Breathing motion severely degrades the quality of magnetic resonance images (MRI) of the thorax and upper abdomen and interferes with the acquisition of quantitative data. To minimize these motion effects, we built an MRI compatible ventilator for use in animal studies. Solid state circuitry is used for controlling ventilation parameters. The ventilator can be triggered internally at frequencies of 0.1 to 30 Hz or it can be triggered externally such as by the MRI pulse sequence. When triggered by the scanner, ventilation is synchronized to occur between image data acquisitions. Thus, image data are obtained when there is no breathing motion and at a minimum lung volume when hydrogen density is maximum. Since the ventilator can be adjusted to operate at virtually any frequency from conventional to high frequency, ventilation can be synchronized to all commonly used repetition times (100 ms to 2000 ms or more; 600 to 30 breaths/min). Scan synchronous ventilation eliminates breathing motion artifacts from most imaging sequences (single and multiple spin echo and inversion recovery). Best image quality is obtained when scan synchronous ventilation is combined with cardiac gating. These methods are also useful for quantitative research studies of thoracic and abdominal organs.

Abdomen↗

PubMed1986

Regional pulmonary distribution of iodine-125-labeled oleic acid. Its relationship to the pattern of oleic acid edema and pulmonary blood flow.

Oleic acid infusion in dogs produces a patchy, predominantly peripheral lesion on CT scans. This study correlates the pattern of oleic acid injury with the distribution of infused oleic acid and pulmonary blood flow. Radiolabeled oleic acid (I-125, 0.05 ml/kg) and radiolabeled 15-micron microspheres (Co-57) were infused into the right atria of 11 dogs. Oleic acid was given after the microspheres in six dogs and before microspheres in five dogs. Ten minutes after infusion, the lungs were removed. Four transverse slices (0.5 cm thick) of the lower lobes were taken from each dog and cubed. Samples were grouped into three regions of the transverse slice: outer, middle, and inner concentric rings. In both groups, I-125 (oleic acid) activity was greater in the outer than the middle and inner concentric layers (P less than 0.001). When Cobalt-57 microspheres were given before oleic acid, Cobalt-57 activity was marginally lower in the outer layer compared with the middle and inner layers. However, when oleic acid was given first, microsphere activity in the outer layer was significantly lower (P less than 0.001) than the middle layer. Thus, oleic acid was preferentially distributed to the peripheral regions of the lung, similar to the regions of injury on CT. This distribution did not correspond to the pattern of pulmonary blood flow as indicated by the microspheres. Immediately after oleic acid infusion, pulmonary blood flow to the periphery was reduced, reflecting a response to the predominantly peripheral injury by oleic acid.

Animals↗

PubMed1986

Impact of revolutionary advances in diagnostic imaging. Where do we go from here?

Explore the source record for details and available documents.

Financing, Government↗

PubMed1986

Distribution of 15- and 137-mu diameter microspheres in the dog lung in the axial plane.

Oleic acid infusion, as a model of fat embolism, produces a predominantly peripheral lesion in the dog lung. The lung injury corresponds to the peripheral distribution of labeled oleic acid. The basis for this distribution of oleic acid is not known. Our hypothesis for this nonuniform distribution is that particle diameter plays a role in the subsequent distribution of infused oleic acid and the resulting lung injury. We injected 15-mu microspheres 85Sr and then 137-mu microspheres (141Ce) into the right atria of seven dogs, which were killed and the lungs removed. Analysis of the distribution of the two different diameter microspheres within axial slices from the left caudal lobe of each dog revealed a peripheral distribution of the larger diameter microspheres not seen with the smaller microspheres.

Animals↗

PubMed1986

Chronic tension pneumothorax presumably due to a "ball valve" bronchopleural fistula.

We have described an unusual variant of bronchopleural fistula whose ball valve characteristics led to a chronic tension pneumothorax without fluid collection in a postpneumonectomy space.

