[Mimics of lung cancer]

Lung cancer is a histologically, immunologically and therefore morphologically and functionally very heterogeneous group of neoplasms with the highest cancer mortality worldwide. Therefore, the range of diseases mimicking lung cancer is also very broad and includes congenital, infectious and inflammatory changes as well as other benign space-occupying lesions and other primary and secondary pulmonary neoplasms. The difficulty in radiology lies in the ability to diagnose lung cancer with a high degree of certainty. This must take the limits of the specific diagnosis, knowledge of the classical pitfalls and rare entities that can imitate lung cancer into consideration. Narrowing the differential diagnosis requires close interdisciplinary cooperation and consideration of the patient's clinical and medical history. An accurate analysis of the computed tomography (CT) pattern and distribution of the lesions as well as consideration of additional changes and involvement of other organ systems can be the key to the diagnosis. The use of fluorodeoxyglucose positron-emission tomography CT (FDG-PET-CT) is helpful only in a few mimics of lung cancer. The article describes clinical and radiological findings of mimics of lung cancer also pointing out the limitations of CT and PET-CT for the diagnosis.

CT in Pancreatic Involvement of Non-Hodgkin Lymphoma

In an attempt to evaluate characteristic CT features of primary pancreatic involvement in non-Hodgkin lymphoma (NHL), scans of 10 patients were reviewed retrospectively and compared to 50 patients with histologically proved different neoplasms of the pancreas. Setting the correct diagnosis of NHL would be essential for planning of treatment and prognosis. CT findings of NHL were characteristic but not specific. Nevertheless, the presence of a homogeneous pancreatic mass with a diameter of 7 cm or more, infiltrating surrounding tissue accompanied by retroperitoneal and/or mesenteric lymphadenopathy strongly suggests NHL. CT-guided needle biopsy can help to establish the diagnosis of pancreatic NHL.

[Management of subsolid pulmonary nodules]

The finding of subsolid pulmonary nodules poses a frequent problem in the daily routine of the radiologist. The biological behavior of such subsolid lesions differs significantly from solid nodules. The risk of malignancy is significantly higher in subsolid nodules as compared to solid or purely ground glass opacities or nodules. The recommendations regarding the diagnostic management of subsolid nodules have been adapted according to the tendency of growth and the risk of malignancy. A benign etiology is also seen quite often in subsolid lesions and in this case they will show a reduction of size or disappear completely by the follow-up examination. Therefore, in many cases a short-term follow-up examination is primarily recommended. As the findings will often show no changes for a long period of time, further annual follow-up examinations over a longer, not yet specified period of time are recommended. Subsolid lesions that grow in size and/or show an increase in density or develop a solid part within a ground glass lesion should remain as suspected malignancies until proven otherwise.

[Lung cancer screening - where are we in 2013?]

Lung cancer is one of the leading causes of death in Europe and the USA. A relatively good prognosis is limited to those patients in whom the tumor is detected at an early stage. As clinical symptoms of lung cancer are a late finding in the natural course of the disease, most of the patients are diagnosed at an advanced tumor stage when palliative care remains the only therapeutic option. For this reason, early diagnosis of lung cancer might save lives. The National Lung Screening Trial (NLST), in the U. S. A., provided evidence that screening with low-dose CT (LD-CT) is able to reduce lung cancer mortality by 20.0 %. The encouraging results of the NLST, however, could not be confirmed by the preliminary results of ongoing European trials. Even if the European trials are able to confirm a reduction in lung cancer mortality by LD-CT, a number of important questions must be answered before the implementation of nationwide screening programs. First of all, the population that might benefit from CT lung cancer screening has to be defined precisely. Furthermore, guidelines have to be established about how to manage screening participants with detected lung nodules, as the vast majority of these pulmonary nodules will prove to be benign. This review article summarizes the results of the NLST and the initial data from the European screening trials, and will discuss some of the major open questions in lung cancer screening with CT.

Dose sensitivity of three phantoms used for quality assurance in digital mammography

Technical quality assurance (QA) is one of the key issues in breast cancer screening protocols. For this QA task, three different methods are commonly used to assess image quality. The European protocol suggests a contrast-detail phantom (e.g. the CDMAM phantom), while in North America the American College of Radiology (ACR) accreditation phantom is proposed. Alternatively, phantoms based on image quality parameters from applied system theory such as the noise-equivalent number of quanta (NEQ) are applied (e.g. the PAS 1054 phantom). The aim of this paper was to correlate the changes in the output of the three evaluation methods (CDMAM, ACR and NEQ) with changes in dose. We varied the time-current product within a range of clinically used values (40-140 mAs, corresponding to 3.5-12.4 mGy entrance dose and detector dose of 32-110 μGy). For the ACR phantom, the examined parameter was the number of detected objects. With the CDMAM phantom we chose the diameters 0.10, 0.13, 0.20, 0.31 and 0.5 mm and recorded the threshold thicknesses. With respect to the third method, we evaluated the NEQ at typical spatial frequencies to calculate the relative changes in NEQ. Plotting NEQ versus dose increment shows a linear relationship and can be described by a linear function (with R > 0.99). Every manually selectable current- time product increment can be detected. With the ACR phantom, the number of detected objects increases only in the lower dose range and reaches saturation at about 9 mGy entrance dose (80 μGy detector dose). The CDMAM can detect a 50% increase in dose over the examined dose range with all five diameters, although the increases of threshold thickness are not monotonous. We conclude that an NEQ-based method has the potential to replace the established detail phantom methods to detect dose changes in the course of QA.

