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Controlled directional transport of molecules is essential to complex natural systems, from cellular transport up to organismal circulatory systems. In contrast to these natural systems, synthetic systems that enable transport of molecules between several spatial locations on the macroscopic scale, when external stimuli are applied, remain to be explored. Now, the transfer of a supramolecular cage is reported with controlled directionality between three phases, based on a cage that responds reversibly in two distinct ways to different anions. Notably, circulatory phase transfer of the cage was demonstrated based on a system where the three layers of solvent are arranged within a circular track. The direction of circulation between solvent phases depended upon the order of addition of anions., (© 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

This study investigated if scores on tests of personal qualities are affected by whether they will determine selection decisions ("high stakes") or not; and whether they are stable for individuals and groups across a four-year medical course. Two tests, one assessing values and one assessing components of personality, were administered either at the same time as a medical university entrance exam (first cohort; N  = 216), or after entry was confirmed (second cohort; N  = 142). Both cohorts took the tests again after four years of medical school. Analysis of variance was used to compare group mean scores and interactions, and correlation coefficients to measure temporal reliability. The high stakes cohort initially presented themselves in a significantly more positive light on the personality test. After four years of medical school scores on both tests changed significantly, towards more communitarian values and less empathic attitudes. Thus, personality scores were affected by both the conditions under which the initial tests were conducted and by the passage of time, but values only by the passage of time. Before and after scores were significantly correlated.

Development of supramolecular methods to further activate a highly reactive intermediate is a fascinating strategy to create novel potent catalysts for activation of inert chemicals. Herein, a supramolecular approach to enhance the oxidizing ability of a high-valent oxo species of a nitrido-bridged iron porphyrinoid dimer that is a known potent molecular catalyst for light alkane oxidation is reported. For this purpose, a nitrido-bridged dinuclear iron complex of porphyrin-phthalocyanine heterodimer 3 5+ , which is connected through a fourfold rotaxane, was prepared. Heterodimer 3 5+ catalyzed ethane oxidation in the presence of H 2 O 2 at a relatively low temperature. The site-selective complexation of 3 5+ with an additional anionic porphyrin (TPPS 4- ) through π-π stacking and electrostatic interactions afforded a stable 1:1 complex. It was demonstrated that the supramolecular post-synthetic modification of 3 5+ enhances its catalytic activity efficiently. Moreover, supramolecular conjugates achieved higher catalytic ethane oxidation activity than nitrido-bridged iron phthalocyanine dimer, which is the most potent iron-oxo-based molecular catalyst for light-alkane oxidation reported so far. Electrochemical measurements proved that the electronic perturbation from TPPS 4- to 3 5+ enhanced the catalytic activity., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Because drug-induced interstitial pneumonia (DIP) is a serious adverse drug reaction, its quantitative risk with individual medications should be taken into due consideration when selecting a medicine. We developed an algorithm to detect DIP using medical record data accumulated in a hospital. Chest computed tomography (CT) is mainly used for the diagnosis of IP, and chest X-ray reports, KL-6, and SP-D values are used to support the diagnosis. The presence of IP in the reports was assessed by a method using natural language-processing, in which IP was estimated according to the product of the likelihood ratio of characteristic keywords in each report. The sensitivity and the specificity of the method for chest CT reports were 0.92 and 0.97, while those for chest X-ray reports were 0.83 and 1, respectively. The occurrence of DIP was estimated by the patterns of presence of IP before, during, and after the administration of the target medicine. The occurrence rate of DIP in cases administered Gefitinib; Methotrexate (MTX); Tegafur, Gimeracil, and Oteracil potassium (TS-1); and Tegafur and Uracil (UTF) was 6.0%, 2.3%, 1.4%, and 0.7%, respectively. The estimated DIP cases were checked by having the medical records independently reviewed by medical doctors. By chart review, the positive predictive values of DIP against Gefitinib, MTX, TS-1, and UFT were 69.2%, 44.4%, 58.6%, and 77.8%, respectively. Although the cases extracted by this method included some that did not have DIP, this method can estimate the relative risk of DIP between medicines.

Cofacial assemblies of metalloporphyrinoids represent a fascinating platform for the fabrication of novel functional molecular assemblies based on π-π, d-d, and d-π interactions between components. In this paper, we present a novel synthetic strategy for the programmable arrangement of different metal ions inside a cofacially stacked trimer of porphyrinoids. A combination of two different assemblies was utilized for our purpose: a tetracationic fourfold rotaxane heterodimer between a porphyrin with four alkylammonium chains and a phthalocyanine bearing four peripheral crown ethers, and a stacked assembly between the fourfold rotaxane heterodimer and an additional tetraanionic porphyrin. Three metal ions, namely Cu(ii), Ag(ii), and Au(iii), were arranged inside the cofacially stacked assembly of three porphyrinoids. Moreover, paramagnetic Cu(ii) ions were arranged inside a cofacially stacked heterotrimer of porphyrinoids and were precisely programmed, affording the desired spin-spin communications as readable information. These results indicated that the developed strategy is effective for arranging various metal ions in cofacially stacked assemblies of porphyrinoids toward the creation of molecular tags or bar codes.

A μ-oxo-dinuclear iron complex of a supramolecular porphyrin-phthalocyanine conjugate was synthesized and its catalytic electrochemical oxygen reduction properties were investigated. In the conjugate, porphyrin and phthalocyanine units were connected to form a cofacial dimeric structure through a flexible fourfold rotaxane linkage, which was advantageous for accommodating small substrates between the iron centers. The conjugate showed efficient catalytic properties, at more positive potentials than those of other reported dinuclear porphyrinoid iron complexes, to selectively afford water through a four-electron reduction process., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Krüppel-like factor 5 (KLF5) transcriptionally controls the proliferation-differentiation balance of epithelium and is overexpressed in carcinomas. Although genomic region modifying KLF5 expression is widespread in different types of cells, the region that commonly regulates basal expression of the genes across cell-types is uncertain. In this study we determined the minimal essential region for the expression and its regulatory transcription factors using oral carcinoma cells. A reporter assay defined a 186bp region downstream of the transcription start site and a cluster of six GC boxes (GC1-GC6) as the minimal essential region. Mutation in the GC1 or GC6 regions but not other GC boxes significantly decreased the reporter expression. The decrease by the GC1 mutation was reproduced in the 2kbp full-length promoter, but not by the GC6 mutation. Additionally, specificity proteins (Sp) that can be expressed in epithelial cells and bind GC box, Sp3 co-localized with KLF5 in oral epithelium and carcinomas and chromatin immunoprecipitation analyses showed Sp3 as the prime GC1-binding protein. Inhibition of Sp-GC box binding by mithramycin A and knockdown of Sp3 by the short interfering RNA decreased expression of the reporter gene and endogenous KLF5. These data demonstrate that a 186bp region is the minimal essential region and that Sp3-GC1 binding is essential to the basal expression of KLF5., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The redox potential of a supramolecular porphyrin-phthalocyanine heterodimer was perturbed by the stacking of an extra metalloporphyrin to the phthalocyanine. This stacking gave rise to π-π and electrostatic interactions between the tetracationic dimer and the tetraanionic metalloporphyrin, with a Au(iii) metalloporphyrin exhibiting a larger effect than Cu(ii) and Pd(ii) complexes among square planar complexes.

