in diameter. As the nodule increased in diameter, diagnostic accuracy declined.
Humans ; Radiography, Thoracic ; Ribs ; Thorax*

We have observed that the companion shadow of the upper rib may be misinterpreted as a small pnemothorax or pleural plaque associated with asbestosis. To observe the radiographic characteristics of the normal companion shadow, we analyzed, on the posteroanterior(PA) chest radiographs, the companion shadow of 50 normal cases. Factors such as occurrence on each rib, the sharpness of the margin, the relative position to the rib, the shape and the thickness were observed. Also, we analyzed the displaced pleura of 4 pneumothorax cases to differentiate their frndings from the findings of normal companion shadows. On 50 normal chest radiographs, 192 compaion shadows were observed on the first to fourth ribs. In 173 of those shadows, the visceral margin of the companion shadow on the second rib simulated pneumothorax more closely than those on any othe rivs due to its apical location and thinness. In six of 50 normal cases, the companion shadow on the first or second rib showed an inw rdly convex lower margin, mimicking pleural plaque. The compaion shadow was suggested on the plain chest radiograph by the following characteristics imultiplicity(47/50), thicker than normal pleura(3/4), persistent on serial filma with the same shape and specific location(4/4).
Asbestosis ; Friends* ; Humans ; Pleura ; Pneumothorax ; Radiography, Thoracic ; Ribs* ; Thinness

PURPOSE: We evaluated the fractal dimension changes on bovine rib radiographs according to the decalcification degree and the exposure time in the bovine rib. MATERIALS AND METHODS: Twenty 5 mm thick cross-sectional blocks from bovine rib bone were progressively decalcified in 30 mL 0.1 N hydrochloric acid for 5, 30, and 90 minutes. They were radiographed at three exposure time settings (0.22, 0.36, 0.43 mAs) before and after each decalcification stage. We selected 100 x 100 pixel-sized regions of interests (ROIs) on trabecular bone and calculated fractal dimensions by box-counting method. RESULTS: Repeated measures ANOVA showed that fractal dimensions gradually decreased after acid-induced demineralization and with more exposure (P<0.001). CONCLUSION: The fact that fractal dimensions decrease after decalcification might support the hypothesis that patients with osteoporosis have decreased radiographic fractal dimension in trabecular bone in comparison to normal subjects.
Bone and Bones ; Fractals* ; Humans ; Hydrochloric Acid ; Osteoporosis ; Radiography ; Ribs*