Sonographic detection of breast microcalcifications - technically feasible and clinically relevant?

Dieses Heft von Ultraschall in der Medizin – European Journal of Ultrasound – (UiM-EJU) hat unter anderem 4 Arbeiten zum Thema Mammasonografie zum Inhalt 1 2 3 4. Neben der pränatalen Sonografie, die ein Schwerpunkt im Heft 03/2012 von UiM-EJU 5 6 7 8 9 10 ist, und neben der Kontrastmittelsonografie, der ein eigener Supplementband 2012 gewidmet ist 11 12 13 14 15 16 17 18, liegt die Mammasonografie unter den angenommenen Manuskripten in UiM unter den „Top 3“ der sonografischen Subspezialitäten. Grund genug daher, auch diesmal das breite Spektrum der technischen US-Applikationen und klinisch-sonografischen Aspekte der Mammasonografie in einem Editorial zu beleuchten 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58.

Dabei sollen 2 Aspekte und Arbeiten besonders beachtet werden, welche die US-gezielte interventionelle Abklärung des Lymphknotenstatus bei Patientinnen mit Mammakarzinom 1 und die sonografische Detektion von Mikrokalk 2 zum Inhalt haben.

I. Gruber et al. fassen in einem ausführlichen Review 1 den derzeitigen Stand der sonografischen Technik und klinischen Bedeutung der interventionellen Abklärung (gemeint ist die US-gezielte Gewebediagnose) sonografisch suspekter axillärer Lymphknoten zusammen. Dieses Thema war vor relativ kurzer Zeit auch Inhalt eines Editorials 41, wobei auf eine Arbeit zur dynamischen Kontrastmittelsonografie in der Unterscheidung benigner–maligner Lymphknoten bei Patientinnen mit Mammakarzinom Bezug genommen wurde 42. Denn, so eine der damaligen Schlussfolgerungen: „Finden wir nach sonografischen Kriterien suspekte axilläre Lymphknoten, dann sollten wir diesen Verdacht feingeweblich (bevorzugt Stanzbiopsie) abklären 41. Die Treffsicherheit der Biopsie ist hoch, die Komplikationsrate gering und der positive Nachweis von Lymphknotenmetastasen vermeidet die unnötige Durchführung einer Sentinellymphknoten-Entfernung (SLNE)“ 41. Die vorliegende Übersicht beleuchtet nun die relevante Literatur zur Gewebediagnose suspekter axillärer Lymphknoten 1 beim Mammakarzinom und schlägt einen Stufenplan zur prätherapeutischen Lymphknotenabklärung mittels sonografisch gesteuerter minimalinvasiver Interventionen vor. Dieser Algorithmus sieht zunächst die Anwendung einer Feinnadelaspiration (FNA, Nadeldurchmesser 20G) vor, bei inkonklusivem Ergebnis der FNA dann die Durchführung einer US-gezielten Stanzbiopsie, die bei gleich hoher Spezifität wie die FNA (beide Methoden 100 % oder nahe 100 %) eine etwas höhere Sensitivität aufweist. Die Autoren führen weiter korrekt aus, dass sowohl eine FNA als auch eine Stanzbiopsie mit für Malignität negativer Zytologie bzw. Histologie einen axillären Lymphknotenbefall keinesfalls „ausschließen“ kann. Daher ist der hohe positive Vorhersagewert beider Techniken relevant, der bei positivem Befund für Malignität die SLNE vermeidet. Bei für Malignität negativem Biopsieergebnis sollte die SLNE durchgeführt werden 1. Die in dieser Übersicht gemachte Unterscheidung FNA-Stanzbiopsie ist sicher diskussionswürdig, im klinischen Alltag wird aber sicher individuell (Größe des suspekten Lymphknotens, seine Beziehung zu Gefäßen, Erfahrung des Untersuchers, Verfügbarkeit zytologisch kompetenter Pathologen) zwischen FNA und Stanzbiopsie entschieden werden.