To improve the efficiency of clinical research, we developed a system to integrate electronic medical records (EMRs) and the electronic data capture system (EDC). EDC is divided into case report form (CRF) reporter and CDMS with CRF receiver with data communication using the operational data model (ODM). The CRF reporter is incorporated into the EMR to share data witth the EMR. In the data transcription type, doctors enter data using a progress note template, which are transmitted to the reporter template. It then generates the ODM. In the direct record type, reporter templates open from the progress note and generate narrative text to make record in the progress note. The configuration files for a study are delivered from the contents server to minimize the setup. This system has been used for 15 clinical studies including 3 clinical trials. This system can save labor and financial costs in clinical research.

Electronic health record (EHR) systems are necessary for the sharing of medical information between care delivery organizations (CDOs). We developed a document-based EHR system in which all of the PDF documents that are stored in our electronic medical record system can be disclosed to selected target CDOs. An access control list (ACL) file was designed based on the HL7 CDA header to manage the information that is disclosed.

Early diagnosis and treatment of pancreatic cancer is challenging. We attempted to find diagnostic rules for pancreatic cancer from laboratory data in the Osaka University Hospital's data warehouse using Bayesian estimation. We calculated the pretest odds based on the number of laboratory tests and the cutoff value at which the diagnostic accuracy is over 20%. By this method, we identified diagnostic rules of 6 types for one item and 79 types for 2 items. Pancreatic cancer is difficult to detect from only general laboratory tests. However, this method may be promising in early diagnosis.

Issues related to ensuring patient privacy and data ownership in clinical repositories prevent the growth of translational research. Previous studies have used an aggregator agent to obscure clinical repositories from the data user, and to ensure the privacy of output using statistical disclosure control. However, there remain several issues that must be considered. One such issue is that a data breach may occur when multiple nodes conspire. Another is that the agent may eavesdrop on or leak a user's queries and their results. We have implemented a secure computing method so that the data used by each party can be kept confidential even if all of the other parties conspire to crack the data. We deployed our implementation at three geographically distributed nodes connected to a high-speed layer two network. The performance of our method, with respect to processing times, suggests suitability for practical use.

There is a great need to reuse data stored in electronic medical records (EMR) databases for clinical research. We previously reported the development of a system in which progress notes and case report forms (CRFs) were simultaneously recorded using a template in the EMR in order to exclude redundant data entry. To make the data collection process more efficient, we are developing a system in which the data originally stored in the EMR database can be populated within a frame in a template. We developed interface plugin modules that retrieve data from the databases of other EMR applications. A universal keyword written in a template master is converted to a local code using a data conversion table, then the objective data is retrieved from the corresponding database. The template element data, which are entered by a template, are stored in the template element database. To retrieve the data entered by other templates, the objective data is designated by the template element code with the template code, or by the concept code if it is written for the element. When the application systems in the EMR generate documents, they also generate a PDF file and a corresponding document profile XML, which includes important data, and send them to the document archive server and the data sharing saver, respectively. In the data sharing server, the data are represented by an item with an item code with a document class code and its value. By linking a concept code to an item identifier, an objective data can be retrieved by designating a concept code. We employed a flexible strategy in which a unique identifier for a hospital is initially attached to all of the data that the hospital generates. The identifier is secondarily linked with concept codes. The data that are not linked with a concept code can also be retrieved using the unique identifier of the hospital. This strategy makes it possible to reuse any of a hospital's data.

In clinical trials, investigating the ratio of patients with each disease who are treated in a hospital is important for determining the number of patients who are allocated to hospitals. The Japanese health insurance claims data includes standardized disease and medicine data. However, the disease data has some problems in terms of reliability, because the healed diseases are sometimes not deleted or because a disease that a patient does not actually have is registered to claim the cost of the examination. On the other hand, therapeutic medicines are administered to target particular diseases. In this study, we developed a system for estimating the number of patients with each disease using the disease data and the therapeutic medicine data. We converted the ICD-10 code to a 4-grade classification code so that we could predict the diseases in the shallow layer (e.g. gastrointestinal disease) when it was difficult to predict the precise diseases in the deep layer (e.g. gastric ulcers). A table showing the disease code and the corresponding therapeutic medicine code was provided by the Japan Pharmaceutical Information Center (JAPIC). We calculated the disease probability score from the diseases and therapeutic medicines and recorded the predicted disease. For the system evaluation, we used the health insurance claims data from Osaka University Hospital for January 2015. A total of 58,526 diseases were predicted from the health insurance claims data of 18,393 patients. One hundred twenty patients were randomly extracted for use in a chart review that was performed by an expert physician. Two hundred twenty-four of 329 predicted diseases, were correctly predicted; 56 were reasonably predicted, and 49 were incorrectly predicted. The main disease was correctly predicted in 71 patients. In conclusion, we could estimate the number of patients with each disease using the health insurance claims data with a certain degree of accuracy.

Proliferation-differentiation balance of epithelial cells is regulated by Krüppel-like factors (KLF) 4 and 5, and the unbalanced expression relates to carcinoma progression. However, little is known about the expression and role in oral carcinomas. This study examined expression of KLF4 and KLF 5 in the carcinomas by immunohistochemistry (n = 67) and the involvement in proliferation and differentiation of carcinoma cells. KLF4 was detected in keratinizing carcinoma cells and KLF5 in non-keratinizing cells. KLF4 staining declined in the patient with lymph node metastasis (P < 0.05) and in parallel with the histological dedifferentiation (P = 0.09). Exogenous overexpression of KLF4 arranged cells in a cobble-like structure with desmosomes and KLF5 elongated cells like fibroblasts without desmosomes. KLF4 suppressed fibronectin expression, and KLF5 down-regulated and degraded E-cadherin. The proliferation was not affected by KLFs. Thus, down-regulation of KLF4 and up-regulation of KLF5 may stimulate oral carcinoma progression through the dedifferentiation of carcinoma cells.

Adverse events are detected by monitoring the patient's status, including blood test results. However, it is difficult to identify all adverse events based on recognition by individual doctors. We developed a system that can be used to detect hematotoxicity adverse events according to blood test results recorded in an electronic medical record system. The blood test results were graded based on Common Terminology Criteria for Adverse Events (CTCAE) and changes in the blood test results (Up, Down, Flat) were assessed according to the variation in the grade. The changes in the blood test and injection data were stored in a database. By comparing the date of injection and start and end dates of the change in the blood test results, adverse events related to a designated drug were detected. Using this method, we searched for the occurrence of serious adverse events (CTCAE Grades 3 or 4) concerning WBC, ALT and creatinine related to paclitaxel at Osaka University Hospital. The rate of occurrence of a decreased WBC count, increased ALT level and increased creatinine level was 36.0%, 0.6% and 0.4%, respectively. This method is useful for detecting and estimating the rate of occurrence of hematotoxicity adverse drug events.

