[Acute aortic diseases. Diagnostic imaging and therapy]. / Akute Aortenerkrankungen. Aktuelle Diagnostik und Therapie.

Diagnostic imaging is crucial in the work-up of acute aortic diseases. Current imaging algorithms enable radiologists differentiating the various entities with subsequent clinically relevant treatment options. Within this educational overview we focus on non-traumatic acute aortic disease. Recent developments of cross sectional imaging are summarized. As for acute aortic disease, we discuss dissections, intramural hematoma, penetrating aortic ulcer, and aortitis. Current treatment options are presented.

[Contrast agents in radiology: current agents approved, recommendations, and safety aspects]. / Kontrastmittel in der Radiologie: Aktuelle Zulassungen, Empfehlungen und Sicherheitshinweise.

The manuscript summarizes current approved contrast media and their indications. Contrast agents that are discussed include iodinated contrast agents, magnetic resonance (MR) contrast agents, and ultrasound contrast agents. Allergic and non-allergic renal adverse events are described. The clinical issue of metformin and the administration of contrast agents are updated. Nephrogenic systemic fibrosis (NSF) is discussed and safety issues of available MR contrast agents are analyzed. The most recent changes in European Society of Urogenital Radiology (ESUR) guidelines are also presented.

[Cerebral vasculitis associated with gemcitabine]. / Zerebrale Vaskulitis unter Gemcitabin.

Neoadjuvant chemotherapy consisting of cisplatin and gemcitabine was given to a 50-year-old woman suffering from transitional cell carcinoma of the bladder. Whereas the first cycle was administered without major side effects, the patient experienced a generalized tonic-clonic seizure and a prolonged cognitive deficit with the second cycle. Magnetic resonance imaging of the brain was consistent with cerebral vasculitis. The short interval between the application of gemcitabine and the neurological deterioration suggests a causal relationship. Although recent reports have linked this drug with leukoencephalopathy and vasculitis in various localizations, this is the first case of cerebral vasculitis associated with gemcitabine.

[Value of MRI in preoperative diagnostics of proximal humeral fractures compared to CT and conventional radiography]. / Wertigkeit der MRT in der präoperativen Diagnostik proximaler Humerusfrakturen vs. CT und konventionelles Röntgen.

PURPOSE: The diagnostic value of X-rays, computed tomography (CT) and magnetic resonance imaging (MRI) for proximal humeral fractures (PHF) was compared in order to test the hypothesis that MRI gives relevant additional information. MATERIALS AND METHODS: In this study 30 displaced PHFs were investigated with X-ray, CT and MRI procedures. Fracture analysis was performed and the diagnostic values of the three methods were compared to each other. In the MRI relevant musculotendinous concomitant injuries and prognostic factors of the head perfusion were also evaluated. RESULTS: In 7 out of 30 PHFs the X-rays did not show the correct number of fragments. The posteromedial metaphyseal extension and the caput-diaphysis angle were measured to be significantly greater in the X-rays than in CT and MRI. Relevant additional information obtained by MRI were 7 out of 30 rotator cuff tears and 11 out of 30 differentiated medial periostal hinges. CONCLUSIONS: X-ray imaging is the basis method for the diagnosis of PHF but needs further multiplanar imaging to demonstrate complete fracture patterns. Imaging of fractures is equally good for MRI and CT and MRI also provides additional therapy-relevant information about the rotator cuff and head perfusion.

Nephrogenic systemic fibrosis.

Nephrogenic systemic fibrosis (NSF) is a relative new disease affecting predominantly patients with severely impaired kidney function. Strict adherence to a concordant clinical and pathological definition has allowed for careful separation of this entity from other fibrosing disorders, leading eventually to the realization that gadolinium based contrast agents were closely associated with its onset. Gadodiamide and similarly unstable Gd-CA should therefore not be used in patients with renal insufficiency. The clinical symptoms of NSF vary considerably from patient to patient. NSF should be suspected in renal failure patients presenting any possible NSF symptom appearing in the weeks after Gd-enhanced MRI. Suspected cases should have a skin biopsy taken from an affected region for the histological confirmation or rejection of the diagnosis. There are no established curative treatments to NSF patients. Prevention is the only alternative. Guidelines for the daily routine seem to be the right way. When NSF is identified the primary goal is reversal of underlying renal failure or renal transplantation. In addition, use of physical therapy and pain control is mandatory. One of the best news in late 2007 is the decreasing rate of newly detected NSF cases. In the case this development continues, NSF may become an historical disease in the near future.

