Image quality and safety of automated carbon dioxide digital subtraction angiography in femoropopliteal lesions: Results from a randomized single-center study.

PURPOSE: To evaluate the image quality and the safety of automated carbon dioxide (CO2) digital subtraction angiography (DSA). MATERIALS AND METHODS: Fifty patients receiving DSA for femoropopliteal peripheral arterial disease (PAD) were enrolled in this single-center prospective study. All patients received iodinated contrast media (ICM) and CO2 as a contrast agent in the same target lesion. As a primary endpoint, four raters independently evaluated the angiography images based on overall image quality, visibility of collaterals, and assessment of stenoses/occlusions. Inter-rater agreement was assessed using the intraclass correlation coefficient (ICC) and differences between the raters were evaluated using Friedmann's test. Secondary endpoints were procedure safety and patient pain assessment. RESULTS: Inter-rater agreement between CO2-DSA and ICM-DSA images was fair to excellent for overall image quality (ICC: 0.399-0.748), fair to excellent for the visibility of collaterals (ICC: 0.513-0.691), and poor to excellent for the assessment of stenoses/occlusions (ICC: -0.065-0.762). There were no significant differences between the raters. Two patients had a hematoma, one reported pain related to puncture, one became nauseous, and one vomited. No other adverse events were observed. Reported pain scores were significantly higher for CO2-DSA vs. ICM-DSA (1.25 vs. 0625; p < 0.028). CONCLUSION: CO2-DSA using automated injection system in combination with proprietary post-processing software is safe and comparable diagnostic test compared to ICM-DSA.

[Whole-body ferromagnetic detector systems in clinical MRI]. / Ganzkörperferrodetektorsysteme in der klinischen MRT.

CLINICAL/METHODICAL ISSUE: In spite of technical and organizational measures, ferromagnetic objects still find their way into the magnetic resonance imaging (MRI) room and can cause severe injuries. STANDARD RADIOLOGICAL METHODS: A detailed patient education and MRI safety training for personnel are necessary to avoid MRI incidents with ferromagnetic objects. METHODICAL INNOVATIONS: Whole body ferromagnetic detection systems should increase patient safety and minimize risks for personnel and MRI equipment in the clinical routine. PERFORMANCE: In a clinical MRI setting, a screener system used for outpatients and inpatients (n = 400) identified unknown ferrous objects in 2 % of the cases. In two of these cases patients were found to be in possession of unknown foreign ferrous objects. Furthermore, a door guard system only used for outpatients (n = 2500) detected unknown ferromagnetic objects in 0.3 % of the cases. ACHIEVEMENTS: The number of ferrous objects that are unknowingly brought into the scanner room can be reduced with a whole body ferromagnetic detection system. For an optimal benefit of the system a ferrous-free environment and perfectly ferrous-free clothing for the medical personnel are necessary. In the clinical routine, the benefit of the system is limited particularly for immobile patients who have to remain in a horizontal position. PRACTICAL RECOMMENDATIONS: A whole body ferromagnetic detection system can complement but not replace patient education and MRI safety training.

Magnetic resonance imaging of the active second stage of labour: proof of principle.

OBJECTIVE: To prove that magnetic resonance imaging of foetal anatomy during the active second stage of vaginal delivery is feasible. MATERIALS AND METHODS: Initially, five pregnant volunteers around the 30th week of gestation were examined in an open MRI. Based on the findings, one vaginal delivery was acquired under real-time imaging. To monitor the birth status during image acquisition, an MR-compatible wireless cardiotocography (CTG) system was built. Single-shot sequence parameters were optimised to compensate motion artefacts during labour. RESULTS: Safety requirements to monitor the birth process under real-time MR imaging were met. High-resolution MR images were acquired immediately before and after delivery. In one patient, TSE single-shot cinematic sequences of the active second stage of labour were obtained. All sequences were adapted to tolerate movement of the mother and infant, as well as residual noise from the CTG. Furthermore, the MR imaging during labour showed only minor image artefacts. CONCLUSION: CTG-monitored acquisition of MRI series during the active second stage of delivery is feasible. Image quality should allow various further studies to improve models for birth simulation as well as potential investigation of obstructed labour and obstetric complications.

CT fluoroscopy-guided percutaneous gastrostomy with loop gastropexy and peel-away sheath trocar technique in 31 amyotrophic lateral sclerosis patients.