Spannend ist die Originalarbeit von T. Fischer et al. 2, welche die sonografische Mikrokalkdetektion in der Mamma zum Inhalt hat. In einer In-vitro-Versuchsanordnung verglichen die Autoren die sonografische Detektion von Mikrokalk in 105 Mamma-Stanzzylindern (unter Verwendung von Frequenzcompounding, Tissue Harmonic Imaging und einer gerätespezifischen software [EMD – easy microcalcification detection, MicroPureTM, Toshiba, Otaware, Japan]) mit der Präparatradiografie und Histologie 2. Während im konventionellen B-Bild keine Darstellbarkeit der Mikroverkalkungen möglich war, konnte Mikrokalk mit EMB erkannt werden, der Mittelwert der Zahl der Verkalkungen im US war 3,5 ± 3,1, der in der Radiografie 4,3 ± 4,8; der Unterschied war nicht signifikant. Allerdings war die Mammografie dem US im Vergleich zum „Goldstandard“ Histologie in der Erkennung von Mikrokalk signifikant überlegen 2. Und subjektiv, schreiben die Autoren, waren besonders feingranuläre Kalkgruppen („cluster“) mit mehr als 14 Einzelverkalkungen mammografisch besser als sonografisch visualisierbar 2. Auch die Größenbestimmung der Verkalkungen war im US problematisch 2. Die Einstellungsstufe 1 (Farbe blau) der EMB-Software wurde gegenüber anderen Einstellungen am angenehmsten empfunden und zeigte geringere Artefakte 2.

Ist es also an der Zeit, hochauflösenden US mit modernen US-Techniken zur Verbesserung der räumlichen Auflösung und dedizierter Software statt der Mammografie einzusetzen, um auch die etwa 40 % der nicht palpablen Karzinome mit US zu erfassen, bei denen Mikrokalk das alleinige oder weitgehende Malignitätskriterium ist? Nein, lautet die Antwort, und die Autoren der Studie 2 schreiben auch in der Einleitung sehr richtig, dass „die Mammografie der Goldstandard in der Detektion, Charakterisierung und Lokalisation von Mikrokalk bleibt“.

Warum ist das so?

Technische US-Weiterentwicklungen verbessern die Erkennbarkeit von Mikrokalk 2 32 34 52. Mikrokalk wird mammografisch nach BI-RADS 59 in „typisch gutartig“, „mittelgradig suspekt“ (amorphe oder unscharfe Verkalkungen) und „höhere Wahrscheinlichkeit für Malignität“ (pleomorphe oder heterogene Verkalkungen [granulär], feine, lineare oder feine, lineare, verästelte Verkalkungen) eingeteilt, wobei das Verteilungsmuster (gruppiert, linear, segmental, regional, diffus/verstreut) ein wichtiger Parameter der Charakterisierung ist. Die BI-RADS-analogen DEGUM-US-Kriterien aus 2006 58 unterscheiden Makrokalk (> 0,5 mm) von Mikrokalk, innerhalb und außerhalb einer Läsion. Das ACR-BI-RADS-US-Lexikon 60 differenziert zwischen Makrokalk und Mikrokalk, letzterem außerhalb und innerhalb eines Herdbefunds. Hier werden hyperechogene Punkte in einem echoarmen Herdbefund als „auffällig“ gewertet 60. Das heißt, die Morphologie der Mikroverkalkungen (und damit die Charakterisierung benigne–maligne) ist im US nicht möglich, was auch die vorgestellte Studie 2 an Mammastanzen zeigt. Es ist auch zu bedenken, dass nicht alle „echoreichen Punkte“ im Mamma-US Mikroverkalkungen sind, sondern dass Kollagenfasern und andere Veränderungen Mikrokalk vortäuschen können 37.

Auch wenn in vitro Mikrokalk mit US erfasst werden kann, ist das Ergebnis nicht auf eine „Routine-US-Untersuchung“ der Mamma übertragbar. Manche Autoren meinen, dass insbesondere Kalk in echoarmen Läsionen und dilatierten Milchgängen gut erkannt wird 19 20 21 23 24 25 27 35, während isolierter Mikrokalk ohne umgebenden Herdbefund viel schlechter erfasst werden kann; dazu gibt es auch wenig Literatur. H. Madjar et al. 44 fanden in ihren 21 primär sonografisch entdeckten Karzinomen (von 86 Karzinomen gesamt) lediglich ein duktales Carcinoma in situ (DCIS), die übrigen Karzinome waren invasiv duktal (n = 16), invasiv lobulär (n = 3) und invasiv tubulär (n = 1), also Herdbefunde mit einem mittleren Durchmesser von 12,6 mm. Daher ist der US zum Screening von suspekten Mikroverkalkungen ungeeignet, da etwa 25 % aller im mammografischen Screening gefundenen Karzinome DCIS sind 28. US wird im österreichischen Screeningprogramm (die Einführung ist für 2013 geplant) auch nicht zur Mikrokalkdetektion, sondern zur Verbesserung der Detektion von Karzinomen bei mammografisch dichter Brust (ACR Grad 3 und 4) eingesetzt werden 26 61.

