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Idiopathic interstitial pneumonias (IIP) comprise seven entities with distinct histologic patterns. In their idiopathic form IIP are rare diseases. They are, nevertheless, considered prototypes of the much more common secondary interstitial pneumonias. The advent of high-resolution computed tomography (HRCT) has had a profound impact on the imaging of IIP, because the detailed delineation of the lung anatomy allows a close correlation between the histologic patterns of IIP and the CT features. On the basis of CT morphology and in the correct clinical context, the radiologist can achieve an accurate diagnosis in many cases. However, due to overlap between the various entities, complementary lung biopsy is recommended in virtually all cases. This article reviews the CT pattern of IIP and offers relevant clinical and histological information for the purpose of enabling the radiologist to understand and participate in the multidisciplinary concept of IIP.

Emphysema is defined as a condition of the lung characterized by abnormal, permanent enlargement of airspaces distal to the terminal bronchiole accompanied by destruction of the alveolar walls and without obvious fibrosis. It is a very common disease with high morbidity and mortality. Histopathologically, there are two types of emphysema: panlobular emphysema, typically occurring in alpha1-antitrypsin deficiency, and centrilobular emphysema, which is strongly associated with cigarette smoking. Computed tomography (CT) allows detection of emphysema with higher sensitivity than conventional chest radiography and pulmonary function tests. CT also allows quantification of emphysema and depicts associated changes and complications. The differential diagnosis of emphysema, which is characterized by the absence of clearly definable walls on CT, includes cystic lung disease, bullae, lung laceration, Langerhans cell histiocytosis, and lymphangioleiomyomatosis -which are all characterized by visible walls on CT.

The radiologic knowledge of tuberculosis-associated lung disease is an essential tool in the clinical diagnosis of tuberculosis. Chest radiography is the primary imaging method, but the importance of CT is still increasing, as CT is more sensitive in the detection of cavitation, of hilar and mediastinal lymphadenopathie, of endobronchial spread and of complications in the course of the disease. In addition, CT has been proven as a valuable technique in the assessment of tuberculosis activity, especially in patients where M. tuberculosis has not been detected in the sputum or in patients with multidrug-resistant tuberculosis. Depending on the immune status of the patient, the morphologic spectrum of tuberculosis is quite variable. Early diagnosis of tuberculosis is essential to prevent further spread of the disease.

Purpose. Gas exchange is the primary function of the lung and the transport of oxygen plays a key role in pulmonary physiology and pathophysiology. Materials and Methods. Molecular oxygen is weakly paramagnetic, so that an increase in oxygen concentration results in shortening T1 relaxation time and thus increasing signal intensity in T1 weighted images. The calculation of parameter maps may allow deeper insights into relaxation mechanisms.T1 maps based on a snapshot FLASH sequence obtained during the inhalation of various oxygen concentrations allow the creation of an oxygen transfer function, providing a measurement of local oxygen transfer.T1 weighted single shotTSE sequences demonstrate the signal changing effects during inhalation of pure oxygen. Results. The average of the mean T1 values over the entire lung during inspiration was 1,199±117 ms, the average of these values during expiration was 1,333±167 ms.T1 maps of patients with emphysema and lung fibrosis show fundamentally different values and respiratory dependence compared to healthy individuals. Oxygen enhanced MR has the potential to assess reduced diffusion capacity and decreased transport of oxygen in patients with emphysema and cystic fibrosis. Discussion. Results published in the literature indicate thatT1 mapping and oxygen enhanced MR are promising new methods in functional imaging of the lung.