BACKGROUND: In amyotrophic lateral sclerosis (ALS) patients with respiratory impairment and/or advanced disease, performing even mild sedation - as is usually necessary for percutaneous endoscopic gastrostomy (PEG) placements - is fraught with risk. These patients are often referred to Interventional Radiology for alternative percutaneous gastrostomy tube placement options. PURPOSE: To report our experience with CT fluoroscopy-guided percutaneous gastrostomy with a novel loop gastropexy and peel-away sheath trocar technique in ALS patients as an alternative to endoscopic techniques. MATERIAL AND METHODS: A consecutive series of 31 amyotrophic lateral sclerosis patients in whom endoscopic gastrostomy was considered too dangerous or impossible to perform underwent CT-guided percutaneous gastropexy and gastrostomy and prospective follow-up. All procedures were performed with a 15 FR Freka® Pexact gastrostomy kit, a 16-row CT scanner (Aquilion 16) and single shot CT fluoroscopy mode. RESULTS: The procedure was performed successfully in 30 of 31 patients (20 men, 11 women; median age 60 years, range 38-80 years). In the remaining case the stomach was punctured under CT fluoroscopy and CO2 insufflation was initiated thereafter, leading to successful gastrostomy without prior gastropexy and without further adverse events during follow-up. Two patients reported unproblematic exchange of a balloon tube due to skin irritations with no further adverse events. One patient reported accidental displacement of an exchanged new balloon tube in domestic environment due to balloon leakage: A new balloon tube was easily re-inserted in a hospital the same day. No serious adverse events such as peritonitis, persistent local bleeding, systemic blood loss, or any local infection requiring surgical intervention were observed. Until August 11, 2011 follow-up resulted in 7473 cumulative gastrostomy-days from the date of first placement. CONCLUSION: Initial results suggest that the described technique under CT guidance is feasible and safe and may especially be advantageous in cases where endoscopic gastrostomy and sedation are contraindicated.

Satisfaction and quality of life: a survey-based assessment in patients with a totally implantable venous port system.

The purpose was to assess the satisfaction and quality of life in patients with a totally implantable central venous port system using a questionnaire-based survey. A self-designed questionnaire to assess patient satisfaction and the impact of the port on daily life was dispatched 180 days after implantation. The questionnaire was combined with the commonly used short form (SF)-12 Health Survey quality of life questionnaire. Of the 98 patients who received a port system, 75 were contacted, and 42 (56%) returned the questionnaire. Most of the responding patients reported high overall satisfaction. The impact of the system on daily life was widely perceived not to be negative. The physical component summary (PCS) and the mental component summary (MCS) scores from the SF-12 were 35.5 and 45.23 respectively (general German population: PCS = 49.6, MCS = 52.3). The multiple stepwise regression showed that the cosmetic result was a predictor of overall satisfaction; the cosmetic result and a painful port together were predictors of the MCS. Overall, it was found that the cosmetic result of the implantation procedure was a predictor of satisfaction and quality of life and should thus not be underestimated.

Minimally invasive magnetic resonance imaging-guided free-hand aspiration of symptomatic nerve route compressing lumbosacral cysts using a 1.0-Tesla open magnetic resonance imaging system.

PURPOSE: To evaluate the feasibility of minimally invasive magnetic resonance imaging (MRI)-guided free-hand aspiration of symptomatic nerve route compressing lumbosacral cysts in a 1.0-Tesla (T) open MRI system using a tailored interactive sequence. MATERIALS AND METHODS: Eleven patients with MRI-evident symptomatic cysts in the lumbosacral region and possible nerve route compressing character were referred to a 1.0-T open MRI system. For MRI interventional cyst aspiration, an interactive sequence was used, allowing for near real-time position validation of the needle in any desired three-dimensional plane. RESULTS: Seven of 11 cysts in the lumbosacral region were successfully aspirated (average 10.1 mm [SD ± 1.9]). After successful cyst aspiration, each patient reported speedy relief of initial symptoms. Average cyst size was 9.6 mm (±2.6 mm). Four cysts (8.8 ± 3.8 mm) could not be aspirated. CONCLUSION: Open MRI systems with tailored interactive sequences have great potential for cyst aspiration in the lumbosacral region. The authors perceive major advantages of the MR-guided cyst aspiration in its minimally invasive character compared to direct and open surgical options along with consecutive less trauma, less stress, and also less side-effects for the patient.

'Low-dose' dopamine worsens renal perfusion in patients with acute renal failure.

