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T E Hartman

Publications and source records attributed to T E Hartman.

At least 19 recordsLinked to original sources
PubMed1999

Idiopathic interstitial pneumonias: diagnostic accuracy of thin-section CT in 129 patients.

PURPOSE: To determine whether idiopathic interstitial pneumonias can be differentiated on the basis of the pattern and distribution of abnormalities at thin-section computed tomography (CT). MATERIALS AND METHODS: Thin-section CT scans in 129 patients with histologically proved idiopathic interstitial pneumonia (35 with usual interstitial pneumonia [UIP], 24 with bronchiolitis obliterans organizing pneumonia [BOOP], 23 with desquamative interstitial pneumonia [DIP], 20 with acute interstitial pneumonia [AIP], and 27 with nonspecific interstitial pneumonia and fibrosis [NIPF]) were independently assessed by two observers without knowledge of clinical or histologic data. The observers recorded the abnormalities, diagnosis, and degree of confidence in their diagnosis. Differential diagnosis was limited to the five types of idiopathic interstitial pneumonia. RESULTS: The two observers made a correct diagnosis, on average, in 74 (57%) cases. On average, the correct diagnosis was made in 25 (71%) cases of UIP, 19 (79%) of BOOP, 14.5 (63%) of DIP, 13 (65%) of AIP, and 2.5 (9%) of NIPF. The two observers made a correct diagnosis with a high degree of confidence in 50 (39%) readings. There was moderate agreement between the observers for the correct diagnosis (k = 0.55) and for the correct diagnosis with a high degree of confidence (k = 0.65). CONCLUSION: Except for NIPF, the various subtypes of idiopathic interstitial pneumonias often have a characteristic appearance that allows differentiation at thin-section CT.

Adult↗
PubMed1999

Lymphocytic interstitial pneumonia: thin-section CT findings in 22 patients.

PURPOSE: To assess the thin-section computed tomographic (CT) findings of lymphocytic interstitial pneumonia. MATERIALS AND METHODS: The study included 22 patients (five men, 17 women; age range, 24-83 years; mean age, 50 years) with biopsy-proved lymphocytic interstitial pneumonia. The CT scans were obtained by using 1-3-mm collimation and reconstructed by using a high-spatial-frequency algorithm. RESULTS: The predominant abnormalities consisted of areas of ground-glass attenuation and poorly defined centrilobular nodules present in all 22 patients and subpleural small nodules seen in 19 patients. Other common findings included thickening of bronchovascular bundles (n - 19), interlobular septal thickening (n = 18), cystic airspaces (n = 15), and lymph node enlargement (n = 15). Less common findings included large nodules, emphysema, airspace consolidation, bronchiectasis, architectural distortion, honeycombing, and pleural thickening. CONCLUSION: Lymphocytic interstitial pneumonia is characterized by the presence of ground-glass attenuation, poorly defined centrilobular nodules, and thickening of the interstitium along the lymphatic vessels. Lymph node enlargement is more common than previously recognized; it was seen in 68% of patients.

Biopsy↗
PubMed1998

Detection of subtle abnormalities on chest radiographs after irreversible compression.

PURPOSE: To assess the effect of wavelet-based compression of posteroanterior chest radiographs on detection of small uncalcified pulmonary nodules and fibrosis. MATERIALS AND METHODS: Computed tomography (CT) of the chest was used to identify 20 patients with normal posteroanterior chest radiographs, 20 with a solitary uncalcified pulmonary nodule 1-2 cm in diameter, and 20 with fibrotic disease. A double-blind protocol for readings of original images and images compressed at 40:1 and 80:1 was analyzed by using the nonparametric receiver operating characteristic to measure differences in diagnostic accuracy and their statistical significance. RESULTS: There was no substantial difference in the overall diagnostic accuracy (measured by the area under the curve index) for both nodules and fibrosis between images compressed at 40:1 and 80:1 and uncompressed images. Readers tended to perform better on images compressed at 40:1 compared with uncompressed images. The "high-sensitivity" portion of the 80:1 compression curve for nodules was below that for the uncompressed curve, although this was not statistically significant. CONCLUSION: Lossy compression of chest radiographs at 40:1 can be used without decreased diagnostic accuracy for detection of pulmonary nodules and fibrosis. There is no statistically significant difference in diagnostic accuracy at 80:1 compression, but detection ability is decreased.

