Hu Kauczor

Diagnosing and staging of cystic echinococcosis: how do CT and MRI perform in comparison to ultrasound?

Background Imaging plays the key role in diagnosing and staging of CE. The description of CE-specific imaging features and the WHO CE cyst classification is based on ultrasound. The reproducibility of the ultrasound-defined features of CE cysts is variable in MR- and CT-imaging. This is of particular importance for cysts that are not accessible by US and because of the increasing availability and overuse of CT and MR imaging. Methodology/Principal Findings Retrospective analysis of patients with abdominal CE cysts of an interdisciplinary CE clinic who had CT and/or MRI scans performed additionally to US imaging. All images were read and interpreted by the same senior radiologist experienced in the diagnosis of CE. US, CT and MR images were staged according to the WHO classification criteria. The agreement beyond chance was quantified by kappa coefficients (κ). 107 patients with 187 CE cysts met the inclusion criteria. All cysts were assessed by US, 138 by CT, and 125 by MRI. The level of agreement beyond chance of the individual CE stages 1–4 was clearly lower for CT, with κ ranging from 0.62 to 0.72, compared to MRI with values of κ between 0.83 and 1.0. For CE5 cysts CT (κ = 0.95) performed better than MRI (κ = 0.65). Conclusions Ultrasound remains the corner stone of diagnosis, staging and follow up of CE cysts. MRI reproduces the ultrasound-defined features of CE better than CT. If US cannot be performed due to cyst location or patient-specific reasons MRI with heavily T2-weighted series is preferable to CT.

Combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures

AIM To report our experience of combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures. PATIENTS AND METHODS Eighteen patients (23 kidneys) with non-obstructive uropathy due to urine leaks underwent combined CT- and fluoroscopy-guided nephrostomy. All procedures were indicated as second-line interventions after failed ultrasound-guided nephrostomy. Thirteen males and five females with an age of 62.3±8.7 (40-84) years were treated. Urine leaks developed in majority after open surgery, e.g. postoperative insufficiency of ureteroneocystostomy (5 kidneys). The main reasons for failed ultrasound-guided nephrostomy included anatomic obstacles in the puncture tract (7 kidneys), and inability to identify pelvic structures (7 kidneys). CT-guided guidewire placement into the collecting system was followed by fluoroscopy-guided nephrostomy tube positioning. Procedural success rate, major and minor complication rates, CT-views and needle passes, duration of the procedure and radiation dose were analyzed. RESULTS Procedural success was 91%. Major and minor complication rates were 9% (one septic shock and one perirenal abscess) and 9% (one perirenal haematoma and one urinoma), respectively. 30-day mortality rate was 6%. Number of CT-views and needle passes were 9.3±6.1 and 3.6±2.6, respectively. Duration of the complete procedure was 87±32 min. Dose-length product and dose-area product were 1.8±1.4 Gy cm and 3.9±4.3 Gy cm2, respectively. CONCLUSIONS Combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures was feasible with high technical success and a tolerable complication rate.

Extrapulmonale Tuberkulose: Die radiologische Bildgebung eines fast vergessenen Verwandlungskünstlers

Tuberculosis (TB) continues to be one of the infectious diseases with the worlds highest rates of avoidable morbidity and mortality. A continuing downward trend has only been observed in highly industrialized countries, including Germany with 4,400 cases in the year 2009 representing an incidence of 5.5 per 100,000 persons. At the same time, the exposure to this patient group and the clinical experience are decreasing. Tuberculosis may affect any organ. The lung was the manifestation site in 80% of cases, and extrapulmonary manifestations were recorded in 20% of cases in Germany in the year 2008. Lymph node involvement is most common with a rate of approximately 50% of all extrapulmonary cases followed by the pleura in 18% of cases, genitourinary tract in 13% of cases, bones and joints in 6% of cases, gastrointestinal tract in 6% of cases, the central nervous system in 3% of cases and the spine in 3% of cases. Symptoms like fever, night sweats and weight loss are non-specific and may be absent. The aim of the review is to raise awareness of this disease, which is increasingly falling into oblivion, with its various radiological manifestations and to point out clinical-epidemiological and demographic factors that raise suspicion of tuberculosis.