Das Staging, d.h. die Bestimmung der Ausdehnung der Erkrankung, dient zur Selektion von Patienten die fur eine chirurgische Therapie unter kurativer Zielsetzung geeignet sind, bzw. zur Definition derjenigen Karzinomtrager, die von einer chirurigischen Intervention nicht profitieren und alternativen Therapieformen (Chemotherapie, Strahlentherapie) zugefuhrt werden. Weiterhin dient es zur Bestrahlungsplanung und bei kleinzelligen Bronchialkarzinomen zu deren Nachweis bzw. zur Kontrolle der Chemotherapie und letztendlich zur Einschatzung der Prognose. Die Computertomographie (CT) des Thorax (inklusive Leber und Nebennieren), die Sonographie des Oberbauches sowie die Skelettszintigraphie sind die radiologischen Standarduntersuchungen fur das Staging des Bronchialkarzinoms. Fur gezielte Fragestellungen, z.B. der nach einer Thoraxwandinfiltration, und bei Patienten mit einer Kontrastmittelallergie kann zusatzlich oder alternativ zu einer CT eine Magnetresonanztomographie (MRT) durchgefuhrt werden. Nuklearmedizinische Techniken wie beispielsweise die Positronenemissionstomographie mit [18F]2-Flouro-2-Desoxy-D-Glucose (FDG-PET) zur Beurteilung der Lymphknoten und Fernmetastasen, In-111-Octreotide/Somatostatin-Scans fur Staging/Diagnose des kleinzelligen Lungenkarzinoms, sowie die Thallium-201 SPECT, deren klinischer Stellenwert derzeit in zahlreichen Studien evaluiert wird, werden ebenfalls immer haufiger zum Staging von Lungentumoren eingesetzt. Methoden, welche zur Zeit noch in experimentellen Studien getestet werden, wie z.B. genetisch-molekulare MRT-Kontrastmittel oder nuklearmedizinische Methoden auf Tumorrezoptorbasis, konnten in der Zukunft eine wichtige Rolle beim Staging des Bronchuskarzinoms spielen.

Fragestellung: Spiral-CT und konventionelle CT zur praoperativen Lokalisation metallischer intraokularer Fremdkorper wurden verglichen. Methode: 18 Patienten mit penetrierenden Augenverletzungen und Verdacht auf metallische intraokulare Fremdkorper wurden alternierend zur Spiral-CT oder konventionellen CT in axialer Schichtebene zugewiesen. Sowohl die Spiral-CT- als auch die konventionellen CT-Daten wurden auf eine Workstation ubertragen und Rekonstruktionen in koronaler und sagittaler Ebene angefertigt. Zusatzliche direkte koronale Bilder wurden erst dann angefertigt, wenn diese zur praoperativen Beurteilung notwendig erschienen. Die Qualitat der axialen Bilder sowie der koronalen und sagittalen Rekonstruktionen wurde getrennt beurteilt. Die Grose der Fremdkorper wurde auf den Bildern gemessen und dem tatsachlichen Durchmesser gegenubergestellt. Die Gesamtuntersuchungszeit sowie die Strahlenbelastung der Linse wurden fur jede Modalitat getrennt beurteilt. Ergebnisse: Auf allen Bildern konnten samtliche Fremdkorper mit beiden Bildgebungsverfahren nachgewiesen werden. Die axialen Bilder waren bei beiden Techniken von vergleichbarer Qualitat. Die Spiral-CT ermoglichte Rekonstruktionen von hoher Qualitat, die in allen Fallen eine genaue Lokalisation der Fremdkorper erlaubten. Rekonstruktionen konventioneller CT-Bilder waren zur praoperativen Beurteilung nicht ausreichend. Die Untersuchungszeit fur das gesamte Orbitavolumen betrug 18 s fur die Spiral-CT und 52 s fur die konventionelle CT. Die Strahlenbelastung an der Linse betrug 35 mGy bei der Spiral-CT und 56 mGy bei der konventionellen CT. Schlusfolgerung: Die multiplanare Bildgebung mittels Spiral-CT erlaubt im Vergleich zur konventionellen CT Vorteile bei der praoperativen Beurteilung metallischer intraokularer Fremdkorper. Diese sind u.a. kurzere Untersuchungszeiten, Minimierung der Bewegungsartefakte, weniger Strahlenbelastung sowie genaue Lokalisation.