[Effect of additive fiber cerclage of the rotator cuff in angle-stable plate-stabilized proximal humeral fractures: a biomechanical study of human shoulder specimens]. / Die additive Zuggurtung der Rotatorenmanschette bei der winkelstabilen Plattenosteosynthese am proximalen Humerus : Eine biomechanische Studie am humanen Schulterpräparat.

OBJECTIVE: Can additive fiber cerclage (FC) reduce secondary displacement in unstable 3-part proximal humeral fractures stabilized by angle-stable plates? Is there any effect of different head screw configurations? METHOD: An unstable 3-part fracture model of the humeral head was developed by preserving the rotator cuff in 24 paired, osteoporotic shoulder specimens. 6 pairs were stabilized by PHILOS plates, and 6 others by HSP. Each left shoulder received FC. 4 groups arose (n=6): I) HSP with FC, II) HSP without FC, III) PHILOS plate with FC, and IV) PHILOS plate without FC. 4 physiological load cases were simulated by a robot-assisted shoulder simulator. Using real-time analysis, interfragmentary motion was measured. RESULTS: Matched-pair analysis of the groups with FC vs. those without FC showed no significant differences in motion at gap I (greater tuberosity head) or II (subcapital) in any load case, apart from interior rotation in groups III and IV at gap II; in these, motion was greater without FC. No differences were seen with different head screw configurations in any load cases. CONCLUSIONS: In cases of anatomical reduction and optimally placed implants, FC did not show an additional stabilizing effect in the unstable 3-part fracture model. Different head screw configurations did not influence stability.

Off-label use of contrast agents.

When contrast agents are approved, the label describes the approved indications and particular circumstances of use such as age, organ function or pregnancy. The use of contrast agents outside their labelled indications is increasing, namely with contrast agents used for MRI. The aim of this paper is to improve the knowledge about this topic. The basis for off-label use is the physician's prerogative, which finds its basis in the "Declaration of Helsinki". Off-label use is allowed under special conditions and might be even the medical state of the art. The necessity for off-label use will continue to increase for MR-contrast agents, as the regulatory requirements for approval of new indications continuously increase, and clinical trials for registration purposes are quite costly and time consuming. As a consequence, manufacturers will concentrate on clinical studies for the essential indications.

[Peripheral arteries]. / Periphere Arterien.

Peripheral arterial disease is a main cause of morbidity in industrialised countries. It chiefly affects older people. The most common causes are atherosclerosis and vasodilatatory abnormalities. In the presence of unexplained leg symptoms, peripheral arterial disease can be diagnosed or ruled out by non-invasive diagnostic methods such as history, clinical examination and the measurement of ankle and brachial artery pressure by Doppler ultrasound, as well as by calculating the ankle brachial index. Colour coded duplex sonography, computer tomography angiography, magnetic resonance angiography and arteriography are the imaging modalities used. Current diagnostic strategies are analysed for the different peripheral artery diseases.

[Imaging of aortic disease]. / Diagnostik von Erkrankungen der Aorta.

Diseases of the aorta are imaged using different modalities according to the cause and clinical situation. Current imaging strategies for the clinically most pertinent aortic diseases are analysed. These disease entities may be differentiated into congenital, acquired and inflammatory diseases. Traumatic and non-traumatic aortic aneurysms and dissections are emphasised in context with endovascular treatment options and subsequent follow-up.

Diagnosis and follow up of aortitis in the elderly.

