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National Mycobacterium Reference Laboratory, Borstel, Germany. : To evaluate the effectiveness of OMNIgene®•SPUTUM (OM-S) reagent in comparison with a method using N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH) with regard to mycobacterial recovery and contamination of broth and solid cultures. : Sputum samples from patients with tuberculosis and other respiratory diseases underwent decontamination with NALC-NaOH-based (MycoDDR™) or OM-S reagent. The decontamination procedure was assigned by block randomisation. Samples were inoculated on Lowenstein-Jensen, Stonebrink and MGIT™ (Mycobacterial Growth Indicator Tubes). Mycobacterial recovery from samples spiked with Mycobacterium tuberculosis following decontamination was determined. : Eighty-five samples were randomised to NALC-NaOH and 84 to OM-S reagent. Mycobacterial recovery was significantly lower for samples processed with OM-S reagent compared with the NALC-NaOH method across all media types. Culture contamination was lower with NALC-NaOH reagent on solid media (9.4-12.9% vs. 28.6-29.8%). Growth was not observed in MGIT among samples spiked with 10 600-16 800 colony-forming units of M. tuberculosis following decontamination with OM-S reagent. : Low mycobacterial recovery, especially in MGIT, observed in the present study suggests that OM-S reagent might not be compatible with the MGIT system. More extensive field evaluations of the OM-S reagent are warranted to demonstrate a significant benefit over currently used methods.

We report our experience concerning lead performance and re-surgery rate of the Medtronic EnRhythm MRI SureScan pacemaker system (MRI-PM) in comparison to standard pacemaker (PM) systems and leads used at our institution.All patients (except patients with transvenous left ventricular leads) with successful PM implantation performed at our institution from 1 March 2009 to 31 October 2009 were included in this analysis and followed until mid January 2010. Lead measurements (assessed at implantation, prehospital discharge interrogation (1st follow-up) and at the first scheduled out-patient follow-up (2nd follow-up) were compared between atrial leads 4592-53 cm and 5086MRI-52 cm (lead group 1), and between ventricular leads 4092-58 cm and 5086MRI-52 cm/-58 cm (lead group 2), respectively. Causes for re-operations were assessed and compared between patients with standard dual chamber PM (DC-PM) and the MRI-PM.A total of 140 patients (VVI-PM: 36 patients; DDD-PM: 102 patients; biventricular PM: 1 patient) were successfully implanted with a PM within the implantation period. Two patients with transvenous left ventricular leads were excluded from further analysis. In an atrial position, lead 4592 was implanted in 51 patients and lead 5086MRI-52 cm was implanted in 40 patients, respectively. Ventricular leads were lead 4092-58 cm (64 patients) and lead 5086MRI (41 patients), respectively. Patients were followed for 26 ± 11 weeks. Comparison of lead measurements of lead group 1 showed significant differences for pacing impedance and pacing threshold at implantation, and for sensing at the 2nd follow-up. Comparison of lead measurements within lead group 2 showed significant differences for pacing impedance at implantation, for pacing threshold at the 1st follow-up, and for sensing, pacing threshold, and impedance at the 2nd follow-up. All assessed mean values were favorable for all leads at any follow-up. The number of re-operations was high in both dual chamber PM groups, but did not differ significantly between the two groups (DC-PM: 5 patients, 8.5%; MRI-PM: 5 patients, 13.2%).Our study demonstrates favorable lead measurements of lead model 5086MRI in comparison to lead 4592 and 4092 in a short-term follow-up. The number of re-operations was higher in the MRI-PM group, but not statistically different in comparison with the standard dual chamber PM group.