Algorithms↗
PubMed1998

Accuracy of high-resolution CT in diagnosing lung diseases.

OBJECTIVE: The purpose of our study was to determine if high-resolution CT facilitates the diagnoses of three diseases that cause cystic air spaces in the lungs: pulmonary eosinophilic granuloma, pulmonary lymphangiomyomatosis, and emphysema. MATERIALS AND METHODS: Retrospective review of high-resolution CT findings in patients with pathologically proven pulmonary eosinophilic granuloma (n = 10), pulmonary lymphangiomyomatosis (n = 9), and emphysema (n = 10) and five control patients without cystic air spaces was conducted by two thoracic radiologists unaware of the pathologic diagnosis. After reviewing the scans, the radiologists made a diagnosis and indicated their level of confidence in the diagnosis on a three-point scale. RESULTS: High-resolution CT allowed the two radiologists to be confident of the diagnosis of pulmonary eosinophilic granuloma in 84% of CT scans, lymphangiomyomatosis in 79%, and emphysema in 95%. When confident, the observers were correct in 100% of the cases. Agreement between observers was good for confident diagnoses based on high-resolution CT scans of pulmonary eosinophilic granuloma (kappa = .77), lymphangiomyomatosis (kappa = .88), and emphysema (kappa = 1). Distribution of cystic changes differed on high-resolution CT scans for lymphangiomyomatosis and pulmonary eosinophilic granuloma. No consistent distribution pattern was observed for emphysema. Lack of a perceptible cyst wall was unique to cases of emphysema. All patients with lymphangiomyomatosis lacked nodules in the intervening lung parenchyma, whereas most patients with pulmonary eosinophilic granuloma had parenchymal nodules. CONCLUSION: High-resolution CT can help radiologists reliably diagnose pulmonary eosinophilic granuloma, lymphangiomyomatosis, and emphysema.

Adult↗
PubMed1998

Idiopathic pulmonary fibrosis: current concepts.

Idiopathic pulmonary fibrosis (IPF) is generally defined as a progressive, fibrosing inflammatory disease of the lung parenchyma of unknown cause. It is characterized by slowly increasing dyspnea, diffuse interstitial lung infiltrates, restrictive lung dysfunction, and impaired gas exchange. Ultimately, it is fatal in most patients, and treatment options remain unsatisfactory. The advent of high-resolution computed tomography of the chest and modifications in the histopathologic classification of interstitial pneumonias have reshaped the concept of IPF. Although initially thought to be a relatively specific clinicopathologic entity, it seems likely that IPF as previously defined is a heterogeneous disorder consisting of several clinicopathologic entities with differing histopathologic patterns, clinical course, response to therapy, and prognosis. The most common histologic pattern in cases previously defined as IPF is usual interstitial pneumonia, which is associated with a median survival of less than 3 years. For accurate prognosis and optimal management of patients, the clinician should attempt to be as precise as possible in distinguishing various clinicopathologic entities that have been included under the clinical heading of IPF. In the future, we recommend that the use of the term "idiopathic pulmonary fibrosis" be restricted to patients with usual interstitial pneumonia and that clinicians recognize the fact that other idiopathic interstitial pneumonias do not have the same prognostic effect traditionally ascribed to IPF.

Diagnosis, Differential↗
PubMed1997

Evaluation of irreversible compression of digitized posterior-anterior chest radiographs.

