Radiology reports: a quantifiable and objective textual approach.

AIM: To examine the feasibility of using automated lexical analysis in conjunction with machine learning to create a means of objectively characterising radiology reports for quality improvement. MATERIALS AND METHODS: Twelve lexical parameters were quantified from the collected reports of four radiologists. These included the number of different words used, number of sentences, reading grade, readability, usage of the passive voice, and lexical metrics of concreteness, ambivalence, complexity, passivity, embellishment, communication and cognition. Each radiologist was statistically compared to the mean of the group for each parameter to determine outlying report characteristics. The reproducibility of these parameters in a given radiologist's reporting style was tested by using only these 12 parameters as input to a neural network designed to establish the authorship of 60 unknown reports. RESULTS: Significant differences in report characteristics were observed between radiologists, quantifying and characterising deviations of individuals from the group reporting style. The 12 metrics employed in a neural network correctly identified the author in each of 60 unknown reports tested, indicating a robust parametric signature. CONCLUSION: Automated and quantifiable methods can be used to analyse reporting style and provide impartial and objective feedback as well as to detect and characterise significant differences from the group. The parameters examined are sufficiently specific to identify the authors of reports and can potentially be useful in quality improvement and residency training.

Sequence and tissue distribution of the integrin alpha 9 subunit, a novel partner of beta 1 that is widely distributed in epithelia and muscle.

The integrin family of adhesion receptors consists of several heterodimeric glycoproteins, each composed of one alpha and one beta subunit. A novel integrin alpha subunit partial cDNA isolated from TGF-beta stimulated guinea pig airway epithelial cells has previously been reported (Erle, D.J., D. Sheppard, J. Bruess, C. Rüegg, and R. Pytela. 1991. Am. J. Respir. Cell Mol. Biol. 5:170-177). We have now determined cDNA and amino acid sequence for the human homolog of this subunit, named alpha 9, from a human lung cDNA library, a human small intestine cDNA library, and cDNA from the cell lines U937, HL-60 and Tera-2. This sequence is predicted to encode a 1006-amino acid mature protein that shares 39% identity with the previously identified integrin subunit alpha 4. By Northern blot analysis, alpha 9 mRNA was detected in the human carcinoma cell lines Tera-2 and Caco-2. Anti-peptide antibodies against the predicted COOH-terminal sequence of alpha 9 immunoprecipitated a heterodimer (140 kD/115 kD nonreduced; 150 kD/130 kD reduced) from Tera-2 lysates. Immunodepletion of beta 1-containing integrins with Tera-2 lysates removed alpha 9 immunoreactivity, suggesting that beta 1 is the principal beta subunit partner for alpha 9 in these cells. alpha 9 was detected by immunohistochemistry in airway epithelium, in the basal layer of squamous epithelium, and in smooth muscle, skeletal muscle, and hepatocytes.

Do diagnostic algorithms always produce a uniform lung scan interpretation?

Several algorithms have been devised to assist in the interpretation of ventilation-perfusion (V/Q) scans performed to diagnose pulmonary embolism. The degree to which adherence to a single algorithm facilitates diagnostic homogeneity among different readers, however, has been little investigated. We evaluated the individual variability in V/Q lung scan interpretation in a large, academic nuclear medicine division to determine the degree of interpretive heterogeneity among a group of physicians all using the same image interpretation algorithm. Ventilation-perfusion scan interpretive patterns and the diagnostic accuracy of individual physicians were evaluated using quantitative parameters to establish group norms and to detect variations from these norms. The performance of each reader was tracked over a 4 yr period. There was a significant variation in V/Q interpretive patterns and diagnostic accuracy between readers despite the attempted use of a uniform diagnostic algorithm. Subgroups of interpretive styles could be defined based on the percentage of intermediate (including both indeterminate and intermediate categories) scans read. Although there was significant variation in diagnostic accuracy among readers, there was no obvious correlation between accuracy and reading style except that the most nonstandard diagnostic patterns were associated with the most variable diagnostic accuracy. These data show a measurable variation in interpretive patterns and accuracy among multiple readers of V/Q scans despite attempted group adherence to an established diagnostic algorithm.

Radionuclide imaging of sequential torsions of the appendix testis.

Radionuclide imaging is the diagnostic procedure of choice for evaluation of acute disorders of the scrotum, permitting rapid differentiation of torsion of the spermatic cord from inflammatory processes. The method is less successful in diagnosing torsion of the testicular appendages. In the majority of reported cases of torsion of the appendix testis the scan appears normal. In a very limited number of cases increased perfusion to the affected side has been noted. We report a case of metachronous torsion of both the appendices testis. In each instance, there was decreased tracer uptake on the affected side, suggestive of early torsion of the testicle. The sequential involvement of each testis with a nine month interval between respective torsions provides a unique example where each testis serves, sequentially, as a normal control for the torsed contralateral appendage.