'Low-dose' dopamine is frequently used in intensive care units (ICU) for its presumed renoprotective effects, but prospective and retrospective studies have so far not proven prevention or amelioration of renal injury. Data on renal perfusion following dopamine infusion are limited. In order to circumvent the problem of patient heterogeneity in the ICU setting, we used a crossover design in a prospective, double-blind randomized controlled study to investigate the effect of 'low-dose' dopamine on renal resistance indices, as determined by Doppler ultrasound. Forty patients, 10 without and 30 with acute renal failure (ARF, defined as doubling of baseline creatinine or an increase above 2 mg/dl), were included. Dopamine (2 mug/kg min) or placebo was given intravenously in alternating sequence for four subsequent periods of 60 min, starting randomly with either dopamine or placebo. Resistive (RI) and pulsatility index (PI) were closely correlated, positively related to serum creatinine values at baseline and highly reproducible during the two paired infusion periods. Dopamine reduced renal vascular resistance in patients without ARF (median RI/PI from 0.70 to 0.65/1.20 to 1.07, P<0.01) but increased resistance indices in patients with ARF (median RI/PI from 0.77 to 0.81/1.64 to 1.79, P<0.01) in the absence of effects on systemic hemodynamics. Subgroup analysis of patients with ARF revealed that dopamine induced renal vasoconstriction above 55 years (n=22) and in patients not receiving norepinephrine (n=20). In conclusion 'low-dose' dopamine can worsen renal perfusion in patients with ARF, which adds to the rationale for abandoning the routine use of 'low-dose' dopamine in critically ill patients.

[Contrast media pressure injection using a portal catheter system--results of an in vitro study]. / Kontrastmitteldruckinjektion in Portkathetersysteme -- Ergebnisse einer In-vitro-Studie.

PURPOSE: Are implanted central venous port catheters suitable for contrast media pressure (power) injection in computed tomography? MATERIAL AND METHODS: In an in vitro study 100 ml of contrast medium (Ultravist 370, Schering, Berlin, Deutschland) was injected through 20 different port catheter systems using a power injector (Stellant, Medrad, Inianola, USA) with a pressure limit of 325 PSI. The injection rate was increased from 2 ml/s to 10 ml/s in increments of 2 ml/s. The maximum injection pressure and maximum injection rate were assessed. RESULTS: An injection rate of 2 ml/s was possible in all catheter systems. Injection rates of 4 ml/s in 18 systems, 6 ml/s in 13 systems and 8 ml/s in 6 systems were achieved. With a given pressure limit of 325 PSI an injection rate of 10 ml/s was not possible in any of the port catheter systems. There were no catheter ruptures, catheter disconnections or contrast extravasations noted. CONCLUSION: Power injection of contrast media with a pressure limit of 325 PSI seems to be tolerated by port catheter systems. Most of the evaluated port systems allow flow rates suitable for multislice computed tomography requiring rapid contrast injection.

[Long-term central venous lines and their complications]. / Langfristige zentralvenöse Zugänge und deren Komplikationsmanagement.

The implantation of permanent (> 14 days) central venous catheters is constantly increasing, accelerated by a trend toward outpatient therapies. Subcutaneous tunneled and non-tunneled catheters as well as port systems are available. The interventional radiologist plays an important role in the implantation of central venous catheters as well as in detection and treatment of any complications. Various access ways via peripheral and central veins are described and the implantation techniques for the different systems explained. The use of peel-away sheaths allows the radiologist to implant subcutaneous tunneled catheters via the Seldinger technique without surgical preparation. Procedure-related early and late complications may occur, and the radiologist plays an important role in the surveillance and management of catheter-associated complications. This review demonstrates the different catheter systems and implantation techniques.

[Ultrasound- and fluoroscopy-guided implantation of peripherally inserted central venous catheters (PICCs)]. / Ultraschall- und durchleuchtungsgesteuerte Implantation peripher inserierter zentral-venöser Katheter (PICC).

