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More than 100 years ago Max von Laue in Munich discovered that X‑rays can be interpreted not only as X‑ray quanta in a particle picture, but also show a wave character. This property has been used for a long time in basic research (e.g. in crystallography for determining the structure of proteins), but so far has had no application in medical imaging. In the last 10 years, however, very impressive technological progress could be made in preclinical research, which also makes the utilization of the wave character of X‑ray light possible for medical imaging. These novel radiography procedures, so-called phase-contrast and dark-field imaging, have a great potential for a pronounced improvement in X‑ray imaging and therefore, also the diagnosis of important diseases. This article describes the basic principles of these novel procedures, summarizes the preclinical research results already achieved exemplified by various organs and shows the potential for future clinical utilization in radiography and computed tomography.

Reported are indications, techniques and clinical outcome of 45 patients with resection of a primary malignant or aggressive benign tumor of the extremities, reconstructed with an allograft. The goal of this procedure is to achieve a wide resection of the tumor and to reconstruct the defect saving the limb. Bridging the osseous defect, we used an osteochondral allograft (14), intercalary allograft (16), allograft arthrodesis (14) and composite reconstruction (1). There were 3 deep infections, 3 superficial infections, 2 pseudarthrosis and 1 rejection found as complications. After local revision of the infections by allograft explantation and temporary implantation of antibiotic-loaded chains, another allograft could be implanted with success. Using different, individual adapted operative methods and allografts, a broad spectrum of bone defects after resection of bone tumors and, if necessary revisions, can be treated.

The interdisciplinary guidelines at the S3 level on the diagnosis of and therapy for hepatocellular carcinoma (HCC) constitute an evidence- and consensus-based instrument that is aimed at improving the diagnosis of and therapy for HCC since these are very challenging tasks. The purpose of the guidelines is to offer the patient (with suspected or confirmed HCC) adequate, scientifically based and up-to-date procedures in diagnosis, therapy and rehabilitation. This holds not only for locally limited or focally advanced disease but also for the existence of recurrences or distant metastases. Besides making a contribution to an appropriate health-care service, the guidelines should also provide the foundation for an individually adapted, high-quality therapy. The explanatory background texts should also enable non-specialist but responsible colleagues to give sound advice to their patients concerning specialist procedures, side effects and results. In the medium and long-term this should reduce the morbidity and mortality of patients with HCC and improve their quality of life.

ZusammenfassungDer Glomus-caroticum-Tumor gehört zu den nicht chromaffinen Para-gangliomen. Aufgrund der geringen Inzidenz mit 1% im Kollektiv einer gefäßchirurgischen Abteilung wird präoperativ nur in 10-20% der Fälle die richtige Diagnose gestellt. Für das chirurgische Vorgehen ist der frühzeitige Nachweis des Primär- oder Rezidiv-Tumors von entscheidender Bedeutung. Bei fortgeschrittenem Tumor-Stadium, z.B. mit Einbeziehung der A. carotis in den Tumorprozeß, steigt die perioperative Mortalität. Außerdem treten als Komplikation häufig Nervenläsionen durch die chirurgische Tumor-Resektion auf. Diese Kasuistik zeigt die Bedeutung der Somatostatin-Rezeptor-Szintigraphie bei der Differenzierung von Glomus-caroticum-Tumor-Rezidiv und postoperativen Narben, die mit röntgenologischen Verfahren Schwierigkeiten bereiten kann. Bei der hier vorgestellten Patientin bestand klinisch schon seit 2 Jahren ein Rezidivverdacht, der jedoch damals durch MRT und Angiographie nicht verifiziert werden konnte.