HIV-associated myositis detected by radionuclide bone scanning.

We report a case of myositis associated with human immunodeficiency virus (HIV) reactivity which was demonstrated on bone scan in the presence of normal muscle enzymes, contrast computed tomography, and electromyography. The diagnosis was confirmed by muscle biopsy. Radionuclide bone scanning may be a valuable diagnostic tool in HIV positive patients who present with muscle pain and an otherwise normal diagnostic evaluation.

Pleural effusion and ventilation/perfusion scan interpretation for acute pulmonary embolus.

UNLABELLED: This study was conducted to determine if pleural effusion size affects ventilation/perfusion (V/Q) scan interpretation algorithms for acute pulmonary embolus (PE). METHODS: Retrospective analysis identified 163 consecutive patients undergoing angiography for PE with radiographic evidence for pleural effusion. V/Q scanning was performed in 94 (58%) of cases and reported using original Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) criteria. Effusions were classified as small, large and/or bilateral. Radiographic and scintigraphic results were compared with regard to size and location of abnormalities. RESULTS: Of the 163 patients, 57 (35%) had angiographically-proven PE, 77 (47%) had at least one large pleural effusion and 86 (53%) had a small effusion; 33 (43%) with large effusions and 24 (28%) with small effusions had emboli at angiography. Thirty-six of 119 patients (30%) with clear chest radiographs (a control group) had PE. Thus, large effusions were associated with a higher incidence of PE than those with small effusions or clear lungs (p < 0.05). Of those with V/Q scanning, 26 of 94 (28%) had a solitary large effusion, with 12 (46%) positive for emboli. V/Q-matched abnormalities limited to effusion size were found in 16 with a solitary large effusion and 10 with a solitary small effusion. In both groups, 50% were angiographically positive for emboli. Twenty-three (66%) of 35 with bilateral effusions had corresponding V/Q-matched defects at one (n = 11) or both (n = 12) lung bases, and 9 (39%) were positive for emboli. In total, 45% with a V/Q-matched defect of equivalent size to the effusion were angiographically positive for PE. CONCLUSION: Pulmonary emboli are associated with pleural effusions of all sizes. Matched V/Q defects corresponding to radiographically-evident pleural effusions are of intermediate probability for PE. Thus, revision of the traditional lung scan interpretive criteria based upon pleural effusion size is not warranted.

Gallium-67 and magnetic resonance imaging in aortic root abscess.

Perivascular abscess in the aortic root is a serious complication of infective endocarditis and is recognized infrequently with noninvasive techniques. This report describes a patient with sepsis who was imaged with 67Ga and magnetic resonance (MR) in order to locate a site of infection. The 67Ga image showed increased activity in the substernal region. Magnetic resonance correctly detected the multilocular aortic root abscess, which had extended into the interatrial septum. The combination of the sensitive 67Ga with the high-resolution MR image provided a useful method to locate aortic root abscesses and to identify contiguous spread.

Scintigraphic findings in large-cell lymphoma of the spleen: concise communication.

The scintigraphic findings from eight patients who underwent splenectomy for splenomegaly secondary to diffuse large-cell lymphoma are described. Large focal photopenic areas were found in all cases, either solitary or multiple. The appearance is relatively typical for large-cell lymphoma, which should be strongly considered in a nontraumatized patient who presents with painful splenomegaly of unknown origin.

Meteorologic influences on the frequency of pulmonary embolism.

RATIONALE AND OBJECTIVES: Reports published earlier this century suggested that meteorologic factors influence the incidence of pulmonary embolism. These observations were based on few patients and often lacked rigorous standards of evidence. In the current study, the authors evaluate the association between barometric pressure changes and pulmonary embolism using radionuclide ventilation-perfusion (V/Q) scan data. METHODS: Daily interpretation data for V/Q lung scans were correlated retrospectively with daily local barometric pressure changes over a 7-year period. RESULTS: The incidence of pulmonary embolic disease was significantly related to a decrease in barometric pressure during the 3 days preceding clinical presentation. CONCLUSIONS: Meteorologic factors are less important than better-known risk factors for pulmonary embolism; however, their effect is demonstrable in a large data sample. This work confirms previously published associations between barometric pressure changes and the incidence of pulmonary embolism.