The purpose of this article is to assess lossy image compression of digitized chest radiographs using radiologist assessment of anatomic structures and numerical measurements of image accuracy. Forty posterior-anterior (PA) chest radiographs were digitized and compressed using an irreversible wavelet technique at 10, 20, 40, and 80:1. These were presented in a blinded fashion with an uncompressed image for A-B comparison of 11 anatomic structures as well as overall quality assessments. Mean error, root-mean square (RMS) error, maximum pixel error, and number of pixels within 1% of original value were also computed for compression ratios from ratios from 5:1 to 80:1. We found that at low compression (10:1) there was a slight preference for compressed images. There was no significant difference at 20:1 and 40:1. There was a slight preference on some structures for the original compared with 80:1 compressed images. Numerical measures showed high image faithfulness, both in terms of number of pixels that were within 1% of their original value, and by the average error for all pixels. Our findings suggest that lossy compression at 40:1 or more can be used without perceptible loss in the representation of anatomic structures. On this finding, we will do a receiver-operator characteristic (ROC) analysis of nodule detection in lossy compressed images using 40:1 compression.

Artifacts↗
PubMed1997

Initial experience with soft-copy display of computed radiography images on three picture archive and communication systems.

We recently installed picture archive and communication systems (PACS) from three different vendors on our campus for evaluation. A major part of this evaluation involved assessing the capabilities of these systems for displaying computed radiography (CR) images for primary interpretation. The three PACS provided different functionality for CR image display in terms of availability of the proprietary Fuji CR image processing algorithms, availability of user-specified contrast look-up tables, and application of the processing at the time of CR image capture or image display. We found that the Fuji processing algorithms were important for printing film, but were not necessary for acceptable soft-copy display. Non-linear contrast processing produced superior results compared to simple linear processing (via standard window width and level controls). Display processing was best applied immediately prior to the display operation, as opposed to at the image capture time. This allows the display to be adjusted to demonstrate the full 10-bit range of the CR image, and also allows raw CR data (i.e. not optimized for any particular display device) to be stored in the long-term archive.

Algorithms↗
PubMed1997

Simulated dose reduction in conventional chest CT: validation study.

PURPOSE: To validate a technique of computer-simulated dose reduction for conventional chest computed tomography (CT). MATERIALS AND METHODS: In 27 patients, CT scans were obtained at 200, 100, and 40 mAs at two levels. The raw data from the 200-mAs scan were modified on a computer workstation to simulate the increased noise present on 100- and 40-mAs scans. Real and simulated 100- and 40-mAs images were independently assessed in random order for overall image quality and radiologic findings by four subspecialty-trained chest radiologists who were blinded to the technique. The four observers were given paired real and simulated images. They were asked to identify the real image and note any difference in diagnostic quality. RESULTS: No difference was seen in overall image quality or radiologic findings between real and simulated images (P > .05). In the paired comparison, 433 of 864 (50.1%) real images were correctly identified. CONCLUSION: Computer modification of 200-mAs raw scan data to simulate 100- and 40-mAs noise levels produces reconstructed images indistinguishable from real 100- and 40-mAs scans. This technique provides realistic reduced-dose images without patient radiation exposure and with identical image registration and motion artifact.

Adult↗
PubMed1997

Mosaic attenuation pattern on thin-section CT scans of the lung: differentiation among infiltrative lung, airway, and vascular diseases as a cause.

PURPOSE: To determine whether infiltrative lung, airway, or vascular disease can be differentiated as the cause of mosaic attenuation on thin-section computed tomographic (CT) scans of the lung. MATERIALS AND METHODS: Thin-section CT scans were reviewed in 70 patients examined at three institutions. A mosaic attenuation pattern and pathologic or clinical proof of a specific type of disease were demonstrated. Causes of the mosaic pattern included infiltrative lung disease (n = 37), airway disease (n = 22), and vascular disease (n = 11). Thin-section CT findings were assessed independently by two observers blinded to clinical findings. RESULTS: The type of disease was identified correctly at CT in 58 (83%) of 70 patients by observer 1 and 57 (81%) of 70 patients by observer 2. Infiltrative lung disease was diagnosed correctly by both observers in 34 (92%) of 37 cases. Observer 1 identified 21 (95%) of 22 cases of airway disease and three (27%) of 11 cases of vascular disease. Observer 2 identified 19 (86%) of 22 cases of airway disease and four (36%) of 11 cases of vascular disease. CONCLUSION: Infiltrative lung disease and airway disease may be differentiated reliably as the cause of mosaic attenuation on lung CT scans, whereas vascular disease is often misinterpreted as infiltrative lung disease or airway disease.