Die rasant fortschreitenden Entwicklungen auf dem Gebiet der Radiodiagnostik eröffnen auch der Intensivmedizin neue Aspekte: Mittels moderner Technik können heute ungleich rascher konklusive Diagnosen gestellt werden. Dies setzt jedoch die Kenntnis der Möglichkeiten und auch der Grenzen bildgebender Methoden in der Intensivmedizin voraus. Im vorliegenden Beitrag werden, ausgehend von relevanten klinischen Fragestellungen und Problemkomplexen, die Möglichkeiten bildgebender Verfahren vorgestellt und diskutiert. Es werden die wichtigsten diagnostischen Röntgenzeichen erläutert und ein diagnostisches Prozedere vorgezeichnet, somit soll der vorliegende Beitrag eine kurze Zusammenfassung der für den Intensivmediziner wichtigen Aspekte der Bildgebung darstellen.

The purpose of our study was to compare the diagnostic performance of a 0.2-T MRI unit and a 1.0-T MRI unit in the evaluation of the anterior cruciate ligament in patients with clinically suspected lesions of this ligament. Twenty four patients with clinically suspected lesions of the anterior cruciate ligament underwent MRI of the knee on both 0.2-T and 1.0-T MRI units. Three independent observers evaluated the examinations for primary and secondary signs of a tear of the anterior cruciate ligament. Frequency of these signs was determined for both modalities, and observer agreement was assessed using the kappa statistic. Sixteen of 24 patients had signs of tears of the anterior cruciate ligament on the 1.0-T unit; the 0.2-T unit detected primary signs in 15/16 (93%) patients and secondary signs in 7/12 (43%) patients. In 8 patients the 1.0 T unit showed neither primary nor secondary signs for tears of the anterior cruciate ligament; in these patients the 0.2-T unit detected primary signs in 1/8 cases (12%), and secondary signs in 3/8 cases (37%). Observer agreement was very good for the 1.0-T unit and fair for the 0.2-T unit. There is no substantial difference between 1.0-T units and 0.2-T MRI units in the visualisation of primary signs of tears of the anterior cruciate ligament. In the visualisation of secondary signs, 1.0-T units are superior to 0.2-T units, and there is a surprisingly high rate of false-positive results with the 0.2-T unit. As to the reproducibility of the results, the 1.0-T unit is far superior to the 0.2-T unit.

The study was performed to determine the diagnostic value of different MR systems and field strengths in patients with occult scaphoid and wrist fractures. Twelve patients with clinical suspicion of a scaphoid fracture but normal plain radiographs were examined by MRI. A dedicated 0.2-T unit (Esaote) and a 1.0-T unit (NT10, Philips) were used. Coronal T1W-SE, STIR, and T2*W-GE sequences were obtained with both systems. Images were evaluated for a bone marrow abnormality, a trabecular or cortical fracture line, and were compared to the 6-week follow-up radiographs. Seven wrist fractures were found at 0.2 T and 1.0 T, proven in the follow-up radiographs. A bone marrow abnormality was present in all seven fractures on both systems. Trabecular and cortical fracture lines were visualized at 0.2 T in four cases and at 1.0 T in seven cases. Low-field MR imaging at 0.2 T and mid-field MR imaging at 1.0 T seem to be equivalent in the diagnosis of a fracture in radiographically occult scaphoid and wrist fractures. In the visualization of fracture details, important for therapeutic and prognostic considerations, 1.0 T seems to be superior.

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.

Lungenveranderungen im Rahmen der rheumatoiden Arthritis stellen einen klinisch bedeutsamen Aspekt dieser in Schuben verlaufenden chronischen Arthropathie dar. Die mit dem Bestehen einer rheumatoiden Arthritis verbundenen pulmonalen Veranderungen konnen alle anatomischen Teile des Lungenparenchyms, die Pleura sowie Teile des knochernen Thorax betreffen. Die wichtigsten thorakalen Veranderungen im Rahmen der rheumatoiden Arthritis sind die nekrobiotischen Rheumaknoten, pleurale Veranderungen, das Caplan-Syndrom, die Lungenfibrose, die Bronchiolitis obliterans und medikamentos induzierte Lungenveranderungen. Der vorliegende Artikel beschreibt das Spektrum der Lungenveranderungen, die im Rahmen der rheumatoiden Arthritis vorkommen. Hierbei werden die klinischen und radiologischen Charakteristika dieser Veranderungen vorgestellt. Die Bedeutung der verschiedenen bildgebenden Methoden im diagnostischen Algorithmus wird diskutiert.