Transarterial embolization (TAE) as add-on to percutaneous radiofrequency ablation (RFA) for the treatment of renal tumors: Review of the literature, overview of state-of-the-art embolization materials and further perspective of advanced image-guided tumor ablation

Percutaneous radiofrequency ablation (RFA) for the treatment of stage I renal cell carcinoma has recently gained significant attention as the now available long-term and controlled data demonstrate that RFA can result in disease-free and cancer-specific survival comparable with partial and/or radical nephrectomy. In the non-controlled single center trials, however, the rates of treatment failure vary. Operator experience and ablation technique may explain some of the different outcomes. In the controlled trials, a major limitation is the lack of adequate randomization. In case reports, original series and overview articles, transarterial embolization (TAE) before percutaneous RFA was promising to increase tumor control and to reduce complications. The purpose of this study was to systematically review the literature on TAE as add-on to percutaneous RFA for renal tumors. Specific data regarding technique, tumor and patient characteristics as well as technical, clinical and oncologic outcomes have been analyzed. Additionally, an overview of state-of-the-art embolization materials and the radiological perspective of advanced image-guided tumor ablation (TA) will be discussed. In conclusion, TAE as add-on to percutaneous RFA is feasible and very effective and safe for the treatment of T1a tumors in difficult locations and T1b tumors. Advanced radiological techniques and technologies such as microwave ablation, innovative embolization materials and software-based solutions are now available, or will be available in the near future, to reduce the limitations of bland RFA. Clinical implementation is extremely important for performing image-guided TA as a highly standardized effective procedure even in the most challenging cases of localized renal tumors.

Super-micro-bland particle embolization combined with RF-ablation: Angiographic, macroscopic and microscopic features in porcine kidneys

PURPOSE To describe angiographic, macroscopic and microscopic features of super-micro-bland particle embolization in combination with RF-ablation in kidneys. Thereby, a special focus was given on the impact of the sequence of the different procedural steps. MATERIALS AND METHODS In ten pigs, super-micro-bland particle embolization combined with RF-ablation was carried out. Super-micro-bland embolization was performed with spherical particles of very small size and tight calibration (40 ± 10 μm). In the left kidneys, RF-ablations were performed before embolization (I). In the right kidneys, RF-ablations were performed after embolization (II). The animals were killed three hours after the procedures. Angiographic (e.g. vessel architecture), macroscopic (e.g. long and short axes of the RF-ablations) and microscopic (e.g. particle distribution) study goals were defined. RESULTS Angiography detected almost no vessels in the center of the RF-ablations in I. In II, angiography could not define the RF-ablations. Macroscopy detected significantly larger long and short axes of the RF-ablations in II compared to I (52.2 ± 3.2 mm vs. 45.3 ± 6.9 mm [P<0.05] and 25.1 ± 3.5mm vs. 20.0 ± 1.9 mm [P<0.01], respectively). Microscopy detected irregular particle distribution at the rim of the RF-ablations in I. In II, microscopy detected homogeneous particle distribution at the rim of the RF-ablations. Microscopy detected no particles in the center of the RF-ablations in I and II. CONCLUSION The sequence of the different procedural steps of super-micro-bland particle embolization combined with RF-ablation impacts angiographic, macroscopic and microscopic features in kidneys in the acute setting.