In a hospital, doctors and nurses shares roles in treating admitted patients. Communication between them is necessary and communication errors become the problem in medical safety. In Japan, verbal instruction is prohibited and doctors write their instruction on paper instruction slips. However, because it is difficult to ascertain revision history and the active instructions on instruction slips, human errors can occur. We developed template-based computerized instruction entry system to reduce ward workloads and contribute to medical safety. Templates enable us to input the instructions easily and standardize the descriptions of instructions. By standardizing and combine the instruction into one template for one instruction item, the systems could prevent instructions overlap. We created sets of templates (e.g., admission set, preoperative set), so that doctors could enter their instructions easily. Instructions entered via any of the sets can be subdivided into separate items by the system before being submitted, and can also be changed on a per-item basis. The instructions were displayed as calendar form. Calendar form represents the instruction shift and current active instructions. We prepared 382 standardized instruction templates. In our system, 66% of instructions were entered via templates, and 34% were entered as free-text comments. Our system prevents communication errors between medical staff.

Recently one patient received care from several hospitals at around the same time. When the patient visited a new hospital, the new hospital's physician tried to get patient information the previous hospital. Thus, patient information is frequently exchanged between them. Many types of healthcare facilities have implemented an electronic medical record system, but in Japan, healthcare information exchange is often done by paper. In other words, after a clinical doctor prints a referral document and sends it to another hospital's physician, another hospital's doctor receives it and scans to store the EMR in his own hospital's system. It is a wasteful way to exchange healthcare information about a patient. In order to solve this problem, we have developed a cross-institutional document exchange system using clinical document architecture (CDA) with a virtual printing method.

Background: The Personal Qualities Assessment (PQA), developed by the University of Newcastle, Australia to assess the aptitude of future medical professionals, has been used in Western countries., Purposes: The objective was to investigate whether the PQA is appropriate for Japanese medical school applicants., Methods: Two of the PQA tests, Libertarian-Dual-Communitarian moral orientations (Mojac) and Narcissism, Aloofness, Confidence, and Empathy (NACE), were translated into Japanese, and administered at the Tokyo Women's Medical University entrance examinations from 2007 to 2009., Results: The distributions of the applicants' Mojac and NACE scores were close to the normal distribution, and the mean scores did not exhibit a large difference from those in Western countries. The only significant difference was that the mean score of the NACE test was slightly lower than the Western norm., Conclusions: The translated PQA tests may be appropriate for use with Japanese applicants, though further research considering cultural differences is required.

EDC system has been used in the field of clinical research. The current EDC system does not connect with electronic medical record system (EMR), thus a medical staff has to transcribe the data in EMR to EDC system manually. This redundant process causes not only inefficiency but also human error. We developed an EDC system cooperating with EMR, in which the data required for a clinical research form (CRF) is transcribed automatically from EMR to electronic CRF (eCRF) and is sent via network. We call this system as "eCRF reporter". The interface module of eCRF reporter can retrieves the data in EMR database including patient biography data, laboratory test data, prescription data and data entered by template in progress notes. The eCRF reporter also enables users to enter data directly to eCRF. The eCRF reporter generates CDISC ODM file and PDF which is a translated form of Clinical data in ODM. After storing eCRF in EMR, it is transferred via VPN to a clinical data management system (CDMS) which can receive the eCRF files and parse ODM. We started some clinical research by using this system. This system is expected to promote clinical research efficiency and strictness.

We report synthesis of a hetero-dinuclear metal complex in a four-fold rotaxane, in which a Cu(2+)-porphyrin and a Zn(2+)-phthalocyanine are cofacially stacked. Interaction between the two metal complexes in the rotaxane was investigated by a UV-Vis absorption spectral study.

We report the preparation and crystal structure of a triply stacked metal complex array in which a Cu-phthalocyanine is sandwiched between different Cu-porphyrins. The discrete heterogeneous assembly was prepared through formation of a fourfold rotaxane from a tetradactyl porphyrin with alkylammonium moieties and a phthalocyanine bearing four crown ethers and the subsequent formation of an ionic complex between the fourfold rotaxane and a tetraanionic porphyrin. The tetraanionic porphyrin, Cu-TPPS(4-), is selectively bound to the fourfold rotaxane through cooperative π-π and ionic interactions. The crystal structure revealed the columnar stacked array of the three planar building components in a precise order and spatial arrangement that promote intermolecular electronic communication.

We developed a system that transfers images via network and started using them in our hospital's PACS (Picture Archiving and Communication Systems) in 2006. We are pleased to report that the system has been re-developed and has been running so that there will be a regional liaison in the future. It has become possible to automatically transfer images simply by selecting the destination hospital that is registered in advance at the relay server. The gateway of this system can send images to a multi-center, relay management server, which receives the images and resends them. This system has the potential to be useful for image exchange, and to serve as a regional medical liaison.

Standard Japanese electronic medical record (EMR) systems are associated with major shortcomings. For example, they do not assure lifelong readability of records because each document requires its own viewing software program, a system that is difficult to maintain over long periods of time. It can also be difficult for users to comprehend a patient's clinical history because different classes of documents can only be accessed from their own window. To address these problems, we developed a document-based electronic medical record that aggregates all documents for a patient in a PDF or DocuWorks format. We call this system the Document Archiving and Communication System (DACS). There are two types of viewers in the DACS: the Matrix View, which provides a time line of a patient's history, and the Tree View, which stores the documents in hierarchical document classes. We placed 2,734 document classes into 11 categories. A total of 22,3972 documents were entered per month. The frequency of use of the DACS viewer was 268,644 instances per month. The DACS viewer was used to assess a patient's clinical history.

We aim at making a diagnosis support system that can be put to practical use. We proposed a diagnostic process model based on simple knowledge which can be gleaned from textbooks. We defined clinical finding (CF) as a general concept for patient's symptom or findings etc., whose value is expressed by Boolean. We call the combination of several CFs a "CF pattern", and a set of CF patterns with concomitant diseases "case base". We consider diagnosis as a process of searching an instance from the case base whose CF pattern is concomitant with that of a patient. The diseases which have the same CF pattern are candidates for diagnosis. Then we select a CF which is present in part of the candidates and check whether it is present or absent in the patient in order to narrow down the candidates. Because the case base does not exist in reality, the probability of CF pattern is calculated by the product of CF occurrence rate assuming that occurrence of CF is independent. Therefore the knowledge required for diagnosis is frequency of disease under sex and age group and CF-disease relation (CF and its occurrence rate in the disease). By processing these two types of knowledge, diagnosis can be made.