OBJECTIVES: To evaluate the correlation of MRI and [(18)F]FDG-PET scans with the clinical course and inflammatory markers in patients with aortitis. METHODS: Eight patients with aortitis presenting with unspecific GCA-like symptoms were examined. Aortitis was diagnosed and followed up by [(18)F]FDG-PET and MRI. The aorta was divided into three vascular regions (ascending aorta, aortic arch, and descending aorta) to localise the aortic inflammation and compare both imaging techniques. RESULTS: were correlated with clinical and laboratory examinations. RESULTS: At diagnosis, 20/24 vascular regions from eight patients were positive by [(18)F]FDG-PET scan and 15/21 aortic regions by MRI. Patients were treated with corticosteroids and followed up for a mean (SD) of 13.3 (4.7) months. In [(18)F]FDG-PET, 11/20 (55%) initially pathological aortic regions returned to normal in the follow up examination, which correlated closely with the clinical and laboratory follow up examination. Conversely, in MRI, 14/15 initially affected vascular regions were unchanged. CONCLUSIONS: [(18)F]FDG-PET and MRI are both effective techniques for detecting early aortitis and have a high correlation with laboratory inflammatory measures. However, during the follow up examination, [(18)F]FDG-PET uptake decreased in line with the clinical symptoms and inflammatory serum markers, whereas MRI scans gave more static results.

[Contrast agents in MRT. Substance, effects, pharmacology and validity]. / Kontrastmittel in der MRT. Substanzen, Wirkungen, Pharmakologie und Zulassung.

The use of intravenous contrast agents in magnetic resonance imaging (MRI) has become well established clinical practice. Contrast agents provide additional information in many applications. Gadolinium chelates constitute the largest group of MR contrast agents and are considered to be safe. Different groups of contrast agents are established for clinical application: low concentrated gadolinium chelates, high concentrated gadolinium chelates, superparamagnetic iron oxide particles and hepatobiliary contrast agents. The review discusses the clinical applications and the safety issues involved with administration of intravenous contrast agents in MR imaging. Several approaches of intravascular or blood pool agents are also presented.

[Magnetic resonance imaging as the primary diagnostic method for ectopic discharging ureteral insertion of a dysplastic kidney]. / Kernspintomographie als Primärdiagnostik ektop mündender Harnleiter bei dysplastischer Niere.

Ectopic ureters associated with dysplastic kidneys remain a diagnostic dilemma. Ultrasound, endoscopy as well as intravenous urography do not always show correct urinary tract morphology and function. We report the case of a 6-year-old girl with continuous urine dribbling to demonstrate the diagnostic value of MR urography.

[Contrast-enhanced MR angiography of the arterial and portovenous system of the liver with varying concentrations of contrast medium]. / Kontrastmittel-gestützte 3D-MR-Angiographie des arteriellen und portalvenösen Gefässsystems der Leber mit unterschiedlicher KM-Konzentration.

PURPOSE: To evaluate the diagnostic value of a higher concentrated contrast medium (gadobutrol) for contrast-enhanced MRA of the hepatic arteries and portovenous system. MATERIALS AND METHODS: The examinations were performed on a 1.5-Tesla whole body imaging system (Magnetom Symphony Quantum, Siemens) with a 30-mTesla/m gradient field strength using a phased-array body coil. A 3D FLASH sequence (TR/TE/FA 3.88 ms/1.44 ms/25(3)) was used imaging the hepatic arteries and portovenous system after determination of the circulation time. The study included 50 patients, with 25 patients (group 1) injected with 0.2 mmol Gd-GTPA/kg body weight and 25 patients (group 2) injected with 0.1 mmol gadobutrol/kg body weight. The signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) were calculated for both groups. The image quality was graded by three radiologists on a 5-point scale. RESULTS: The highest SNR was measured in group 1, with no statistically significant differences of the SNR in the abdominal aortal, coeliac trunk and common hepatic artery. CNR was also similar in both groups. Likewise, portal, superior mesenteric and splenic veins showed no statistically significant differences. All cases were found to have a good image quality. CONCLUSION: For MRA of the hepatic arteries and the portal veins, the higher concentrated Gd-DTPA contrast medium gadobutrol can be used at half the dosage recommended for the standard Gd-DTPA contrast medium.