Intraductal papillary mucinous neoplasms of the pancreas: radiological predictors of malignant transformation and the introduction of bile duct dilation to current guidelines

OBJECTIVE To evaluate the current guidelines as a model to predict malignancy and to determine further radiological predictors of malignancy in intraductal papillary mucinous neoplasms (IPMNs). METHODS 384 patients who had undergone a pancreatic operation with the pathological diagnosis of IPMN as well as applicable pre-operative imaging (CT/MRI) were included in the study. Images were evaluated retrospectively in consensus by two radiologists, using a standardized checklist. Descriptive statistics, binary logistic regression and receiver operator curve analysis were performed to assess the International Consensus Guidelines and other radiological predictors of clinical malignancy (defined as carcinoma in situ and invasive carcinoma). RESULTS The best independent predictors of malignancy (n = 191) were solid components [odds ratio (OR) 3.98], parenchymal atrophy with main pancreatic duct dilation 5-9 mm (OR: 5.1) and common bile duct (CBD) dilation (OR: 31.26). >96% of all cases with CBD dilation were malignant IPMNs (positive-predictive value 96.4%; negative-predictive value 63.1%). Analysis of the current guidelines showed a diagnostic improvement with the addition of CBD dilation on determining the malignancy of IPMNs (sensitivity 82.2%/86.9%; specificity 72.7%/74.6%). Subanalysis of branch duct intraductal papillary mucinous neoplasms (BD-IPMNs; n = 168) also resulted in a diagnostic improvement with the addition of CBD dilation (sensitivity 28.6%/45.2%; specificity 92.9%/92.1%). The best independent predictors of malignancy for BD-IPMNs were parenchymal atrophy (OR: 4.00) and CBD dilation (OR: 29.3). Frequency analysis revealed that even small BD-IPMNs had already undergone malignant transformation (≤1 cm: 15%; 1-2 cm: 26%; 2-3 cm: 20%) with about 10% of those having a dilated bile duct. CONCLUSION CBD dilation was a significant positive predictor of malignancy in IPMNs regardless of their size. ADVANCES IN KNOWLEDGE Introduction of CBD dilation as a radiological predictor for malignancy might increase the diagnostic accuracy of current imaging-based guidelines.

Dual-energy CT-cholangiography in potential donors for living-related liver transplantation: Improved biliary visualization by intravenous morphine co-medication

PURPOSE To prospectively evaluate whether intravenous morphine co-medication improves bile duct visualization of dual-energy CT-cholangiography. MATERIALS AND METHODS Forty potential donors for living-related liver transplantation underwent CT-cholangiography with infusion of a hepatobiliary contrast agent over 40 min. Twenty minutes after the beginning of the contrast agent infusion, either normal saline (n=20 patients; control group [CG]) or morphine sulfate (n=20 patients; morphine group [MG]) was injected. Forty-five minutes after initiation of the contrast agent, a dual-energy CT acquisition of the liver was performed. Applying dual-energy post-processing, pure iodine images were generated. Primary study goals were determination of bile duct diameters and visualization scores (on a scale of 0 to 3: 0--not visualized; 3--excellent visualization). RESULTS Bile duct visualization scores for second-order and third-order branch ducts were significantly higher in the MG compared to the CG (2.9±0.1 versus 2.6±0.2 [P<0.001] and 2.7±0.3 versus 2.1±0.6 [P<0.01], respectively). Bile duct diameters for the common duct and main ducts were significantly higher in the MG compared to the CG (5.9±1.3 mm versus 4.9±1.3 mm [P<0.05] and 3.7±1.3 mm versus 2.6±0.5 mm [P<0.01], respectively). CONCLUSION Intravenous morphine co-medication significantly improved biliary visualization on dual-energy CT-cholangiography in potential donors for living-related liver transplantation.

Medical Liability and Patient Law in Germany: Main Features with Particular Focus on Treatments in the Field of Interventional Radiology.