Purpose: To evaluate the potential of tetrahedral diffusion-weighted imaging (DWI) compared to orthogonal DWI for detection and localization of early enhanced breast mass lesions at 1.5T., Materials and Methods: Sixty-seven consecutive patients (mean age 51.7 years, range 14-84 years) with 68 solitary early enhanced breast lesions suspicious for cancer on dynamic contrast-enhanced magnetic resonance imaging (MRI) were enrolled in this retrospective study. Two radiologists independently observed maximum intensity projection images of orthogonal and tetrahedral DWI and the diagnostic accuracy and background tissue visibility between two DWI techniques were compared. Contrast-enhanced MRI was used as the reference standard. Background tissue visibility was assessed based on whether the "breast quadrant" and "skin line" were determined. A phantom validation study for apparent diffusion coefficient (ADC) values was also conducted., Results: Sensitivity (93%) and specificity (96%) on tetrahedral DWI were equivalent to those on orthogonal DWI (sensitivity, 88%; specificity, 95%). Background tissue was more easily determined with tetrahedral DWI (breast quadrant, 90%; skin lines, 95%) than with orthogonal DWI (breast quadrant, 61%; skin lines, 16%). ADC values of tetrahedral DWI were highly correlated with those of orthogonal DWI., Conclusion: Tetrahedral DWI provided equivalent detectability of mass lesions with improved visibility of surrounding anatomical structure., (Copyright © 2011 Wiley-Liss, Inc.)

The aim of the present study was to investigate the difference in doubling time between squamous cell carcinoma (SCC) and adenocarcinoma of solid pulmonary cancer using three-dimensional volumetric software. We included 40 patients with adenocarcinoma and 11 patients with SCC, who underwent CT examinations more than once before surgical treatment. Tumor volumes and doubling times were obtained using three-dimensional volumetric computer software. Statistical analysis was performed using Mann-Whitney's U-test except for negative doubling times (doubling times less than 0 day). Negative doubling time was found in 5 of the 40 adenocarcinomas (13%), but not in any of the patients with SCC. Doubling time was beyond 400 days in 11 of the 40 adenocarcinomas (28%), but was always less than 400 days in SCC. The mean doubling time of SCC was 126+/-58 days (range, 39-221 days; median, 131 days), while that of adenocarcinomas, except for the negative doubling times, was 976+/-3134 days (range, 69-18,678 days; median, 258 days). Doubling time differed significantly between adenocarcinomas and SCC (p<0.01). In conclusion, the median doubling time of SCC lung cancers is less than that of adenocarcinomas, as measured with automated volumetric measurement software.

Rationale and Objectives: Most studies of computer-aided detection (CAD) for pulmonary nodules have focused on solid nodule detection. The aim of this study was to evaluate the performance of a commercially available CAD system in the detection of pulmonary nodules with or without ground-glass opacity (GGO) using 64-detector-row computed tomography compared to visual interpretation., Materials and Methods: Computed tomographic examinations were performed on 48 patients with existing or suspicious pulmonary nodules on chest radiography. Three radiologists independently reported the location and pattern (GGO, solid, or part solid) of each nodule candidate on computed tomographic scans, assigned each a confidence score, and then analyzed all scans using the CAD system. A reference standard was established by a consensus panel of different radiologists, who found 229 noncalcified nodules with diameters > or = 4 mm. True-positive and false-positive results and confidence levels were used to generate jackknife alternative free-response receiver-operating characteristic plots., Results: The sensitivity of GGO for 3 radiologists (60%-80%) was significantly higher than that for the CAD system (21%) (McNemar's test, P < .0001). For overall and solid nodules, the figure-of-merit values without and with the CAD system were significantly different (P = .005-.04) on jackknife alternative free-response receiver-operating characteristic analysis. For GGO and part-solid nodules, the figure-of-merit values with the CAD system were greater than those without the CAD system, indicating no significant differences., Conclusion: Radiologists are significantly superior to this CAD system in the detection of GGO, but the CAD system can still play a complementary role in detecting nodules with or without GGO.

The film digitizer plays an important transitory role as an analog-to-digital bridge for the implementation of PACS on screen-film mammography. The objective of this phantom study was to compare the observer performance of a digitized mammogram on liquid crystal displays (LCDs) with that of the original film mammogram, and to clarify which matrix size of LCDs is adequate for the interpretation of digitized mammography. The American College of Radiology mammographic accreditation phantom containing variously sized fibrils, simulated microcalcifications, and tumor-like masses was radiographed with a screen-film mammographic system. The original film was digitized with a sampling pitch of 50 mum and a density depth of 12 bit. Six observers who were trained in mammography individually viewed digitized images on LCDs and original film. Observer performance of a digitized mammogram with a 2-megapixel LCD was compared with that of original film. The observers were asked to rate the detectability of each test object according to a three-point scale (obviously visible=2, barely detectable=1, undetectable=0). The difference in the mean score between two systems at each object was evaluated by the Wilcoxon's test. In addition, the dependence of observer performance on the matrix size of LCDs ranging from 1-to 5-megapixel was tested with Scheffé's multiple comparison. The observers also judged the detectability according to the three-point scale. The results show that the digitized mammogram provides acceptable but slightly inferior detectability than original film. There was no dependence of matrix size in observer performance with more than 2-megapixel LCDs.

Purpose: To determine the pathological correlation with various high-resolution CT (HRCT) findings in cases with nonspecific interstitial pneumonia (NSIP), paying special attention to pathological subgroups., Material and Methods: The study involved 29 patients diagnosed with NSIP by surgical lung biopsy. A total of 54 specimens were obtained and grouped according to Katzenstein's classification (groups 1-3) for NSIP. Two observers then evaluated the HRCT findings for every biopsy site and classified the findings according to the main pattern evident into the following four radiologic pattern groups: A, ground-glass attenuation and fine reticulation; B, ground-glass and coarse reticulation; C, consolidation and D, ground-glass attenuation and consolidation., Results: The pathological pattern was NSIP group 1 in 6 patients, group 2 in 22 and group 3 in 25, while 1 specimen was normal. The main HRCT pattern was pattern A in 15 specimens, B in 8, C in 9 and D in 21. Although there were no significant correlation between HRCT patterns and histological subgroups (Chi-square test, p=0.07), pattern C was more frequently seen in group 2 (7 of 9) and pattern A was more common in group 3 (11 of 15). HRCT pattern A corresponded pathologically to areas of thickened alveolar septa with temporal uniformity. Pattern B correlated with areas with airspace enlargement/emphysema or dilation of small airways superimposed on thickened alveolar septa. Pattern C was pathologically associated with areas of severe thickened alveolar septa, mucin stasis in the small airways and intraluminal organization., Conclusion: The pathological backgrounds of the same CT findings in patients with NSIP varied among all pathological subgroups. Areas of ground-glass attenuation and air-space consolidation did not always correspond to reversible pathological findings.

