CT of solitary pulmonary vascular lesions.
Explore the source record for details and available documents.
Arteriovenous Fistula↗
Biomedical subjects
W R Webb
Publications and source records attributed to W R Webb.
Nuclear magnetic resonance of pulmonary arteriovenous fistula: effects of flow.
Nuclear magnetic resonance (NMR) imaging can be of value in distinguishing vascular and nonvascular lesions in the lung and mediastinum, in that rapidly flowing blood results in little or no NMR signal. We wish to report a patient having a pulmonary arteriovenous fistula evaluated using physiological studies, dynamic computed tomography, and spin-echo NMR. On the NMR images, the fistula was invisible because of rapid flow through its lumen.
Aged↗
Computed tomography in congenital heart disease.
The CT results in defining anatomic and certain physiologic features in patients with congenital heart and great vessel anomalies were reviewed in 32 patients with a variety of congenital cardiac and aortic arch anomalies. Most of these cases (18 patients) were selected on the basis of angiocardiographic or echocardiographic studies performed prior to the CT evaluation. In 14 patients CT was performed as the initial study. All examinations were contrast enhanced and performed on a third generation CT scanner with scan time of 2 or 4 s. The CT demonstration of abnormalities of the great vessels such as positional anomalies, atresias, and hypoplasias was equivalent to angiocardiography and usually superior to two-dimensional echocardiography. The CT results in 14 patients were sufficient to obviate catheterization and angiography; most of these cases were abnormalities of the thoracic aorta. The CT evaluation of intracardiac anatomy was inconsistent. It adequately defined septal defects and configurational (Ebstein anomaly) and bulboventricular loop abnormalities of the ventricles. However, valve anomalies were not adequately demonstrated by CT. The three-dimensional representation of cardiac and mediastinal vascular anatomy provided by this relatively noninvasive technique gives unique information in some cardiovascular anomalies. When faster scanning times are introduced, more definition of the cardiac structures should be possible, further increasing the diagnostic potential of CT.
Adolescent↗
CT appearances of rheumatoid lung disease.
The plain radiography and CT of four patients with rheumatoid lung disease are reviewed. One patient had histologically confirmed rheumatoid nodules. The subpleural location of the nodules and cavitation were more easily diagnosed using CT. Also on CT the nodules were commonly seen in clusters, a finding not previously reported and not visible on plain films. In three patients honeycombing was visible on both plain radiography and CT. However, the areas of cystic destruction visible on CT were larger than those appreciated on the plain films.
Aged↗
Magnetic resonance imaging of the neck. Part I: Normal anatomy.
Magnetic resonance (MR) images of the neck were obtained in 24 patients using a specially designed radio-frequency coil, standard and high-resolution imaging techniques, and a variety of spin echo and inversion recovery pulse sequences. Cervical vascular structures were more easily identified with MR than with CT because of the inherent contrast of flowing blood. The laryngeal skeleton, paralaryngeal tissues, trachea, thyroid, esophagus, and muscles were identified in all cases by MR using morphologic criteria comparable with CT criteria. The spatial resolution of high-resolution MR was slightly inferior to high-resolution CT. However, streak artifacts due to motion and x-ray beam hardening often limited CT, but did not affect MR. Anatomic resolution was best using high-resolution spin echo images obtained with TR = 2.0 seconds and TE = 28 msec because this imaging technique offered excellent contrast between normal tissues and had the highest signal-to-noise ratio. With further improvements in spatial resolution MR is likely to become an important technique for imaging the neck.
Adolescent↗
Magnetic resonance imaging of the neck. Part II: Pathologic findings.
Magnetic resonance (MR) images of the neck were obtained in 14 patients with thyroid, parathyroid, lymph node, or laryngeal lesions. Tumors and lymph nodes were more easily differentiated from muscle and blood vessels with MR than with CT because of the superior soft tissue contrast of MR. Tissue characterization allowed MR differentiation of thyroid nodules, thyroid cysts, and parathyroid tumors from normal thyroid tissue; however, nonspecifically increased T1 and T2 relaxation times overlapped for a variety of neoplastic and inflammatory conditions. Thyroid cyst fluid had the greatest water content and longest T1 and T2 times of all tissues studied. Parathyroid hyperplasia could not be differentiated from parathyroid adenoma; however, parathyroid tumors had slightly longer T1 and T2 times than thyroid nodules or lymph nodes. With further experience, MR tissue characterization may become a useful technique for evaluating neck masses.
Adolescent↗
Multisection sagittal and coronal magnetic resonance imaging of the mediastinum and hila. Work in progress.