Die interdisziplinare Leitlinie der Qualitat S3 zur Diagnose und Therapie des hepatozellularen Karzinoms (HCC) ist ein evidenz- und konsensbasiertes Instrument, um die Diagnostik und Therapie des HCC zu verbessern, da die Diagnostik und Therapie des HCC ein auserst diffiziles Vorgehen erfordert. Es ist die Aufgabe der Leitlinie, dem Patienten (mit Verdacht auf HCC oder nachgewiesenem HCC) angemessene, wissenschaftlich begrundete und aktuelle Verfahren in der Diagnostik, Therapie und Rehabilitation anzubieten. Dies gilt sowohl fur die lokal begrenzte oder lokal fortgeschrittene Erkrankung als auch bei Vorliegen eines Rezidivs oder von Fernmetastasen. Die Leitlinie soll neben dem Beitrag fur eine angemessene Gesundheitsversorgung auch die Basis fur eine individuell zugeschnittene, qualitativ hochwertige Therapie bieten. Mit den erklarenden Hintergrundtexten ist es auch nicht spezialisierten, mitbehandelnden Kollegen moglich, den Patienten uber das Vorgehen der Spezialisten, Nebenwirkungen und Ergebnisse gut zu beraten. Mittel- und langfristig sollen so die Morbiditat und Mortalitat von Patienten mit HCC gesenkt und die Lebensqualitat erhoht werden.

Ziel der Arbeit war es, die Genauigkeit des Bildgebungsverfahren (3D) k-t space broad-use linear acquisition speed-up technique (BLAST) im Bezug auf die Bestimmung der globalen Herzfunktion mit der segmentierten (2D) Steady-State-free-Precession - (SSFP) Sequenz (Referenztechnik) zu vergleichen. Bei jedem Patienten wurde eine segmentierte SSFP- Sequenz mit mehreren Atemanhaltephasen verwendet (eine Schicht pro Atemanhalt). Desweiteren wurden nach einem Trainingscan zwei kt-BLAST 3D-Sequenzen wahrend einer Atemanhaltephase akquiriert: kT1 (26 Schichten pro Atemanhalt) und kT2 (13 Schichten pro Atemanhalt). Folgende linksventrikulare Parameter wurden bestimmt: EF, EDV, ESV und linksventrikulare MM. 3D kt-BLAST erlaubt es, LV Funktionsparameter mit hoher Korrelation zu der Referenztechnik zu bestimmen. Die EF wurde leicht unterschatzt, die LV Masse leicht uberschatzt.

The aim of this study was to determine the value of a combined magnetic resonance imaging (MRI) protocol including steady-state free precession (SSFP) imaging, phase-contrast measurements and contrast-enhanced MR angiography (CE-MRA) for presurgical or preinterventional diagnostic imaging in patients with suspected atrial septum defects.Out of 65 MRI studies of patients with suspected atrial septum defects, 56 patients were included in the study. The atrial septum defects were identified on cine images. Velocity encoded flow measurements were used to determine shunt volumes, which were compared with invasive oxymetry in 24 patients. Contrast-enhanced MRI was used to assess the thoracic vessels in order to detect vascular anomalies. The findings were compared with the intraoperative results.A total of 24 patients with high shunt volumes were treated either surgically (16 patients) or interventionally (8 patients) and 32 patients with low shunt volumes did not require surgical or interventional treatment. The vascular anomaly, which in all cases was anomalous pulmonary venous return, was confirmed by the intraoperative findings. The type and location of atrial septal defects which required treatment, were confirmed intraoperatively or during the intervention. The results of shunt quantification by MRI showed a good correlation with the results of invasive oximetry (r=0.91, p0.0001).A combined MRI protocol including cine SSFP images, velocity-encoded flow measurements and CE-MRA is an accurate method for preoperative and preinterventional evaluation of atrial septum defects.

In contrast to the intramedullary (80%) and intracortical (14%) subtypes, the subperiostal subtype of aneurysmatic bone cysts (sABC) is relatively rare (6%). Females are affected more frequently than males, whereby the diaphysis is predominantly affected and less frequently the metaphysis of long bones as well as the vertebral column. Especially in conventional radiography sABCs can mimic aggressive lesions. Cross-sectional imaging can potentially reduce the wide range of differential diagnoses. Due to typical imaging features magnetic resonance imaging (MRI) is the most valuable modality to reduce the range of possible differential diagnoses. MRI usually presents a multicystic appearance with a hypointense rim of the lesion, contrast-enhancing cyst walls, fluid levels and edema-like changes in the adjacent tissue. In sABCs with solid components the diagnosis cannot be made with confidence and the suspicion must be confirmed by biopsy. The therapy of primary lesions consists of curettage or the complete excision of the sABC and the defects are subsequently filled with spongiosa or bone cement depending on the size of the lesion.