Purpose: Motion artifacts, which can mimic thickened bronchial wall and the cystic appearance of bronchiectasis, constitute a potential pitfall in the diagnosis of interstitial or bronchial disease. Therefore, purpose of our study was to evaluate whether 64-detector row CT (64-MDCT) enables a reduction in respiratory or cardiac motion artifacts in the lung area on thin-section CT without ECG gating, and to examine the correlation between cardiac motion artifact and heart rate., Materials and Methods: Thirty-two patients with suspected diffuse lung disease, who underwent both 8- and 64-MDCT (gantry rotation time, 0.5 and 0.4s, respectively), were included. The heart rates of an additional 155 patients were measured (range, 48-126 beats per minute; mean, 76 beats per minute) immediately prior to 64-MDCT, and compared to the degree of cardiac motion artifact. Two independent observers evaluated the following artifacts on a monitor without the knowledge of relevant clinical information: (1) artifacts on 8- and 64-MDCT images with 1.25-mm thickness and those on 64-MDCT images with 0.625-mm thickness in 32 patients; and (2) artifacts on 64-MDCT images with 0.625-mm thickness in 155 patients., Results: Interobserver agreement was good in evaluating artifacts on 8-MDCT images with 1.25-mm thickness (weighted Kappa test, kappa=0.61-0.71), and fair or poor in the other evaluations (kappa<0.31). Two observers stated that cardiac motion artifacts were more significant on 8-MDCT than on 64-MDCT in all 32 patients. Statistically significant differences were found at various checkpoints only in comparing artifacts between 8- and 64-MDCT for 1.25-mm thickness (Wilcoxon's signed-rank test, p<0.0017). Cardiac motion artifacts on 64-MDCT had no significant correlation with heart rate (Spearman's correlation coefficient by rank test)., Conclusion: The high temporal resolution of 64-MDCT appears to reduce cardiac motion artifact that can affect thin-section scans of the lung parenchyma.

Purpose: To determine thin-section computed tomography (CT) characteristics of acute eosinophilic pneumonia (AEP)., Materials and Methods: Thin-section CT scans of 29 patients (14 males, 15 females; mean age, 26+/-15 years; age range, 15-72 years) with AEP were included this retrospective study. The clinical diagnosis of AEP was established by Allen's criteria. Each thin-section CT was reviewed by two observers., Results: Bilateral areas with ground-glass attenuation were observed on thin-section CT in all patients. Areas of air-space consolidation were present in 16 (55%) of 29 patients. Poorly defined centrilobular nodules were present in 9 patients (31%). Interlobular septal thickening was present in 26 patients (90%). Thickening of bronchovascular bundles was present in 19 patients (66%). Pleural effusions were present in 23 patients (79%) (bilateral=22, right side=1, left side=0). The predominant overall anatomic distribution was central in only 2 (7%) of 29 patients, peripheral in 9 patients (31%), and random in 18 patients (62%). The overall zonal predominance was upper in 4 patients (14%), lower in 8 patients (28%), and random in 17 patients (58%)., Conclusion: CT findings in AEP patients consisted mainly of bilateral areas of ground-glass attenuation, interlobular septal thickening, thickening of bronchovascular bundles, and the presence of a pleural effusion without cardiomegaly. The most common overall anatomic distribution and zonal predominance of the abnormal CT findings were random.

Purpose: The purpose of this study was to evaluate software designed to calculate whole tumor volumes and the ratio of the solid component to whole volume (%solid) in pulmonary nodules with ground-glass opacity in three dimensions., Methods: The study included 49 patients with histologically diagnosed adenocarcinomas smaller than 2 cm in diameter. The %solid was calculated both automatically using new software, and by manual measurement of the following four parameters by two observers: the ratio of the largest diameter (a) and the area (b) at the mediastinal window to those at the lung window, and the ratio of the largest diameter (c) and the area (d) of the solid component to those of the ground-glass component at the lung window. Agreement of intra- and inter-observer data by both Spearman's rank correlation test and Bland-Altman's method, and a comparison by Spearman's rank correlation test of the %solid in both Noguchi sub-classifications and vessel invasion in histologic specimens, between the software and manual methods, were assessed., Results: Of the 49 nodules, 48 were successfully measured and assessed. The agreement of the observers with the software was better (Bland-Altman's method; mean difference, -0.3%; 95% limits of agreement, -3.1 to 2.5%) than with the manual measurements (a: 5.3%, -17.6 to 28.3%; b: 8.3%, -10.6 to 26.9%; c: 10.7%, -17.6 to 39%; d: 6.4%, -22 to 34.8%). The correlation between %solid and the histological group was worse with the software (Spearman's rank correlation test; r=0.487, p<0.001) than with the manual method (a, r=0.534; b, r=0.557; c, r=0.552; d, r=0.545)., Conclusion: Although the software requires improvement in the calculation of %solid with volumetric analysis, this is a reproducible and promising quantitative method for determining the grades of malignancy of small lung cancers.

Purpose: To retrospectively evaluate the effect of contrast medium on the three-dimensional volumetric measurement of pulmonary nodules., Materials and Methods: The study was approved by the local institutional review committee, with waiver of informed consent. Sixty pulmonary nodules in 60 patients (17 women, 43 men; age range, 29-82 years) were imaged before and after administration of contrast medium with a 64-channel multidetector computed tomographic (CT) scanner; reconstructed images with a section thickness of 0.625 mm were obtained by using a bone algorithm and a standard algorithm. Volumetric measurements of pulmonary nodules were performed by using commercially available software, and the postcontrast volume ratio was calculated by dividing the postcontrast volume by the precontrast volume. Precontrast and postcontrast volumes were then analyzed by using a Wilcoxon signed rank test., Results: The median measured volumes of pulmonary nodules were 817 mm(3) (precontrast imaging, bone algorithm), 887 mm(3) (postcontrast imaging, bone algorithm), 812 mm(3) (precontrast imaging, standard algorithm), and 855 mm(3) (postcontrast imaging, standard algorithm). The measured volumes obtained with the bone algorithm were significantly larger than those obtained with the standard algorithm, both before and after administration of contrast medium (P < .01); with both the standard algorithm and the bone algorithm, the measured postcontrast volumes were significantly larger than the precontrast volumes (P < .01). The postcontrast volume ratio was more than 1.0 in 45 cases (75%) when the bone algorithm was used and in 53 cases (88%) when the standard algorithm was used. The mean postcontrast volume ratio was 1.054 with the bone algorithm and 1.065 with the standard algorithm., Conclusion: The measured volume of pulmonary nodules obtained by using three-dimensional volumetric software increased after administration of contrast medium. Moreover, the measured volume of pulmonary nodules that was obtained with the bone algorithm was larger than that obtained with the standard algorithm, regardless of whether contrast medium was used., ((c) RSNA, 2007.)

Objective: The aim of this study was to evaluate volume histogram analysis between usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP)., Methods: Sixty cases (UIP, n = 22; NSIP, n = 38) were evaluated retrospectively. Three parameters (contrast, variance, and entropy) were calculated in 3 types of regions of interest (ROIs): (a) whole lung, (b) right lower lobe, and (c) cubic ROIs. To evaluate the influence of extent of abnormal findings, the numbers of voxels with low or high density in whole lung were compared with the 3 parameters., Result: No significant differences were observed between the ROIs of whole lung and the right lower lobe. In all cubic ROIs, entropy in UIP was larger than that in NSIP (P < 0.001). The numbers of voxels with low-density areas significantly correlated with the values of contrast and entropy, whereas those with high-density areas significantly correlated with all 3 parameters., Conclusion: Volume histogram analysis for cubic ROIs may be feasible for differentiating between UIP and NSIP.