Adult↗
PubMed1997

Mosaic pattern of lung attenuation on CT scans: frequency among patients with pulmonary artery hypertension of different causes.

OBJECTIVE: The purpose of this study was to determine the frequency with which a mosaic pattern of lung attenuation is seen on chest CT scans in patients with various causes of pulmonary artery hypertension (PAH). MATERIALS AND METHODS: Chest CT scans of 64 patients with known PAH were reviewed to assess the patterns of lung attenuation. Patterns of lung attenuation were divided into three categories: class I, homogeneous lung parenchymal attenuation; class II, slightly heterogeneous lung attenuation that does not conform to the anatomic boundaries of the secondary pulmonary lobule; and class III (mosaic pattern), heterogeneous lung attenuation in geographic regions with well-defined borders corresponding to the anatomic units of single or multiple secondary pulmonary lobules. The patients medical histories were reviewed to determine the primary cause of PAH for each patient. RESULTS: Peak pulmonary artery pressure of the patients in our study averaged 74 mm Hg (range, 36-194 mm Hg). Twenty-one patients had PAH due to lung disease: 17 patients, due to cardiac disease; and 23 patients, due to vascular disease. Three other patients had PAH due to miscellaneous causes. Of the 23 patients with PAH due to vascular disease, 17 patients (74%) had a mosaic pattern of lung attenuation. Of the 21 patients with PAH due to lung disease, one patient (5%) had a mosaic pattern of lung attenuation. Among the 17 patients with PAH due to cardiac disease, two patients (12%) had a mosaic pattern of lung attenuation. A mosaic pattern of lung attenuation was seen significantly more often in patients with PAH due to vascular disease than in patients with PAH due to cardiac or lung disease. CONCLUSION: A mosaic pattern of lung attenuation can be seen on CT scans in patients with PAH due to vascular disease, cardiac disease, or lung disease. However, the mosaic pattern is seen significantly more often in patients with PAH due to vascular disease than in patients with PAH due to cardiac or lung disease.

Adult↗
PubMed1996

Disease progression in usual interstitial pneumonia compared with desquamative interstitial pneumonia. Assessment with serial CT.

OBJECTIVE: To determine the outcome of areas of ground-glass attenuation and assess disease progression on serial high-resolution CT (HRCT) scans of patients with biopsy specimen-proved usual interstitial pneumonia (UIP) and desquamative interstitial pneumonia (DIP). MATERIALS AND METHODS: Twelve patients with biopsy specimen-proved UIP and 11 patients with biopsy specimen-proved DIP who had initial and follow-up HRCT scans (median interval, 10 months) were reviewed. Eleven patients with UIP and 11 with DIP received treatment between the initial and follow-up CT scans. The scans were evaluated for the presence and extent of ground-glass attenuation, irregular linear opacities and honeycombing, and overall extent of parenchymal involvement. RESULTS: On initial CT scans, all 12 patients with UIP had areas of ground-glass attenuation (mean +/- SD extent, 30 +/- 16%) and irregular lines (mean +/- SD extent, 17 +/- 7%) and 10 patients had honeycombing (mean +/- SD extent, 10 +/- 6%). All 11 patients with DIP had areas of ground-glass attenuation on initial HRCT scans (mean +/- SD extent, 51 +/- 26%), 5 patients had irregular linear opacities (mean +/- SD extent, 5 +/- 5%), and 1 patient had honeycombing. Nine of the 12 patients with UIP showed increase in the extent of ground-glass attenuation (n = 6) or progression to irregular lines (n = 2) or honeycombing (n = 4) on follow-up as compared with only 2 patients with DIP who showed progression to irregular lines (n = 1) or honeycombing (n = 1) (p < 0.01 chi 2 test). CONCLUSION: In patients with UIP, areas of ground-glass attenuation usually increase in extent or progress to fibrosis despite treatment. Areas of ground-glass attenuation in most patients with DIP remain stable or improve with treatment.