Die meisten Studien zum Thema US und Mikrokalk untersuchten daher auch gezielt bereits mammografisch detektierte und bekannte Mikroverkalkungen 19 21 22 23 24 25 27 30 32 33 34 35 37 38, wobei übereinstimmend vor allem der Vorteil einer US-gezielten Stanz- oder Vakuum-Biopsie des Mikrokalks angeführt wird, wenn es gelingt, die mammografisch sichtbaren Mikroverkalkungen auch sonografisch zuzuordnen. Das Thema ist sicher weiter in Diskussion, und auch sehr schlechte Ergebnisse für die US-Detektion von mammografisch sichtbarem Mikrokalk wurden berichtet 38. Auf der anderen Seite des Spektrums steht eine rezente Publikation, die den sinnvollen Einsatz von US (zusammen mit der Mammografie) bei DCIS im Rahmen der brusterhaltenden Operation beschreibt 36.

Der letzte Satz in der Arbeit von T. Fischer et al. lautet: „Die Mammografie bleibt der Goldstandard zur Detektion von Mikrokalk“ 2. Dieses Statement könnte bald durch die überlagerungsfreie digitale Tomosynthese der Brust falsifiziert werden. Wir sollten aber das Erscheinungsbild von Mikrokalk im US innerhalb und außerhalb von Herdbefunden kennen, um US vor allem in der US-geleiteten Gewebediagnose dieser Veränderungen schonend für die Patientinnen und ökonomisch einsetzen zu können.

Radiologische Diagnostik der Lungentuberkulose

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.

Gluteal injection site granulomas: false positive finding on FDG-PET in patients with non-small cell lung cancer

Positron-emission-tomography (PET) with fludeoxyglucose F-18 ([(18)F] fluoro-2-deoxy-D-glucose, FDG) has become an established imaging modality in patients with lung cancer for mediastinal lymph node staging and the detection of extrathoracic metastases. However, tracer accumulations are not limited to malignant tissue but are also found in muscles and benign inflammatory processes. We report on two patients with lung cancer in whom FDG-PET revealed suspicious tracer accumulations in the buttock. Ultrasound (US) revealed a hyperechogenic nodule with poorly defined margins in both patients. On specific inquiry both patients reported on repeated "intramuscular" gluteal injections. Histology after US guided biopsy showed an accumulation of macrophages within fibrous tissue, compatible with injection site granulomas. The reported cases underline that (18)F-FDG may accumulate in benign, ancillary processes that have to be distinguished from distant metastases. Tracer accumulation in the buttocks may be highly suggestive of injection site granulomas, especially if the patient reports on "intramuscular" injections. In this setting, US is a widely available modality to distinguish metastasis from adipose tissue necrosis.

[Evaluation of a portable ultrasound device immediately after spiral computed tomography]

AIM

Portable ultrasound devices are an established diagnostic tool. They are frequently used in trauma and emergency wards. Multidetector computed tomography (MD-CT) represents the standard imaging method for many diagnostic questions. In some patients, however, there are findings on CT which remain unspecific. In these cases, a complementary ultrasound (US) examination may help to obtain a specific diagnosis. Aim of this study is the evaluation of a portable US device immediately after MD-CT for further work-up of unclear lesions.

METHODS

257 MD-CT examinations were performed during a 3-week period. A portable US device (LogiqBook, GE Medical Systems, Solingen, Deutschland) was used when a lesion found at MD-CT remained unclear. Time intervals between CT and US as well as US examination times were registered.

RESULTS

US was used in 23 of 257 CT examinations (8.9 %), but 3 of these examinations had to be terminated due to unfavourable US conditions. Thus, there remained 19 questions regarding parenchymal lesions in the liver (n = 13), kidney (n = 1) or suprarenal gland (n = 2). Pleural empyema was suspected in the 4 remaining patients. In all of the 20 patients, US helped to narrow down the differential diagnosis of MD-CT results. The mean time span between CT and US was 2.5 min, and the mean US examination time was 6.5 min.

CONCLUSION

Portable US immediately after MD-CT helps to narrow down the differential diagnosis of hepatic and pleural lesions with minimal additional effort in time and organization.

["Disappearance" of retroperitoneal vessels - a case report]

We report the ultrasound findings in a case of pneumo-retroperitoneum. The 74-year-old patient was admitted because of severe dyspnoea. Chest X-ray revealed a left-sided pleural effusion, and a drainage was performed. Later on the patient for the first time complained about severe pain in the lower abdomen. Ultrasound of the abdomen was performed. Sonographically, it was remarkably difficult to obtain images of the right kidney and the retroperitoneal vessels, as massive reverberation artifacts in the retroperitoneum were present. Plain radiography of the abdomen revealed free retroperitoneal and intraabdominal gas. At laparotomy a perforated diverticulitis of the sigma was discovered. Postoperative follow-up was uneventful, but the recurrent pleural effusion was later confirmed to be due to a malignant mesothelioma. This article discusses the characteristic sonomorphologic features of pneumo-retroperitoneum and its differential diagnosis. Although free retroperitoneal air is a rare condition, it is crucial for the examiner to be aware of the characteristic sonographic findings in order to initiate appropriate therapy.