PURPOSE: Evaluation of ultrasound- and fluoroscopy-guided implantation of peripherally inserted central venous catheters (PICCs). MATERIALS AND METHODS: In 32 patients (12 males, 20 females; mean age 64.1 +/- 11.9 years) with clinical indication for long term central venous catheter (chemotherapy: N = 5; parenteral nutrition and fluid substitution: N = 26; parenteral pain therapy: N = 1) a PICC was placed by an interventional radiologist using ultrasound guidance. RESULTS: The placement of the PICC was technically successful in 31 (96.9%) patients, with placement of 20 single-lumen 5F PICCs, 4 double-lumen 6F PICCs and 7 double-lumen 7F PICCs. The mean duration of catheter usage was 28.4 (2 - 161) days with a total of 910 catheter days. No catheter occlusions were recorded. Two patients developed a superficial venous thrombosis of the upper extremity. The resulting thrombotic rate was 2.2 per 1000 catheter days. No catheter associated infection was recorded. CONCLUSION: The ultrasound guided placement of peripherally inserted central venous catheters (PICCs) via a superficial vein of the upper extremity is a practical alternative to central catheters via central veins.

[Methods of process management in radiology]. / Methoden des Prozessmanagements in der Radiologie.

The main emphasis in health care has been on quality and availability but increasing cost pressure has made cost efficiency ever more relevant for nurses, technicians, and physicians. Within a hospital, the radiologist considerably influences the patient's length of stay through the availability of service and diagnostic information. Therefore, coordinating and timing radiologic examinations become increasingly more important. Physicians are not taught organizational management during their medical education and residency training, and the necessary expertise in economics is generally acquired through the literature or specialized courses. Beyond the medical service, the physicians are increasingly required to optimize their work flow according to economic factors. This review introduces various tools for process management and its application in radiology. By means of simple paper-based methods, the work flow of most processes can be analyzed. For more complex work flow, it is suggested to choose a method that allows for an exact qualitative and quantitative prediction of the effect of variations. This review introduces network planning technique and process simulation.

[Prospective cost-benefit analysis of a fully digitized working environment in an ultrasound division applying process simulation]. / Prozesssimulation zur prospektiven Nutzwertanalyse einer voll digitalisierten Arbeitsumgebung am Beispiel eines sonographischen Arbeitsplatzes.

PURPOSE: Quantification of expected savings of work load and personnel costs after implementation of a digital infrastructure in an ultrasound division of a radiology department. MATERIALS AND METHODS: The work flow of an ultrasound examination was simulated by means of a computer model. After validation, the computer model was modified to represent a work flow with PACS, electronic patient record, and automatic scheduling. The simulation results of work load, equipment utilization, and personnel costs were compared for both scenarios. RESULTS: The total number of work steps was reduced from 29 in the conventional scenario to 14 work steps in the scenario with digital infrastructure. The work load of administrative activities decreased by 89 % whereas the work load of activities directly related to the ultrasound examination remained unchanged. The productive personnel costs declined from euro; 24 to euro; 16 per examination. The gross labor costs declined from euro; 33 to euro; 20 per examination. Given unchanged equipment and number of patients, the required number of physicians can be reduced from 3 to 2 and that of technicians from 2 to 1 by use of a digital infrastructure. CONCLUSION: A digital infrastructure possesses a great potential for efficiency provided that it is implemented comprehensively and the work flow is adapted utilizing the capabilities of automation in all work processes.

Central venous access catheters: radiological management of complications.

A great variety of central venous access devices such as tunneled and non-tunneled central venous catheters (CVC) as well as port systems are implanted by interventional radiologists at an increasing rate. There are some possible immediate, early, and late complications related to the implantation technique, care, and maintenance of CVCs. This review will illustrate possible complications of CVCs and will discuss risk factors. Different strategies will be shown regarding the prevention and treatment of complications.

[Conception and data transfer analysis of an open-source digital image archive designed for radiology]. / Aufbau und Datentransferanalyse eines proprietären digitalen Open-Source-Bildarchivs für radiologische Dienstleistungen.

PURPOSE: Implementation of a self-designed, web-based digital image archive incorporating the existing DICOM infrastructure to assure distribution of digital pictures and reports and to optimize work flow. Assessment after three years. MATERIALS AND METHODS: Open-source software was used to guarantee highest reliability and cost effectiveness. In view of rapidly increasing capacity and decreasing costs of hard discs (HDs), HDs were preferred over slower and expensive magneto-optical disk (MOD) or tape storage systems. The number of installed servers increased from one to 12. By installing HDs with increased capacities, the number of servers should be kept constant. Entry and access of data were analyzed over two 4-month periods (after 1.5 and 2 years of continuous operations). RESULTS: Our digital image archive was found to be very reliable, cost effective and suitable for its designated tasks. As judged from the measured access volume, the average utilization of the system increased by 160 %. In the period from January to April 2002, the users accessed 239.8 gigabyte of the stored 873.7 gigabyte image data (27 %). The volume of the stored data added 20%, mainly due to an increase in cross-section imaging. CONCLUSION: The challenge of developing a digital image archive with limited financial resources resulted in a practicable and expandable solution. The utilization, number of active users and volume of transferred data have increased significantly. Our concept of utilizing HDs for image storage proved to be successful.