Die drei häufigsten Ursachen des Lungenödems sind die Herzinsuffizienz, die Niereninsuffizienz und der diffuse Alveolarschaden (Permeabilitätsödem). Das Permeabilitätsödem lässt sich von dem kardialen und renalen Lungenödem relativ leicht abgrenzen durch die typisch periphere fleckförmige alveoläre Transparenzminderung mit Bronchopneumogramm, ohne interstitielle Transsudation und nur selten mit Pleuraergüssen. Sowohl das kardiale als auch das renale Lungenödem sind meistens von einer Herzvergrößerung, einer Verbreiterung des sogenannten Vascular Pedicles und einer Umverteilung der Lungenzirkulation begleitet. Beide beginnen interstitiell und gehen dann oft in ein alveoläres Stadium über. Pleuraergüsse kommen oft vor. Das Verteilungsmuster hilft oft bei der Unterscheidung: das kardiale Lungenödem folgt der Gravitation (basal betont) und das renale Lungenödem liegt oft zentrobasal.

Technische Innovationen in der Magnetresonanztomographie (MRT) haben die bildgebende Diagnostik in der Rheumatologie masgeblich verbessert. Wahrend sich bei der rheumatoiden Arthritis die MRT zunehmend als diagnostisches Instrument etabliert, wird sie bei den selteneren Erkrankungen, wie den Konnektivitiden (Systemsklerose, Lupus) oder den Myositiden (Polymyositis, Dermatomyositis), bisher nur in Einzelfallen eingesetzt. Die MRT kann jedoch gerade dann wertvolle Informationen uber das Ausmas der Erkrankung, ihre Folgeerscheinungen und Komplikationen liefern, wenn Rontgenaufnahmen oder ultrasonographische Untersuchungen unauffallig waren. Die sinnvolle Verankerung der MRT in Diagnosealgorithmen und Therapiemonitoring der Kollagenosen ist zukunftig einer der Schwerpunkte in der Zusammenarbeit von Rheumatologen, Dermatologen und Radiologen.

Die virtuelle Endoskopie der oberen, zentralen und peripheren Atemwege (virtuelle Laryngoskopie oder virtuelle Bronchoskopie) erzeugt eine der fiberoptischen Endoskopie vergleichbare Ansicht und kommt insbesondere zur Diagnostik von tracheobronchialen Stenosen und Tumoren mit endoluminaler Ausdehnung zur Anwendung. Vor allem seit Einfuhrung der Mehrzeilen-Spiral-CT lassen sich qualitativ hochwertige Rekonstruktionen der Atemwege erstellen. Das erfolgt entweder mittels Oberflachenrekonstruktion (Surface rendering) oder Volumenrekonstruktion (Volume rendering). Die semitransparente, farbkodierte Volumenrekonstruktion bietet den Vorteil, dass zusatzlich zur endoluminalen Darstellung auch die Umgebungsstrukturen beurteilt werden konnen. Weitere wesentliche Vorteile der virtuellen gegenuber der fiberoptischen Endoskopie sind deren Nichtinvasivitat, die Moglichkeit der Passage subtotaler Stenosen mit Beurteilung der nachgeschalteten Atemwege und Navigationshilfen. Nachteilig sind die fehlende Farbwiedergabe und Interventionsmoglichkeiten. Im Vergleich zu anderen CT-Darstellungsformen ist virtuell-endoskopisch eine wirklichkeitsgetreuere Beurteilung tracheobronchialer Stenosen moglich als mit axialen Schnittbildern oder multiplanaren Reformationen. Als erganzende Methode zur fiberoptischen Endoskopie kann die virtuelle Endoskopie der Atemwege sowohl praoperativ vor Tracheotomie, Stenting oder Resektion als auch bei der postoperativen Verlaufsbeurteilung Verwendung finden. Die virtuelle Endoskopie wird zunehmend assistierend bei bronchoskopischen und chirurgischen Eingriffen an den Atemwegen eingesetzt werden.