Pulmonale Infektionen und Tumore sind eine wesentliche Todesursache bei Patienten, die am erworbenen Immunmangelsyndrom AIDS leiden. In den meisten Fallen gelingt es, durch Zusammenschau klinischer, radiologischer, labortechnischer und pathohistologischer Befunde das differentialdiagnostische Spektrum erheblich einzuengen oder eine spezifische Diagnose zu stellen. Dennoch ware eine Beschleunigung des diagnostischen Prozedere wunschenswert, um fruher und gezielter therapeutisch wirksam werden zu konnen. Neben dem konventionellen Thoraxrontgen hat sich die Computertomographie als hilfreich in der Bildgebung AIDS-assoziierter Thoraxveranderungen gezeigt. Ziel dieser Ubersicht soll es sein, anhand typischer Beispiele die Einsatzmoglichkeiten der Computertomographie in der Diagnostik AIDS-assoziierter Erkrankungen des Thorax zu beschreiben. Informationen uber das Spektrum wichtiger Erreger sowie wichtige differentialdiagnostische Zeichen sind als Erganzung in Tabellen zusammengefast.

Die Pulmonalembolie ist eine haufige und lebensbedrohende Erkrankung, deren klinische Manifestationen uncharakteristisch sind. Daher beruht die Diagnose der Pulmonalembolie bislang auf der Ventilations-/Perfusionsszintigraphie und der Pulmonalisangiographie. Beide Methoden haben im klinischen Einsatz aber Schwachen, so das weiterhin der Bedarf nach einer moglichst genauen und nichtinvasiven Methode besteht. Die Spiral-CT der Pulmonalarterien ist eine neue bildgebende Methode, die verlaslich eine direkte Darstellung von Thromben und Emboli in der Lungenstrombahn bis auf Ebene der Segmentarterien erlaubt. Der vorliegende Beitrag stellt die Untersuchungstechnik, die typischen Befunde sowie mogliche diagnostische Fehlerquellen dieser neuen Technik vor. Die potentielle Stellung der Spiral-CT im diagnostischen Algorithmus bei Verdacht auf Pulmonalembolie wird anhand klinischer Beispiele diskutiert.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare result of recurrent pulmonary embolism and is treated by pulmonary thromboendarterectomy. Knowledge of the exact location of the thrombi is necessary in planning this operation. To date, pulmonary, angiography is the diagnostic imaging gold standard. Since the introduction of spiral CT excellent vascular opacification of the pulmonary arteries has become feasible, and thrombi in the pulmonary arteries can be visualized directly. Spiral CT is superior to angiography in demonstrating thrombi in the central pulmonary arteries, whereas angiography proves superior to CT in the evaluation of abnormalities within segmental arteries. The sensitivity of spiral CT in confirming the diagnosis of CTEPH is reported to be more than 90%. According to the literature and based on our own results, the decision concerning operability is possible on the basis of spiral CT images in more than 80% of patients with CTEPH. Spiral CT as a non-invasive tool may be used for CTEPH screening, for postoperative follow-up after pulmonary thrombendarterectomy and, combined with pulmonary angiography, to optimize operation planning.

Idiopathic interstitial pneumonias (IIP) comprise seven entities with distinct histologic patterns. In their idiopathic form IIP are rare diseases. They are, nevertheless, considered prototypes of the much more common secondary interstitial pneumonias. The advent of high-resolution computed tomography (HRCT) has had a profound impact on the imaging of IIP, because the detailed delineation of the lung anatomy allows a close correlation between the histologic patterns of IIP and the CT features. On the basis of CT morphology and in the correct clinical context, the radiologist can achieve an accurate diagnosis in many cases. However, due to overlap between the various entities, complementary lung biopsy is recommended in virtually all cases. This article reviews the CT pattern of IIP and offers relevant clinical and histological information for the purpose of enabling the radiologist to understand and participate in the multidisciplinary concept of IIP.