STATEMENT OF PROBLEM: Successful osseointegration of endosseous threaded implants is dependent on many factors. These may include the surface characteristics and gross geometry of implants, the quality and quantity of bone where implants are placed, and the magnitude and direction of stress in functional occlusion. Therefore clinical quantitative measurement of primary stability at placement and functional state of implant may play a role in prediction of possible clinical symptoms and the renovation of implant geometry, types and surface characteristic according to each patients conditions. Ultimately, it may increase success rate of implants. PURPOSE: Many available non-invasive techniques used for the clinical measurement of implant stability and osseointegration include percussion, radiography, the Periotest., Dental Fine Tester. and so on. There is, however, relatively little research undertaken to standardize quantitative measurement of stability of implant and osseointegration due to the various clinical applications performed by each individual operator. Therefore, in order to develop non-invasive experimental method to measure stability of implant quantitatively, the resonance frequency analyzer to measure the natural frequency of specific substance was developed in the procedure of this study. MATERIAL AND METHOD: To test the stability of the resonance frequency analyzer developed in this study, following methods and materials were used: 1) In-vitro study: the implant was placed in both epoxy resin of which physical properties are similar to the bone stiffness of human and fresh cow rib bone specimen. Then the resonance frequency values of them were measured and analyzed. In an attempt to test the reliability of the data gathered with the resonance frequency analyzer, comparative analysis with the data from the Periotest was conducted. 2) In-vivo study: the implants were inserted into the tibiae of 10 New Zealand rabbits and the resonance frequency value of them with connected abutments at healing time are measured immediately after insertion and gauged every 4 weeks for 16 weeks. RESULTS: Results from these studies were such as follows: The same length implants placed in Hot Melt showed the repetitive resonance frequency values. As the length of abutment increased, the resonance frequency value changed significantly (p<0.01). As the thickness of transducer increased in order of 0.5, 1.0 and 2.0 mm, the resonance frequency value significantly increased (p<0.05). The implants placed in PL-2 and epoxy resin with different exposure degree resulted in the increase of resonance frequency value as the exposure degree of implants and the length of abutment decreased. In comparative experiment based on physical properties, as the thickness of transducer increased, the resonance frequency value increased significantly(p<0.01). As the stiffness of substances where implants were placed increased, and the effective length of implants decreased, the resonance frequencies value increased significantly (p<0.05). In the experiment with cow rib bone specimen, the increase of the length of abutment resulted in significant difference between the results from resonance frequency analyzer and the Periotest.. There was no difference with significant meaning in the comparison based on the direction of measurement between the resonance frequency value and the Periotest. value (p<0.05). In-vivo experiment resulted in repetitive patternes of resonance frequency. As the time elapsed, the resonance frequency value increased significantly with the exception of 4th and 8th week (p<0.05). CONCLUSION: The development of resonance frequency analyzer is an attempt to standardize the quantitative measurement of stability of implant and osseointegration and compensate for the reliability of data from other non-invasive measuring devices. It is considered that further research is needed to improve the efficiency of clinical application of resonance frequency analyzer. In addition, further investigation is warranted on the standardized quantitative analysis of the stability of implant.
Humans ; Osseointegration ; Percussion ; Rabbits ; Radiography ; Ribs ; Tibia ; Transducers

Periosteal osteosarcoma is an extremely rare chondroblastic osteosarcoma in the flat bone. There were authors reporting of two cases of periosteal osteosarcoma in the highly unusual sites. One of them arose from the rib, in a 17-year-old male, which appeared as a hypodense juxtacortical mass with periosteal reaction on CT. The other one arose from the scapula, in a 17-year-old female, which showed the intermediate signal intensity (SI) on T1-weighted image (WI), heterogeneous high SI on T2WI, and rim-enhancement on contrast-enhanced T1WI with cortical destruction on MRI.
Adolescent ; Bone Neoplasms/*radiography ; Contrast Media/diagnostic use ; Female ; Humans ; Male ; Osteosarcoma/*radiography ; Ribs/*radiography ; Scapula/*radiography

PURPOSE: We compared the soft-copy images produced by an amorphous silicon flat-panel-detector system with the images produced by a storage-phosphor radiography system for their ability to visualize anatomic regions of the chest. MATERIALS AND METHODS: Two chest radiologists independently analyzed 234 posteroanterior chest radiographs obtained from 78 patients on high-resolution liquid crystal display monitors (2560x2048x8 bits). In each patient, one radiograph was obtained with a storage-phosphor system, and two radiographs were obtained via amorphous silicon flat-panel-detector radiography with and without spatial frequency filtering. After randomizing the 234 images, the interpreters rated the visibility and radiographic quality of 11 different anatomic regions. Each image was ranked on a five-point scale (1 = not visualized, 2 = poor visualization, 3 = fair visualization, 4 = good visualization, and 5 = excellent visualization). The statistical difference between each system was determined using the Wilcoxon's signed rank test. RESULTS: The visibility of three anatomic regions (hilum, heart border and ribs), as determined by the chest radiologist with 14 years experience (p<0.05) and the visibility of the thoracic spine, as determined by the chest radiologist with 8 years experience (p=0.036), on the amorphous silicon flat-panel-detector radiography prior to spatial frequency filtering were significantly superior to that on the storage-phosphor radiography. The visibility of 11 anatomic regions, as determined by the chest radiologist with 14 years experience (p<0.0001) and the visibility of five anatomic regions (unobscured lung, rib, proximal airway, thoracic spine and overall appearance), as determined by the chest radiologist with 8 years experience (p<0.05), on the amorphous silicon flat-panel-detector radiography after spatial frequency filtering were significantly superior to that on the storage-phosphor radiography. CONCLUSION: The amorphous silicon flat-panel-detector system depicted the anatomic structures on chest radiographs comparably or significantly better as compared to the storage-phosphor system. The superiority of the amorphous silicon flat-panel-detector system compared to the storage-phosphor system was more obvious after performing spatial frequency filtering.
Heart ; Humans ; Liquid Crystals ; Lung ; Radiographic Image Enhancement ; Radiography* ; Radiography, Thoracic ; Ribs ; Silicon* ; Spine ; Thorax*