Adult↗
PubMed1995

Pulmonary tuberculosis and Mycobacterium avium-intracellulare: a comparison of CT findings.

PURPOSE: To compare the computed tomographic (CT) findings of tuberculosis and Mycobacterium avium-intracellulare (MAI) infection in immunocompetent patients. MATERIALS AND METHODS: Seventy-seven consecutive immunocompetent patients with culture-proved pulmonary mycobacterial infection (45 with pulmonary tuberculosis, 32 with MAI) underwent thin-section CT. CT scans were randomized and reviewed by two observers; decisions were reached by consensus. RESULTS: Micronodules, consolidation, and cavity formation in the lung were seen with similar frequency in pulmonary tuberculosis and MAI cases. Twenty-three patients (51%) with tuberculosis and four patients (12%) with MAI had interlobular septal thickening (P < .001). Twelve patients (27%) with tuberculosis and 30 patients (94%) with MAI had bronchiectasis (P < .001). Bronchiectasis was seen in a mean of 4.6 +/- 1.8 and 1.8 +/- 1.6 lobes (+/- standard deviation) in each patient with MAI and with tuberculosis, respectively (P < .01). CONCLUSION: Although CT findings of pulmonary tuberculosis and MAI are similar, interlobular septal thickening is more common in patients with tuberculosis and bronchiectasis is more common and more extensive in patients with MAI.

Adolescent↗
PubMed1995

Diaphragmatic rupture: CT findings in 11 patients.

PURPOSE: To determine the signs of diaphragmatic rupture at computed tomography (CT) and the frequency of preoperative diagnosis with CT. MATERIALS AND METHODS: CT scans in 11 consecutive patients with surgically proved tears of the diaphragm due to blunt trauma were reviewed by two chest radiologists. The observers assessed the presence of discontinuity of the diaphragm, herniation of abdominal viscera or omentum, and waistlike constriction of the herniated stomach or bowel (collar sign). Hospital records were reviewed to confirm surgical findings and ascertain whether the diagnosis has been suggested at CT. RESULTS: In eight of 11 patients, rupture of the diaphragm was on the left, and in three it was on the right. In nine patients, diagnostic findings were identified retrospectively on CT scans; these included discontinuity of the diaphragm (n = 9), herniation of the abdominal organs or bowel (n = 7), and constriction of the stomach (n = 3). CONCLUSION: CT enables detection of most diaphragmatic tears due to blunt trauma.

Adult↗
PubMed1995

CT of the chest: minimal tube current required for good image quality with the least radiation dose.

OBJECTIVE: We wanted to determine minimal tube current (mAs) required for consistently good image quality on conventional 10-mm collimation chest CT and effect of tube current reduction on detection of mediastinal and lung abnormalities. Tube current reduction is desirable to reduce patient radiation dose. SUBJECTS AND METHODS: Prospectively, 30 consecutive patients (mean weight, 68 kg; range, 34-93 kg) older than 45 undergoing conventional chest CT with standard technique (120 kVp, 400 mAs) had four additional sections imaged at reduced tube current (200, 140, 80, 20 mAs) at two levels (tracheal carina and left atrium). CT scans were evaluated in random order by two independent observers who were blinded to technical factors used. Subjective image quality was graded on a five-point scale from non-diagnostic to excellent. Visualization of mediastinal adenopathy (n = 18), pleural plaques (n = 17), effusions (n = 28), lung parenchymal nodules (n = 37), and emphysema (n = 15) were assessed. The 400 mAs scan was considered the reference standard. RESULTS: When compared with the reference technique (400 mAs), the first and second (200 mAs and 140 mAs) reduction levels showed no significant difference (p > .05) in subjective image quality. A significant difference (p < .001) was seen at the third and fourth (80 mAs and 20 mAs) reduction levels. However, no significant difference (p > .05) was seen in detection of mediastinal or lung parenchymal abnormalities with different tube currents. CONCLUSION: A twofold reduction in tube current (400-140 mAs) and resultant radiation dose did not cause a significant change in subjective image quality or in detection of mediastinal or lung abnormalities with conventional chest CT. One hundred forty milliampere-seconds is the minimal tube current required to provide good image quality in patients of average weight.

