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PubMed1988

Inflammatory pulmonary edema and positive end-expiratory pressure: correlations between imaging and physiologic studies.

The anatomic and physiologic response to positive end-expiratory pressure (PEEP) was investigated using computed tomography (CT) in patients with adult respiratory distress syndrome (ARDS). The lesions (densities) in ARDS are distributed inhomogeneously but tend to concentrate in the dependent regions. The estimated lung weight (by CT scan, quantitative analysis, and lung gas volume measured with helium dilution) is, on the average, 200% higher than expected. Changing the body position from supine to prone causes a change in the density distribution in response to gravitational forces. The main effect of PEEP is to clear the densities through alveolar anatomic recruitment. Anatomic recruitment changes the mechanical characteristics of the lung and parallels the improvement in gas exchange. The effects of PEEP on pulmonary arterial pressure appear to be related to anatomic recruitment.

Humans↗
PubMed1993

CT and MR evaluation of pericardial constriction: a new diagnostic and therapeutic concept.

Eighty patients with pericardial constriction confirmed by catheter data were studied by CT (n = 79), MR imaging (n = 24), or both. To determine the validity of these imaging methods for subsequent treatment, 30 patients' studies were evaluated retrospectively (1980-1984) and 50 (1985-1991) prospectively. Twenty patients from the first group and 30 patients from the second group underwent pericardiectomy. By systematic analysis of CT scans and MR images it was possible to characterize the morphology of pericardial constriction (n = 80); to identify global (n = 27), right-sided (n = 46), left-sided (n = 2), annular (n = 2), effusive (n = 2), and epicardial (n = 1) forms of pericardial constriction; and to define parameters of myocardial atrophy and fibrosis (n = 17). Seventeen patients had myocardial atrophy, fibrosis, or both. Seven of them underwent pericardiectomy; all died of acute myocardial failure (100%). Four (9.3%) of 43 patients without myocardial atrophy or fibrosis died as a consequence of other complications. The method of thoracotomy and periepicardiectomy was continuously adjusted to the preoperative CT and MR findings. Thus, the clinical use of CT and MR imaging in patients with known or suspected pericardial constriction is based on (a) exclusion of patients with restrictive hemodynamics from diagnostic thoracotomy, (b) preoperative determination of the method of thoracotomy and extent of pericardiectomy, and (c) exclusion of patients with myocardial atrophy or fibrosis from pericardiectomy.

Adult↗
PubMed2005

Intrathoracic airway trees: segmentation and airway morphology analysis from low-dose CT scans.

The segmentation of the human airway tree from volumetric computed tomography (CT) images builds an important step for many clinical applications and for physiological studies. Previously proposed algorithms suffer from one or several problems: leaking into the surrounding lung parenchyma, the need for the user to manually adjust parameters, excessive runtime. Low-dose CT scans are increasingly utilized in lung screening studies, but segmenting them with traditional airway segmentation algorithms often yields less than satisfying results. In this paper, a new airway segmentation method based on fuzzy connectivity is presented. Small adaptive regions of interest are used that follow the airway branches as they are segmented. This has several advantages. It makes it possible to detect leaks early and avoid them, the segmentation algorithm can automatically adapt to changing image parameters, and the computing time is kept within moderate values. The new method is robust in the sense that it works on various types of scans (low-dose and regular dose, normal subjects and diseased subjects) without the need for the user to manually adjust any parameters. Comparison with a commonly used region-grow segmentation algorithm shows that the newly proposed method retrieves a significantly higher count of airway branches. A method that conducts accurate cross-sectional airway measurements on airways is presented as an additional processing step. Measurements are conducted in the original gray-level volume. Validation on a phantom shows that subvoxel accuracy is achieved for all airway sizes and airway orientations.

Algorithms↗
PubMed2004

Electrocardiographically gated 16-section CT of the thorax: cardiac motion suppression.

