[Diagnostic imaging in intensive care. Techniques, indications, diagnostic signs--II].
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Brain Damage, Chronic↗
Biomedical subjects
D Fleischmann
Publications and source records attributed to D Fleischmann.
[Contrast optimization in CT angiography].
This paper compares different contrast injection techniques for optimizing vessel contrast in CT angiography (CTA). The optimal vessel contrast shall be defined as constant strong enhancement confined to the scanning interval. This "plateau enhancement" guarantees high-quality CTA images and should therefore be approximated during every CTA examination by an appropriate contrast injection protocol. With well-established injection techniques such as the standard bolus technique (constant uniphasic contrast bolus for all patients) or adjustment of the scan delay, considerable individual differences in the arterial enhancement can be observed, and a nondiagnostic examination or an inefficient use of contrast agent might be the result in a particular patient. Therefore, two sophisticated mathematical models have recently been developed for analyzing the individual enhancement characteristics. These models can be exploited to predict the arterial enhancement for any given intravenous contrast bolus in any patient and to optimize the contrast bolus in order to approach the ideal "plateau enhancement." These techniques have to prove their effectiveness in larger clinical series.
Aged↗
[Dissection of the sinus valsalvae aortae as a complication of coronary angioplasty].
The localized dissection of the aortic sinus of valsalvae is a rare complication of coronary angioplasty involving mainly the right coronary artery. In all previously published case reports (n = 10), a coronary dissection provided the entry door with subsequent retrograde progression of the dissection into the aortic root. In our case of a 75 year old female patient with symptomatic three vessel disease, a chronic occlusion of a proximal RCA could not be passed by a coronary guide wire. During the procedure an aneurysm of the aortic sinus occurred near the ostium of the RCA. The patient was referred for immediate aortocoronary bypass surgery. The inspection of the aortic sinus showed, as the entry of the dissection, a small puncture hole, adjacent to the ostium of the RCA, probably caused by the stiff 0.014 coronary guide wire, and no retrograde dissection of the right coronary artery. The localized dissection could easily be fixed by a prolene suture during the bypass surgery procedure with an uncomplicated postoperative course. If the entry of the dissection is within the coronary artery, forced contrast injections and balloon inflations promote its propagation and should be avoided. If the entry could be sealed by an intracoronary stent and the aneurysm remained localized, confirmed by echocardiographic controls, the aneurysm tends to resolve spontaneously in the first month without need for surgery. A progression of the aneurysm into the ascending aorta or a failure of an entry sealing with a stent is an indication for urgent surgical treatment.
Aged↗
Quiz case 5. Pneumococcal sepsis in a patient with hereditary hypoplasia of the spleen.
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Adult↗
Subjective differentiation of normal and pathological bronchi on thin-section CT: impact of observer training.
The effect of observer training on sensitivity, specificity and interobserver agreement in the differentiation between normal and pathological bronchi on computed tomography (CT) was studied. The wall thickness of bronchi with normal walls and with pathologically thickened walls were subjectively scored by three independent observers before and after a training period of 2 weeks. Sensitivity, specificity and interobserver agreement were calculated for reading sessions before and after training. Increase and decrease in agreement after training were determined. There was a statistically significant difference (p=0.001) between objectively measured wall thickness of normal and pathological bronchi, both for reference bronchi and for bronchi used for reading sessions. While training increased interobserver agreement, it had no effect on sensitivity (0.46 versus 0.44 after training) and specificity (0.71 versus 0.72 after training) in detecting pathological bronchi. Increased agreement after training was significantly (p=0.001) more frequent than decreased agreement. There is a discrepancy between the effect of training on interobserver agreement and on sensitivity and specificity in the subjective differentiation between normal and pathological bronchi. Interobserver agreement alone is not a reliable indicator of a beneficial effect of training in the evaluation of this parameter.
Bronchi↗
Thoracic venous anatomy delineated by malpositioned central venous catheters on plain chest films.
The aim of this essay was to demonstrate the thoracic venous anatomy as delineated by malpositioned central venous catheters on plain chest radiographs. We therefore used the didactic advantage of clinically inadvertent catheter positions. This approach was chosen to illustrate venous anatomy with plain chest radiographs, and, thereby, to recognize malpositions promptly on the modality with which positions of central venous catheters is routinely performed.
Catheterization, Central Venous↗
Evolution of CT findings in patients with cystic fibrosis.
