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1.
Won-Jin Yi Min-Suk Heo Sam-Sun Lee Soon-Chul Choi Kyung-Hoe Huh 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2006,101(4):523-529
OBJECTIVE: We evaluated the influence of surrounding anatomical structures on the registration accuracy of a diagnostically important region, by varying the ROI (region of interest) window used in an automatic ROI-based digital subtraction method. STUDY DESIGN: Pairs of radiographs were taken at 2 molar regions using paralleling techniques of XCP devices (Rinn Co., Elgin, Ill) attached with and without a bite block. The global and local registration accuracies were measured by the RMS (root mean square) of subtraction images for various ROIs. RESULTS: No significant differences were found in global registration accuracies among various ROI sizes in all the paralleling techniques. The local registration accuracies decreased with extension of the ROI size. CONCLUSION: Registration using an ROI restricted to the anatomical region of diagnostic interest provides higher accuracy than using a larger ROI. 相似文献
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Sasagawa T Kunogi J Masuyama S Ogihara S Takeuchi Y Takeshita Y Fukushima M Kamiya N Murakami H Tsuchiya H 《Journal of orthopaedic science》2012,17(4):346-351
Background
The interpretation of thoracic spine X-rays is difficult because these images cannot clearly visualize the thoracic spine because of the overlap with soft tissues, such as the heart and pulmonary blood vessels. Thus, to improve the clarity of thoracic spine radiographs using existing radiograph equipment, we have investigated a one-shot energy subtraction method to visualize thoracic spine radiographs. Our objective was to evaluate whether the thoracic spine radiographs generated using this method could visualize the spine more clearly than the corresponding original thoracic spine radiographs.Methods
This study included 29 patients who underwent thoracic spine radiographs. We used a one-shot energy subtraction method to improve the clarity of thoracic spine radiographs. Image definition was evaluated using vertebrae sampled from each region of the thoracic spine. Specifically, these were: Th1, Th5, Th9, and Th12. Image definition was assessed using a three-point grading system. The conventional and processed computed radiographs (both frontal and lateral views) of all 29 study patients were evaluated by 5 spine surgeons.Results
In all thoracic regions on both frontal and lateral views, the processed images showed statistically significantly better clarity than the corresponding conventional images, especially at all sampling sites on the frontal view and T5 and 9 on the lateral view.Conclusions
Thoracic spine radiographs generated using this method visualized the spine more clearly than the corresponding original thoracic spine radiographs. The greatest advantages of this image processing technique were its ability to clearly depict the whole thoracic spine on frontal views and the middle thoracic spine on lateral views. 相似文献3.
Anatomical distribution of bronchoalveolar lavage fluid as assessed by digital subtraction radiography. 总被引:4,自引:2,他引:2 下载免费PDF全文
A digital subtraction imaging technique was used to visualise directly the anatomical distribution of 3 X 60 ml aliquots of saline containing a low concentration of radio-opaque dye, introduced sequentially into a segment of the middle lobe. It was possible to estimate the relative movement of fluid within the segment during the sequential aspiration of each of these aliquots. The first 60 ml aliquot introduced stayed close to the bronchoscope and probably sampled only the proximal airways. With the introduction of cumulative volumes of 120 ml or more, the fluid filled the segment more evenly. Aspiration then moved fluid back from the periphery, implying that the aspirate had also lavaged both distal airways and alveoli. 相似文献
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A retrospective review of ultrasound guided breast excisional biopsies performed in a Surgical Unit of Princess Alexandra Hospital in 1998-99 was undertaken to assess the use of ultrasound specimen radiography. In this series a total of 55 localization biopsies were performed for impalpable lesions in 53 women. In 21 patients (38%), specimen ultrasound was used to confirm that the lesion in question had been excised, whereas for 34 lesions (62%), specimen X-ray was undertaken. In a total of six cases (10.9% overall) the radiographic abnormality was seen on ultrasound only. Real-time specimen sonography is a technique which is very appropriately utilized in conjunction with ultrasound guided excisions and can be easily performed either in the radiology department or the operative suite with minimal time delay. It could have particular application for lesions that are detected in younger women with dense breast parenchyma. The results of this review confirm specimen sonography to be a reliable technique. 相似文献