Thirty patients underwent 16-section multi-detector row computed tomographic (CT) angiography of the thorax with retrospective electrocardiographic gating. Institutional review board approval was obtained for retrospective analysis of CT scan data and records; patient informed consent was not required. Images reconstructed at six different time points (0%, 20%, 40%, 50%, 60%, 80%) within the R-R interval on the electrocardiogram were analyzed by two radiologists for diagnostic quality, to identify suitable reconstruction intervals for optimal suppression of cardiac motion. Five regions of interest (left coronary artery, aortic root, ascending and descending aorta, pulmonary arteries) were evaluated. Best image quality was achieved by referencing image reconstruction to middiastole (50%-60%) for the left coronary artery, aortic root, and ascending aorta. The pulmonary arteries are best displayed during mid- to late diastole (80%).

Adult↗
PubMed2002

Abnormalities on cardiopulmonary exercise test in a dyspneic patient. A case report of unsuspected pulmonary embolism.

The cardiopulmonary exercise test (CPET) is frequently used for the quantitative evaluation of exercise tolerance and for the qualitative assessment of the origin of dyspnea. Although reasonably safe, CPET is contraindicated in acute clinical situations and relatively contraindicated in severe pulmonary hypertension. Pulmonary emboli are usually present during the acute onset of pulmonary hypertension; however, in situations where pulmonary vascular disease is more unsuspected, CPET may help with the diagnosis. We present a report of a 47-year-old Caucasian female with a 2-month history of exertional dyspnea. She had a normal pulmonary function test, arterial blood gas analysis and CT scan of the chest. On CPET she was found to have a higher than normal physiological dead space to tidal volume ratio, increased ventilatory equivalent for the elimination of CO(2) (V(E)/VCO(2)), persistently positive arterial-end-tidal PCO(2 )difference at peak exercise, and a low anaerobic threshold suggestive of pulmonary vascular disease. She was subsequently diagnosed with pulmonary embolic disease by her ventilation/perfusion scan and pulmonary arteriogram. This report highlights the importance of recognizing the hallmarks of unsuspected pulmonary vascular disease on CPET.

Contraindications↗
PubMed1994

Late CD8+ lymphocytic alveolitis after allogeneic bone marrow transplantation and chronic graft-versus-host disease.

Late-onset interstitial pneumonitis following allogeneic bone marrow transplantation (BMT) is a rare condition usually caused by a variety of infective agents, although in some cases these are idiopathic. We investigated noninfectious late interstitial pneumonitis with lymphocytic alveolitis in seven allogeneic BMT recipients using bronchoalveolar lavage (BAL), lymphocyte phenotyping analysis, CT lung scans, and pulmonary function tests. The results were compared with those of a control group composed of similar patients with no pulmonary symptoms. Of 65 long-term survivors, seven were included in the study. All had chronic graft-versus-host disease (GVHD) and developed interstitial pneumonitis a median of 210 d (range 120 to 445 d) after BMT. BAL revealed lymphocytosis, with an overall expansion of CD8+ subsets (38 to 90%). Lymphocytic alveolitis was not observed in the control group. Pulmonary function tests revealed a restrictive syndrome, and biopsy samples obtained from 2 patients showed interstitial lymphoid infiltration with fibrosis of the alveolar walls. Of the 7 patients, six were cured by starting immunosuppressive drugs or increasing the dosage with a drastic improvement in respiratory symptoms within 1 mo. These findings suggest that CD8+ alveolitis may be observed in late interstitial pneumonitis in allogeneic BMT recipients and may be a pulmonary manifestation of chronic GVHD.

Adult↗
PubMed1987

Inflammatory and obstructive disorders of salivary glands.

