Radiation protection in CT-guided interventions: does real-time dose visualisation lead to a reduction in radiation dose to participating radiologists? A single-centre evaluation.

AIM: To evaluate if real-time dose visualisation during computed tomography (CT)-guided interventions leads to a reduction in radiation dose to participating radiologists. MATERIALS AND METHODS: The individual radiation dose radiologists are exposed to during CT interventions was measured using dedicated dosimeters (RaySafe i2-system, Unfors RaySafe GmbH, Billdal, Sweden) worn over the usual radiation protective apron. Initially, only the total radiation dose was measured, without visualisation (control group). In the following study period, the radiation dose was shown to participants on a live screen in real-time (experimental group). In both groups, the dose was recorded in 1-second intervals. The results collected were evaluated by comparison using descriptive statistics and mixed-effect models. In particular, the variables experience, gender, role, and position during the intervention were analysed. RESULTS: In total, 517 measurements of 304 interventions (n=249 with and n=268 without live screen) performed by 29 radiologists acting as interventionalists or assistants were analysed. All CT-guided interventions were performed percutaneously, the majority of which (n=280) were microwave ablations (MWA). Radiation doses in the group without visualisation were comparable with usual dose rates for the corresponding intervention type. The mean total radiation dose was reduced by 58.1% (11.6 versus 4.86 µSv) in the experimental group (p=0.034). The highest reduction of 78.5% (15.55 versus 3.35 µSv) was observed in radiologists with the role of assistant (p=0.002). Sub-analysis showed significant dose reduction (p<0.0001) for the use of live screen in general; considering all variables, the role "assistant" alone had a statistically significant influence (p=0.002). CONCLUSION: The real-time visualisation of active radiation dose during CT interventions leads to a relevant reduction in radiation dose to participating radiologists.

Comparison of contrast-enhanced videofluoroscopy to unenhanced dynamic MRI in minor patients following surgical correction of velopharyngeal dysfunction.

OBJECTIVES: To compare dynamic magnetic resonance imaging (MRI) with videofluoroscopy (VFS) regarding image quality and assessment of gap size between soft palate (SP) and posterior pharyngeal wall (PPW) in children and adolescents following surgical correction of velopharyngeal dysfunction (VPD). METHODS: Twenty-one patients undergoing unenhanced 3-T MRI and contrast-enhanced VFS were included in this IRB-approved prospective study. The MRI scan protocol comprised refocused gradient-echo sequences in transverse and sagittal planes during speech, with TE 1.97 ms, TR 3.95 ms, flip angle 8°, matrix size 128 × 128, and 5-mm slice thickness. Radial k-space sampling and sliding window reconstruction were used to achieve an image acquisition rate of 28 frames per second (fps). VFS with 30 fps was similarly performed in both planes. Closure of the velopharyngeal port during phonation was evaluated by two experienced radiologists. RESULTS: Eleven (52.4%) patients displayed a complete closure, whereas ten (47.6%) patients showed a post-operative gap during speech. VFS and MRI equally identified the cases with persistent or recurrent VPD. Differences in SP-PPW distance between VFS (3.9 ± 1.6 mm) and MRI (4.1 ± 1.5 mm) were not statistically significant (p = 0.5). The subjective overall image quality of MRI was rated inferior (p < 0.001) compared with VFS, with almost perfect inter-rater agreement (κ = 0.90). The presence of susceptibility artifacts did not limit anatomical measurements. CONCLUSION: Dynamic MRI is equally reliable as VFS to assess persistent or recurrent inadequate velum closure in patients following surgical treatment of VPD. KEY POINTS: • Unenhanced 3-T dynamic MRI and contrast-enhanced videofluoroscopy are equally useful for the identification of patients with incomplete velopharyngeal closure during speech. • MRI using refocused gradient-echo acquisition with radial k-space sampling and sliding window reconstruction generates diagnostic images with 28 frames per second. • MRI can offer a radiation-free alternative to currently established videofluoroscopy for young patients.

CT-guided percutaneous biopsy of suspect pancreatic lesions: radiological and clinical outcome.

AIM: To evaluate the clinical utility of computed tomography (CT)-guided percutaneous biopsies of suspect pancreatic lesions regarding safety, efficiency, radiation dose, intervention time, diagnostic yield, and complications. MATERIALS AND METHODS: Between 2015 and 2018, 48 patients (18 female, 30 male; mean age: 64.2 years) with suspect pancreatic lesions underwent CT-guided percutaneous biopsy. Ultrasound-guided biopsy of all lesions was not possible or without any result. CT-guided interventions were compared according to the following intervention parameters: radiation dose, procedure duration, number of needle correction scans. Evaluation criteria included technical success as well as major and minor complications according to the Society of Interventional Radiology. RESULTS: Biopsies were performed successfully in 100% of patients. No major side effects occurred during intervention. As a minor complication, 29.2% showed focal haemorrhage. Seventy-seven percent of lesions had a malignant appearance, and benign inflammatory lesions were found in 23%. The mean size of the target lesions was 2.9 cm (range: 0.7-2.3 cm). The mean target access path within the patient was 8 cm (range: 3-14 cm). The duration to completion was 12 minutes (range: 3 minutes 30 seconds to 30 minutes). The dose-length product of the intervention was 89.5 mGy·cm (range: 11-350 mGy·cm). The average number needle correction scans was 31.1 (range: 6-36). CONCLUSION: CT-guided biopsy of suspect pancreatic lesions is an efficient and safe method. It can be performed within short intervention times and low radiation exposure for differentiation of unclear lesions.