MRI in the evaluation of müllerian duct anomalies.

OBJECTIVE: Müllerian duct anomalies (MDAs) result from nondevelopment or nonfusion of the müllerian ducts and occur in 1-5% of women. Accurate diagnosis of the various subtypes is of great importance as MDAs are frequently associated with a broad variety of clinical symptoms. Recently, evidence arose that MRI might play a major role in diagnosis of MDAs. We present four cases of diverse subtypes of MDAs and the corresponding MRI findings. MATERIALS AND METHODS: Patients (n = 4) with clinical suspicion of MDAs were examined with MRI. Coronal and transaxial T1- and T2-weighted images were acquired. Diagnosis was made and patients were grouped according to the American Fertility Society's classification. Patients underwent laparoscopy or laparotomy in order to confirm the diagnosis. RESULTS: MRI revealed MDAs in all patients. In detail, one patient was diagnosed with hypoplastic uterus, one with unicornuate uterus with a noncommunicating rudimentary horn, one with bicornuate uterus bicollis with a double vagina and one with septate uterus. MRI diagnosis was correct in all cases, as confirmed by subsequent surgical intervention. CONCLUSION: MRI is a valuable tool in diagnosis of MDA subtypes. Its use will help to spare patients mutilating surgery and to prevent pregnancy-associated complications.

[Refixation of osteochondral fragments using absorbable implants. First results of a retrospective study]. / Refixation osteochondraler Fragmente mit resorbierbaren Implantaten. Erste Ergebnisse einer retrospektiven Studie.

An osteochondral lesion in a weight bearing joint causes therapeutic problems. Surgical therapy focuses on the restoration of the articular surface, unlimited motion of the joint and prevention of cartilaginous degeneration. A causal therapy to prevent posttraumatic osteoarthritis is the fixation of osteochondral fragments. Various absorbable implants for the purpose of refixation are available, but only a few have proved to be biocompatible. This retrospective study presents the preliminary results after refixation of osteochondral fragments of the ankle and knee joints. We used self-reinforced absorbable pins, nails and screws made of polylactide acid. The results for 15 patients with 17 fractures of 16 joints were evaluated. All patients were scored by the Tegner-activity-level, the McDermott-score and the DGKKT-score, and 13 of them were monitored by postoperative magnetic resonance imaging (MRI). The follow-up extended for an average of 14.3 months (range: 4-43 months). The clinical results for all patients were good (McDermott-score: Ø 89 points, DGKKT-score: Ø 78.8 points, Tegner: pre-op vs post-op=Ø 4.6 vs Ø 5.1) and the surgical therapy proved to be successful. The MRI showed the complete incorporation and vitality of the fragment as well as a congruence of the joint surface. The clinical course and the MRI gave little reference to an inflammatory reaction due to the implants that complicated the course of two patients. These results indicate that absorbable implants made of polylactide acid are biocompatible and effective in the fixation of osteochondral fragments.

Early diagnosis and follow-up of aortitis with [(18)F]FDG PET and MRI.