Aged↗
PubMed1995

CT mosaic pattern of lung attenuation: distinguishing different causes.

Areas of variable lung attenuation in a lobular or multilobular distribution are occasionally seen on CT or high-resolution CT scans of the lungs [1], although never as a normal finding. This mosaic pattern of lung attenuation presents a challenge to the radiologist when deciding which are the abnormal regions of lung--those of low attenuation, those of high attenuation, or both. We have observed three categories of disease known to cause a CT mosaic pattern of lung attenuation: small-airway disease, vascular lung disease, and infiltrative disease. Diseases from each of these categories can cause similar patterns of mosaic lung attenuation on CT scans. However, it is sometimes possible to distinguish among these categories by using additional CT findings. We illustrate the known causes of a CT mosaic pattern of lung attenuation and highlight distinguishing features.

Aged↗
PubMed1995

CT mosaic pattern of lung attenuation: etiologies and terminology.

Areas of variable lung attenuation forming a "mosaic pattern" are occasionally seen on computed tomography (CT) or high-resolution CT (HRCT) images of the lungs. This CT mosaic pattern of lung attenuation is a nonspecific finding that can reflect the presence of vascular disease, airway abnormalities, or ground-glass interstitial or air-space infiltrates. However, it is often possible to distinguish among these categories. In small airways disease and pulmonary vascular disease, the pulmonary vessels within the lucent regions of lung are small relative to the vessels in the more opaque lung. In infiltrative diseases, the vessels are more uniform in size throughout the different regions of lung attenuation. The distinction of small airways disease from primary vascular disease requires the use of paired inspiratory/expiratory CT scans. The terms "mosaic perfusion" or "mosaic oligemia" have also been used to describe this heterogeneous pattern of lung attenuation. We believe that the term "mosaic pattern of lung attenuation" is preferable when describing areas of variable lung attenuation because the term "mosaic perfusion" implies pulmonary vascular pathology.

Adolescent↗
PubMed1994

CT of bronchial and bronchiolar diseases.

Computed tomography (CT) is useful in evaluating bronchial and bronchiolar abnormalities. Common bronchial and bronchiolar abnormalities include bronchiectasis, asthma, bronchial obstruction, and various forms of bronchiolitis. Causes of bronchiectasis include cystic fibrosis, childhood viral infection, allergic bronchopulmonary aspergillosis, and pulmonary fibrosis. On CT scans, cystic fibrosis may manifest with bronchial wall thickening, bronchiectasis (usually cylindrical, with varicose and cystic forms seen in advanced cases), and mucus plugs in the bronchi. Allergic bronchopulmonary aspergillosis is characterized by central, varicose or cystic bronchiectasis, predominantly in the upper lobes, with mucoid impaction in the bronchi. Traction bronchiectasis may be seen on CT scans of pulmonary fibrosis. Asthma is characterized by bronchial wall thickening due to inflammation. Bronchial dilatation and air trapping may also be seen. Bronchiolitis obliterans is manifested by direct and indirect signs on CT scans; the former consist of centrilobular branching structures and nodules, and the latter consist of bronchiectasis and bronchiolectasis, mosaic perfusion, and air trapping. CT findings of bronchiolitis obliterans organizing pneumonia (also known as cryptogenic organizing pneumonia) include air-space consolidation and nodules, with occasional bronchial dilatation and pleural effusions.

Adult↗