[Mediocarpal instability of the wrist]. / Mediokarpale Instabilitäten der Handwurzel.

Typical lesions of the carpal ligaments are mostly found after a fall on the wrist in hyperextension or as complex injuries after severe trauma, e. g. after a fall from a significant height, motorcycle accident or as accompanying lesions in multiple trauma. The typical mechanisms, patterns and diagnostic algorithms are well known for the common ligamentous injuries (e.g. scapholunate, lunotriquetral and perilunate); therefore, consistent diagnostic procedures and adequate therapy are increasingly performed after such lesions, e. g. by early ligament repair or by ligament reconstruction through augmentation. Within appropriate operative treatment, accompanying fractures are also treated and instabilities are addressed by transfixation of joints by Kirschner wires. If followed by immobilization with a cast or stable brace, healing can be achieved in most cases; however, more problems occur if ligamentous lesions or instabilities are not clearly due to a trauma mechanism and more the result of laxity or hypermobile situations due to a congenital predisposition. In such cases, wrist pain is often described and misdiagnosed as the result of overload or tenovaginitis.

[Imaging techniques in modern trauma diagnostics]. / Bildgebende Verfahren der modernen Schockraumdiagnostik.

Modern trauma room management requires interdisciplinary teamwork and synchronous communication between a team of anaesthesists, surgeons and radiologists. As the length of stay in the trauma room influences morbidity and mortality of a severely injured person, optimizing time is one of the main targets. With the direct involvement of modern imaging techniques the injuries caused by trauma should be detected within a very short period of time in order to enable a priority-orientated treatment. Radiology influences structure and process quality, management and development of trauma room algorithms regarding the use of imaging techniques. For the individual case interventional therapy methods can be added. Based on current data and on the Frankfurt experience the current diagnostic concepts of trauma diagnostics are presented.

[Imaging techniques in modern trauma diagnostics]. / Bildgebende Verfahren der modernen Schockraumdiagnostik.

Modern trauma room management requires interdisciplinary teamwork and synchronous communication between a team of anaesthesists, surgeons and radiologists. As the length of stay in the trauma room influences morbidity and mortality of a severely injured person, optimizing time is one of the main targets. With the direct involvement of modern imaging techniques the injuries caused by trauma should be detected within a very short period of time in order to enable a priority-orientated treatment. Radiology influences structure and process quality, management and development of trauma room algorithms regarding the use of imaging techniques. For the individual case interventional therapy methods can be added. Based on current data and on the Frankfurt experience the current diagnostic concepts of trauma diagnostics are presented.

[Imaging techniques in modern trauma diagnostics]. / Bildgebende Verfahren der modernen Schockraumdiagnostik.

Modern trauma room management requires interdisciplinary teamwork and synchronous communication between a team of anaesthesists, surgeons and radiologists. As the length of stay in the trauma room influences morbidity and mortality of a severely injured person, optimizing time is one of the main targets. With the direct involvement of modern imaging techniques the injuries caused by trauma should be detected within a very short period of time in order to enable a priority-orientated treatment. Radiology influences structure and process quality, management and development of trauma room algorithms regarding the use of imaging techniques. For the individual case interventional therapy methods can be added. Based on current data and on the Frankfurt experience the current diagnostic concepts of trauma diagnostics are presented.

Minimally invasive screw fixation of fractures in the thoracic spine: CT-controlled pre-surgical guidewire implantation in routine clinical practice.

AIM: To evaluate the feasibility and accuracy of minimally invasive, transpedicular screw placement in cervicothoracic fractures with the help of computed tomography (CT)-controlled guidewires. MATERIALS AND METHODS: Two hundred and ninety-three guidewires were inserted in 35 patients (42.9±21.2 years) under CT fluoroscopy (286 thoracic, seven cervical). There were 28 traumatic cases, three pathological fractures, three fractures due to infectious infiltrations, and one osteoporotic fracture. In 151 pedicles, screw placement was performed in the CT room. CT images were reviewed regarding accuracy and cortical violations using the popular 2 mm increment deviation classification of Gertzbein and Robbins. RESULTS: Guidewire implantation resulted in only 28 cortical contacts. Minor encroachments of the pedicle wall by inserted screws occurred in 39.1% (59 of 151) and in 23.8% if taking unavoidable encroachments into account (30 of 59). Pedicular isthmus width correlated to cortical guidewire contacts (r=-0.449; p=0.077) and pedicle violations (all graded "A") by the inserted screws (r=-0.581; p=0.049). Total procedural duration was 138.6±44.2 minutes, representing 14.5±11.6 minutes for each pedicle, while showing a significant correlation against higher vertebral levels (r=-0.849; p=0.0002) and the occurrence of pedicle violations (r=-0.641; p=0.027). CONCLUSIONS: The treatment of vertebral fractures with a guidewire-based pedicle screw insertion technique under CT imaging results in very high accuracy and a low complication rate.