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Advances in the computer technology and the introduction of new digital imaging detectors offer the potential for digital image acquisition and several new mammography techniques, such as tomosynthesis and digital subtraction mammography. Tomosynthesis is a method of obtaining tomographic images of a breast. In tomosynthesis, any number of tomographic planes may be reconstructed from a set of images obtained as the X-ray source is moved in an arc above the breast. By shifting and adding the information obtained at different source positions, any plane of the breast can be brought into a sharp focus, while structures outside this selected plane are blurred. This may lead to improved lesion detection, especially in dense breast tissue. Thus, tomosynthesis may play a role in improving breast cancer screening and lesion characterization. Digital subtraction mammography is a method of breast angiography. It is performed by obtaining a digital radiographic image before, and one or more digital radiographic images after the injection of a contrast agent such as iodine. The pre- and post-contrast images are subtracted, resulting in an image of the vascular structures in the breast. Because breast cancer lesions have increased vascularity, digital subtraction mammography may play an important role in improving lesion detection, characterizing lesions, monitoring response to therapy, and determining lesion extent.Thus, both of these new digital techniques have the potential to address the major limitation of conventional mammography, namely the difficulty in detecting cancer in radiographically dense breasts. 相似文献
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Bazzocchi A Ciccarese F Diano D Spinnato P Albisinni U Rossi C Guglielmi G 《Journal of clinical densitometry》2012,15(2):198-204
The objective of this study was to evaluate the diagnostic performance of the new dual-energy X-ray absorptiometry equipment vs digital radiography (DR) in the detection and scoring of abdominal aortic calcifications (AACs). Seventy-five patients with indication for morphometric evaluation of the spine underwent vertebral fracture assessment (VFA) and spinal DR (gold standard). The radiographic and VFA images were analyzed to detect AAC using a previously validated 24-point scale (AAC-24) and a simplified 8-point scale (AAC-8). The evaluation was conducted by 2 expert radiologists and repeated by the more experienced of the 2 after 7d to verify the results. Patients with a score of 5 or more in AAC-24 and 3 or more in AAC-8 were considered at risk for cardiovascular diseases (CVDs). The aorta was not completely visible in 11 VFA and 1 DR images. DR detected AAC in 42 of the 63 patients (66.7%), whereas 15 patients (23.8%) were considered at risk for CVD. The VFA showed sensitivity, specificity, and accuracy in the detection of AAC with values of 78.6%, 85.7%, and 81.0%, respectively, with both AAC-24 and AAC-8; in the identification of patients at risk for CVD, VFA demonstrated sensitivity, specificity, and accuracy, respectively, with values of 86.7%, 100%, and 96.8% using AAC-24 and 86.7%, 93.8%, and 92.1% using AAC-8. In the detection of AAC, intraobserver agreement was superimposable using both the techniques (κ=1.00), whereas in the identification of patients at risk for CVD, kappa values were 0.96 and 0.95 using AAC-24 and 1.00 and 0.96 using AAC-8 for DR and VFA, respectively. Interobserver agreement in the evaluation of the presence/absence of AAC showed a kappa value of 0.76 for DR and 0.71 for VFA, whereas kappa values of 0.91 and 0.87 for DR and 0.85 and 0.83 for VFA were achieved for CVD risk using AAC-24 and AAC-8, respectively. AAC can be easily and accurately diagnosed by VFA with satisfactory accuracy, reproducibility, and repeatability. VFA may be used in the assessment and monitoring of AAC. 相似文献
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The introduction of dual-energy computed tomography systems (ie, scanners that can simultaneously acquire images at different
energies) has significant and unique applications for urologists. Imaging data from these scanners can be used to evaluate
composition of urinary calculi and, by “removing” iodine from an image, significantly decrease radiation dose to patients
referred for hematuria. Further, the ability to create a virtual noncontrast image obviates the need for repeated scanning
in patients with incidentally detected renal and adrenal masses. Finally, the ability to quantify the regional concentration
of iodine in a renal neoplasm may provide a method to monitor effectiveness of therapy before size changes become apparent. 相似文献
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Robert S. Weinstein Katheryn D. New Linda J. Sappington 《Calcified tissue international》1991,49(5):313-316
Summary Radial diaphyseal bone mineral density (BMD) was measured at the standard one-third site by dual-energy X-ray absorptiometry
(DEXA) and by125I single photon absorptiometry (SPA) in 70 consecutive subjects, aged 12–86 years, with metabolic disorders of the skeleton.
