Measurement of focal ground-glass opacity diameters on CT images: interobserver agreement in regard to identifying increases in the size of ground-glass opacities.

PURPOSE: To evaluate interobserver agreement in regard to measurements of focal ground-glass opacities (GGO) diameters on computed tomography (CT) images to identify increases in the size of GGOs. MATERIALS AND METHODS: Approval by the institutional review board and informed consent by the patients were obtained. Ten GGOs (mean size, 10.4 mm; range, 6.5-15 mm), one each in 10 patients (mean age, 65.9 years; range, 58-78 years), were used to make the diameter measurements. Eleven radiologists independently measured the diameters of the GGOs on a total of 40 thin-section CT images (the first [n = 10], the second [n = 10], and the third [n = 10] follow-up CT examinations and remeasurement of the first [n = 10] follow-up CT examinations) without comparing time-lapse CT images. Interobserver agreement was assessed by means of Bland-Altman plots. RESULTS: The smallest range of the 95% limits of interobserver agreement between the members of the 55 pairs of the 11 radiologists in regard to maximal diameter was -1.14 to 1.72 mm, and the largest range was -7.7 to 1.7 mm. The mean value of the lower limit of the 95% limits of agreement was -3.1 ± 1.4 mm, and the mean value of their upper limit was 2.5 ± 1.1 mm. CONCLUSION: When measurements are made by any two radiologists, an increase in the length of the maximal diameter of more than 1.72 mm would be necessary in order to be able to state that the maximal diameter of a particular GGO had actually increased.

Magnetic resonance imaging (MRI) detection of synovitis and bone lesions of the wrists and finger joints in early-stage rheumatoid arthritis: comparison of the accuracy of plain MRI-based findings and gadolinium-diethylenetriamine pentaacetic acid-enhanced MRI-based findings.

OBJECTIVE: To explore whether synovitis and bone lesions in the wrists and finger joints visualized by plain magnetic resonance imaging (MRI)-based findings correspond exactly or not to those judged by gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA)-enhanced MRI-based findings. METHODS: Magnetic resonance imaging of the wrists and finger joints of both hands were examined in 51 early-stage rheumatoid arthritis (RA) patients whose median disease duration from the onset of articular manifestations to entry was 5 months, by both plain (T1 and short-time inversion recovery images) and Gd-DTPA-enhanced MRI (post-contrast fat-suppressed T1-weighted images) simultaneously. We focused on 15 sites per hand, to examine the presence of synovitis and bone lesions (bone edema and bone erosion). Gd-DTPA-enhanced MRI-based findings were considered "true" lesions, and we evaluated the accuracy of plain MRI-based findings in comparison to Gd-DTPA-enhanced MRI-based findings. RESULTS: Synovitis, judged by plain MRI-based findings, appeared as false-positive at pretty frequency; thus, the specificity, positive predictive value and accuracy of the findings were low. The rate of enhancement (E-rate) in false-positive synovitis sites was significantly low compared with true-positive synovitis sites where Gd-DTPA enhancement appears. In contrast to synovitis, the false-positivity of bone lesions, judged by plain MRI-based findings, was very low compared with Gd-DTPA-enhanced MRI-based findings. CONCLUSION: Synovitis judged by plain MRI-based findings is sometimes considered false-positive especially in sites where synovitis is mild. However, plain MRI is effective in identifying bone lesions in the wrist and finger joints in early-stage RA.

[Imaging of fungal infection in diabetic patients].

Diabetes mellitus is an important risk factor for infections caused by fungi. Candidiasis is the most frequent fungal infection in diabetic patients, followed by aspergillosis, cryptococcosis, and mucormycosis. Fungal infection is a serious cause of morbidity and mortality in immunocompromised hosts. Diagnostic imaging plays an important role in the early diagnosis and treatment for these infections, especially for the pulmonary infection. Although imaging findings of pulmonary fungal infection are various, ground-glass opacity surrounding nodules or masses called "CT halo sign" is a relatively characteristic finding. In this review, we discuss the imaging finding of fungal infection particularly focusing on the pulmonary lesions.