Objective: To establish computed tomographic findings that enable accurate differentiation between malignant and benign cavitary lung nodules., Methods: Computed tomographic scans from 39 patients with malignant cavitary nodules and from 39 patients with benign cavitary nodules were independently assessed by 2 observers. They recorded the computed tomographic findings of both types of cavitary nodules and surrounding pulmonary parenchyma. The computed tomographic findings were then compared using chi test., Results: The notch was found in 29% of benign cavitary nodule cases and in 54% of malignant cavitary nodule cases (P < 0.01). An irregular internal wall was found in 26% of benign nodules and in 49% of malignant nodule cases (P < 0.01). A linear margin (P < 0.01), satellite nodule presence (P < 0.01), bronchial wall thickening (P < 0.05), consolidation (P < 0.05), and ground-glass attenuation (P < 0.01) were significantly more frequent in benign cavitary nodules than in malignant ones., Conclusions: Although the computed tomographic findings of benign and malignant cavitary nodules overlap, some computed tomographic findings are useful for differentiating cavitary nodules.

Purpose: Preoperative localization of the thymic veins is considered important to prevent intraoperative severe bleeding prior to video-assisted thoracoscopic thymectomy. The purpose of this study was to determine the optimal dose of contrast material for preoperative CT imaging for the detection of thymic veins on the basis of patient weight., Materials and Methods: The records of 31 patients who underwent thymectomy were examined retrospectively. All patients were scanned using an eight-channel multidetector-row computed tomography (CT) scanner at 1.25 mm collimation and a 0.625-mm reconstruction interval. CT scans were obtained after injection of 300 mg I/ml nonionic contrast material at a rate of 2 ml/s. A 90-ml contrast bolus was used for the first 16 consecutive patients (group I), and a 150-ml bolus was used for the following 15 patients (group II). The scan delay was 60 s and 90 s in groups I and II respectively. Two independent radiologists who were blinded to the surgical results evaluated the number of thymic veins observed on preoperative CT, which was later correlated with the actual number of thymic veins clipped during surgery. The responses were analyzed with respect to contrast amount by single bolus and per kilogram of body weight., Results: Thymic veins were correctly detected in 9 of 16 (56%) patients in group I and 14 of 15 (93%) patients in group II. Thymic vein detection was significantly better in patients who received the >or=2.0 ml/kg contrast medium compared to those who received the 1.00-1.99 ml/kg medium (P < 0.05)., Conclusion: An intravenous contrast material volume of 2 ml/kg (300 mg I/ml) is appropriate for the identification of thymic veins on prethymectomy CT.

Purpose: To investigate differences in volumetric measurement of pulmonary nodules caused by changing the reconstruction parameters for multi-detector row CT., Materials and Methods: Thirty-nine pulmonary nodules less than 2 cm in diameter were examined by multi-slice CT. All nodules were solid, and located in the peripheral part of the lungs. The resultant 48 parameters images were reconstructed by changing slice thickness (1.25, 2.5, 3.75, or 5 mm), field of view (FOV: 10, 20, or 30 cm), algorithm (high-spatial frequency algorithm or low-spatial frequency algorithm) and reconstruction interval (reconstruction with 50% overlapping of the reconstructed slices or non-overlapping reconstruction). Volumetric measurements were calculated using commercially available software. The differences between nodule volumes were analyzed by the Kruskal-Wallis test and the Wilcoxon Signed-Ranks test., Results: The diameter of the nodules was 8.7+/-2.7 mm on average, ranging from 4.3 to 16.4mm. Pulmonary nodule volume did not change significantly with changes in slice thickness or FOV (p>0.05), but was significantly larger with the high-spatial frequency algorithm than the low-spatial frequency algorithm (p<0.05), except for one reconstruction parameter. The volumes determined by non-overlapping reconstruction were significantly larger than those of overlapping reconstruction (p<0.05), except for a 1.25 mm thickness with 10 cm FOV with the high-spatial frequency algorithm, and 5mm thickness. The maximum difference in measured volume was 16% on average between the 1.25 mm slice thickness/10 cm FOV/high-spatial frequency algorithm parameters and overlapping reconstruction., Conclusion: Volumetric measurements of pulmonary nodules differ with changes in the reconstruction parameters, with a tendency toward larger volumes in high-spatial frequency algorithm and non-overlapping reconstruction compared to the low-spatial frequency algorithm and overlapping reconstruction.

Purpose: To retrospectively analyze computed tomographic (CT) findings of chronic idiopathic interstitial pneumonia (IIP) and to determine which findings are most helpful for distinguishing IIP from usual interstitial pneumonia (UIP) with univariate and multivariate analyses., Materials and Methods: Institutional review board approval and informed consent were not required for this retrospective review of patient records and images. Two observers working independently and without knowledge of the diagnosis evaluated the extent and distribution of various thin-section CT findings (ground-glass opacity, consolidation, reticulation, and honeycombing) in 92 patients (51 men, 41 women; mean age, 56 years; age range, 29-81 years) with a histologic diagnosis of UIP (n = 20), cellular nonspecific interstitial pneumonia (NSIP) (n = 16), fibrotic NSIP (n = 16), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) (n = 11), desquamative interstitial pneumonia (DIP) (n = 15), or lymphoid interstitial pneumonia (LIP) (n = 14). Observers used univariate and multivariate statistical analyses to compare their findings with the extent and distribution of UIP., Results: Observers made the correct diagnosis in 145 (79%) of 184 readings. Multivariate logistic regression analysis showed that the independent findings that distinguished UIP from cellular NSIP were the extent of honeycombing and the most proximal bronchus with traction bronchiectasis (odds ratio, 5.16 and 0.37, respectively); the finding that distinguished UIP from fibrotic NSIP was the extent of honeycombing (odds ratio, 2.10). CT features that distinguished UIP from RB-ILD and DIP included extent of ground-glass opacity (odds ratio, 0.76), thickening of bronchovascular bundles (odds ratio, 1.58), the most proximal bronchus with traction bronchiectasis (odds ratio, 0.22), and the number of segments with traction bronchiectasis (odds ratio, 3.64)., Conclusion: UIP has a characteristic appearance that usually facilitates distinction from other types of chronic IIPs at thin-section CT. The most useful finding when differentiating UIP from NSIP was the extent of honeycombing., ((c) RSNA, 2006.)