Each patient was measured once by the DEXA (Hologic QDR-1000) instrument and four times by the SPA (Norland 2780) instrument
on the same day by one or the other of 2 technicians. The DEXA and SPA measurements were linearly related and highly correlated
(r=0.975,P<0.0001) over a range from severe osteopenia to high normal BMD. Ninety-five percent of the variation in the BMD determined
by SPA was accounted for by DEXA, so that the BMDSPA=1.035±0.027 (SEM)×BMDDEXA−0.007±0.019 (SEM). This permits continued use of previously accumulated SPA databases. The coefficient of variation for repeat
measurements by DEXA was 1.2% and by SPA 1.6%. Examination time by DEXA was 6–7 minutes, about 45% shorter than the corresponding
SPA determinations. DEXA is the superior method for evaluation of the radius, as it provides faster and more precise measurements
in clinical practice. 相似文献
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R J Belsole S F Quinn T L Greene M E Beatty J M Rayhack 《The Journal of bone and joint surgery. American volume》1990,72(6):846-851
Digital subtraction arthrography of the wrist was used to identify abnormalities in eighty-six (60 per cent) of 139 patients during a fifteen-month period. Multiple abnormalities were noted in thirty-four (25 per cent) of the wrists. The clinical signs and symptoms in the eighty-six wrists did not always correlate with the defects that were seen on the arthrograms. Three of five patients who had an isolated tear of the scapholunate ligament, six of thirteen who had an isolated tear of the lunotriquetral ligament, and seven of nineteen who had an isolated tear of the triangular fibrocartilage complex also had signs and symptoms on the opposite side of the wrist. Many of the lesions that were seen on arthrography may have been serendipitous, degenerative, or unrelated to a specific injury. There was a high prevalence of positive ulnar variance in patients who had at least one ulnar abnormality. Capsular tears, most often seen on the radiovolar aspect of the wrist, were best outlined by contrast medium injected into the radiocarpal joint. The arthroscopic findings differed from the arthrographic findings in five of the twenty patients in whom both studies were done. The three-compartment technique of injection is a valuable diagnostic tool. Injections of contrast medium into the distal radio-ulnar joint outlined five of thirteen tears of the triangular fibrocartilage complex that were not seen after injection into the radiocarpal joint. Of the eleven tears that were seen after injection into the radiocarpal joint, five were not seen when contrast medium was injected into the distal radio-ulnar joint. 相似文献
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F Gattoni A Avogadro U Baldini C Pozzato M T Bonfanti D Gandini L Franch C Uslenghi 《British journal of urology》1988,62(3):214-218
Intravenous and intra-arterial digital subtraction angiography (DSA) was performed in 88 patients: 34 with tumours, 10 with renal trauma, 26 with suspected renovascular hypertension, 6 with vascular impression on the renal pelvis, 8 with nephrolithiasis and 4 with sonographically abnormal kidneys. Venous and arterial DSA always gave diagnostically useful images. Intravenous DSA is valuable in patients with suspected renovascular hypertension or after vascular surgery, percutaneous transluminal angioplasty and transcatheter embolisation. Arterial DSA is preferable to venous DSA in other clinical situations, particularly in the evaluation of renal tumours, and may be recommended in preference to conventional angiography. 相似文献
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Dual-energy X-ray absorptiometry (DXA) of the lumbar spine provides an estimation of the bone mineral content (BMC) corrected by the projected area of the spine and expressed in g/cm2. This two-dimensional estimate of the bone mineral density (BMD) is influenced by the skeletal size, assessed by the subject's height. In order to obtain an estimate of the volumetric BMD, we measured BMC with a new DXA device (Sophos L-XRA) equipped with 24 detectors and a rotating arm, thus allowing scanning of the lumbar spine in both an anteroposterior (AP) projection and a lateral (LAT) projection with the patient in a supine position. Comparison between the results obtained on the third (L3) and fourth (L4) lumbar vertebrae with automatic or manual analysis showed that the best precision was obtained with the lateral measurement of L3 alone with an automatic soft tissue baseline determination. Results were expressed in g/cm2 and in g/cm3 (by dividing the g/cm2 value by the width (AP area divided by the height of the vertebra) of L3), and were compared with those obtained by conventional AP scanning of L2–4 (g/cm2). The in vivo precision error evaluated by triplicate measurements on 10 controls was 17 mg/cm2 (1.96%) and 5.2 mg/cm3 (2.31%) for LAT L3 as compared with 13 mg/cm2 (1.15%) for AP L2–4. Volumetric BMD (g/cm3) measurement, assessed in vitro on a calibrated hydroxyapatite phantom, and the absolute values obtained in normal women were similar to those obtained by quantitative computed tomography (QCT). In 39 healthy adults (27±4 years) BMD expressed in g/cm2 was correlated with height (r=0.36 for AP L2–4 andr=0.39 for LAT L3;p<0.05 for both) but not with LAT L3 