Application of an artificial neural network to high-resolution CT: usefulness in differential diagnosis of diffuse lung disease.

OBJECTIVE: The purpose of our study was to evaluate the diagnostic performance of an artificial neural network (ANN) in differentiating among certain diffuse lung diseases using high-resolution CT (HRCT) and the effect of ANN output on radiologists' diagnostic performance. MATERIALS AND METHODS: We selected 130 clinical cases of diffuse lung disease. We used a single three-layer, feed-forward ANN with a back-propagation algorithm. The ANN was designed to differentiate among 11 diffuse lung diseases by using 10 clinical parameters and 23 HRCT features. Therefore, the ANN consisted of 33 input units and 11 output units. Subjective ratings for 23 HRCT features were provided independently by eight radiologists. All clinical cases were used for training and testing of the ANN by implementing a round-robin technique. In the observer test, a subset of 45 cases was selected from the database of 130 cases. HRCT images were viewed by eight radiologists first without and then with ANN output. The radiologists' performance was evaluated with receiver operating characteristic (ROC) analysis with a continuous rating scale. RESULTS: The average area under the ROC curve for ANN performance obtained with all clinical parameters and HRCT features was 0.956. The diagnostic performance of four chest radiologists and four general radiologists was increased from 0.986 to 0.992 (p = 0.071) and 0.958 and 0.971 (p < 0.001), respectively, when they used the ANN output based on their own feature ratings. CONCLUSION: The ANN can provide a useful output as a second opinion to improve general radiologists' diagnostic performance in the differential diagnosis of certain diffuse lung diseases using HRCT.

Artificial neural networks (ANNs) for differential diagnosis of interstitial lung disease: results of a simulation test with actual clinical cases.

RATIONALE AND OBJECTIVES: To evaluate the performance of an artificial neural network (ANN) scheme with use of consecutive clinical cases and its effect on radiologists with an observer test. MATERIALS AND METHODS: Artificial neural networks were designed to distinguish among 11 interstitial lung diseases on the basis of 26 inputs (16 radiologic findings, 10 clinical parameters). Chest radiographs of 96 consecutive cases with interstitial lung disease were used. Five radiologists independently rated their radiologic findings on the 96 chest radiographs. Based on their ratings of radiologic findings and clinical parameters obtained from the hospital information system, the output values indicating the likelihood of each of the 11 interstitial lung diseases were determined. Subsequently, 30 cases were selected from these 96 cases for an observer test. Five radiologists marked their confidence levels for diagnosis of 11 possible diseases in each case without and with ANN output. The performance of ANNs and radiologists was evaluated by receiver operating characteristic analysis based on their outputs and on confidence levels, respectively. RESULTS; The average Az value (area under the receiver operating characteristic curve) indicating ANN performance for the 96 consecutive cases was 0.85 +/- 0.03. The average Az values indicating radiologists' performance without and with ANN outputs were 0.81 +/- 0.11 and 0.87 +/- 0.06, respectively. The diagnostic accuracy was improved significantly when radiologists read chest radiographs with ANN outputs (P < .05). CONCLUSION: Artificial neural networks for differential diagnosis of interstitial lung disease may be useful in clinical situations, and radiologists may be able to utilize the ANN output to their advantage in the differential diagnosis of interstitial lung disease on chest radiographs.

Chronic aortic dissection complicated by disseminated intravascular coagulation: successful treatment with endovascular stent-grafting.

PURPOSE: To report endovascular repair of a chronic aortic dissection complicated by disseminated intravascular coagulation (DIC). CASE REPORT: A 61-year-old man developed DIC associated with a chronic Stanford type B aortic dissection that occurred during cardiac catheterization 12 years earlier. At the current admission, computed tomography showed a partially thrombosed false lumen extending from the aortic arch to the left common iliac artery. On angiography, entry and re-entry tears were identified at the right subclavian and left common iliac arteries, respectively. After stent-graft implantation at the entry and re-entry sites, not only was the false lumen completely thrombosed but the DIC also resolved. The patient is doing well with no complication at 16 months after treatment. CONCLUSIONS: Endovascular stent-grafting is an acceptable alternative to surgical repair for aortic dissection accompanied by DIC.