Inferior mesenteric artery as outflow vessel in endoleaks after abdominal aortic stent-graft implantation: 36-month follow-up CT study

The aim of this study was to determine the role of the inferior mesenteric artery (IMA) as an outflow vessel in endoleaks after abdominal aortic stent-graft implantation. Forty consecutive patients in whom abdominal aortic aneurysms (AAA) had been treated with stent-graft implantation were evaluated retrospectively. Spiral-CT examinations and angiographies up to 36 months after implantation were analyzed. In 29 (73%) of the 40 patients the IMA was perfused prior to implantation. In 5 (17%) of these 29 cases, the artery remained perfused after stent-graft insertion. In all 5 cases, endoleaks were detected; however, in none of these cases was the IMA the sole cause. In 3 of these 5 cases, angiography showed antegrade flow in the IMA. Implantation of extension stent grafts caused thrombosis of the aneurysmal sac and the IMA. There were no secondary endoleaks caused by the IMA at the 36-month follow-up examinations. The majority of IMAs which are patent prior to intervention occlude after successful stent-graft insertion. In cases with leaks and angiographically proven antegrade flow in the IMA, implantation of extension stent grafts is a therapeutic alternative to embolization. In this study, the IMA was not responsible for secondary endoleaks.

Treatment of a malignant stenosis of the corpus of the stomach with a self-expanding stent

In a 50-year-old man, a self-expandable stent was implanted under fluoroscopic guidance to treat symptoms of an inoperable carcinoma of the corpus of the stomach. Foreshortening of the stent necessitated implantation of a proximal extension stent 5 weeks later. Secondary symptoms of advanced stage of the disease negatively influenced clinical success of the procedure, although free passage through the stents was achieved. We conclude that stent implantation for palliation of a carcinoma of the corpus of the stomach seems to be a viable method. The operator has to be aware of the special limitations and problems associated with the procedure.

[Spontaneous healing of retroperitonea fibroasis after successful therapy of sigmoid carcinoma]

In a 64 year old man sigma cancer was diagnosed unexpectedly during an operation for retroperitoneal fibrosis (histologically benign fibrosis), that had caused unilateral hydronephrosis. In the following hemicolectomy this tumor of the colon turned out to be a medium high grade adenocarcinoma (tumor staging pT2, pN1, DUKES C). Chemotherapy with 450 mg/m2 5-FU once a week and a concomitant therapy with laevamisol was added for 6 months. Computer-tomography revealed a significant reduction of the retroperitoneal masses already before induction of chemotherapy. One year after termination of chemotherapy retroperitoneal fibrosis was no longer detectable. The course of events makes us assume that the retroperitoneal fibrosis of our patient was paraneoplastic and therefore completely reversible by successful removal of the underlying tumor.

Amplitude-coded color doppler: clinical applications

Amplitude-coded color Doppler sonography (ACD) has become an useful adjunct to gray-scale US and conventional color Doppler sonography (CD) for the assessment of vascular diseases and pathologic conditions that might affect or alter tissue vascularization or perfusion. Basically, all US units that generate conventional color Doppler information through autocorrelation technique are capable of displaying ACD. This technique is also referred to as power Doppler, amplitude-mode color Doppler US, color Doppler energy (CDE), or US angiography. Amplitude-coded color Doppler sonography has already emerged as a valuable adjunct to conventional CD, particularly for evaluating flow in parts of the body where CD signal is weak because of slow flow, small blood vessels, or both.

Differentiation of benign and malignant tumors of the parotid gland: value of pulsed Doppler and color Doppler sonography

To establish criteria for the differentiation of benign and malignant tumors of the parotid gland using color Doppler sonography (CDS) and pulsed Doppler sonography (PDS) we examined 37 patients with parotid tumors by gray-scale ultrasound, CDS, and PDS. Tumor vascularization displayed by CDS was graded subjectively on a 4-point scale (0 = no vascularization, 3 = high vascularization). From the Doppler spectrum, the highest systolic peak flow velocity, the resistive index (RI), and the pulsatility index (PI) were calculated. There were 11 malignant and 26 benign tumors. Tumor vascularization by CDS was grade 0 or 1 in 88.5% of benign lesions, whereas it was grade 2 or 3 in 82% of malignant lesions (P < 0.0001). The highest systolic peak flow velocity was statistically significantly higher in malignant lesions than in benign lesions. Using a threshold systolic peak flow velocity of 25 cm/s, sensitivity was 72% and specificity was 88% for the detection of a malignant tumor. Evaluation of tumor vascularization by CDS and PDS cannot differentiate between benign and malignant parotid tumors with certainty. However, high vascularization and high systolic peak flow velocity in tumor vessels should raise the suspicion of malignancy, even if tumor morphology on gray-scale sonography indicates a benign lesion.