BACKGROUND: The literature on variations of rib is limited. Very little has been written in the radiological journal of this country on the subject. It seemed of interest to investigate the nature and incidence of congenital variations in a series of routine chest roentgenograms. The topic of rib variations has not been covered extensively in the radiological journals in Korea. This has presented an opportunity to investigate the nature, type, shape and incidences of congenital rib variations in normal Korean adults from a series of routine roentgenograms. METHODS: Chest radiographs of 5,000 adults (,) who visited our hospital for a routine check-up or for employment physical examinations from January 1996 to September 1998, were consecutively reviewed. The sex distribution consisted of 2,827 male males and 2,173 females (ratio of 1.3:1) with the age range between 19 and 65 years (mean age: 34.6 years). The chest PAs was were analyzed for the presence, type, location, and shape of the rib variations (.) From this data, and we the incidence of each type of variations was calculated. RESULTS: Seventy-six of the 5000 adults (1.52%), 63 male (2.23%) and 13 female (0.6%), showed 88 cases of rib variation (Table 1). Bifid rib (n=35) was the The most common variation was the bifid rib (n=35), followed by hypoplasia of the rib (n=22), flaring of the rib (n=18), bridging of the ribs (n=7), cervical ribs (n=3), and fusion of between ribs (n=3) (Table 2). (New paragraph)Bifid The bifid rib (Table 1) was found most frequent in the right fourth rib (12/35, 34.3%), followed by the left fifth rib (6/35, 17.1%) and right third rib (6/35, 17.1%). Hypoplasia of the rib was common in first rib (20/22, 90.9%). Flaring of the rib was common at fourth rib (8/18. 44.4%, right and left combined) (,) and bridging between ribs was common between first and second rib (3/7, 42.9%). CONCLUSION: The percentage of incidence of rib variations in adults was 1.52%. Bifid rib was the most common variation, followed by hypoplasia, flaring, bridging, cervical rib, and fusion of ribs(,) in decreasing order.
Adult ; Cervical Rib ; Employment ; Female ; Humans ; Incidence* ; Korea ; Male ; Physical Examination ; Radiography ; Radiography, Thoracic* ; Ribs* ; Sex Distribution ; Thorax*

Primary hemangiopericytoma of the rib is extremely rare and only a few cases have been reported. A 62-yr-old man presented with an aching chest pain and dyspnea. Thoracic computed tomography revealed a homogenous mass expanding the right seventh rib. A diagnosis of hemangiopericytoma was established by percutaneous needle biopsy. Preoperative embolization of the feeding vessels of the tumor was performed in order to prevent perioperative bleeding. There was no significant bleeding during the surgery, where complete resection of the tumor with 7th to 9th ribs with a surgical margin of 5 cm was performed. Postoperative course was uneventful and there has been no recurrence for thirteen months. To our knowledge, there has been no report to apply a preoperative embolization of a primary hemangiopericytoma of the rib.
Bone Neoplasms/pathology/radiography/*surgery ; *Embolization, Therapeutic ; Hemangiopericytoma/pathology/radiography/*surgery ; Humans ; Male ; Middle Aged ; *Ribs ; Tomography, X-Ray Computed