Coil embolization of iliac artery aneurysms developing after abdominal aortic aneurysm repair with a conventional bifurcated graft.

PURPOSE: To evaluate the efficacy of embolizing iliac artery aneurysms (IAAs) developing after abdominal aortic aneurysm (AAA) repair. METHODS: The records of 6 patients (5 men; mean age 79 years, range 61-87) with unilateral (n=3) or bilateral (n=3) IAAs that had developed after AAA repair were reviewed. In all patients, the limbs of the bifurcated graft were anastomosed end-to-end or end-to-side with the external iliac arteries during AAA repair. Before embolization, superior mesenteric artery (SMA) arteriography was done in all patients to evaluate collateral pathways to the inferior mesenteric artery (IMA). RESULTS: The unilateral IAAs were treated by proximal and distal embolization. In 2 patients with bilateral IAAs, SMA angiography showed sufficient collateral flow to the IMA, so the aneurysms were treated by proximal embolization and packing. In the other bilateral IAA case, the left 6-cm IAA was treated by proximal and distal embolization, while the contralateral 3-cm IAA was not embolized because angiography demonstrated inadequate collateral flow to the IMA, indicating a possible risk of colon ischemia if both IAAs were embolized. Immediate postprocedural angiography in all patients showed complete exclusion of the IAAs. Mild buttock claudication occurred in 1 patient. There were no episodes of rupture over a mean 46-month follow-up. CONCLUSIONS: Embolization is a safe and effective alternative to open surgery for the treatment of IAAs that develop after AAA repair. However, before embolization, angiographic evaluation of collateral pathways to the IMA is essential to reduce the risk of colon ischemia.

Change in the composition of the microflora on vacuum-packaged beef during chiller storage.

Five fresh beefcut samples were divided into 10 pieces, respectively, vacuum-packaged and stored at 2 degrees C for up to 6 weeks. The average pH values of five pieces from five beef samples were 5.62 +/- 0.04 at the start of storage and 5.12 +/- 0.07 after 6 weeks of storage. The pieces were homogenized, diluted and cultivated at weekly intervals on glucose-blood-liver (BL), de Man Rogosa and Sharpe (MRS) and trypticase soya (TS) agars at 7 degrees C for 10-14 days. From plates with 30-300 colonies, or the highest number if below 30, 15 colonies were randomly picked from each of the three media used for each beef sample. Based on morphologies, SDS-PAGE whole-cell protein profiles and physio-chemical characteristics, a total of 1493 strains isolated were identified as Brochothrix thermosphacta (64), Carnobacterium divergens (79), Carnobacterium piscicola (27), Lactobacillus algidus (637), Lactobacillus sp. (4), Lactococcus piscium (270), Leuconostoc gelidum (375), Acinetobacter (3), Aeromonas (1), Bacillus (10), Corynebacterium (3), Enterobacteriaceae (1), Pseudomonas (13) or Psychrobacter (6). A wider range of organisms was isolated from TS (13 organisms) and BL (7) agars than from MRS agar (3). Leuc. gelidum, Lc. piscium and L. algidas increased in numbers during the first 3 weeks of storage from about 5 x 10(3) cfu/g to the level of about 10(8) cfu/g and persisted at this level thereafter. C. divergens and C. piscicola were inconsistently detected, but seemed to persist at the relatively low level of about 5 x 10(7) cfu/g during the last 3 weeks of storage. B. thermosphacta increased to the level of about 7 x 10(5) cfu/g during the first 2 weeks of storage, but was not detected thereafter. Remaining organisms were detected sporadically at levels of <3.5 x 10(2) cfu/g during the first 2 weeks of storage.