OBJECTIVE: The aim of our study was to assess the evolution of pulmonary CT findings in cystic fibrosis patients. MATERIALS AND METHODS: Serial CT examinations were performed in four different follow-up periods on 107 patients with cystic fibrosis. Lung images of the initial and follow-up CT were reviewed and scored for specific morphologic findings. CT findings were correlated with the results of the pulmonary function tests and clinical (Shwachman-Kulczycki) scores. RESULTS: Morphologic changes were minor within the first 18 months of follow-up compared with the period after 18 months. The increase of the overall score was significantly higher in groups with follow-up periods longer than 18 months compared with groups with follow-up periods shorter than 18 months. Various components of morphologic changes contributed to the sequential changes seen on the CT scans. All morphologic changes and the CT scores correlated significantly (p < .0001) with pulmonary function tests and clinical score. CONCLUSION. Serial CT scans allow assessment of the evolution of pulmonary abnormalities in patients with cystic fibrosis. CT seems to have advantages over pulmonary function tests and clinical scoring in the depiction of pulmonary changes over time.
Adolescent↗
Computed tomographic angiography: historical perspective and new state-of-the-art using multi detector-row helical computed tomography.
Since its clinical introduction in 1991, volumetric computed tomography scanning using spiral or helical scanners has resulted in a revolution for diagnostic imaging. In addition to new applications for computed tomography, such as computed tomographic angiography and the assessment of patients with renal colic, many routine applications such as the detection of lung and liver lesions have substantially improved. Helical computed tomographic technology has improved over the past eight years with faster gantry rotation, more powerful X-ray tubes, and improved interpolation algorithms, but the greatest advance has been the recent introduction of multi detector-row computed tomography scanners. These scanners provide similar scan quality at a speed gain of 3-6 times greater than single detector-row computed tomography scanners. This has a profound impact on the performance of computed tomography angiography, resulting in greater anatomic coverage, lower iodinated contrast doses, and higher spatial resolution scans than single detector-row systems.
Angiography↗
[Spiral CT angiography in diagnosis of acute pulmonary embolism. What factors modify implementation of standard algorithms?].
PURPOSE: Debate about the potential implementation of Spiral-CT in diagnostic algorithms of pulmonary embolism are often focussed on sensitivity and specificity in the context of comparative methodologic studies. We intend to investigate whether additional factors might influence this debate. MATERIALS AND METHODS: On the basis of the current literature and of own experience we study the influence of factors such as availability, acceptance, patient-outcome, and cost effectiveness-studies on the potential implementation of Spiral-CT in diagnostic algorithms of pulmonary embolism. This information is analyzed together with data from comparative methodologic studies. RESULTS: The factors availability, acceptance, patient-outcome, and cost-effectiveness-studies do have substantial influence on the implementation of Spiral-CT in the diagnostic algorithms of pulmonary embolism. Incorporation of these factors into the discussion might lead to more flexible and more patient-oriented algorithms for the diagnosis of pulmonary embolism. CONCLUSION: Availability of equipment, acceptance among clinicians, patient-outcome, and cost-effectiveness evaluations should be implemented into the debate about potential implementation of Spiral-CT in routine diagnostic imaging algorithms of pulmonary embolism.
Acute Disease↗
[Imaging in intensive care. Methods, indications, diagnostic signs. I].
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Cholecystitis↗
[Imaging in intensive medicine. Techniques. Indications, diagnostic signs. II].
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Cerebral Angiography↗
Radiographic findings in patients with acquired immunodeficiency syndrome, pulmonary infection, and microbiologic evidence of Mycobacterium xenopi.
The authors studied radiographs and clinical histories of 29 patients with acquired immunodeficiency syndrome, symptoms of pulmonary infection, and simultaneous microbiologic evidence of Mycobacterium xenopi in the respiratory tract. The presence, nature, and distribution of radiographic abnormalities were determined and analyzed in accord with clinical information. In 26 (90%) patients, M. xenopi was the only microorganism that could be isolated. Chest radiographs were normal in 13 patients (45%) and abnormal in 16 patients (55%). Radiographic abnormalities were bilateral in 94% of cases and predominantly involved the lower lobes. Patchy peribronchial opacities (44%) and miliary nodules (24%) were the most common abnormalities. Reticular opacities and parenchymal consolidation were seen in 12% of patients. Pleural effusion was seen in 18% of patients. No patients had cavitations or adenopathy. There was no statistically significant difference regarding the mean age (38.7+/-7.3 years vs. 40.2+/-11.0 years), the duration of clinically evident human immunodeficiency virus infection (2.7+/-1.2 years vs. 2.8+/-1.4 years), and the mean of CD4 cell counts (50.6+/-15.3 cells/ml vs. 47.4+/-15.9 cells/ml) between the patients with and without abnormalities on chest radiographs. In patients with acquired immunodeficiency syndrome, pulmonary infection, and simultaneous microbiologic evidence of M. xenopi, chest radiographs can be normal in a substantial number of cases. When radiographic abnormalities are present, they differ from those seen in patient not infected with the human immunodeficiency virus who had pulmonary infection caused by M. xenopi and from patients with acquired immunodeficiency syndrome and pulmonary infection with nontuberculous mycobacteria other than M. xenopi. Although these findings are not specific, they may be of importance in the imaging of patients with acquired immunodeficiency syndrome, notably in areas where M. xenopi is endemic.