The case of a female Patient with increasing pain and a palpable mass in the right popliteal fossa shows the spectrum of possible differential diagnoses for the radiologist. The diagnosis of a juxtaarticular myxoma made on the interpretation of conventional x-ray and magnetic resonance imaging was finally confirmed by biopsy.

For the better understanding of esophageal motility, the muscle texture and the distribution of skeletal and smooth muscle fibers in the esophagus are of crucial importance. Esophageal physiology will be shortly mentioned as far as necessary for a comprehensive understanding of peristaltic disturbances. Besides the pure depiction of morphologic criteria, a complete esophageal study has to include an analysis of the motility. New diagnostic tools with reduced radiation for dynamic imaging (digital fluoroscopy, videofluoroscopy) at 4-30 frames/s are available. Radiomanometry is a combination of a functional pressure measurement and a simultaneous dynamic morphologic analysis. Esophageal motility disorders are subdivided by radiologic and manometric criteria into primary, secondary, and nonclassifiable forms. Primary motility disorders of the esophagus are achalasia, diffuse esophageal spasm, nutcracker esophagus, and the hypertonic lower esophageal sphincter. The secondary motility disorders include pseudoachalasia, reflux-associated motility disorders, functionally caused impactions, Boerhaave's syndrome, Chagas'disease, scleroderma, and presbyesophagus. The nonclassificable motility disorders (NEMD) are a very heterogeneous collective.

Evaluation of the prognostic value of morphological cardiac parameters in patients with suspected and incidental acute pulmonary embolism (PE) using multidetector-row chest CT (MSCT).2335 consecutive MSCT scans were evaluated for the presence of PE. The arterial enhancement and analysability of pulmonary arteries and the heart were assessed as parameters of the scan quality. The diastolic right and left ventricular short axes (RV (D), LV (D)) and the interventricular septal deviation (ISD) were measured in all PE-positive patients and the echocardiography reports were reviewed. The clinical data assessment included cardio-respiratory and other co-morbidities, systemic anticoagulant therapy (ACT), and the 30-day outcome. Predictors of acute cor pulmonale and the short-term outcome were calculated by univariate and multivariate logistic regressions including odds ratios (OR) and ROC analyses using positive (PPV) and negative predictive values (NPV).90 patients with acute PE were included (36 with clinically suspected PE, 54 with incidental PE). 26 patients had cardio-respiratory co-morbidities. Four patients underwent systemic thrombolysis, 43 underwent anticoagulation in therapeutic doses, 19 underwent anticoagulation in prophylactic doses, and 24 patients did not undergo ACT. 15 of 41 patients had echocardiographic evidence of acute cor pulmonale. 8 patients died within 30 days. The RV (D) was the best independent predictor of acute cor pulmonale (p = 0,002, OR = 9.16, PPV = 0.68, NPV = 1 at 4.49 cm cut off) and short-term outcome (p = 0,0005, OR = 2.82, PPV = 0.23, NPV = 0.98 at 4.75 cm cut off). The RV (D)/LV (D) ratio had a PPV of 0.85 for cor pulmonale.The RV (D) and RV (D)/LV (D) ratio were suitable for identifying patients with acute cor pulmonale and for benign short-term prognosis. Further studies should prospectively address the combined use of CT-morphological and clinical parameters for the prediction of patient outcome.