Amplitude-coded colour Doppler sonography: physical principles and technique

The purpose of this review is to help in understanding the principles of a new ultrasound Doppler technique called amplitude-coded colour Doppler (power) mode. All pertinent information available in the literature on the physical principles of this technique has been revised in order to give a detailed survey. The main components and the key characteristics of this mode are discussed together with illustrative examples. In addition, work-in-progress developments and other future aspects of US imaging in combination with this technique are discussed.

Conflicting results of ileoscopy and small bowel double-contrast barium examination in patients with Crohn's disease

BACKGROUND AND STUDY AIMS

Ileoscopy has become a routine procedure for the diagnosis of Crohn's disease of the terminal ileum. The aim of this study was to compare the diagnostic accuracy of small bowel barium examination with that of ileoscopy.

PATIENTS AND METHODS

In a retrospective study the two methods were compared in 55 patients with Crohn's disease. First, routine radiology reports and second, reevaluation of the small bowel barium study by gastrointestinal radiologists with scoring of examination quality were compared with the results of ileoscopy.

RESULTS

Using routine radiology reports, 66% sensitivity and 82% specificity were reached for inflammatory changes of the terminal ileum by small bowel barium study. Sensitivity and specificity increased to 68% and 91% with double reading by experienced radiologists. Disagreement between endoscopic and radiologic results changed from 31% to 27% and were mainly because of false-negative barium studies. Sensitivity and specificity of barium studies were influenced by the quality of the examination with a sensitivity of 91% and specificity of 100% when the quality was good.

CONCLUSIONS

In patients in whom the terminal ileum is successfully intubated, ileoscopy is superior to barium examination in the evaluation of Crohn's disease of the terminal ileum. Results of the barium study were strongly influenced by the quality of the examination.

[Radiologic evaluation of Crohn disease]

PURPOSE

This paper discusses the role of different imaging modalities in the diagnostic work-up of Crohn's disease (CD).

METHODS

We present a concept, which emphasizes different diagnostic aspects with regard to primary diagnosis, follow-up and assessment of complications of CD. The most effective imaging approach to various diagnostic problems of CD is discussed in detail.

DISCUSSION

With regard to the primary diagnosis barium studies should contribute to differentiate between CD and ulcerative colitis. Beyond that, these studies should evaluate location and extent of disease. During the follow-up bowel sonography provides staging of disease and enables the detection of complications at an early stage. CT is a valuable tool in the preoperative assessment of complications, such as fistulae and abscesses.

[Present views on indications and techniques in kidney biopsy]

In the current situation there are available many data on renal biopsies. Nevertheless a lot of questions remain unanswered the effectivity and safety of the technique of renal biopsy. We demonstrate the current insight on indications, contraindications and the technique of renal biopsy. A number of studies in recent years have found the biopsy to be of major value in patients with high levels of proteinuria, those with signs of systemic disease, and certain patients with acute renal failure. We demonstrate our technique of localization of the kidney, with marking of location and depth. Continuous ultrasonic guidance is used as the needle is inserted into the kidney. Biopsy of kidney is performed by an automated technique with Biopty instrument for its safety and better effectivity. (Tab. 1, Fig. 6, Ref. 13.)

Spiral CT evaluation of deep venous thrombosis

Spiral CT venography is a technical innovation in vascular imaging that can optimize vessel contrast in the deep venous system and, therefore, is an accurate diagnostic tool to detect deep venous thrombosis. Compared with conventional venography, the amount of contrast material can be reduced by 80%. While using spiral CT as the primary imaging technique for the detection of pulmonary embolism, the cause of embolism can be evaluated within a short period of additional imaging time without further patient mobilization. This review outlines fundamental techniques in spiral CT venography and summarizes our clinical experience at Vienna University Medical Center.

[Diagnostic imaging after liver transplantation]

INTRODUCTION

Orthotopic liver transplantation (OLT) has become an accepted treatment for end-stage liver disease. However, postoperative complications result in significant patient morbidity and mortality. Early detection and treatment of these complications is therefore of utmost importance.

MATERIALS AND METHODS

We retrospectively reviewed the postoperative complications of the patients who underwent OLT at our institution. Duplex Doppler sonography and cholangiography were the primary imaging modalities in postoperative evaluation of the transplanted liver. Other important techniques were CT, MRI and angiography, which may contribute to a reliable diagnosis of vascular or biliary complications.

RESULTS

Second to primary organ dysfunction, vascular complications are the most frequent cause of graft loss. Thrombosis of the hepatic artery is the most common and most serious vascular complication, with a reported incidence from 4 to 42%. Bile duct sludge, leaks and strictures are frequent complications after liver transplantation, which can contribute to graft dysfunction. Biliary tract complications usually occur within the first 3 months and require interventional radiological or surgical therapy. Since liver transplant recipients undergo immunosuppressive therapy, they are at increased risk of developing late post-transplant malignancies, which are best depicted by US, CT or MRI. However, radiological diagnosis of lympho-proliferative disorder has to be confirmed by liver biopsy.