AIDS-Related Opportunistic Infections↗
[Diagnostic imaging within the scope of lung transplantation].
PURPOSE: Recent progress in both surgical techniques and therapeutic medication of immunosupression have made lung transplantation a promising option for patients with untreatable diseases of the lung parenchyma. Because preoperatively and postoperatively diagnostic imaging has crucial importance for patient management and clinical decision making we aim to describe imaging features of frequent pathologies in patients after lung transplantation. MATERIALS AND METHODS: We reviewed radiological examinations of patients after lung transplantation performed at our institution over a period of four years, and exemplary cases were selected for presentation. Our interest was focussed on both conventional and CT-imaging of postoperative alterations, infections, organ rejection, and pathologies of the airways. Moreover, post-biopsy alterations and lymphoproliferative disorders were documented. Together with clinical information we aimed to give a concise description of specific pathologic entities. Also, the diagnostic impact of more recent techniques such as spiral-CT and thin-section CT should be discussed. RESULTS: In cases of early postoperative pathologies and in infections conventional radiography is diagnostically reliable when interpreted together with clinical information. In cases of acute or chronic organ rejection, of lymphoproliferative disorders, of diseases of central or small airways, and for the choice of an appropriate biopsy site, CT has proved to be a valuable imaging modality. Spiral-CT allows airway volumetry in cases of strictures or dehiscence, thin-section CT enables assessment of subtle parenchymal pathologies, notably in cases of chronic organ rejection. DISCUSSION: The radiographic findings described below represent specific pathogenetic entities in lung-transplant patients (postoperative alterations, infections, posttransplant lymphoproliferative disorders). Their accurate recognition will have a positive impact on the further clinical history. In the near future, more sophisticated CT techniques should widen our pathogenetic knowledge of alterations in transplanted lungs.
Biopsy↗
[Pulmonary hypertension and cor pulmonale].
Pulmonary hypertension is a severe disorder of the pulmonary circulation and occurs in a variety of vascular and parenchymal lung diseases. It leads to volume and/or pressure overload of the right ventricle and finally to right heart failure. Pulmonary vascular diseases such as chronic pulmonary embolism cause a drastic increase in pulmonary vascular resistance, which results in extremely high pulmonary artery pressures that can even reach systemic levels. On the other hand, moderate pulmonary hypertension can also occur in chronic obstructive and restrictive lung diseases. For a long time, the diagnosis of pulmonary hypertension and cor pulmonale was based upon findings in echocardiography and right heart catheterization. Today modern imaging techniques allow the radiologist to assess right ventricular and pulmonary artery morphology and function. The application of spiral CT, electron-beam CT and MRT permits the diagnosis and differential diagnosis of pulmonary hypertension and also the evaluation and follow-up of underlying vascular or parenchymal lung disorders. In addition, quantification of right ventricular function and calculation of pulmonary hemodynamic parameters are possible.
Adult↗
Radiographic detection of intrabronchial malpositions of nasogastric tubes and subsequent complications in intensive care unit patients.
OBJECTIVE: The aim of our study was to illustrate the radiographic spectrum of the intrabronchial malposition of nasogastric tubes and subsequent complications, and to discuss the role of radiography in the detection of such malpositions. DESIGN: Retrospective clinical investigation. SETTING: Tertiary care university teaching hospital. PATIENTS AND METHODS: We reviewed chest radiographs of 14 intensive care patients with nasogastric tubes malpositioned in the tracheobronchial tree. The site and anatomic location of the malposition were recorded. Complications due to tube malpositioning were monitored on follow-up radiographs and on computed tomographic examinations, which were available in 4 patients. RESULTS: Nine of 14 nasogastric tubes were inserted in the right and 5 in the left tracheobronchial tree. Tube tips were malpositioned in the lower lobe bronchi (50%), the intermediate bronchus (36%), and the main bronchi (14%). There was perforation of the bronchial system with subsequent pneumothorax in 4 patients. In 4 other patients, pneumonia developed at the former site of the malpositioned tube tip. Radiographic detection of nasogastric tube malpositioning was prompt in 9 patients and delayed in 5 patients. CONCLUSIONS: Whereas clinical signs of nasogastric tube malpositioning in intensive care patients may be absent or misleading, chest radiography can accurately detect nasogastric tube malpositions in the tracheobronchial tree, may prevent complications, and avoid the use of further costly or invasive diagnostic techniques.