Fragestellung: Verdient die CT-Strahlenexposition beim Kind besondere Beachtung? Methode: Literaturubersichtsarbeit. Ergebnisse: Indikationserweiterung und Frequenzzunahme der modernen CT haben bei erheblicher Einzeldosis den CT-Anteil an der medizinischen Strahlenbelastung auf 38–60% ansteigen lassen. Beim Kind treten die biologisch bis 10-mal hohere Strahlenempfindlichkeit, die langere Lebenserwartung und eine Uberdosierung als Grunde fur ein reelles, wenn auch kleines Krebsinduktionsrisiko hinzu. Die gezielte Nutzung der modernen CT bringt bei Indikation und Protokollwahl eine wesentliche Dosisreduktion. Schlussfolgerung: Es geht ebenso sehr um die Realisation der kindlichen CT-Problematik wie um die Erkennung und Vermeidung der Ursachen einer erhohten biologischen CT-Wirkung.

PURPOSE A controlled trial was performed to compare non-invasive multislice CT (virtual laryngoscopy, axial CT slices, coronal and sagittal reformats) in the detection and grading of upper airway stenosis with fiberoptic laryngoscopy. MATERIAL AND METHODS Multislice CT and fiberoptic laryngoscopy were used to examine 111 upper airway sections (supraglottis, glottis, subglottis, trachea) in 29 patients. CT data were acquired on a multirow detector CT (collimation 4 x 1 mm, reconstruction interval 1 mm, IV contrast) and postprocessing was performed using multiplanar reformatted images (MPR) and virtual laryngoscopy. RESULTS All CT methods accurately detected upper airway stenosis (accuracy was 96 % for virtual laryngoscopy and MPR and 94 % for axial CT-slices). Correlation of fiberoptic and virtual laryngoscopy (r = 0.94) for grading of stenosis was closer than with sagittal reformats (r = 0.80), coronal reformats (r = 0.72), and axial CT slices (r = 0.57). Even high grade stenosis could be passed with virtual laryngoscopy that was impassable for fiberoptic laryngoscopy. CONCLUSIONS Virtual laryngoscopy enabled better assessment of stenosis as compared to reading of axial CT slices or MPR. Virtual laryngoscopy is complementary to fiberoptic laryngoscopy and should be combined with axial CT slices and MPR readings for evaluation of the surrounding structures.

Diagnostic evaluation of the pancreas using CT and MRI has been improved and protocols have been specified in much more detail during recent years. Computed tomography affords high-resolution, nearly isotropic 3D imaging, is highly sensitive for calcification and is usually preferred in trauma and intensive care patients as well as in case of a need of imaging multiple regions. MRI, due to its higher contrast, often provides a better differentiation between different etiologies and an improved staging in case of neoplastic disease; non-invasively it allows for a simultaneous evaluation of the pancreas, the pancreatic and biliary ducts as well as the blood vessels. Modern techniques and protocols of both imaging procedures, their advantages and disadvantages and the clinical results with different types of pathology are presented.

The purpose of this study was to provide an overview of the spectrum of pediatric chest masses, to present the results of cross-sectional imaging with CT and/or MRI, and to define diagnostic criteria to limit differential diagnosis. Seventy-eight children with thoracic mass lesions were retrospectively evaluated using CT (72 patients) and/or MR imaging (12 patients). All masses were evaluated for tissue characteristics (attenuation values or signal intensity, enhancement, and calcification) and were differentiated according to age, gender, location, and etiology. Twenty-eight of 38 (74 %) mediastinal masses were malignant (neuroblastoma, malignant lymphoma). Thirty of 38 (79 %) pulmonary masses were metastatic in origin, all with an already known primary tumor (osteosarcoma, Wilms tumor). With one exception, all remaining pulmonary lesions were benign. Seventeen of 21 (81 %) chest wall lesions were malignant (Ewing sarcoma, primitive neuroectodermal tumor). The majority of mediastinal and chest wall tumors in children is malignant. Lung lesions are usually benign, unless a known extrapulmonary tumor suggests pulmonary metastases. Cross-sectional imaging with CT and/or MRI allows narrowing of the differential diagnosis of pediatric chest masses substantially by defining the origin and tissue characteristics. Magnetic resonance imaging is preferred for posterior mediastinal lesions, whereas CT should be used for pulmonary lesions. For the residual locations both modalities are complementary.