Purpose: The aim of this study was to determine magnetic resonance imaging (MRI) features of various subtypes of thymic epithelial tumors based on the World Health Organization classification., Materials and Methods: The study included 64 patients with histologically proven thymic epithelial tumors. Two observers evaluated the MRI findings in terms of tumor size, contour, lobulation, shape, homogeneity, the presence of intratumor high- and low-signal foci, enhancement degree and pattern, the presence of capsule and septum, and associated mediastinal lymphadenopathy and pleural effusion., Results: Type A tumors were more likely to have a smooth contour, round shape, distinct capsule, and smaller size compared to any other type of thymic epithelial tumor. Thymic carcinomas demonstrated a higher prevalence of low-signal foci within the mass on T2-weighted images and mediastinal lymphadenopathy than any other types. The frequency of heterogeneous intensity on T2-weighted images increased from type A tumors to thymic carcinomas., Conclusion: The presence of a smooth contour, round shape, and capsule is highly suggestive of a type A tumor. Foci of low signal intensity in the mass on T2-weighted images and mediastinal lymphadenopathy are highly suggestive of thymic carcinomas.

Objectives: : The aim of this study was to achieve the quantitative analysis of the characteristic computed tomography (CT) findings and course of interstitial pneumonia using the volume histogram method., Methods: : Contrast (CNT), variance (VAR), and entropy (EPY) values from whole-lung volume data were compared between normal lungs and 5 diseases that have characteristic CT findings. Thirteen cases with nonspecific interstitial pneumonia (NSIP) were evaluated before and after treatment., Results: : In cases with thickening of the bronchovascular bundles and interlobular thickening, ground-glass attenuation, airspace consolidation, and honeycombing, the values of VAR and EPY were greater than those in the normal cases (P < 0.05). In the cases with NSIP, the CNT value after treatment was significantly greater and the values of VAR and EPY after treatment were significantly lower than those before treatment (P < 0.05)., Conclusions: : Volume histogram analysis is a promising method for the evaluation of diffuse lung diseases and the effectiveness of treatment.

Mucosa-associated lymphoid tissue (MALT) type lymphoma has generally been thought not to show increased fluorine 18-fluorodeoxyglucose (FDG) accumulation on positron emission tomography (PET), based on previous research. Only a limited numbers of articles have been published on this topic, however, involving a small number of cases. Although positive FDG PET results might be uncommon in this entity, a case of increased FDG accumulation in a case of MALT type lymphoma of the lung is presented.

Purpose: To compare observer performance in the detection of subtle interstitial abnormalities on 3,520 x 3,520 (4K) matrix and 1,760 x 1,760 (2K) matrix full-size digital storage phosphor (DSP) chest radiographs., Materials and Methods: Thirty-five 4K DSP chest radiographs with subtle interstitial abnormalities (n=27) or normal lungs (n=8) were processed with a half-band low-pass filter to produce 2K DSP radiographs. Although the actual matrix size of the 2K DSP radiographs remained 4K, the effective matrix size was reduced to 2K. Four chest radiologists independently evaluated full-sized hard-copy of the 4K and 2K DSP radiographs, and scored the presence of interstitial abnormalities for both right and left lungs on a five-point confidence scale. With findings on high-resolution computed tomography as the reference standard, observer performance was evaluated using multireader-multicase receiver operating characteristic (ROC) analysis., Results: The average area under the ROC curve (Az) values for 4K and 2K DSP radiographs were 0.791+/-0.055 and 0.804+/-0.050, respectively. Both individual and averaged Az values showed no statistically significant differences (p>0.05) between 4K and 2K DSP radiographs., Conclusion: Observer performance in the detection of subtle interstitial abnormalities on 4K full-size DSP chest radiographs was equivalent to that on 2K full-size DSP chest radiographs.

Purpose: To determine the effect of changing pitch and collimation on depiction of pulmonary metastases on scans of 5-mm section thickness obtained with multi-detector row computed tomography (CT) compared with those obtained with single-detector row CT., Materials and Methods: In five autopsy lungs, 1,013 metastatic 0.5-30.0-mm nodules were detected at helical CT with 1-mm collimation and histopathologically diagnosed as metastases. Each nodule was numbered, and its localization was recorded as the standard for subsequent studies. Four types of scans of 5-mm section thickness were obtained with multi-detector row CT and four sets of helical pitch and table speed, respectively, as follows: set A, 3:1 and 7.5 mm per rotation; set B, 6:1 and 15 mm per rotation; set C, 6:1 and 30 mm per rotation; set D, conventional and 5-mm interval. Conventional helical CT scans (set E) were obtained with 5-mm collimation at single-detector row CT. Two independent observers evaluated the five sets of CT scans., Results: Acquisition times for sets A-D, respectively, were 1.9, 3.8, 7.5, and 1.5 times faster than they were for set E. The mean numbers of detected nodules were 671 (66%) in set A, 661 (65%) in set B, 678 (67%) in set C, 654 (65%) in set D, and 656 (65%) in set E; there was no significant difference in the number of detected nodules among the five sets (P =.997, McNemar test and Bonferroni equation)., Conclusion: Regardless of varying pitch or detector collimation, multi- and single-detector row CT scans obtained with 5-mm section thickness have almost the same ability to depict pulmonary metastases and are equivalent., (Copyright RSNA, 2002)

Objective: The purpose of this study was to compare the quality of coronal multiplanar reconstructions with the quality of direct coronal thin-section multidetector CT (MDCT) scans., Materials and Methods: Axial multidetector CT (MDCT) scans were obtained through the entire lung in 10 normal autopsy lung specimens using an MDCT scanner. Four protocols were used: 0.5-mm collimation with a 0.5-mm reconstruction interval; 0.5-mm collimation with a 0.3-mm reconstruction interval; 1-mm collimation with a 0.5-mm reconstruction interval; and 2-mm collimation with a 1-mm reconstruction interval. Multiplanar reconstruction images with 0.5-mm slice thickness were obtained from the four types of data sets. Direct coronal thin-section CT of the same 10 autopsy lung specimens was performed using 0.5-mm scan collimation, a 0.3-mm reconstruction interval, a 25.6-cm field of view, and a 512 x 512 matrix. Two independent observers compared the image quality of each of the four coronal multiplanar reconstruction sets with that of direct coronal thin-section CT scans. The observers analyzed visualization of anatomic features and artifacts., Results: The total image quality of the multiplanar reconstructions obtained from 0.5-mm collimation data with or without 0.3-mm overlapping reconstruction was equal to that of direct coronal thin-section CT scans in all 20 interpretations. The image quality of multiplanar reconstruction images from 0.5-mm collimation data either with or without overlapping reconstruction was superior to multiplanar reconstruction images obtained from 1- or 2-mm collimation scans (p < 0.01, Fisher's exact test). Stairstep artifacts in multiplanar reconstructions using 0.5-mm collimation without overlapping reconstruction were equal to those with overlapping reconstruction and were fewer than those on 1- or 2-mm collimation (p < 0.01, Mann-Whitney U test)., Conclusion: The image quality of coronal multiplanar reconstructions from isotropic voxel data obtained using 0.5-mm collimation, with or without overlapping reconstruction, is similar to that of direct coronal thin-section CT scans.