To optimize contrast agent dose and pulse sequence parameters in order to achieve a maximal T1 enhancement in arthritic knee joints with ultra small superparamagnetic iron oxides (USPIO)-enhanced MRI.Antigen-mediated arthritis was induced in the right knee of nine Sprague Dawley rats. The arthritic knee joint as well as the contralateral normal knee were investigated in a 2 Tesla MR scanner before as well as in short intervals up to 2 h after USPIO injection, using T1-weighted gradient echo (GE) sequences. Three rats each received intravenous injections of the new USPIO SHU 555 C (SH U 555 C, Schering AG, Berlin) at doses of 40, 100 and 200 micromol Fe/kg. Pulse sequence parameters of the GE-sequence were optimized by varying flip angles (alpha) and echo times (TE). Changes in signal intensities (SI) of the arthritic knee and contralateral normal knee were quantified as DeltaSI (%) = /([SIpost - SIpre] / SIpre) x 100 %/ and compared with histopathology.Histology of the arthritic knees demonstrated a marked inflammatory proliferation of the synovium. The USPIO SH U 555 C caused a significant increase in signal intensity of the arthritic joints on T1-weighted MR images (p0.05). This effect was optimized using a flip angle of 60-70 degrees, a minimal TE and a dose of 200 micromol Fe/kg. Visually the contralateral normal knee did not show any USPIO enhancement.Inflammation can be depicted with marked T1 enhancement by the USPIO SH U 555 C using high contrast agent doses and optimized MR pulse sequence parameters.

Modern imaging technology has allowed imaging of the liver to excel in ways not dreamed possible just ten or 15 years ago. It is imperative for radiologists to be aware of new capabilities and opportunities for evaluating liver disease by imaging. Imaging of the liver, similar to other organs, runs the gamut from the detection of anatomic variations and congenital anomalies, visualization of vascular disease, detection, characterization and staging of liver tumors and infections, and evaluation of trauma and post-surgical changes. Differing modalities and the understanding of different imaging techniques, including contrast utilization, is essential to optimize patient diagnoses.

This contribution presents clinical and technical aspects of combining positron emission tomography (PET) and computed tomography (CT) for patients with colorectal tumors and characterization of unclear liver foci. In which manner and for which patients combined PET/CT is superior to PET or CT alone is also discussed. PET/CT can fulfil most prerequisites for imaging in pre- and postoperative management of patients with colorectal tumors and best meets the desire for optimal imaging procedures. Some of the disadvantages encountered in frequently employed CT can be overcome by the combination of PET and CT while increasing both sensitivity in detecting lesions and specificity in their characterization. Questions regarding treatment response offer an opportunity for devising novel study concepts and initiating research on new PET tracers. Although few publications are available, we are of the opinion that the combination of functional and anatomical imaging provided by PET/CT can improve both preoperative management and aftercare. To this end, however, optimum cooperation between practitioners of nuclear medicine and radiology is imperative.

Classic catheter angiography is compared with 3D gadolinium MR angiography for evaluation of the vascular anatomy of the celiac trunk, liver supplying arteries, and the portal venous system. Based on 10 patients, this study shows the value of this new non-invasive method of angiography for the diagnosis of visceral vascular anatomy. For this diagnosis MR angiography is expected to replace conventional angiography in the near future.

Classic catheter angiography is compared with 3D gadolinium MR angiography for evaluation of the vascular anatomy of the celiac trunk, liver supplying arteries, and the portal venous system. Based on 10 patients, this study shows the value of this new non-invasive method of angiography for the diagnosis of visceral vascular anatomy. For this diagnosis MR angiography is expected to replace conventional angiography in the near future.

The purpose of this study was to assess the role of spiral computed tomography (SCT) and magnetic resonance imaging (MRI) in the preoperative work-up of patients with pancreatic carcinoma, regarding local resectability and vascular involvement.A total of 28 patients (19 men and 9 women; mean age 58 years) with known or highly suspected carcinoma of the pancreas were included in this study. All patients prospectively underwent MRI ( +/- gadolinium-DTPA ) and SCT (3-phase examination) as preoperative diagnostic imaging studies, and laparotomy was carried out within 7 days, irrespective of the MRI or SCT findings. SCT and MR studies were reviewed independently by two radiologists, without knowing the results of the surgical exploration. Standardized image analysis was correlated with findings at laparatomy.Laparotomy identified 10 patients to be suitable for surgical resection and 18 pancreatic carcinomas to be unresectable. In 17 of 18 non-resectable carcinomas MRI and SCT were able to obtain correct information about unresectability (sensitivity 94%), in 7 (MRI), resp. 8 (SCT) carcinomas were correctly considered to be resectable (sensitivity 70% of MRI and 80% for SCT). The presence of vascular involvement was depicted by SCT with a sensitivity of 82-100% and 62-100% by MRI. The specificity varied between 85-100% for SCT and 77-100% for MRI.Both MRI and SCT are good techniques for the preoperative work-up of pancreatic carcinomas in order to obtain a correct assessment of local resectability.