Purpose: Protective occlusion of the gastroduodenal artery (GDA) is required to avoid severe adverse effects and complications in radioembolization procedures. Because of the expandable features of HydroCoils, our goal was to occlude the GDA with only one HydroCoil to provide particle reflux protection. Methods: Twenty-three subjects with unresectable liver tumors, who were scheduled for protective occlusion of the GDA before radioembolization therapy, were included. The primary end point was to achieve a proximal occlusion of the GDA with only one detachable HydroCoil. Evaluated parameters were duration of deployment, and early (during the intervention) and late (7-21days) occlusion rates of GDA. Secondary end points included complete duration of the intervention, amount of contrast medium used, fluoroscopy rates, and adverse effects. Results: In all cases, the GDA was successfully occluded with only one HydroCoil. The selected diameter/length range was 4/10mm in 2 patients, 4/15mm in 6 patients, and 4/20mm in 15 patients. HydroCoils were implanted, on average, 3.75mm from the origin of the GDA (range 1.5-6.8mm), with an average deployment time of 2:47 (median 2:42, range 2:30-3:07) min. In 21 (91%) of 23 patients, a complete occlusion of the GDA was achieved during the first 30min after the coil implantation; however, in all patients, a late occlusion of the GDA was present after 6 to 29days. No clinical or technical complications were reported. Conclusion: We demonstrated that occlusion of the GDA with a single HydroCoil is a safe procedure and successfully prevents extrahepatic embolization before radioembolization

In this prospective study we evaluated if atherosclerosis of crural and pedal arteries differs in diabetic and non-diabetic patients suffering from chronic ischemia. We performed intraoperative angiography after completion of a femoro-popliteal or femoro-distal bypass. No statistically significant difference was found between the two groups (25 diabetic and 44 non-diabetic patients) concerning the severity and localisation of the arteriosclerosis in the three crural arteries and the pedal arch. The prerequisite for a successful arterial reconstruction were identical in our patients with or without diabetes and a similar number of potential recipient arteries were found at below knee and foot level in both groups.

High altitude pulmonary edema (HAPE) is characterized by marked pulmonary hypertension. Treatment of 6 subjects suffering from radiographically documented HAPE with the calcium channel blocker nifedipine, lowered pulmonary artery pressure and resulted in clinical improvement, better oxygenation, reduction of alveolar-arterial oxygen gradient and a progressive clearing of alveolar edema on chest x-ray. This amelioration occurred despite continued exercise at an altitude above 4000 m and without supplementary oxygen. Prophylactic application of nifedipine slow release preparation, 20 mg every 8 hours, prevented HAPE in 9 out of 10 subjects with a history of radiographically documented HAPE upon rapid ascent and subsequent stay to an altitude of 4559 m. Seven of 11 comparable subjects who received placebo developed pulmonary edema at 4559 m. As compared with the subjects who received placebo, those who received nifedipine had a significantly lower mean systolic pulmonary artery pressure, alveolar-arterial pressure gradient of oxygen and symptom score of acute mountain sickness at 4559 m. Thus nifedipine offers a potential emergency treatment of HAPE when descent or evacuation is impossible and oxygen is not available. Prophylactic administration of nifedipine prevents HAPE in susceptible subjects. High pulmonary artery pressure has an important role in the pathogenesis of HAPE.