Bronchial Fistula↗

PubMed1986

Reassessing the standard chest radiograph for intraparenchymal activity.

The results concerning the activity or inactivity of the alveolitis determined with our proposed scoring system were comparable to those determined with gallium scanning in 68.2% of the patients with biopsy-proven sarcoidosis in our study. Certainly, further evaluation of a larger series of patients over a longer period of time will be required to more adequately evaluate this classification method. We also believe this methodology is reproducible and can be utilized by experienced interpreters of chest radiographs. If we closely reevaluate the 32% of the cases in which the radiographic results disagreed with the gallium assessment of activity, two points worthy of mention become evident. In one group the gallium indices were borderline for activity whereas in the other group the radiographic criteria were most likely indicative of irreversible parenchymal changes. When the radiographs for the latter group were reevaluated for signs of fibrosis such as volume loss, cystic changes, and alteration in vascular patterns, it was possible to delineate a significant false-positive group of patients. We will be reporting the long-term results of our observations over the next several years as well as adding more groups of patients to our initial study analysis. At that time, correlation with all other measurable parameters in determining high-intensity alveolitis versus low-intensity alveolitis will be compared to these new chest radiographic profiles.

Adult↗

PubMed1986

Role of chest CT in non-Hodgkin lymphoma.

A retrospective study of 48 patients with non-Hodgkin lymphoma (NHL) who underwent 54 computed tomographic (CT) examinations of the chest evaluated the role of chest CT in the management of this disease. Of 18 cases in which chest radiographs were not indicative of NHL, CT scans showed abnormalities consistent with NHL in five (28%). Of 11 cases where radiographs were questionable, CT confirmed NHL in five (45%) and excluded it in six (55%). Of 25 cases where radiographs were consistent with NHL, CT confirmed the findings in 23 (92%) and added information in all 25. Chest CT affected management in eight of 25 treated and five of 19 untreated patients. It appears to be useful in untreated patients with stage I or II NHL but no definite radiographic abnormalities, or with abnormal radiographs but no extrathoracic spread, and in treated patients with questionable radiographs. CT is not helpful in untreated patients with stage III or IV NHL or treated patients with normal radiographs.

Adolescent↗

PubMed1986

Centrilobular emphysema: CT-pathologic correlation.

Over a 5-year period, 25 patients who had undergone chest computed tomography (CT) died and were autopsied. Their lungs were fixed in the inflated state and were assessed for the presence and severity of centrilobular emphysema (CLE). Three radiologists independently evaluated the CT scans for nonperipheral low-attenuation areas, peripheral low-attenuation areas, pulmonary vascular pruning, pulmonary vascular distortion, and pulmonary density gradient. The CT criterion that best correlated with the presence and severity of CLE was the nonperipheral low-attenuation area. With this CT criterion, lung destruction was correctly identified in 13 of 15 cases. The absence of this criterion resulted in correct identification of eight of ten normal lungs. These preliminary data suggest that CLE can be reliably identified and quantified with current CT scanners.

Emphysema↗

PubMed1985

CT of obstructive lobar collapse.

The varied computed tomographic (CT) appearance of obstructive lobar collapse is described in 25 cases. CT is helpful in understanding the morphology and mechanisms of lobar collapse and in diagnosing atypical cases. The final shape of the collapsed lobe is dependent on the size and location of the obstructing tumor and on the amount of retained lung fluid. Focal bulging of the fissure (S-sign) is the most helpful sign in identifying the obstructing tumor. Differential enhancement could not separate the tumor from collapsed lung in six of eight (75%) of the cases studied with intravenous contrast, a finding at variance with previous reports. The limitations of CT in evaluating mediastinal or pleural invasion in the presence of lobar collapse are discussed.

Adult↗

PubMed1985

Advanced prostatic carcinoma: pulmonary manifestations.