PURPOSE: To investigate the impact of post-processing on a PACS workstation before and after use of thedynamic range suppression method for the normal chest radiographs. MATERIALS AND METHODS: Forty normal chestradiographs of healthy adult volunteers aged 20 to 33 (average 27; M:F = 29:11) were acquired by FCR using adigital interface and then transferred to an in-house-developed PACS workstation. The image size of computed chestradiographs was 7.5MB with 1760 x 2140 matrix. An image enhancement processing named DRS, developed by theauthors, was applied to the acquired images and generated a total of 40 chest radiographs. These were presented tothree groups of observers, each consisting of one radiologist and one technician on the PACS workstation, whichhad two monitors of 1712 x 2100 resolution. So that external light would not affect the visibility of imagesduring observation, these were displayed in a light-controlled room. The J.J.Vucich method, suitably modified, wasused to evaluate the anatomical structures and physical parameters of processed and unprocessed radiographs. Usinga percentage scale, the observers evaluated both anatomical sections (seven anatomical items : cortical margins ofribs, left diaphragms, thoracic vertebrae, trachea, pulmonary vasculature, trabeculae of ribs and clavicle,diaphragm outline) and physical sections (four items : contrast, graininess, density, detail). The results for thethree groups, both before and after DRS processing, were then compared. RESULTS: There was a statisticallysignificant difference between the three groups: in the anatomical section, 78.64 before DRS and 82.55 after ; andin the physical section, 75.48 and 79.78 (p<0.05). The average values of all items were 77.06 before DRS and 81.17after (p<0.05). CONCLUSION: Post-processing of computed chest radiographs on the PACS workstation improves boththe visibility of anatomical features and general image quality. Thus, in a PACS environment, it can be a usefultool for enhancing the diagnostic efficacy of radiography.
Adult ; Diaphragm ; Humans ; Image Enhancement ; Radiographic Image Enhancement ; Radiography ; Radiography, Thoracic* ; Ribs ; Thoracic Vertebrae ; Thorax* ; Trachea ; Volunteers

PURPOSE: To investigate the impact of post-processing on a PACS workstation before and after use of thedynamic range suppression method for the normal chest radiographs. MATERIALS AND METHODS: Forty normal chestradiographs of healthy adult volunteers aged 20 to 33 (average 27; M:F = 29:11) were acquired by FCR using adigital interface and then transferred to an in-house-developed PACS workstation. The image size of computed chestradiographs was 7.5MB with 1760 x 2140 matrix. An image enhancement processing named DRS, developed by theauthors, was applied to the acquired images and generated a total of 40 chest radiographs. These were presented tothree groups of observers, each consisting of one radiologist and one technician on the PACS workstation, whichhad two monitors of 1712 x 2100 resolution. So that external light would not affect the visibility of imagesduring observation, these were displayed in a light-controlled room. The J.J.Vucich method, suitably modified, wasused to evaluate the anatomical structures and physical parameters of processed and unprocessed radiographs. Usinga percentage scale, the observers evaluated both anatomical sections (seven anatomical items : cortical margins ofribs, left diaphragms, thoracic vertebrae, trachea, pulmonary vasculature, trabeculae of ribs and clavicle,diaphragm outline) and physical sections (four items : contrast, graininess, density, detail). The results for thethree groups, both before and after DRS processing, were then compared. RESULTS: There was a statisticallysignificant difference between the three groups: in the anatomical section, 78.64 before DRS and 82.55 after ; andin the physical section, 75.48 and 79.78 (p<0.05). The average values of all items were 77.06 before DRS and 81.17after (p<0.05). CONCLUSION: Post-processing of computed chest radiographs on the PACS workstation improves boththe visibility of anatomical features and general image quality. Thus, in a PACS environment, it can be a usefultool for enhancing the diagnostic efficacy of radiography.
Adult ; Diaphragm ; Humans ; Image Enhancement ; Radiographic Image Enhancement ; Radiography ; Radiography, Thoracic* ; Ribs ; Thoracic Vertebrae ; Thorax* ; Trachea ; Volunteers