The aim of the present study was to better understand previously reported changes in lung function at high altitude. Comprehensive pulmonary function testing utilising body plethysmography and assessment of changes in closing volume were carried out at sea level and repeatedly over 2 days at high altitude (4,559 m) in 34 mountaineers. In subjects without high-altitude pulmonary oedema (HAPE), there was no significant difference in total lung capacity, forced vital capacity, closing volume and lung compliance between low and high altitude, whereas lung diffusing capacity for carbon monoxide increased at high altitude. Bronchoconstriction at high altitude could be excluded as the cause of changes in closing volume because there was no difference in airway resistance and bronchodilator responsiveness to salbutamol. There were no significant differences in these parameters between mountaineers with and without acute mountain sickness. Mild alveolar oedema on radiographs in HAPE was associated only with minor decreases in forced vital capacity, diffusing capacity and lung compliance and minor increases in closing volume. Comprehensive lung function testing provided no evidence of interstitial pulmonary oedema in mountaineers without HAPE during the first 2 days at 4,559 m. Data obtained in mountaineers with early mild HAPE suggest that these methods may not be sensitive enough for the detection of interstitial pulmonary fluid accumulation.

Conventional radiography and, in recent years, more sophisticated modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) play an important role in the detection of a rich spectrum of extrapulmonary diseases that may exist alone or accompany pulmonary and mediastinal lesions. The present chapter will discuss specific abnormalities of the pleura and the chest wall with special attention to the most reliable imaging techniques in this area.

Continuous computed tomographic (CT) scanning of organ volumes during a single breath hold was studied. The authors modified the table feed mechanism of a continuously rotating CT scanner to allow patient transport at low, but accurately controlled, speeds (0.1-11.0 mm/sec) during continuous 1-second scanning. An algorithm was designed to reconstruct artifact-free images for arbitrary table positions from the helical data by interpolating between adjacent scans. Section sensitivity profiles were enlarged; the section width for a 10-mm section and a speed of 10.0 mm/sec was increased by a factor of 1.3, compared with the nominal value. Clinical examples were presented for studies of lung nodules and studies enhanced with contrast medium. Major advantages are the possibility of continuous scanning of extended volumes within a breath-hold period and retrospective, arbitrary selection of anatomic levels.

Six healthy subjects performed endurance training of the same duration with legs and arms consecutively. Performance and muscle structure were measured before and after training in lower and upper limbs. Training induced similar increases in maximal oxygen consumption (6 +/- 1 vs. 7 +/- 2 mL min-1 kg-1: legs vs. arms, P > 0.05) and mitochondrial volume in leg and arm muscles (42 +/- 12 vs. 31 +/- 11%: legs vs. arms, P > 0.05). The gain in mitochondrial volume after training was achieved solely by increasing the fraction of mitochondria (+40 +/- 11%, P < 0.05) in the same muscle volume (+2 +/- 2%, P > 0.05) in the legs. In contrast, increased muscle volume (+14 +/- 3%, P < 0.05), in addition to a tendency for an increase in mitochondrial fraction (+16 +/- 11%, P > 0.05), occurred in the arms after training. Thus, similar improvements in muscle oxidative capacity in upper and lower limbs were brought about by different mechanisms. It is suggested that due to infrequent use and a lack of load-bearing function, arm muscle volume is underdeveloped in untrained, sedentary or detrained/injured subjects and that the mode of endurance training used in this study is sufficient to enlarge arm muscle volume as well as aerobic capacity.

Radiolucent filling defects of the upper urinary tract (UUT) are a relatively common finding in intravenous urography (IVU) and ureteropyelography (UPG). Despite further evaluation by additional imaging modalities such as sonography and conventional computed tomography (CT), a conclusive diagnosis cannot be made in some of these patients. Endoscopy combined with cytology and histology reveals further information regarding the nature of some of the lesions but is invasive, with a chance of complications, inconclusive with regard to invasiveness, and not economic [1, 2].

Continuous scanning of volumes during a single breathhold should provide decisive advantages in several clinical applications; continuously rotating CT scanners, in principle, offer the required technology. We modified the table feed mechanism of a SOMATOM PLUS to transport the patient at low, but accurately controlled speeds (0.1-11.0 mm/s) during continuous 1 s-scanning, resulting in a spiral scanning geometry. A special reconstruction software was developed to calculate artifact-free planar images from the volume data. As a particular advantage, it allows calculating images for arbitrary table positions. Physical performance characteristics are discussed; clinical examples are presented for lung nodule and contrast medium studies. Major advantages are the possibilities to scan extended volumes continuously and to retrospectively select arbitrary slice levels.