Glomus caroticum tumours belong to the non chromaffine paragangliomas. As the incidence is very poor with 1% in the collective of a vascular-surgery department, the correct diagnosis is preoperatively only found in 10-20% of the cases. The early detection of primary- or recurrence-tumour is important for the surgical proceedings. With advanced tumour-stage, i.e. with involvement of the carotid artery in the tumour-process, the perioperative mortality increases. Furthermore nerve lesions following surgical tumour-resection as a complication are more frequent. This case-report point out the importance of the somatostatin-receptor-scintigraphy in the differentiation of glomus caroticum tumour-recurrence and postoperative scar. In our patient the suspicion of tumour-recurrence came up already 2 years ago, but could not be verified by MRT and angiography.

Reported are indications, techniques and clinical outcome of 45 patients with resection of a primary malignant or aggressive benign tumor of the extremities, reconstructed with an allograft. The goal of this procedure is to achieve a wide resection of the tumor and to reconstruct the defect saving the limb. Bridging the osseous defect, we used an osteochondral allograft (14), intercalary allograft (16), allograft arthrodesis (14) and composite reconstruction (1). There were 3 deep infections, 3 superficial infections, 2 pseudarthrosis and 1 rejection found as complications. After local revision of the infections by allograft explantation and temporary implantation of antibiotic-loaded chains, another allograft could be implanted with success. Using different, individual adapted operative methods and allografts, a broad spectrum of bone defects after resection of bone tumors and, if necessary revisions, can be treated.

Die Magnetresonanztomographie (MRT) gewinnt aufgrund ihres hohen Weiehteilkontrastes und durch die Einfuhrung verbesserter Techniken zunehmend an Bedeutung im Bereich der abdominellen Bildgebung. Besonders bewahrt hat sich dieses Verfahren inzwischen bei der Erkennung und Differenzierung von fokalen Leberlasionen. Im Vergleich zu anderen radiologischen Verfahren ist die Bildqualitat jedoch von einer deutlich groseren Anzahl einzelner Faktoren abhangig. Diese lassen sich unterteilen in geratespezifische (Hardware) Komponenten (Feldstarke, Homogenitat des Magnetfeldes, Qualitat der Gradienten- und RF-Spulen u. a.) und Faktoren, die vom Bediener frei einstellbar sind (Art der Pulssequenz, Repetitionszeit, Echozeit, Anzahl der Bildmittelungen, Technik der Artefaktunterdruckung). Daher ist es von entscheidender Bedeutung moglichst optimale Parameter zur Detektion und Differenzierung von Leberlasionen zu definieren um die diagnostische Aussagekraft der MR-Bilder zu optimieren [11, 14, 29].

SPECT has been used in a comparative study with planar bone scintigraphy in 54 patients. Spatial resolution of the method is sufficient to localise the vertebral bodies, the spinous processes, the intervertebral, costotransverse and costovertebral joints. In all patients it was possible to relate the areas of increased uptake to specific anatomical sites of the spine known to be affected in the different conditions. A detailed localisation is rarely possible using planar scintigraphy alone, due to the complex osseous anatomy of the spine. In some patients lesions could be seen only with SPECT. SPECT is an invaluable supplement to planar scintigraphy of the spine.