[Accuracy of the sonographic determination of the splenic weight in comparison with the weight at autopsy]. / Genauigkeit der sonographischen Milzgewichtsbestimmung am Lebenden im Vergleich zum pathologischen Korrelat.

PURPOSE: The weight of the spleen can be easily calculated from sonographic measurements. This study investigates the correlations between the weight of the spleen determined sonographically and the weight measured at autopsy or after splenectomy. MATERIALS AND METHODS: The splenic weight at autopsy or after splenectomy was correlated with the calculated sonographic splenic weight in 55 patients who had a sonographic examination within the preceding three weeks. RESULTS: A significant correlation (r = 0.978) was found between the sonographically calculated splenic weight (460.82 grams) and the measured weight of the removed spleen (average weight 463.18 grams). Spleens weighing more than 1 kg showed a slightly weaker correlation. CONCLUSION: This study proves that the simple formula of length x transverse diameter x vertical diameter x 0.6 provides a reliable calculation of the weight of the spleen.

[Use of portable computed tomography in non-transportable patients on the intensive care unit: preclinical experience]. / Einsatz der mobilen Computertomographie bei nicht transportfähigen Patienten auf der Intensivstation - Ein Erfahrungsbericht.

PURPOSE: To evaluate different concepts of the application of a portable CT (PCT) directly in a patient's ICU room versus in a specially designed interventional suite (IS). METHODS: 13 patients with maximum ICU treatment were examined by PCT and assessed with regard to their health status by ICU scores (TISS 28, MODS). Only patients with a therapeutic intervention scoring system 28 (TISS 28) value of 40 or greater were included in the study. A TISS 28 value of 40 or more characterizes a patient requiring maximal ICU treatment. Patients were examined by PCT either in the patient's room or in the IS on the ICU. Scanning time and personnel resource expense were determined. The multiple organ dysfunction score (MODS) was utilized for patient characterization. RESULTS: An average of 1.4 hours was needed to perform a PCT scan in the interventional room. A minimum of 4.5 hours or up to a maximum of 7.2 hours were required to perform a bedside scan in the patient's room. There is a noticeable difference between patients with respect to TISS 28. Patients examined by bedside CT were more acutely ill than the others by reason of MODS (8 - 18 patient-room group vs. 3 - 12 IS group). CONCLUSIONS: PCT performed on an ICU assures optimal treatment of patients during CT examination. Portable CT had more time exposure and required more personnel resources than examination in the IS. All PCT examinations performed directly in the patient's room demonstrated the diagnostic value and had direct therapeutic consequences.

[MRI diagnosis of injuries and diseases of peroneal tendons]. / MR-Diagnostik von Verletzungen und Erkrankungen der Peronäussehnen.

Injuries of the peroneus tendons are common and both the athlete and the older population are at risk. MR imaging is a useful technique for revealing injuries of the peroneus tendons as well as showing anatomic factors associated with these lesions. This article reviews clinical factors and MR imaging characteristics of injuries of the peroneus tendons.

Anatomical variations in the internal jugular veins of cancer patients affecting central venous access. Anatomical variation of the internal jugular vein.

PURPOSE: Establishing a reliable central venous access is an important procedure in clinical haematology and oncology. The purpose of this study was to determine how anatomical variations in the internal jugular vein (IJV) and its position in relation to the common carotid artery (CCA) in cancer patients affects external landmark puncture. PATIENTS AND METHODS: In 113 patients with haematological or oncological diseases we examined sonographically potential target regions for placement of a central catheter via the IJV. RESULTS: 36% of our patients showed anatomical variations in the IJV and surrounding tissue. CONCLUSIONS: External landmark puncture may be difficult in a considerable number of patients since the IJV might not be situated in the presumed location anteriorly or laterally to the CCA, or a normal lumen may not be present in approximately 1/3 of cancer patients. This study supports the use of ultrasound-guided techniques for central venous catheters particularly in haematological and oncological patients.