Digital Chest Radiography with an Amorphous Silicon Flat-Panel-Detector Versus a Storage-Phosphor System: Comparison of Soft-Copy Images

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.

The Clinical Significance of Normal Mammograms and Normal Sonograms in Patients with Palpable Abnormalities of the Breast

PURPOSE: We wanted to evaluate the clinical significance of normal mammograms and normal sonograms in patients with palpable abnormalities of the breast. MATERIALS AND METHODS: From Apr 2003 to Feb 2005, 107 patients with 113 palpable abnormalities who had combined normal sonographic and normal mammographic findings were retrospectively studied. The evaluated parameters included age of the patients, the clinical referrals, the distribution of the locations of the palpable abnormalities, whether there was a past surgical history, the mammographic densities and the sonographic echo patterns (purely hyperechoic fibrous tissue, mixed fibroglandular breast tissue, predominantly isoechoic glandular tissue and isoechoic subcutaneous fat tissue) at the sites of clinical concern, whether there was a change in imaging and/or the physical examination results at follow-up, and whether there were biopsy results. This study period was chosen to allow a follow-up period of at least 12 months. RESULTS: The patients' ages ranged from 22 to 66 years (mean age: 48.8 years) and 62 (58%) of the 107 patients were between 41 and 50 years old (58%). The most common location of the palpable abnormalities was the upper outer portion of the breast (45%) and most of the mammographic densities were dense patterns (BI-RADS Type 3 or 4: 91%). Our cases showed similar distribution for all the types of sonographic echo patterns. 23 patients underwent biopsy; all the biopsy specimens were benign. For the 84 patients with 90 palpable abnormalities who were followed, there was no interval development of breast cancer in the areas of clinical concern. CONCLUSION: Our results suggest that we can follow up and prevent unnecessary biopsies in women with palpable abnormalities when both the mammography and ultrasonography show normal tissue, but this study was limited by its small sample size. Therefore, a larger study will be needed to better define the negative predictive value of combined normal sonographic and mammographic findings.

The Clinical Significance of Normal Mammograms and Normal Sonograms in Patients with Palpable Abnormalities of the Breast

PURPOSE: We wanted to evaluate the clinical significance of normal mammograms and normal sonograms in patients with palpable abnormalities of the breast. MATERIALS AND METHODS: From Apr 2003 to Feb 2005, 107 patients with 113 palpable abnormalities who had combined normal sonographic and normal mammographic findings were retrospectively studied. The evaluated parameters included age of the patients, the clinical referrals, the distribution of the locations of the palpable abnormalities, whether there was a past surgical history, the mammographic densities and the sonographic echo patterns (purely hyperechoic fibrous tissue, mixed fibroglandular breast tissue, predominantly isoechoic glandular tissue and isoechoic subcutaneous fat tissue) at the sites of clinical concern, whether there was a change in imaging and/or the physical examination results at follow-up, and whether there were biopsy results. This study period was chosen to allow a follow-up period of at least 12 months. RESULTS: The patients' ages ranged from 22 to 66 years (mean age: 48.8 years) and 62 (58%) of the 107 patients were between 41 and 50 years old (58%). The most common location of the palpable abnormalities was the upper outer portion of the breast (45%) and most of the mammographic densities were dense patterns (BI-RADS Type 3 or 4: 91%). Our cases showed similar distribution for all the types of sonographic echo patterns. 23 patients underwent biopsy; all the biopsy specimens were benign. For the 84 patients with 90 palpable abnormalities who were followed, there was no interval development of breast cancer in the areas of clinical concern. CONCLUSION: Our results suggest that we can follow up and prevent unnecessary biopsies in women with palpable abnormalities when both the mammography and ultrasonography show normal tissue, but this study was limited by its small sample size. Therefore, a larger study will be needed to better define the negative predictive value of combined normal sonographic and mammographic findings.

Differential Diagnosis of Solitary Pulmonary Nodule: Chest Radiography vs CT

PURPOSE: The purpose of this study was to compare the diagnostic accuracies of chest radiographs and chest CTin the diagnosis of a solitary pulmonary nodule(SPN), and to determine the role of CT and CT findings which aid inthe differential diagnosis of nodules. MATERIALS AND METHODS: A retrospective study was done on 54 patients inwhom SPN was found on chest radiographs and chest CT was carried out. The study involved 25 benign and 29 malignant nodules, confirmed histopathologically and clinically. Chest radiographs and CT scans were reviewed separately in randomized order by two chest radiologists who for each film listed the three most likely diagnose sin descending order. The radiologists recorded the confidence value of the most probable diagnosis, and also the marginal and internal characteristics of nodules and their size, as nodules seen on chest CT scans. RESULTS: Diagnostic rates in the differential diagnosis of benign and malignant nodules were 65.7% by radiography and 77.8% by CT. Correct first-choice diagnosis was by radiography in 30.6 % of cases, and by CT in 41.7%. Using radiographs, and the correct diagnosis was among the top-three choices in 61.1% of cases ; with CT, the corresponding figure was 76.8%. Overall, a confident diagnosis was reached more often with the CT(41.7%) than with the chest radiograph(21.4%) ; diagnaotic accuracy was 60.0% and 52.2%, respectively. CT findings which imply abenign nodule include smooth margins and diffuse internal calcifications, whereas marginal lobulations, air-bronchograms, internal low density without cavitation, eccentric calcifications, and large size suggest malignancy. We faund that CT findings such as well-defined margins, spiculations, pleural tail or internal homogeneity did not contribute in the differentiation between benign and malignant nodules. CONCLUSION: CT issuperior to chest radiography in the differential diagnosis of the solitary pulmonary nodule. Using CT, diagnosis was accurate and made with a high level of confidence, especially with the application of CT findings which aid inthe differential diagnosis of nodules.