Impact of fluorodeoxyglucose positron emission tomography on the clinical management of patients with glioma.

The past decade has seen the identification of many clinical settings in the treatment of primary brain tumors in which information from fluorodeoxyglucose positron emission tomography (FDG-PET) might be useful, if not essential, to therapeutic formulation. FDG-PET is currently used at referral centers in the management of primary brain tumors. The clinical pattern of FDG-PET use was assessed and its value compared to other information sources in clinical decision making. The clinical records of 75 glioma patients who were evaluated by FDG-PET were reviewed. The range of circumstances in which FDG-PET was employed included: pretherapeutic baseline studies for monitoring the effect of a therapy (1% of all cases), mapping of hypermetabolic regions before surgery or biopsy (2%), mapping of hypermetabolic regions before radiotherapy (2%), postsurgical evaluation for residual tumor (2%), assessment of the malignancy of a mass as a substitute for biopsy (11%), and distinguishing between radiation necrosis and recurrent tumor (87%). Other sources of information that contributed to the therapeutic management of patients included: gadolinium-enhanced MRI, contrast-CT, and clinical findings.

A pilot study to assess the possible methods of determining the burden of obstructive sleep apnoea syndrome in primary care.

INTRODUCTION: A significant minority of otherwise healthy adults may suffer from disordered breathing during sleep. The commonest problem, known as Obstructive Sleep Apnoea Syndrome (OSAS), results in poor quality sleep, daytime hypersomnolence and excess risk of road traffic crashes. It is also associated with occupational injuries. OSAS can be successfully treated, reducing costs of hospitalisation. There is a gap in the literature regarding the burden of patients with OSAS in primary care, particularly because there is no agreed method for screening. OBJECTIVES: This pilot study was designed to determine the feasibility of screening for OSAS in a UK inner-city multi-ethnic primary care population, to investigate ways in which it might be detected, and to gain an awareness of the potential size of the burden of OSAS METHODS: We tested two methods of screening: firstly, postal questionnaires to a random sample of 240 patients from a subset of the population at highest risk of OSAS (men aged 35-65 years); and secondly, the same questionnaire plus two screening tools for detecting hypersomnolence, given to patients attending the practice for pre-registration health checks. RESULTS: Despite reminders, only 40% of postal questionnaires were returned and there were only 67 (28%) usable responses. The prevalence of snoring was 55%. Almost half of those patients who responded (46%) had a Body Mass Index (BMI) associated with a high risk of OSAS. This was not a positive responder bias because there were no significant differences in BMI between responders and non-responders. 12% had a collar size of greater than 17.5, whilst 34% reported daytime sleepiness, and 24% reported witnessed apnoea. Screening during pre-registration health checks proved both feasible and productive with 38 patients of differing linguistic abilities completing the assessment. CONCLUSION: Screening for OSAS in primary care by means of a postal questionnaire produced a low response. Whilst there was no evidence of a responder bias in terms of BMI, the numbers reporting large collar size, daytime sleepiness and witnessed apnoea suggest that a sizeable proportion of the population is at risk of OSAS. Questionnaires used in this study provide a means of identifying patients with symptoms suggestive of OSAS, although the sensitivity, specificity and positive predictive value of a self-administered instrument needs to be confirmed by a larger study incorporating ventilatory monitoring during sleep. The addition of screening to pre-registration health checks is feasible, but it would take a long time to screen all those at risk for OSAS by this route.

Neural network analysis of ventilation-perfusion lung scans.

A neural network model was constructed to interpret ventilation-perfusion (V/Q) lung scans. This model was trained with data from 100 consecutive V/Q scans with pulmonary angiographic correlation. The network was constructed from 28 input parameters that described various standard V/Q findings, which were fed into a single hidden layer that contained 10-20 nodes. The network output indicated the percentage probability of pulmonary embolism for each set of findings on V/Q scans. This network was then used to classify 28 new scans; the resultant classifications were compared with the rankings of an experienced observer who read the scans without knowledge of the correlative angiographic data. The network with 15 hidden nodes outperformed the experienced observer in prediction of the likelihood of pulmonary embolism in the 28-case test set (P = .039). The neural network has several advantages over current algorithms for interpretation of V/Q scans, including the ability to synthesize many variables into a single conclusion and to learn, or modify itself, at exposure to additional data.

Cancer and humiliation: The "catch 22" of disease.

In the author's own words: I am a cancer patient involved in an agonizing struggle against disease. I decided to write about the humiliating aspects of cancer because I have experienced them firsthand. I know them all too well. I have incorporated my feelings about the humiliation of disease ... hoping they may help the reader better understand.