CONCLUSION

Cholangiography and Duplex sonography are routinely used in the postoperative evaluation of patients with OLT. CT, MRI, and angiography are problem-solving tools in equivocal cases.

Response of untreated stage IV Wilms' tumor to single dose carboplatin assessed by "up front" window therapy

A total of nine children with previously untreated stage IV Wilms' tumor of favorable histology were treated according to the Austrian/Hungarian Wilms' Tumor Protocol 89 and received a preoperative single dose of carboplatin as an "up front" window therapy. The treatment consisted of carboplatin as a single-dose of 600 mg/m2 over 30 minutes on day 1. Response evaluation by chest X-ray, serial CT scans, and sonography was performed on day 22. Investigation of the abdominal tumors revealed seven partial responses (78%), one nonresponse, and one progressive disease with a median tumor volume reduction of 62%. Response of metastases evaluated by CT scans was as follows: four complete remission, four partial response, and one nonresponse. Thrombocytopenia (WHO grade III 1, grade II 2, grade I 2) and leukocytopenia (WHO grade II 1, grade I 5) were the main side effects. No renal or liver toxicity were observed. The overall response rate after a preoperative single-dose of 600 mg/m2 carboplatin in untreated patients with stage IV Wilms' tumor is encouraging and the toxicity acceptable. This data indicate that carboplatin seems to be an additional effective drug in patients with previously untreated Wilms' tumor of favorable histology.

High-dose cyclophosphamide, adriamycin, and vincristine (HD-CAV) in children with recurrent solid tumor

A dose-intensive regimen of cyclophosphamide (140 mg/kg over 2 days), doxorubicin (Adriamycin, 75 mg/m2 over 3 days), and vincristine (1 mg/m2 on days 1, 2, and 3 and 1.5 mg/m2 on day 9) was tested in 18 children and adolescents with poor-prognosis recurrent or refractory solid tumors. Nine were affected by neuroblastoma, 3 by Ewing's tumors, 2 by rhabdomyosarcoma, 2 by synovial sarcoma, 1 by hepatocellular carcinoma, and 1 by osteogenic sarcoma. All enrolled patients were heavily pretreated, including 2 patients after bone marrow transplantation. Forty courses were applied (median, 2). The overall response rate was 33% (2 complete remissions and 4 partial remissions). Responses were obtained in children with neuroblastoma, Ewing's tumors, and hepatocellular carcinoma. Myelosuppression [World Health Organization (WHO) grade IV after all courses] and cardiac toxicity (3 WHO grade I, 5 WHO grade III, and 3 WHO grade IV) were the main side effects. Nephrotoxicity and hepatoxicity were not observed. With further therapy consisting of surgery, radiotherapy, and high-dose chemotherapy [cisplatin, carboplatin/etoposide (VP16), or ifosfamide/VP16 with or without autologous stem cell reinfusion after conditioning with melphalan/VP16/carboplatin], 3 complete remissions and 5 very good partial remissions were obtained. Ten of 18 patients are alive after a median follow-up of 16 months.

MR-appearance of the pituitary gland before and after resection of pituitary macroadenomas

Pituitary macroadenomas can cause severe compression and displacement of the pituitary gland. This study was undertaken to determine the value of contrast administration for the detection of the pituitary gland in patients with pituitary macroadenomas, to evaluate the preoperative location and configuration of the pituitary gland and to describe its postoperative changes after tumour resection. Preoperative and postoperative MR imaging examinations of 30 patients with histologically proven pituitary macroadenomas were retrospectively evaluated. The examinations were performed on a 1.5 T unit, by obtaining T1-weighted sagittal and coronal images after administration of gadopentetate dimeglumine. On preoperative MR images, contrast administration increased the detectability of the anterior lobe from 30% to 80%. Depending on the size and extension of the adenoma, the pituitary gland was displaced to the suprasellar space (53%) and/or deformed to a club-shaped (27%) or sickle-shaped (47%) configuration. In six patients, the sickle-shaped pituitary gland was interposed between the cavernous sinus and the adenoma ('rim-sign'), which was seen only on gadopentetate dimeglumine-enhanced images. In these cases, there was no infiltration of the cavernous sinus at surgery. Postoperatively, descent of the pituitary gland was found in 63%, and reexpansion in 54%. We conclude that contrast administration improves the detectability of the pituitary gland on preoperative MR images, and that the displacement and deformation of the pituitary gland depend on the size, location and extension of the adenoma. Preoperatively, demonstration of the pituitary gland interposed between the cavernous sinus and the adenoma ('rim-sign') is a very useful sign for exclusion of cavernous sinus infiltration, best seen on contrast-enhanced coronal MR images. The normal postoperative changes of the pituitary gland after tumour resection include repositioning and re-expansion.

[Color Doppler ultrasound of kidney transplants. Does the resistance index facilitate diagnosis of chronic kidney failure?]