BMD expressed in g/cm3 (r=0.02; NS). The age-related bone loss between 30 and 80 years of age, derived from the normal values for 101 healthy women (age range 19–73 years) was 36% for AP L2–4, 52% for LAT L3 (g/cm2) and 60% for LAT L3 (g/cm3). In a group of 22 women with untreated postmenopausal vertebral osteoporosis (one or more non-traumatic vertebral crush fractures) the mean decrease in BMD, expressed as a percentage of the age-adjusted normal value, was more pronounced (p<0.001) for LAT L3 BMD (–21% in g/cm2,Z-score –1.08; –22% in g/cm3,Z-score –0.94) than for AP L2–4 BMD (–9%,Z-score –0.66). We conclude that: 1) BMD measurement restricted to the vertebral body of L3 can be achieved with a low precision error with this new DXA device; 2) it allows an estimate of the volumetric density (g/cm3) which does not seem to be influenced by skeletal size; 3) lateral BMD appears to be more sensitive than conventional AP scanning for assessing age-related bone loss and should be useful in the investigation of trabecular osteoporosis. 相似文献
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Temmerman OP Raijmakers PG Berkhof J David EF Pijpers R Molenaar MA Hoekstra OS Teule GJ Heyligers IC 《Archives of orthopaedic and trauma surgery》2006,126(5):316-323
Background: Plain radiography, subtraction arthrography, nuclear arthrography, and bone scintigraphy are imaging techniques commonly used to identify aseptic femoral component loosening. Controversy exists about the relative utility of these techniques. Patients and methods: We evaluated the diagnostic accuracy and interobserver reliability of the four techniques in 78 consecutive patients (mean age 70 years, range 29–88 years) referred for evaluation of their femoral hip prostheses. The standard evaluation protocol consisted of plain radiography followed by subtraction arthrography, nuclear arthrography, and bone scintigraphy. Surgery or the subsequent clinical course of the patient was used as gold standard. Results: Overall, plain radiography had a sensitivity and specificity of 81 and 74%, respectively. Subtraction arthrography had a sensitivity of 47% and a specificity of 78%. Nuclear arthrography had a sensitivity of 69% and a specificity of 76%, and bone scintigraphy had a sensitivity of 88% with a specificity of 50%. Conclusion: We found considerable interobserver variability in all four techniques. Multivariate regression analysis revealed that bone scintigraphy and nuclear arthrography together made a significant contribution to the diagnosis when used in combination with plain radiography and are, when plain radiography is inconclusive, useful additional diagnostic techniques for the detection of femoral component loosening. 相似文献
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Kyung-Hoe Huh Sam-Sun Lee In-Seong Jeon Won-Jin Yi Min-Suk Heo Soon-Chul Choi 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2005,100(6):750-755
OBJECTIVE: This study compared the difference between 3 intraoral radiographic techniques on digital subtraction radiography (DSR) in vivo that are commonly used in a clinical setting. STUDY DESIGN: We evaluated and statistically analyzed the errors in the DSR image in 6 regions with 3 radiographic techniques: paralleling technique with a bite block attached to XCP, paralleling technique using XCP, and bisecting-angle technique. RESULTS: The amount of error using the bisecting-angle technique was too large for DSR, compared to that of the paralleling technique with a bite block attached to XCP. In the mandibular anterior region, the paralleling technique using XCP was not different from paralleling technique with a bite block attached to XCP. The lowest degree of error was present in the anterior region whereas the highest was present in the molar region. CONCLUSION: Bisecting-angle technique should be avoided, and paralleling technique using XCP can be used in the mandibular anterior region for DSR. 相似文献
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Noriyuki Tohnosu Kazuaki Okuyama Yoshio Koide Toshiyuki Kikuchi Tomotaka Awano Hiromasa Matsubara Tomoaki Sano Hitoshi Nakaichi Yutaka Funami Kazuyuki Matsushita Kaichi Isono 《Surgery today》1993,23(8):704-710
Ultrasound (US) was compared with mammography (MMG), computed tomography (CT), and digital subtraction angiography (DSA) in its effectiveness to detect breast cancer masses and metastatic axillary nodes. Forty-seven breast cancer patients who all underwent MMG, US, CT, and DSA preoperatively in our institution between 1986 and 1990 were studied. US was able to detect tumors in all cases regardless of tumor size, whereas DSA detected T1-size tumors and MMG detected T2-size tumors in 40% and 64.7% of cases, respectively, being specifically inferior to US. It was found that MMG was least likely to detect papillotubular carcinoma, although microcalcification alone without a tumor mass on MMG improved detectability from 46.2% to 76.9%, according to the histological type. CT was found to be most sensitive to axillary node metastases (81.8%), followed by US (72.7%), but DSA was significantly unfavorable (42.9%). Thus, we concluded that US was superior to MMG, CT, and DSA for detecting breast cancer masses, but that CT was more advantageous than US, while DSA was of little value for evaluating axillary nodal status. 相似文献