Adult↗
Progressive multifocal leukoencephalopathy in AIDS: initial and follow-up CT and MRI.
We sought to determine the value of follow-up CT and MRI in patients with acquired immuno-deficiency syndrome (AIDS) and progressive multifocal leukoencephalopathy (PML). We reviewed 50 CT and 19 MRI examinations performed in 21 biopsy- or autopsy-proven cases of PML; 17 patients had follow-up examinations (mean time 5.9 weeks). The radiological examinations were correlated with pathological findings at autopsy. On initial imaging studies, 73 lesions were found. On follow-up, the most striking feature was rapid progression in both size and number of the lesions (from a mean of 3.2 to 6.9 per patient). One third of the patients showed increasing mass effect. A central area suggesting necrosis, of variable size, was found in 12/16 patients. Autopsy revealed macroscopic necrotic changes in the lesions in 11/16 patients.
AIDS Dementia Complex↗
Azygos arch cannulation by central venous catheters: radiographic detection of malposition and subsequent complications.
The aim of this study was to determine the frequency of radiographically evident central venous catheter misplacement in the azygos arch and to analyze whether the frequency of azygos arch cannulation is dependent on the anatomical site of catheter insertion. We reviewed 1,287 postprocedural examinations and 3,441 follow-up examinations. Catheters had been inserted through the left (6%) or right (15%) internal jugular veins and through the left (32%) or right (46%) subclavin veins. Radiographs were analyzed for possible catheter malposition in the azygos arch and for complications related to this malposition. Catheter malposition in the azygos arch was seen on 16/1,287 (1.2%) postprocedural radiographic examinations. Of the 16 malpositioned catheters, 11 (69%) had been inserted in the left subclavian vein, three (19%) in the left jugular vein, two (12%) in the right subclavian vein, and none (0%) in the right jugular vein. There was a statistically significant difference in the frequency of azygos arch cannulation between left- and right-sided catheters (p = 0.001). All complications consisted of venous perforations and were seen in three of 16 cases (19%). Azygos arch cannulation is a rare but hazardous central venous catheter malposition that occurs early after catheter insertion and carries a substantial risk for complication. The risk for azygos arch cannulation is substantially increased if catheters are inserted in left-sided veins. Because of the severity of subsequent complications, radiologists should be vigilant in the detection of this rare malposition.
Azygos Vein↗
Severity assessment of acute pulmonary embolism with spiral CT: evaluation of two modified angiographic scores and comparison with clinical data.
Spiral computed tomography (CT) has shown promising results in the detection of acute pulmonary embolism. The aim of this study was to investigate whether the severity of acute pulmonary embolism could be quantitatively assessed with spiral CT examinations and to test the potential clinical impact of this information. In a consecutive series of 123 patients screened with spiral CT for suspected acute pulmonary embolism, 31 patients (25%) had evidence of emboli. The severity of pulmonary arterial obstruction in those 31 spiral CT examinations was evaluated by two independent observers using angiographic scores previously described by Walsh (29) and Miller (30), adapted to the needs of spiral CT. Clinical patient subgroups were defined according to oxygen saturation, heart rate, and echocardiographic signs of right ventricular strain. CT severity scores were then correlated to each other and to clinical parameters using the Spearman rank test. Interobserver agreement was calculated using the analysis of variance. Both modified Walsh and Miller scores were readily reproducible and showed interobserver agreements of 0.85 and 0.96, respectively (p = 0.001). Patients with mild and marked clinical abnormalities showed statistically significant differences between CT severity scores. Differences between severity scores of patients with moderate and marked clinical abnormalities were somewhat significant. No significant mean severity score differences were seen between patients with mild and moderate clinical abnormalities. Although correlations of severity scores and detailed clinical parameters within the defined subgroups were moderate to poor, threshold scores greater than 10 (Miller) and greater than 11 (Walsh) always indicated marked clinical abnormalities. The modified scores presented in this study constitute a readily reproducible method for the quantitative assessment of acute pulmonary embolism severity on spiral CT examinations.
Acute Disease↗