Gas exchange is the primary function of the lung and the transport of oxygen plays a key role in pulmonary physiology and pathophysiology.Molecular oxygen is weakly paramagnetic, so that an increase in oxygen concentration results in shortening T1 relaxation time and thus increasing signal intensity in T1 weighted images. The calculation of parameter maps may allow deeper insights into relaxation mechanisms. T1 maps based on a snapshot FLASH sequence obtained during the inhalation of various oxygen concentrations allow the creation of an oxygen transfer function, providing a measurement of local oxygen transfer. T1 weighted single shot TSE sequences demonstrate the signal changing effects during inhalation of pure oxygen.The average of the mean T1 values over the entire lung during inspiration was 1,199+/-117 ms, the average of these values during expiration was 1,333+/-167 ms. T1 maps of patients with emphysema and lung fibrosis show fundamentally different values and respiratory dependence compared to healthy individuals. Oxygen enhanced MR has the potential to assess reduced diffusion capacity and decreased transport of oxygen in patients with emphysema and cystic fibrosis.Results published in the literature indicate that T1 mapping and oxygen enhanced MR are promising new methods in functional imaging of the lung.

Staging of any tumor, i.e. determination of the extent of the disease, serves to select the patients who might profit from curative surgical intervention or to define those patients with inoperable carcinomas who should be referred for other therapies, such as chemotherapy or irradiation. Furthermore, accurate staging is necessary for assessment of prognosis, for radiation therapy planning, and for differentiation of those with small-cell lung cancer or for follow-up examinations of small-cell lung cancer patients after during and after chemotherapy. The primary radiological staging and diagnostic modalities for assessment of bronchial carcinomas are computed tomography (CT) of the thorax including liver and adrenal glands, abdominal sonography, and bone scintigraphy. Magnetic resonance imaging (MRI) should be reserved for specific indications, e.g. infiltration of the chest wall or staging of patients with intolerance/allergy to intravenous contrast medium. The clinical value of nuclear medicine techniques, such as [18F]2-fluoride-2-desoxy-D-glucose positron emission tomography (FDG-PET) for evaluation of lymph nodes and distant metastases, In-111 octreotide/somatostatin receptor scans for staging of small-cell lung cancer, and thallium-201 SPECT are currently being assessed in numerous studies, although these techniques are already in routine use. In future these or nuclear medicine techniques, as well as techniques using molecular-based contrast material, especially for MR imaging, currently in experimental status, may yield serious potential for staging purposes.

To compare the effectiveness of spiral CT versus conventional CT in the preoperative assessment of metallic intraocular foreign bodies.Eighteen patients with penetrating eye injuries and suspected metallic intraocular foreign bodies were assigned to undergo either spiral CT or conventional CT in the axial plane. The spiral and the conventional CT data were transferred to a workstation, and reconstructions in the coronal and sagittal planes were performed. Additional direct coronal scanning was performed only when necessary for preoperative assessment. The quality of the axial as well as the reconstructed coronal and sagittal images was assessed for each imaging modality. The size of the foreign bodies was measured and compared to the actual diameter. Total examination time and radiation dose delivered to the lens were measured for each imaging modality.All foreign bodies were detected by each scanning modality on the axial and on the reconstructed planes. The quality of the axial images was similar for spiral and conventional CT. The spiral technique provided high-quality reconstructed images which allowed accurate localization of the foreign bodies in all cases. Reconstructions by conventional technique were inadequate for preoperative assessment. The examination time for the total orbital volume was 18 s for spiral CT and 52 s for conventional CT. Radiation dose delivered to the lens was 35 mGy for spiral CT and 56 mGy for conventional CT axial scanning.Spiral CT multiplanar imaging offers several significant advantages for the preoperative assessment of metallic intraocular foreign bodies compared to the conventional CT technique in clinical practice, including short examination time, minimized motion artifacts, reduced radiation exposure, and accurate localization.

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.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.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.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.