Obstructive and inflammatory diseases of the salivary glands can have a congenital, traumatic, metabolic, or infectious-inflammatory cause. The acute inflammatory conditions include bacterial and viral infections, and the chronic conditions include sialoliths, strictures, chronic sialadenitis, sialectasis, and lymphoepithelial disease. The neoplastic disease can cause obstruction and/or infection and often make the diagnosis elusive. In addition to a working knowledge of possible etiology, one needs experience with clinical examination, salivary analysis, sialography, CT scans, MRI, and fine-needle aspiration and cytology in order successfully to evaluate and manage patients with these conditions.

Acute Disease↗
PubMed1983

Mood change following bilateral hemisphere brain injury.

Fifteen patients with bilateral hemisphere brain injury secondary to thromboembolic stroke or trauma were evaluated for depression, cognitive impairment, and functional physical impairment. Analysis of CT scans and standardized mood scales revealed that patients with left anterior brain injury were significantly more depressed than patients without such injury. Depression severity was directly and significantly correlated with left lesion proximity to the frontal pole. Left lesion age, lesion temporal sequence, right lesion location, cognitive impairment, and functional physical impairment did not significantly correlate with depression. Depressive symptomatology previously shown to be associated with single left frontal lobe lesions appeared to dominate post-brain injury psychopathology regardless of location or temporal sequence of other brain lesions.

Activities of Daily Living↗
PubMed1998

Dynamic positron emission tomography with F-18 fluorodeoxyglucose imaging in differentiation of benign from malignant lung/mediastinal lesions.

PURPOSE: This study was done to evaluate the diagnostic utility of dynamic positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) imaging in patients with suspected malignant pulmonary lesions. We wanted to test the hypothesis that the rate of FDG uptake (FDG influx constant values) would differentiate malignant from benign lung or mediastinal lesions. MATERIALS AND METHODS: We performed segmental dynamic PET imaging studies following administration of FDG in 19 patients with indeterminate pulmonary lesions based on chest radiograph and/or CT scans. Patlak analysis was done to compute Ki (FDG influx constant) values and compared with FDG standardized uptake values (SUVs) and histology. RESULTS: FDG Ki values (mean+/-SD) were significantly greater (p < 0.01) in all 12 malignant lesions (0.029+/-0.02) as compared with 7 benign lesions (0.0024+/-0.0011) with good correlation to the SUV values. Distinct time activity curve patterns were identified in malignant and benign lesions with continued uptake in malignant lesions. CONCLUSION: Dynamic PET-FDG imaging accurately differentiates malignant from benign pulmonary lesions. In certain cases with equivocal findings on visual analysis and SUV values, dynamic imaging may be further helpful in differentiating benign and malignant lesions.

Adenocarcinoma↗
PubMed1978

Computed tomography of cerebellar astrocytoma.

Analysis of CT scans of 25 patients with cerebellar astrocytoma indicates that a typical spectrum of findings exists for the cerebellar astrocytomas. CT is highly accurate in delineation and characterization of new and recurrent tumors. Recurrences may be demonstrated long before symptoms occur. The density of the fluid in the tumor cyst is twice that of cerebrospinal fluid. Thus differentiation from nonneoplastic cystic lesions and postoperative defects is possible. CT findings of solid or cystic tumor frequently correlate with histologic categorization, and in such cases prognostic information can be derived from the CT appearance.

Adolescent↗
PubMedDate not supplied

Automated CT segmentation and analysis for acute middle cerebral artery stroke.