Thoracic computer tomography was performed in 135 patients with bronchial carcinoma. 1) In 90% a precise estimate of the extent of the primary tumour was possible. The computer tomogram was markedly superior to traditional radiological methods in showing invasion of the chest wall and mediastinum. 2) Regional lymph node metastases were demonstrated correctly in 82%. Lymph node enlargement must be differentiated from that due to benign causes. 3) In 92%, the extent of distal metastases could be correctly established. The computer tomogram makes it possible to avoid exploratory thoracotomy if there is transpleural invasion, extensive mediastinal lymph node metastasation or distant metastasation. Where there is doubt, computer tomography-guided needle aspiration should be employed.

Most computed tomographic (CT) scans of the chest show the inferior pulmonary ligament and an associated septum in the lower lobe, although CT descriptions of these structures have not been reported. Conventional radiography of the ligament has relied on indirect signs: the position of the lower lobe in the presence of pneumothorax or pleural effusion, soft-tissue peaks along the upper surface of the diaphragm, and the rare traumatic paramediastinal pneumatocele (attributed to air in the ligament). CT clarifies the anatomic relations of the ligament and alterations caused by pleural effusion and pneumothorax. The ligament is probably responsible for some long linear shadows at the lung bases, and CT helps to distinguish these from scars, walls of bullae, and normal structures such as the phrenic nerve and the interlobar fissures.

The radiological features of cystic and alveolar echinococcal disease of the liver is described, based on 17 patients. Conventional radiographs, liver ultrasound and liver angiography are described.

The hemodynamic changes during intravenous urography were studied in 120 non-selected patients (60 patients with bolus injection, 60 with infusion: 30 of each group with methylglucamine ioxitalamate, while the other 30 with sodium methylglucamine diatrizoate). There was a uniform statistically significant increase in heart rate (p less than 10(-9) as well as in cardiac output (p less than 10(-9)) (measured by means of a non-invasive impedance method). The observed changes were more marked following bolus injection than infusion. With the application of methylglucamine ioxitalamate the increase in heart rate, but not in cardiac output, was significantly less (p less than 0,01) than with that of sodium methylglucamine diatrizoate.

Computed tomographic (CT) lung density measurements were prospectively correlated with pulmonary haemodynamic data in 33 patients with chronic heart disease. Cardiac catheterisation and five specific computed tomographic scans (three at nearly total lung capacity, one at functional residual capacity, and one at residual volume) were performed. There was a significant correlation between anterior lung density and mean pulmonary artery pressure (r = 0.86), pulmonary vascular resistance (r = 0.80), and pulmonary artery wedge pressure (r = 0.65). Lung density, as measured by CT, thus provides a valuable estimate of pulmonary arterial pressure and pulmonary vascular resistance, but is affected by other pathological conditions, such as emphysema and congestional or post-inflammatory fibrosis.

A computer method that calculates tracheal cross-sectional area by compensating for partial volume averaging was developed and validated in a study with phantoms. The program was then used to determine the tracheal cross-sectional area of 30 normal children who ranged in age from four months to 18 years. CT-derived cross sections were correlated with age, height, weight, and body-surface area, and they were compared with findings of published clinical and post-mortem studies. CT cross-sectional areas ranged from 20-275 mm2, varied by as much as 22% at the three different tracheal levels studied, and appeared to correlate most closely with body height. CT-derived tracheal cross-sectional areas are quite similar to those in published reports of postmortem and clinical studies. Measurement of tracheal cross section by CT may prove useful in quantitating tracheal compromise by intrinsic or extrinsic causes.

Four patients with retroperitoneal fibrosis (Ormond's disease) were examined by computer tomography; the appearances are described and the differential diagnosis discussed. Computer tomography clearly defines the proliferative-inflammatory process and together with conventional radiology, angiography and lymphangiography it permits a presumptive diagnosis of retroperitoneal fibrosis. The non-invasive nature of computer tomography makes it the method of choice for follow-up of this disease.