Objective: Our purpose was to assess the CT features of various subtypes of thymic epithelial neoplasms on the basis of the 1999 World Health Organization classification., Materials and Methods: Thymic epithelial neoplasms in 53 patients who underwent thymectomy were retrospectively assessed histologically according to the 1999 World Health Organization classification. Type A and B neoplasms correspond to thymomas and type C, to thymic carcinoma. The study included four patients with type A, 14 with type AB, nine with type B1, 14 with type B2, four with type B3, and eight with type C epithelial tumors. Two observers independently assessed the CT scans without knowledge of the histologic findings., Results: Type A tumors were more likely to have smooth contours on CT (4/4, 100%) and round shapes (3.5/4, 88%) than any other type of thymic epithelial tumor (all, p < 0.05). Type C tumors had a higher prevalence of irregular contours (6/8, 75%) than any other type of thymic epithelial tumor (all, p < 0.05). Calcification was more frequently seen in type B1 (4/9, 44%), type B2 (8.5/14, 61%), and type B3 (3/4, 75%) tumors than in type AB (2/14, 14%) and type C (0.5/8, 6%) tumors (all, p < 0.05)., Conclusion: Smooth contours and a round shape are most suggestive of type A thymic epithelial tumor, whereas irregular contours are most suggestive of type C tumor. Calcification is suggestive of type B tumors. CT is of limited value, however, in differentiating type AB, B1, B2, and B3 tumors.

Objective: The purpose of this study was to evaluate the accuracy of temporal subtraction with a commercially available computer-assisted diagnosis system for the detection of multifocal hazy pulmonary opacities on chest radiographs, which are sometimes difficult to detect directly on chest radiographs., Materials and Methods: Thirty healthy patients and 30 patients with new multifocal hazy pulmonary opacities that were confirmed by serial chest CT examinations were evaluated with and without temporal subtraction images. Chest radiographs were taken from either film-screen or digital radiography images and were digitized with a spatial resolution of 0.171 mm per pixel. Temporal subtraction images were produced by an iterative image-warping technique. We designed an observer performance study in which observers (six chest radiologists and four residents) indicated their confidence level for the presence or absence of hazy pulmonary opacities on two sets of images, current and previous radiographs only (set A), and current and previous radiographs with temporal subtraction images (set B). Receiver operating characteristic curves were generated., Results: For chest radiologists, observer performance with set B (with temporal subtraction images; A(z) = 0.947) was superior to that with set A (without temporal subtraction images; A(z) = 0.916) (p < 0.05). For residents, no statistically significant difference was found between sets A and B., Conclusion: The temporal subtraction technique clearly improves diagnostic accuracy for the detection of multifocal hazy pulmonary opacities on chest radiographs, especially when the observers are experienced chest radiologists who have sufficient skill to evaluate the patient's condition as revealed on the images.

This study compared high-resolution computed tomography (CT) findings between 10 survivors and 21 nonsurvivors of acute interstitial pneumonia and evaluated whether the CT findings were predictive of patients' response to treatment. The survivor and nonsurvivor groups with pathologically or clinically diagnosed acute interstitial pneumonia were similar in age, sex, disease duration, and lung injury score. Retrospective, subjective evaluations of the CT scans were conducted by two independent observers without knowledge of patient outcomes. CT findings were graded on a one to six scale corresponding to consecutive pathologic phases as follows: areas of (1) normal attenuation, (2) ground-glass attenuation, (3) consolidation, (4) ground-glass attenuation associated with traction bronchiolectasis or bronchiectasis, (5) consolidation associated with traction bronchiolectasis or bronchiectasis, and (6) honeycombing. An overall score was obtained by quantifying the extent of each abnormality in three lung zones in each lung. The extent of ground-glass attenuation or consolidation associated with traction bronchiolectasis or bronchiectasis was less in survivors than nonsurvivors (p = 0.004 and p = 0.009, respectively). Architectural distortion was less frequent, and ground-glass attenuation or consolidation without traction bronchiolectasis or bronchiectasis was more extensive in survivors than in nonsurvivors (p = 0.007, p = 0.002, and p = 0.029, respectively). Overall CT scores of survivors were significantly lower than those of nonsurvivors (p = 0.0003). A CT score of less than 245 had an 80% positive and a 90% negative predictive value for survival. There was good interobserver agreement in the assessment of the CT findings (Kappa 0.75). The results indicate that CT assessment is potentially helpful in predicting patient prognosis in acute interstitial pneumonia regardless of the degree of physiologic abnormality.

Purpose: To evaluate the usefulness of a commercially available computer-aided diagnosis (CAD) system that incorporates temporal subtraction for the detection of solitary pulmonary nodules on chest radiographs by readers with different levels of experience., Materials and Methods: Sixty pairs of chest radiographs in 30 patients with newly detected solitary pulmonary nodules and 30 normal cases, all confirmed with serial chest computed tomography (CT), were obtained from screen-film or digital radiographic systems and were digitized (spatial resolution, 0.171 mm/pixel). Temporal subtraction images were produced with an iterative image-warping technique. Five chest radiologists and five residents evaluated both image sets for solitary nodules: set A, current and prior radiographs with temporal subtraction images, and set B, current and prior radiographs only. Assessment was performed with receiver operating characteristic (ROC) analysis of the images on a monitor (pixel size, 1,280 x 1,024) equipped with the system. The reading time needed by each reader was recorded in each case., Results: For the chest radiologists, no statistically significant difference was found between set A (area under the ROC curve [A(z)] = 0.934) and set B (A(z) = 0.964). For the residents, however, observer performance in set A (A(z) = 0.907) was superior to that in set B (A(z) = 0.855) (P <.05). For both groups, the mean reading time per case for set A (chest radiologists, 16.7 seconds; residents, 15.7 seconds) was significantly (P <.05) shorter than that for set B (chest radiologists, 20.4 seconds; residents, 26.2 seconds)., Conclusion: For the detection of solitary pulmonary nodules, the CAD system with temporal subtraction can promote efficiency for established chest radiologists and improvement in accuracy for less experienced readers.

The goals of this study were (1) to evaluate the quality of compressed lung CT images obtained using high resolution CT (HRCT: 2 mm slice thickness) for degree of compression and conventional CT (10 mm slice thickness) images by using physical and subjective evaluations, and (2) to analyze the distortion of density distribution on lung CT images using histogram analysis for each compression ratio. The coding method was performed according to the Joint Photographic Experts Group (JPEG). We physically evaluated the quality of compressed lung CT images using the peak signal-to-noise ratio (PSNR) as given by the square root of the ratio of the peak value of the gray level squared to the mean square error (dB) and subjectively evaluated the CT images using the mean opinion score (MOS). The acceptable compression ratio for diagnosis was about 1:6 to 1:7 for conventional CT images and about 1:4 to 1:5 for HRCT images as determined by MOS. The PSNR corresponding to acceptable compression ratios was about 50 dB. The difference in density distribution between HRCT and conventional CT was statistically significant (Friedman test: p<0.02) in histogram analysis. Results suggested that, in comparison with conventional CT, a high compression ratio was not suitable for HRCT.