BACKGROUND AND PURPOSE: The quantitative nature of CT should make it amenable to semiautomated analysis using modern neuroimaging methods. The purpose of this study was to begin to develop automated methods of analysis of CT scans to identify putative hypodensity within the lentiform nucleus and insula in patients with acute middle cerebral artery stroke. METHODS: Thirty-five CT scans were retrospectively selected from our CT archive (scans of 20 normal control participants and 15 patients presenting with acute middle cerebral artery stroke symptoms). The DICOM data for each participant were interpolated to a single volume, scalp stripped, normalized to a standard atlas, and segmented into anatomic regions. Voxel densities in the lentiform nucleus and insula were compared with the contralateral side at P <.01 using the Wilcoxon two-sample rank sum statistic, corrected for spatial autocorrelation. RESULTS: The quality of the registration for the anatomic regions was excellent. The control group had two false-positive results. The patient group had two false-negative results in the lentiform nucleus, two false-negative results in the insular cortex, and one false-positive finding for the insular cortex. The remainder of the infarcts were correctly identified. The original clinical reading, performed at the time of presentation, produced five false-negative interpretations for the patient group, all of which were correctly identified by the automated algorithm. CONCLUSION: We present an automated method for identifying potential areas of acute ischemia on CT scans. This approach can be extended to other brain regions and vascular territories and may aid in the interpretation of CT scans in cases of hyperacute stroke.

Brain Mapping↗
PubMed2001

Herpes simplex encephalitis in North West India.

All patients admitted with provisional diagnosis of an encephalitic illness over a period of 30 months, were studied. Special investigations included CSF analysis, EEG, CT scan and MRI. Herpes simplex virus (HSV) antibody estimation in CSF and blood was done simultaneously using ELISA. Patients with diagnosis of cerebral venous thrombosis, cerebral malaria, tubercular meningitis etc, who resembled herpes simplex encephalitis (HSE), were excluded systematically with relevant investigations. 28 patients showed electroencephalographic, serologic and/or neuroradiological evidence of herpes simplex encephalitis. Males were affected more than females. Age ranged from 4 years to 65 years. Main clinical features included altered sensorium (100%) and seizures (89%). Serological test for HSV antibody in CSF and blood was positive in 14 patients. Fronto-temporal localisation was seen in EEG of 18 patients. CT and MRI were fairly characteristic with bilateral asymmetric fronto-temporal lesions. Patients with mild disease and who reported earlier responded well to treatment with acyclovir. Mortality was higher if treatment was delayed or if the disease was severe. Delayed treatment even in less severe cases produced neurological deficit in many survivors. Despite limitations of non-availability of CSF-PCR and serial estimation of HSV antibodies, the study is an attempt to highlight the value of high index of suspicion of HSE on clinical grounds, systematically excluding cases with different aetiologies resembling HSE and planning early antiviral therapy to reduce both mortality and morbidity associated with this fatal disease.

Acyclovir↗
PubMed2003

[A comparison of early and late reconstruction and repositioning of orbital blow-out fracture].

OBJECTIVE: To study and compare the operative results of the early and late treatment of orbital blow-out fracture. METHODS: Orbital blow-out fractures were reconstructed and repositioned. Three dimensional measurements, CT scanning, diplopia analysis, Medpor filling of the orbit were used for the operation and the study. The operative results were compared between 15 cases of early and 16 cases of late reconstruction of blow-out fracture. RESULTS: In the early treatment group, there were 8 cases of diplopia, 15 cases of orbital invagination and 10 cases of disesthesia of the infraorbital nerve. After surgery, diplopia was corrected in 7 cases; invagination was corrected in all the 15 cases; disesthesia of the infraorbital nerve was corrected in 8 cases. In the late treatment group, there were 10 cases of diplopia, 16 cases of orbital invagination and 9 cases of disesthesia of the infraorbital nerve. After surgery, diplopia was corrected in 3 cases, unimproved in 4 cases, aggravated in 2 cases. 5 of them received reoperation of extraocular muscle for diplopia. Orbital invagination was uncorrected in 3 cases. 2 of them were re-operated on. Disesthesia of the infraorbital nerve was unimproved in 2 cases. By comparing the operation results, of the two groups using FISHER accuracy inspection, the significant difference was only in the correction of the double visions (chi 2 = 4.865, P < 0.05). CONCLUSION: Early operation for orbital blow-out fracture is easier, with better results, fewer complications and reoperations than the late operation.

Adolescent↗
PubMed2004

[Lymphangioleiomyomatosis].