A systematic evaluation of the fissures, segmental bronchi and arteries, bronchopulmonary segments, and peripheral pulmonary parenchyma was made from computed tomographic (CT) scans of 50 patients with normal chest radiographs. Seventy percent of the segmental bronchi and 76% of the segmental arteries were identified. Arteries could be traced to their sixth- and seventh-order branches; their orientation to the plane of the CT section allowed gross identification and localization of bronchopulmonary segments.

In a laboratory at 4559 m six subjects with high altitude pulmonary oedema (HAPO) characterised by clinical signs, severe hypoxaemia, widened alveolar-arterial oxygen gradient, pulmonary hypertension, and alveolar oedema on chest radiography were treated with nifedipine. Despite continued exercise at the same altitude this treatment, without supplementary oxygen, resulted in clinical improvement, better oxygenation, reduction of alveolar arterial oxygen gradient and pulmonary artery pressure, and progressive clearing of alveolar oedema. Nifedipine offers a potential emergency treatment for HAPO when descent or evacuation is impossible and oxygen is not available. The findings also suggest that hypoxic pulmonary hypertension is essential in the pathogenesis of HAPO.

In a retrospective evaluation of 12 children with blunt liver trauma studied by computed tomography (CT), all patients studied preoperatively had subcapsular hematomas (6/6). Eleven of twelve patients had parenchymal lesions that were located predominantly in the superior subsegments of the right lobe: 9/12 posteriorly (segment no. 7) and 7/12 anteriorly (segment no. 8) where transections were most frequent. Lacerations were accompanied by intraparenchymal hematomas. Intravenous bolus contrast enhancement visualizes segmental anatomy and is absolutely necessary in order to map lacerations, recognize nonviable tissue, and relate them to major vessels. Except in critically unstable patients, noninvasive imaging of hepatic and other combined abdominal lesions can avoid diagnostic laparotomy or justify planning of a tailored, maybe less radical surgical procedure. Complications, such as abscess formation, can be demonstrated and drained percutaneously. Despite cost, CT is currently the single best imaging method in acute liver trauma.

Classically, the middle lobe syndrome has been described as being caused by a central obstruction. Clinical records and radiologic findings were reviewed in 129 patients examined between 1955-1981 who had chronic disease in the right middle lobe and/or lingula. Fifty-eight patients (45%) had no evidence of a central obstructive lesion. The majority were middle-aged women with histories of chronic cough and chest pain. Bronchoscopic and radiologic evaluation served to exclude central lesions. Surgical confirmation was available in 38 patients. Pathologic study showed varying degrees of chronic inflammation, pneumonia, and bronchiectasis. Surgical results were excellent in isolated disease. Chronic atelectasis and pneumonitis of the right middle lobe and/or lingula do not always imply central obstruction. A lack of collateral ventilation is a plausible theory to explain the pathophysiology in such patients.

A software system has been developed to support analysis of CT images for tissue densitometry. Analysis can be done on either whole organ areas in a slice open subregions of these areas. CT numbers can he calibrated to absolute density. The system has been used to analyze lung and liver density in animal studies and lung density in a limited number of patients.

Computer tomography conclusively demonstrates the topographical anatomy of both the thoracic wall and the adjacent pleura, thus closing the diagnostic gap between the superficial areas, accessible to clinical investigation, and the lungs, which are displayed to good advantage on conventional radiographs.