The effects of pentobarbital anesthesia on the energy metabolism of FSaII and MCaIV foot tumors in mice were studied by 31P MRS. Using an 8.5 T spectrometer, in vivo spectra were obtained in 15 animals before and after pentobarbital anesthesia (0.05 mg/g ip). The average phosphocreatine/inorganic phosphate ratios (PCr/Pi) with and without pentobarbital were similar for both tumor histologies. Effects on individual tumors, however, were greater than 20% in 9/15 animals and greater than 50% in 6/15 animals. Pentobarbital anesthesia increased the variability of tumor intracellular pH, and the phosphomonoester/nucleotide triphosphate (PME/NTP) and nucleotide triphosphate/inorganic phosphate ratios (NTP/Pi). When examining the average in a cohort, pentobarbital anesthesia had no significant effect on the PCr/Pi, PME/NTP, NTP/Pi ratios or the pH. However, approximately equal to 50% of individual tumors do have significant changes in these parameters. The anesthesia-induced variability of tumor energy metabolism may explain the decrease in TCD50 observed in previous studies using multifraction radiation.

A case of infundibular pulmonary stenosis occurring years after a mediastinal radiation for Hodgkin's disease is reported. As far as the literature is known to us, a similar case has not yet been described. It is most likely that the development of the stenosis is due to the radiation therapy, since a murmur was not heard before radiation and a mild stenosis was proved several years after radiation. Now, a high gradient with the typical signs of an infundibular pulmonary stenosis was present. Unfortunately the patient refused the operation. Further possibilities for acquired pulmonary stenosis and cardial complications after mediastinal radiation for Hodgkin's disease will be discussed.

Der klinisch tatige Radiologe sieht das rasche Heraufziehen einer neuen diagnostischen Methode mit gemischten Gefuhlen. Vor allem die exponentiell wachsende Zahl von Firmen, welche NMR-Tomographiegerate produzieren (zur Zeit werden weltweit uber 70 Hersteller genannt), zeigt das riesige Interesse der Industrie und die grosen Erwartungen, die dieser neuen Methode entgegengebracht werden. Im vorangegangenen Beitrag wurden die physikalischen Grundlagen der Methode demonstriert, ich kann daher darauf verzichten und fasse die wesentlichen Punkte noch einmal zusammen: 1. Im Unterschied zur Rontgendiagnostik, wo die Schwachung der Rontgenstrahlung die Kontraste im Bild bedingt, haben wir bei der Kernspintomographie mindestens 4 Parameter (die Relaxationszeiten T1 und T2, die Protonendichte und den Flus), die zum Bildkontrast beitragen, wir haben daher theoretisch eine weitaus hohere Kontrastauflosung und spezifischere Aussagemoglichkeiten bei zur Zeit noch schlechterer raumlicher Auflosung als bei der vergleichbaren Computertomographie. 2. Das bedingt aber eine weitgehende Manipulierbarkeit der Kontraste im Bild je nach angewendeter Technik (Pulssequenz, Feldstarke, Rekonstruktionsmethode). 3. Praktisch bedeutet dies, das wir z.B. Fett von Muskel und Nierenparenchym gut differenzieren konnen, dies aber nur bei gunstiger Wahl der Pulssequenz. Bei ungunstiger Wahl konnen diese Kontraste vollig verschwinden, so das die Organe nicht voneinander getrennt werden konnen. Es konnen aber pathologische Befunde gerade bei dieser, fur die Differenzierung anatomisch normaler Strukturen ungunstigen Pulssequenz, sehr deutlich werden. An Hirntumoren konnten wir dies bereits nachweisen [3]. 4. Ein wesentlicher Vorteil der Methode ist die Moglichkeit der Bilderstellung in allen drei Raumebenen, ohne den Patienten zu verlagern. 5. Ein weiterer Vorteil gegenuber Rontgen-CT ist das Fehlen von ionisierenden Strahlen, so das Verlaufsuntersuchungen von daher problemloser werden.

Superparamagnetic iron oxide (ferrite), a novel, reticuloendothelial cell-specific contrast agent used for magnetic resonance imaging (MRI), was evaluated in the detection of liver and spleen tumors in animal models and in phase I and II clinical trials in 33 patients. The initial results obtained in experimental cancer models showed a dramatic improvement in tumor detection. Our first clinical trials confirmed the experimental results and showed that ferrite-enhanced MRI significantly (p less than 0.05) increases the detection of individual lesions. Furthermore, the threshold of detectable tumor size decreased significantly, to 3 mm, when standard MR spin echo imaging techniques were used.