UNLABELLED On February 26th, 2013 the patient law became effective in Germany. Goal of the lawmakers was a most authoritative case law for liability of malpractice and to improve enforcement of the rights of the patients. The following article contains several examples detailing legal situation. By no means should these discourage those persons who treat patients. Rather should they be sensitized to to various aspects of this increasingly important field of law. To identify relevant sources according to judicial standard research was conducted including first- and second selection. Goal was the identification of jurisdiction, literature and other various analyses that all deal with liability of malpractice and patient law within the field of Interventional Radiology--with particular focus on transarterial chemoembolization of the liver and related procedures. In summary, 89 different sources were included and analyzed. The individual who treats a patient is liable for an error in treatment if it causes injury to life, the body or the patients health. Independent of the error in treatment the individual providing medical care is liable for mistakes made in the context of obtaining informed consent. Prerequisite is the presence of an error made when obtaining informed consent and its causality for the patients consent for the treatment. Without an effective consent the treatment is considered illegal whether it was free of treatment error or not. The new patient law does not cause material change of the German liablity of malpractice law. KEY POINTS •On February 26th, 2013 the new patient law came into effect. Materially, there was no fundamental remodeling of the German liability for medical malpractice. •Regarding a physicians liability for medical malpractice two different elements of an offence come into consideration: for one the liability for malpractice and, in turn, liability for errors made during medical consultation in the process of obtaining informed consent. •Forensic practice shows that patients frequently enforce both offences concurrently.

Untersuchung von Dual-energy (DE) Mischverhältnissen in Abhängigkeit der Strahlenexposition und des DE-Aufnahmemodus zur Erzeugung optimaler linearer DE-Mischbilder

Zielsetzung: Inhalt der Studie war die systematische Untersuchung der DE-Mischverhaltnisse α in Abhangigkeit der Strahlenexposition und des DE-Aufnahmemodus mit dem Ziel der Berechnung von DE-Mischbildern mit gleicher oder besserer Bildqualitat im Vergleich zu dosisaquivalenten Single-energy (SE) Aufnahmen. Material und Methodik: Neun Patienten mit Leberlasionen wurden mindestens einmal mittels CT, die aus drei unabhangigen Serien mit gleicher Dosis bestand (SE 120kVp, DE 80/Sn140kVp, DE 100/Sn140kVp, insgesamt 17 Untersuchungen), untersucht. Die CT-Untersuchungen unterteilen sich in drei Gruppen unterschiedlicher Dosisstufen mit CTDIvol = 10mGy; 7mGy; 5mGy. Zu jeder aufgenommen SE-Bildschicht wurden 100 dosisequivalente lineare DE-Mischbilder der gleichen Schicht mit α zwischen 0,0 und 1,0 berechnet. In Abhangigkeit vom DE-Aufnahmemodus und der Dosisstufe wurden fur jedes DE-Mischbild quantitative Bildqualitatsparameter (CT-Wert, Rauschen, Kontrast-zu-Rauschen (CNR) und Signal-zu-Rauschen (SNR)) ermittelt und mit denen der entsprechenden SE-Bildschicht verglichen. Ergebnisse: Der optimale Wert fur α ist unabhangig von der Dosisstufe. Bestmogliche α unterscheiden sich signifikant (p < 0,05) je nach untersuchtem Bildqualitatsparameter und DE-Aufnahmemodus: Optimales α_CNR/SNR (α_CNR≈0,7/α_SNR≈0,6) liefert nicht nur ein signifikant hoheres CNR/SNR (bis zu 40%; p < 0,05) als die entsprechende SE-Bildschicht fur beide DE-Modi, sondern unterscheidet sich auch signifikant von den DE-Standard Mischverhaltnissen (α_80/Sn140kVp = 0,3; α_100/Sn140kVp = 0,5). Der DE80/Sn140kVp Modus liefert ein hoheres CNR/SNR als der DE100/Sn140kVp Modus. Das kleinste Bildrauschen wurde bei α≈0,3 in beiden DE-Modi gemessen. Aquivalente CT-Werte und CNR-Verhaltnisse werden mit dem DE-Standardwert im DE80/Sn140kVp Modus erreicht. Schlussfolgerungen: DE-Mischbilder, die mit bestmoglichem DE-Mischverhaltnis berechnet wurden, erreichen eine hohere Bildqualitat als entsprechende dosisequivalente SE-Bildschichten und bieten Potenzial fur Dosiseinsparungen.