A morphometric method to calculate liver volumes from transverse sections is evaluated (point-integrating method). In the first part of the study, 10 liver specimens were investigated by computed tomography (CT) and ultrasound (US); the calculated volumes were compared to the volumes obtained by water displacement of the organs. While CT showed an ideal agreement (r = 0.994), volumes calculated from US sections correlated less well (percentage differences from +12.5% to -9%, r = 0.915). In the second part of the study, the livers of 10 randomly selected patients were investigated by CT and US. Liver volumes were calculated using the point-integration method. Compared to the CT examination, US results show a good correlation with a correlation coefficient of r = 0.977. The point-integration method is very valuable to measure organ volumes from transverse sections. The method can be applied "offline" to photographic films, data do not have to be recorded electronically. The time required to calculate the volume of an organ is comparable to other methods.

Neurological signs and computed tomographic morphology were compared in 60 patients. The primary neurological deficit was most commonly located in the sacral (n = 31) or lumbar plexus (n = 23) and was most commonly caused by a neoplasm (n = 40). In 78% of the patients it correlated with the lesions detected by computed tomography (CT). CT reliably demonstrates extraspinal mass lesions, but only moderately well predicts functional signs.

Computed tomography (CT) may be used in the diagnosis and management of acute pancreatitis (AP) in several ways. The diagnosis of AP can be confirmed, and the extent and severity of pathologic changes in the pancreas and peripancreatic tissues assessed (1, 2, 7, 8). The differentiation between edematous and necrotizing forms of pancreatitis is important for both prognosis and management. Computed tomography monitoring of the course of AP permits earlier and more precise diagnosis of complications and is a superb document of the natural history of the disease. Much has been learned by CT on how the disease progresses in the gland and peripancreatic tissues and how exudates and necrotic tissues may regress and diminish spontaneously in some cases and give rise to life-threatening complications in others. The diagnosis of necrotic changes in the pancreas is now possible with even greater accuracy thanks to the introduction of contrast enhancement after intravenous bolus injection of contrast material (3, 5, 6).

Summary— Seventy-seven patients with carcinoma of the urinary bladder were investigated by computed tomography (CT) and the results compared with those of pathological staging. The overall accuracy rate was 81 % for the estimation of local tumour extension. Perivesical tumour extension was overestimated by CT owing to previous bladder surgery or radiotherapy in about half of the cases. Nevertheless, CT gives unrivalled diagnostic information in advanced tumour invasion. The diagnostic accuracy rate of CT in the detection of lymph node metastases was 89%, compared with 73% for lymphography.

The computed tomographic (CT) appearance of pulmonary edema induced by elevated left atrial (LA) pressure was examined. Dogs, in the prone position, were scanned during suspended ventilation at functional residual capacity. A surgically implanted LA balloon was inflated to elevate LA pressure for 30 to 140 minutes to a mean pressure of 29.8 mm Hg. Lung water, measured gravimetrically, averaged 14.7 ml/kg body weight compared with 5.7 ml/kg in nonedema control dogs. Lung density in dogs with edema was 69.5% higher than base-line density, while in the control group final lung density was only 4% higher than base line. Analysis of regional density indicated that there were greater increases in density in more central and dependent (ventral) zones of the lung and relatively smaller increases in nondependent (dorsal) peripheral zones. These results are in contrast to the previously reported pattern of density change seen with oleic acid injury in which density increases were primarily in peripheral zones of the lung.

Of 21 cases of cardiophrenic angle adenopathy (CAA) detected on computed tomography (CT) examination, 12 were due to malignant lymphomas, seven to carcinomas, and two to mesotheliomas. Of the nine lesions that were not malignant lymphomas, four were of supradiaphragmatic and five of infradiaphragmatic origin. On average, CAA was detected 4.6 years after the primary neoplasm was diagnosed. Only 29% of the patients were alive 14 months after CAA was detected on CT scans. Radiography was inferior to CT in the detection of CAA, with only 35% of radiography results clearly positive. Malignant lymphoma is a major but not exclusive cause of CAA, and it must be differentiated from lymphatic seeding of supradiaphragmatic and infradiaphragmatic malignancies. Unilateral CAA may point to supradiaphragmatic neoplasms or, if right-sided, to ovarian carcinoma, and bilateral CAA may indicate another neoplasm of infradiaphragmatic origin.