The retrospective study under report assessed the diagnostic capability of colour Doppler sonography (CDS) with measurement of the resistive index (RI) in the long-term follow-up of patients with renal allografts. 210 CDS examinations were performed in 115 patients. The time since transplantation ranged from 6 months to 22 years. The RI was correlated to laboratory parameters of renal allograft function (serum creatinine, urinary protein levels and serum-cyclosporine). In 97 of 210 examinations, serum creatinine was elevated (> 1.5 mg% or an increase of more then 0.3 mg% within the last 6 months). In 35 out of these examinations RI was > 70%, in 62 RI was < or = 70%. Thus, with a threshold RI of 70%, sensitivity of the RI in the diagnosis of renal allograft dysfunction is 36% and specificity 62%, respectively. There was no significant difference in the RI between examinations of allografts with normal function (68.2% +/- 7.5%) and those with dysfunction (68.5% +/- 8.5%). Furthermore, there was no significant correlation between the RI and any of the laboratory parameters. CDS with calculation of the RI cannot differentiate in the long-term follow-up between allografts with normal function and those with dysfunction.

Quantification of left to right atrial shunts with velocity-encoded cine nuclear magnetic resonance imaging

OBJECTIVES

The purpose of this study was to evaluate the ability of velocity-encoded nuclear magnetic resonance (NMR) imaging to quantify left to right intracardiac shunts in patients with an atrial septal defect.

BACKGROUND

Quantification of intracardiac shunts is clinically important in planning therapy.

METHODS

Velocity-encoded NMR imaging was used to quantify stroke flow in the aorta and in the main pulmonary artery in a group of patients who were known to have an increased pulmonary to systemic flow ratio (Qp/Qs). The velocity-encoded NMR flow data were used to calculate Qp/Qs, and these values were compared with measurements of Qp/Qs obtained with oximetric data derived from cardiac catheterization and from stroke volume measurements of the two ventricles by using volumetric data from biphasic spin echo and cine NMR images obtained at end-diastole and end-systole.

RESULTS

Two independent observers measured Qp/Qs by using velocity-encoded NMR imaging in 11 patients and found Qp/Qs ranging from 1.4:1 to 3.9:1. These measurements correlated well with both oximetric data (r = 0.91, SEE = 0.35) and ventricular volumetric data (r = 0.94, SEE = 0.30). Interobserver reproducibility for Qp/Qs by velocity-encoded NMR imaging was good (r = 0.97, SEE = 0.20).

CONCLUSIONS

Velocity-encoded NMR imaging is an accurate and reproducible method for measuring Qp/Qs in left to right shunts. Because it is completely noninvasive, it can be used to monitor shunt volume over time.

[The technic of adrenal biopsy. Ultrasound versus CT as the guidance method]

Forty-seven needle biopsies of the adrenal glands have been performed under ultrasound or CT guidance. The aim was to clarify the best guidance method, the best approach, the choice of biopsy needle and possible complications. Analysis of the results provided the following answers: 1. A mass in the right adrenal can be biopsied under ultrasound control by a transhepatic approach. Small lesions of the left adrenal are best approached under CT guidance. In these cases a subcostal angled approach is advised. 2. Cutting biopsy needles provide better results than aspiration biopsy needles. 3. The complication rate of adrenal biopsies is very low if thin cutting needles are used.

CT in pancreatic involvement of non-Hodgkin lymphoma

In an attempt to evaluate characteristic CT features of primary pancreatic involvement in non-Hodgkin lymphoma (NHL), scans of 10 patients were reviewed retrospectively and compared to 50 patients with histologically proved different neoplasms of the pancreas. Setting the correct diagnosis of NHL would be essential for planning of treatment and prognosis. CT findings of NHL were characteristic but not specific. Nevertheless, the presence of a homogeneous pancreatic mass with a diameter of 7 cm or more, infiltrating surrounding tissue accompanied by retroperitoneal and/or mesenteric lymphadenopathy strongly suggests NHL. CT-guided needle biopsy can help to establish the diagnosis of pancreatic NHL.

Renal transplant hemodynamics in children: prospective analysis of colour coded versus pulsed Doppler sonography

In 30 children with renal allografts the diagnostic validity of pulsed Doppler (PD) versus colour coded Doppler (CD) sonography was assessed prospectively. 46 PD examinations were performed calculating the resistive index (RI) in the segmental arteries in comparison to 46 CD scans, where renal blood flow throughout the grey-scale image was displayed. In addition, point-spectral analysis with calculation of the RI was also performed on the CD scans. The time for examination ranged from five to ten minutes for the PD and from three to five minutes for the CD study. Concordant findings for the PD and CD technique were generally obtained (normal blood flow pattern on PD-excellent visualization of renal blood flow on CD, reduced or reversed diastolic flow on PD-poor visualization of renal blood flow on CD). There was close correlation of the RI values obtained by the PD and CD scans. CD sonography facilitated point-spectral analysis in shortening the time for examination. The ability to visualize focal hemodynamic alterations provided a higher diagnostic accuracy in comparison to PD sonography.