Lymphangioleiomyomatosis (LAM) is a progressive and usually fatal interstitial lung disease characterized by an abnormal smooth-muscle proliferation in the lung and axial lymphatics. It affects almost exclusively young women of childbearing age. The presenting features most commonly include dyspnea, symptoms of pneumothorax and cough. Less commonly patients can present with chest pain, pleural or pericardial effusion and lymphedema. Our patient, a 41-year-old woman, complained mainly of fatigue that had lasted for 2 months and finally became febrile and dispneic, especially when lying down. Pulmonary diagnostic procedures revealed several multicystic destruction of lung parenchyma. There was also respiratory insufficiency with O2 saturation of 87% and lung diffusion capacity reduced to 48%. The retroperitoneum was filled with neoplastic mass as shown on an abdominal CT scan. Pathohistologic analysis of retroperitoneal mass together with the radiologic finding of the lungs correlated with the diagnosis of LAM. The patient was prescribed corticosteroid therapy, which led to rapid clinical improvement. After making a definite diagnosis, the patient was recommended further treatment with medroxyprogesterone. This case shows that LAM, although rare, can present a diagnostic problem to clinicians and should always be considered as one of the diagnostic possibilities in young women with nonspecific pulmonary symptoms.

Adult↗
PubMed1991

[Apparently primary cerebrospinal rhinorrhea. Apropos of 4 cases].

While rhino-liquorrhea is a severe condition, its incidence is not exceptionally rare, and it raises problems, namely etiopathogenic, diagnostic and therapeutical ones, which call for the close collaboration of ENT doctors, neuroradiologists and neurosurgeons. 4 relatively recent cases are reported here, whereby the diversity of the problems encountered is made apparent. ENT specialists must be aware of those when faced with refractory aqueous rhinorrhea, often triggered by forward head motion, Valsalva's maneuver... Screening for rhinorrhea is readily achieved by biochemical tests, or simply using a Labstix-type diagnostic strip. Rhinoscopic examination should be accurate and carried out optically to check for any congenital malformation (meningocele). Most of the times, but not always, a thorough radio-neurological workup (isotopic analysis, CT-scan with contrast medium, MR imaging) will provide precise data regarding the infraction site and its possible cause, invariably warranting surgical management. Surgery should be case-adapted (CSF derivation, filling of the gap via the extra- or intracranial approach).

Adolescent↗
PubMedDate not supplied

[X-ray computed tomographic anatomy of the diaphragm].

The paper is concerned with retrospective analysis of CT scans of 507 patients without signs of diaphragmatic pathology to investigate normal roentgeno-anatomy of the diaphragm in CT imaging. The four main variants (types) in the structure of the lumbar diaphragm were singled out. CT was shown effective in the determination of pathological changes of the lumbar diaphragm and adjacent zones. It is an informative method among diagnostic procedures used in diaphragmatic diseases.

Diaphragm↗
PubMed1987

[Benign encephalitis of the brain stem].

Seven cases of an encephalitic brainstem syndrome are reported. All had an initial flu-like phase, with a febrile state. Then, all had eye movements disturbances and ataxia. Six had a variable dysfunction of other cranial nerves, five had dysmetria of limbs and three had pyramidal signs. In all, the topographic diagnosis was based on clinical, neurophysiological (electromyography, evoked potentials) and neuroradiological (swelled brainstem on CT scan) findings. Analysis of cerebro-spinal fluid revealed pleocytosis (mean; 165 cells/ml), without profile indicative of multiple sclerosis. Serologic tests for Adenovirus or Echovirus were positive in three cases. All recovered spontaneously. With a mean follow-up of three years there was no relapse and the clinical examination remained normal. These seven cases had, after exclusion of other brainstem syndromes, a Bickerstaff's encephalitis. Previous reports are discussed and a post-infectious origin is proposed to this benign syndrome.

Adult↗