Sagittal or coronal thoracic magnetic resonance (MR) images were obtained in 7 individuals - 4 normal subjects and 3 patients with thoracic masses. In 2 of the abnormal cases, sagittal or coronal MR provided significant anatomic information that was either less evident or invisible on transaxial MR or computed tomographic (CT) images or CT reformations. In the third abnormal patient, a pretracheal lymph node was more clearly seen on transaxial images than on coronal images.
Adult↗
Magnetic resonance imaging of benign mediastinal masses.
Eight patients who had benign mediastinal masses underwent CT and magnetic resonance (MR) imaging. The intensity difference between mass and surrounding mediastinal fat was greater on MR than CT images. Although the masses were clearly identified with both modalities, delineation of a mass from surrounding mediastinal structures was better with CT. Heterogeneity on CT and MR images was a prominent feature of most larger benign mediastinal masses, although this should not be considered indicative of benignity. These benign mediastinal masses were best demonstrated on MR images obtained using a long TR and short TE. In general, the MR studies provided information comparable to but not identical to that of CT scanning. The viewing of mediastinal masses using a variety of TR and TE imaging parameters appeared to be an important aspect of the MR studies.
Adenoma↗
EKG-gated digital subtraction angiography in the detection of pulmonary emboli.
Detection of pulmonary emboli was investigated using electrocardiographically gated (EKG-gated) intravenous digital subtraction angiography (DSA) in 6 anesthetized and paralyzed dogs. Six autologous blood clots were introduced into the internal jugular vein of each dog and both conventional pulmonary angiography and EKG-gated DSA performed in frontal and oblique projections. When two observers scored any definite or equivocal embolus as positive, sensitivity was 82.1% for one and 92.9% for the other; the respective positive predictive values (PPV) were 88.5% and 65%. When only definite emboli were considered positive, sensitivity was 75% for one observer and 71.4% for the other; PPV was 100% for both. The authors conclude that DSA can demonstrate individual emboli with good sensitivity and excellent precision. If several emboli are present, EKG-gated DSA should prove highly accurate; however, care must be taken because overinterpretation is more likely with DSA than with conventional pulmonary angiography.
Angiography↗
Hydropneumothorax: detection on supine radiographs.
Hydropneumothorax may be diagnosed on a supine radiograph by recognition of a pleural line with increased density lateral to it in the pleural space. Recognition of this condition may have implications for therapeutic chest tube placement.
Adolescent↗
Magnetic resonance imaging of the normal and abnormal pulmonary hila.
Magnetic resonance (MR) images of the hila were reviewed in 25 normal subjects and 12 patients with unilateral or bilateral hilar masses. On spin echo MR images in normal patients, collections of soft tissue large enough to be confused with an abnormally enlarged lymph node were seen in three locations. In patients with a hilar mass, the mass was differentiated from hilar vasculature more easily using MR than contrast-enhanced CT. In five of these patients, hilar lymph nodes approximately 1 cm in diameter were easily seen using MR, but were difficult or impossible to appreciate prospectively on CT. However, because the spatial resolution of MR is inferior to that of CT, bronchi were difficult to evaluate using MR. In general, images obtained with a short TR (0.5 sec) provided the best definition of mediastinal extension of the hilar mass, and images with a longer TR (1.5 to 2.0 sec) provided a better signal-to-noise ratio and showed increased signal strength from hilar masses. Electrocardiographic-gated images showed better resolution of hilar structures but may not be necessary for large masses.
Adult↗
Experimental pulmonary emboli detected using magnetic resonance.
Experimental pulmonary emboli that were labelled with non-magnetic barium threads and produced using aminocaproic acid were introduced into the internal jugular veins of five dogs. Transverse axial magnetic resonance (MR) images (0.35 T, 15 MHz) and CT scans (2.0 or 4.8 seconds, G.E. 9800 or 8800 scanner) were obtained from the lung apex to base in each animal. The MR images were gated to the cardiac cycle, and spin echo techniques were used (TR = gated to the cardiac cycle; TE = 28 and 56 msec). Nineteen sites of embolism were determined from the CT scans. Two observers, who had no knowledge of the number or position of the emboli, individually assessed the MR images and marked the sites of emboli on clear acetate overlays. Each observer detected 12 of 19 emboli (63%) and each had one false positive result. Of the 19 emboli, six were central or parahilar and 13 were in the outer two thirds of the lungs. Three (first observer) or four (second observer) of the seven false negative results were central. In retrospect, two central emboli were mistaken for hilar fat. One peripheral embolus was not visible, even in retrospect. The potential for MR to demonstrate relatively small pulmonary emboli has been shown. Clinical trials in patients seem warranted.
Animals↗
Pulmonary embolus: detection and follow-up using magnetic resonance.
Magnetic resonance imaging (MRI) of an angiographically confirmed pulmonary embolus was performed. The thrombus appeared as an intense intraluminal signal within the left descending pulmonary artery; this signal was absent on repeat examination after clot lysis. Because MR will not image flowing blood, it provides a potential method of non-invasive identification of stationary emboli within the pulmonary vascular tree.