The study was performed to determine the diagnostic value of different MR systems and field strengths in patients with occult scaphoid and wrist fractures. Twelve patients with clinical suspicion of a scaphoid fracture but normal plain radiographs were examined by MRI. A dedicated 0.2-T unit (Esaote) and a 1.0-T unit (NT10, Philips) were used. Coronal T1W-SE, STIR, and T2*W-GE sequences were obtained with both systems. Images were evaluated for a bone marrow abnormality, a trabecular or cortical fracture line, and were compared to the 6-week follow-up radiographs. Seven wrist fractures were found at 0.2 T and 1.0 T, proven in the follow-up radiographs. A bone marrow abnormality was present in all seven fractures on both systems. Trabecular and cortical fracture lines were visualized at 0.2 T in four cases and at 1.0 T in seven cases. Low-field MR imaging at 0.2 T and mid-field MR imaging at 1.0 T seem to be equivalent in the diagnosis of a fracture in radiographically occult scaphoid and wrist fractures. In the visualization of fracture details, important for therapeutic and prognostic considerations, 1.0 T seems to be superior.

The purpose of our study was to compare the diagnostic performance of a 0.2-T MRI unit and a 1.0-T MRI unit in the evaluation of the anterior cruciate ligament in patients with clinically suspected lesions of this ligament. Twenty four patients with clinically suspected lesions of the anterior cruciate ligament underwent MRI of the knee on both 0.2-T and 1.0-T MRI units. Three independent observers evaluated the examinations for primary and secondary signs of a tear of the anterior cruciate ligament. Frequency of these signs was determined for both modalities, and observer agreement was assessed using the kappa statistic. Sixteen of 24 patients had signs of tears of the anterior cruciate ligament on the 1.0-T unit; the 0.2-T unit detected primary signs in 15/16 (93%) patients and secondary signs in 7/12 (43%) patients. In 8 patients the 1.0 T unit showed neither primary nor secondary signs for tears of the anterior cruciate ligament; in these patients the 0.2-T unit detected primary signs in 1/8 cases (12%), and secondary signs in 3/8 cases (37%). Observer agreement was very good for the 1.0-T unit and fair for the 0.2-T unit. There is no substantial difference between 1.0-T units and 0.2-T MRI units in the visualisation of primary signs of tears of the anterior cruciate ligament. In the visualisation of secondary signs, 1.0-T units are superior to 0.2-T units, and there is a surprisingly high rate of false-positive results with the 0.2-T unit. As to the reproducibility of the results, the 1.0-T unit is far superior to the 0.2-T unit.

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.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.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.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.

Pulmonary complications caused by rheumatoid arthritis are a clinically relevant aspect of this chronic arthropathy. Those complications can involve all parts of the thorax, including the lung parenchyma, the pleura, and the thoracic cage. The most common complications are necrobiotic nodules, pleural abnormalities, Caplan's syndrome, parenchymal fibrosis, bronchiolitis obliterans, and iatrogenic damage of lung the parenchyma. This article reviews pulmonary abnormalities induced by rheumatoid arthritis and their clinical and radiological findings. In addition, the role of different imaging modalities in the diagnostic work-up of pulmonary complications caused by rheumatoid arthritis is discussed.

Pulmonary infections and tumors are a major cause of death in patients with AIDS. The combination of clinical, radiological, laboratory, and pathohistological data helps to narrow the spectrum of differential diagnoses or even allows a specific diagnosis in many patients. Nevertheless, an accurate diagnosis should be obtained as soon as possible during the clinical course of the illness to initiate treatment in time. Computed tomography (CT) has proven to provide promising results in the diagnosis of AIDS-related thoracic diseases. The aim of this paper was to demonstrate the diagnostic capacities of CT in the context of particular AIDS-related thoracic pathologies. Additional information on the spectrum of pathological agents and on differential diagnostic signs is summarized.

Pulmonary embolism is a frequent and potentially life-threatening event with uncharacteristic clinical manifestations. Diagnosis is commonly established by ventilation/perfusion scintigraphy and pulmonary angiography. Both methods, however, carry substantial drawbacks. Therefore, clinicians claim that there is a need for an accurate and non-invasive diagnostic modality. Spiral CT of the pulmonary arteries is a recent modality, that allows reliable visualization of emboli in pulmonary arteries up to fourth-order branches. This paper reviews the technical aspects, typical findings and diagnostic pitfalls of this recent technique. The potential role of spiral CT in the screening of patients with suspected pulmonary embolism is discussed and selected cases are presented.