To clarify the role of standard chest radiography in prostatic adenocarcinoma, the pulmonary manifestations of 198 patients with Stage D disease were evaluated. All patients were treated with chemotherapeutic protocols allowing for adequate clinical and radiographic correlation. Retrospective interpretation of serial chest radiographs revealed that 35% of our patients had visible intrathoracic abnormalities; however, only 24% of the patients had abnormalities attributable to intrathoracic metastases. Twenty-two percent of patients had pleural effusions, 16% reticular opacities, 3.5% reticulonodular opacities, 8% isolated or discrete pulmonary nodules, and 4.5% adenopathy. Etiologies of these opacities included metastatic disease in 93.5% of those with adenopathy and nodular or reticulonodular opacities, but 39% of pleural effusions and 52% of reticular opacities were best attributed to concomitant processes. Four patients had intrathoracic metastases without bone metastases. Standard chest radiography is a valuable screening procedure that should be correlated with clinical data to differentiate metastases from concomitant processes.

Aged↗

PubMed1985

Methods for detecting pulmonary edema.

Pulmonary edema appears to develop in three phases: after an initial injury to the lung, permeability of the air-blood barrier to water increases; a subsequent increase in movement of extra-vascular fluid; and finally, there is a significant increase in extravascular fluid volume (interstitial and alveolar). Ideally, early detection should monitor the initial phases of pulmonary edema, namely, the injury and the increased permeability. All established clinical and most of the research methods, however, monitor only the final or volume phase of the edema process. The chest radiograph is perhaps the most commonly used method for clinical detection of pulmonary edema, although it lacks the sensitivity for assessment of edema much before clinical signs are apparent. This paper reviews some of the clinical and research methods for detecting pulmonary edema with special emphasis on radiographic methods.

Acetylene↗

PubMed1985

The chest radiograph and sarcoidosis. Reevaluation of the chest radiograph in assessing activity of sarcoidosis: a preliminary communication.

Classic radiographic staging of sarcoidosis, utilizing stages 0 through III, is a purely descriptive classification and bears no relation to the clinical activity of the disease. We propose a new method of determining sarcoidosis activity based solely on the chest radiograph. This "staging" is based on the presence or absence of air bronchograms, peribronchial cuffing, and subpleural thickening. Adenopathy, reticular, reticulonodular, and nodular opacities are not included in our methodology. Other diagnostic methods currently utilized for staging activity include Gallium scanning, bronchoalveolar lavage, and physiologic studies. In 85 studies performed in 51 patients with biopsy-proven sarcoidosis, this staging method agreed with Gallium scintigraphy results in 68.2%. The system failed in specific and identifiable subgroups of patients. We feel that the chest radiograph compares favorably with other staging methods in detecting the alveolitis phase of sarcoidosis, and is reproducible, noninvasive, and cost efficient.

Adult↗

PubMed1984

CT of localized lucent lung lesions.

Explore the source record for details and available documents.

Adolescent↗

PubMed1984

Pulmonary blastomycosis: radiologic manifestations.

Blastomycosis, an airborne fungal disease with the lung the portal of entry, is endemic to the central and south central areas of the United States. The disease occurs in patients who range from asymptomatic to those with symptoms of acute pneumonia. Retrospective review of 27 cases from our institution revealed four well-defined radiographic patterns including air-space disease, nodular masses, interstitial disease, and cavitation. Some patients with air-space disease have symptoms of an acute pneumonia; more commonly they have no pulmonary symptoms. Air-space disease was the most frequent radiographic pattern in chronic blastomycosis with proved nonpulmonary disease; therefore, it cannot be regarded as indicative of early or acute blastomycosis. There was no relationship between the radiographic pattern and distribution, pulmonary symptomatology, or clinical stage of the disease. Our material does not support the previously suggested association of lower lobe air-space disease with early disease and upper lobe involvement with the chronic and often disseminated form. A more precise understanding of the variety of radiographic patterns and the spectrum of clinical presentations will facilitate diagnosis of pulmonary blastomycosis.

Adolescent↗