Adult↗
Legionnaires' disease in the renal transplant patient: clinical presentation and radiographic progression.
The clinical presentation and radiographic progression of Legionnaires' disease is described in 10 renal transplant patients, the majority undergoing treatment for rejection. Presentation with pleuritic chest pain, fever, hypoxia, and hemoptysis was typical and in some cases led to confusion with pulmonary embolism. The radiographic appearance was that of rapidly progressive, dense, sublobar consolidation, occasionally showing patchy spread to other areas and usually accompanied by pleural effusion. Cavitation occurred in seven of 10 patients.
Adult↗
Coronal magnetic resonance imaging of the chest: normal and abnormal.
In order to determine the value of coronal magnetic resonance (MR) in diagnosing thoracic abnormalities, the multisection coronal spin echo MR images were reviewed of 10 normal subjects and 20 patients with thoracic abnormalities. In the abnormal patients, coronal images were compared with transaxial MR images obtained with TR values of 0.5 and 2.0 sec. In general, coronal imaging was of value in several situations. It allowed structures oriented in the coronal plane to be imaged along their longitudinal axes, provided an additional perspective and increased the confidence of diagnosis, and helped clarify anatomic relationships difficult or impossible to resolve on transaxial images because of volume averaging. Specifically, coronal images were sometimes superior to transaxial images in evaluating the aorticopulmonary window and masses at the lung apex or base. Transaxial images were often superior in evaluating the pretracheal space, subcarinal space, and hili. Within the pulmonary hili, lateral hilar masses were better defined on coronal images than were anterior or posterior hilar masses. Coronal images obtained with a TR of 1.0 sec (10 sections) allow evaluation of most node-bearing mediastinal compartments and provide adequate mass/fat contrast.
Adult↗
Radiographic recognition of chest tube malposition in the major fissure.
Twelve patients with a chest tube positioned in the major fissure of either lung were collected prospectively in a two-year period. In eight of these 12, there was evidence of chest tube malfunction, with poor drainage of pleural air or fluid collections; in six of these eight, placement of additional tubes or tube repositioning resulted in improved pleural drainage. In all 12, the tube had been placed through the lateral chest wall. Although tube placement in the major fissure can sometimes be suspected on the anteroposterior portable chest roentgenogram because of the tube's characteristic course, in such cases a lateral roentgenogram is not usually obtained for confirmation of location unless there is evidence of tube malfunction.
Adult↗
Intrathoracic adenopathy: differential feature of AIDS and diffuse lymphadenopathy syndrome.
The presence of mediastinal and/or hilar adenopathy was assessed from the chest radiographs of two groups of homosexual men: 30 with diffuse, persistent lymphadenopathy syndrome and 45 with acquired immunodeficiency syndrome (AIDS). Intrathoracic adenopathy was not seen on the chest radiographs of the 30 men having diffuse, persistent lymphadenopathy and is therefore not a manifestation of that syndrome. Nine of the 45 men with AIDS demonstrated intrathoracic adenopathy. In each instance, adenopathy was indicative of serious intrathoracic disease. Seven of the nine had minimal or no respiratory symptoms. In four of the nine, the intrathoracic adenopathy detected from the chest radiographs was the first indication of AIDS. In six of the nine patients, one or more opportunistic infections were diagnosed from material obtained at bronchoscopy. Two patients had Hodgkin disease, diagnosed by lymph-node biopsy. The ninth patient, who died, had an immunoblastic sarcoma. Mediastinal and/or hilar adenopathy in patients with AIDS, or in patients at high risk for AIDS, necessitates immediate investigation, including bronchoscopy or lymph-node biopsy.
Acquired Immunodeficiency Syndrome↗
Posterior wall of the bronchus intermedius: radiographic-CT correlation.
The posterior wall of the bronchus intermedius (PWBI) is visible on lateral chest radiographs and computed tomographic (CT) scans and can become abnormally thickened in the presence of right hilar disease. The appearances of the PWBI on plain radiographs and CT were correlated in groups of 20 normal patients and 20 patients with a right hilar abnormality. Among 10 patients with an abnormal hilum who had thickening of the PWBI on CT, the lateral radiograph showed thickening of similar degrees in seven. However, in two of the 10, the lateral chest radiograph significantly underestimated the degree of thickening of the PWBI, and in one the PWBI was not visible. Among 10 patients with an abnormal right hilum who had no thickening of the PWBI on CT, the PWBI appeared to be abnormal on lateral chest radiographs in four because of adenopathy in the lateral or medial hilum. One other finding of note was the presence in one patient of an anomalous pulmonary vein passing posterior to the bronchus intermedius, simulating a small posterior hilar mass.
Adolescent↗