The aim of this prospective study was to compare fluorine-18 fluorodeoxyglucose ([(18)F]FDG) positron emission tomography (PET) with magnetic resonance imaging (MRI) in patients with early aortitis, at the time of initial diagnosis and during immunosuppressive therapy. The study population consisted of 15 patients (nine females and six males; median age 62 years, range 26-76 years) who presented with fever of unknown origin or an elevated erythrocyte sedimentation rate or elevated C-reactive protein and who showed pathological aortic [(18)F]FDG uptake. Fourteen of these patients had features of early giant cell arteritis (GCA), while one had features of early Takayasu arteritis. During follow-up, seven PET scans were performed in six patients with GCA 4-30 months (median 19 months) after starting immunosuppressive medication. The results of [(18)F]FDG imaging were compared with the results of MRI at initial evaluation and during follow-up and with the clinical findings. At baseline, abnormal [(18)F]FDG uptake was present in 59/104 (56%) of the vascular regions studied in 15 patients. Seven follow-up PET studies were performed in six patients. Of 30 regions with initial pathological uptake in these patients, 24 (80%) showed normalisation of uptake during follow-up. Normalisation of [(18)F]FDG uptake correlated with clinical improvement and with normalisation of the laboratory findings. All except one of the patients with positive aortic [(18)F]FDG uptake were investigated with MRI and MRA. Thirteen of these 14 patients showed inflammation in at least one vascular region. Of 76 vascular regions studied, 41 (53%) showed vasculitis on MRI. Of 76 vascular regions studied with both PET and MRI, 47 were concordantly positive or negative on both modalities, 11 were positive on MRI only and 18 were positive on PET only. MRI was performed during follow-up in six patients: of 17 regions with inflammatory changes, 15 regions remained unchanged and two showed improvement. Whole-body [(18)F]FDG PET is valuable in the primary diagnosis of early aortitis. The results of [(18)F]FDG PET and MRI in the diagnosis of aortitis in this study were comparable, but FDG imaging identified more vascular regions involved in the inflammatory process than did MRI. In a limited number of patients [(18)F]FDG PET was more reliable than MRI in monitoring disease activity during immunosuppressive therapy.

Value of F-18 FDG hybrid camera PET and MRI in early takayasu aortitis.

Takayasu aortitis (TA) is a chronic inflammatory and fibrotic vasculitis of large- and medium-sized arteries. Early stages of the disease show a panarteritis and inflammatory wall thickening of the aorta and its branches, whereas advanced (fibrotic) stages comprise stenosis, aneurismatic transformation and occlusion. Magnetic resonance imaging visualises early-stage disease with high accuracy and is considered to be the method of choice in the diagnosis of TA. The aim of this article is the detailed comparison of FDG-PET performed with a hybrid camera and MR imaging in five patients with early TA. Five patients (median age 60 years) were enrolled during an ongoing prospective study on [18F]2'-deoxy-2-fluoro-D-glucose (FDG) hybrid camera PET in patients with fever of unknown origin (FUO). These patients underwent MR imaging after establishing the diagnosis of TA. Abnormal FDG uptake in the wall of the aorta was noted in all patients. The bracheocephalic artery and the common carotid arteries were visualized in 3 cases. Increased uptake of the subclavian artery was found in 3 patients and in 4 patients pathological uptake was noted in the ilio-femoral vessels. Of 34 vascular regions studied, 26 (76%) showed elevated FDG uptake. On transversal MR images vessel wall thickening and contrast enhancement of the thoracic aorta was found in 4 patients (ascending aorta/aortic arch: n=2; descending aorta: n=3; abdominal aorta: n=1). Additionally, vessel wall pathologies of the subclavian and the common carotid arteries could be shown in 1 patient and in another patient in the ilio-femoral arteries. No abnormalities were found using contrast-enhanced MR angiography. Of 28 vascular regions studied, 9 (32%) showed vasculitis on MRI. The FDG-PET is a suitable whole-body screening method in the primary diagnosis of early TA, especially in those cases with early disease that present with uncharacteristic symptoms such as FUO. Both MRI and MRA remain indispensable in the exact determination of the pathomorphological changes and in the documentation of complications such as stenosis, aneurismatic transformation and occlusion.

Comparative study in patients with microcalcifications: full-field digital mammography vs screen-film mammography.

The goal of this prospective study was to compare a full-field digital mammography system (FFDM) to a conventional screen-film mammography system (SFM) for the detection and characterization of microcalcifications. Fifty-five patients with 57 isolated microcalcification clusters were examined using a FFDM system (Senographe 2000D, GE Medical Systems, Milwaukee, Wis.) and a SFM system (Senographe DMR, GE Medical Systems, Milwaukee, Wis.). A conventional screen-film mammogram and a digital contact mammogram were obtained of each cluster. The image quality and the number of calcification particles were evaluated, and a characterization (BI-RADS 1-5) of microcalcifications was given by four experienced readers. Histopathology revealed 16 benign lesions (sclerosing adenosis, dysplasia, hamartoma, radial scar) in 15 patients and 21 malignant tumors (in situ carcinoma, invasive carcinoma) in 20 patients. Twenty patients had benign changes verified by long-term follow-up. Image quality of FFDM was assessed as superior to SFM in more than 50% of the cases. The FFDM showed more calcifications in 41% of all cases. Sensitivity and specificity for FFDM vs SFM were 95.2 vs 91.9% and 41.4 vs 39.3%, respectively. Moreover, FFDM demonstrated a higher diagnostic accuracy (deviation: 0.86 BI-RADS steps) compared with FSM (deviation 0.93 BI-RADS steps). The FFDM system with a 100- micro m pixel size provides better image quality than SFM in patients with mammographic microcalcifications. The FFDM has a higher sensitivity and a higher reliability in characterizing microcalcifications.

[Quality management in a radiology department]. / Qualitätsmanagement in einer radiologischen Abteilung.

PURPOSE: To increase the quality of internal and external interactions (patients, clinical colleagues, technicians, radiologists) in a department of radiology. METHOD: Accompanied by a well-experienced adviser workshops have been performed dealing with different topics like "contact to patients," "performance of the radiological report and interaction with the referring colleague" or "research and teaching." A catalogue of different actions was defined to reduce hindrances within the internal and external work-flow. RESULTS: A total number of 53 actions was defined and related to different persons who were responsible for the realisation of the measures within a time interval. Six months after starting the quality management 46 (86%) of the defined actions were realised successfully, and another 4 (8%) measures were still running. There was a moderate increase of satisfaction of the patients and clinical colleagues considering the waiting time. CONCLUSIONS: A quality management in a radiological department allows an optimisation of the internal and external interactions. However, the guidance of a well-experienced adviser is as essential as the continuous control of successful finished measures.

Classification of hypervascularized lesions in CE MR imaging of the breast.

The purpose of this paper is to define and evaluate a classification category for contrast-enhanced (CE) MR imaging of the breast based on the BI-RADS mammographic categories of the American College of Radiology. Using five evaluation criteria for MR findings (initial signal increase, post-initial signal behavior, shape, border, and contrast material distribution within enhancing tumors) 522 patients (1031 breasts) were analyzed. Scores were given from 0 to 8 points and classified into five categories (group I: 0 points, negative; group II: 1-2 points, benign; group III: 3 points, probably benign; group IV: 4-5 points, suspicious abnormality; group V: 6-8 points, highly suspicious for malignancy) to 265 focal hypervascularized breast lesions in 244 breasts (patient group A). These findings were correlated with histology or follow-up. Additionally, this classification was correlated to the contrast medium uptake within the parenchyma of the remaining 787 breasts without any focal lesion (patient group B). Two hundred sixty-five hypervascularized lesions in 238 patients (244 breasts, patient group A) were classified into group I: 0%; group II: 27.3%; group III: 22.3%; group IV: 18.6%; and group V: 31.8%. Histology revealed 115 benign and 134 malignant tumors in these groups. Sixteen benign lesions were controlled by follow-up. Sensitivity for the detection of malignancy using the presented multifactorial MRM classification was 92%, and specificity was 92%. Excluding cases of ductal carcinoma in situ specificity increased to 95%. Seven hundred eighty-seven breasts without any focal hypervascularized lesion (patient group B) were classified into groups I or II. Follow-up ( n=771) or histology ( n=14) confirmed the diagnosis in 785 of these breasts. Histopathology revealed, however, malignant tumors in the remaining two cases. The classification of lesions based on a multifactorial analysis is very helpful in the interpretation of CE MRI of the breast. The evaluation of all diagnostic imaging modalities, however, is essential in determining the correct diagnosis and/or in deciding on the appropriate therapeutic procedure.