Radiation dose and quickness of needle CT-interventions using a laser navigation system (LNS) compared with conventional method.

PURPOSE: The aim of this study was to analyse the radiation dose and quickness of needle interventions using a Laser Navigation System (LNS-group) compared with conventional method (control-group). MATERIALS AND METHODS: In this prospective, randomized, comparative study 58 patients (19 females, 39 males; mean age, 62.9 years) were punctured either with LNS (n=29) or with conventional method with a skin mark of the puncture site (n=29). In the LNS method the puncture site was marked with laser without additional CT. Thoracic and abdominal intervention was performed in 30 and 28 patients, respectively. Radiation dose and time of the procedures were analysed. Statistical significance was calculated according to the Mann-Whitney-U-test. RESULTS: Mean target access path in the patients of the LNS group was 6.0 cm (range, 3.0-10.1cm) and in the control group 6.0 cm (range, 1.0-10.3 cm). Time duration of complete intervention in the LNS group was 20:25 min (range, 07:00-34:00 min) and in the control group 28:00 min (range, 13:00-51:00 min). The dose-length-product (DLP) of intervention scan of the LNS group was 42.3 mGy cm (range, 10-125 mGy cm), and of the control group 59.7 mGy cm (range, 25-176.42 mGy cm). CONCLUSION: Using the LNS for CT-guided interventions results in faster intervention time with a lower dose.

Magnetic resonance imaging evaluation of lipodystrophy in HIV-positive patients receiving highly active antiretroviral therapy.

We evaluated retrospectively an automated method for the separate detection of subcutaneous and visceral fat in the abdominal region by magnetic resonance studies in HIV-positive patients on highly active antiretroviral therapy. The patients were divided into four different groups: lipoatrophy, lipohypertrophy, mixed and the control group. The use of software for the automated detection of abdominal compartment visceral adipose tissue (VAT), total adipose tissue (TAT) and subcutaneous adipose tissue (SAT) was compared to manual evaluation methods (fuzzy C-mean). The results of ROC analysis showed that the parameters, particularly the VAT, are better than the VAT/TAT and at identifying patients with the symptoms of abdominal fat accumulation. A sensitivity of 80.3% and a specificity of 79.5% resulted from a threshold VAT value of >87 cm(2). Moreover, the manual evaluation method was shown to provide greater values for VAT and the VAT/TAT ratio than those given by the automated method. In the present study, a rapid MRI protocol for the detection and assessment of the course of lipodystrophy was presented and tested on a group of patients with signs of HALS, as well as on an antiretroviral naïve control group.

The health technology assessment of the compulsory accident insurance scheme of hand transplantation in Switzerland.

UNLABELLED: Recently the decision-making committee of the compulsory Swiss accident insurance scheme needed to make a basic decision as to whether to fund hand transplantation under that scheme or not. A Health Technology Assessment was commissioned to inform decision-making and gain experience with applicability of the method. The following were main findings from various domains. Compared with prosthesis fitting, the outcome of hand transplantation is satisfactory for function and sensibility. Complications due to immunosuppression are frequent, sometimes severe and potentially life-shortening. The direct medical costs over the entire life span calculated for a 35-year-old unilaterally amputated base case patient were CHF 528,600 (EUR 438,500) higher than for a prosthesis. There are challenging ethical, legal and organizational issues. The committee decided not to reimburse hand transplantation for ethical reasons. The Health Technology Assessment has been shown to be a useful tool for decision-making in the context of Swiss accident insurance. LEVEL OF EVIDENCE: IV.

Body packers on your examination table: How helpful are plain x-ray images? A definitive low-dose CT protocol as a diagnosis tool for body packers.

AIM: To analyze the clinical value and radiation dose of plain x-rays and CT in examining patients suspected of ingesting drug-filled packets. MATERIALS AND METHODS: Thirty-eight patients with suspected internal concealment of drug-filled packets who were examined with plain x-rays or CT or both were included in the study. CT studies were performed using low-dose and standard-dose techniques. All radiographic images were analysed by two radiologists regarding identification of the packets and estimating the effective radiation dose from standard- and low-dose CT versus conventional x-ray examinations. Descriptive calculations were made regarding the number and density of packs and radiation dosage. The diagnostic performance of both radiologists with standard- and low-dose CT was calculated by analysing differences in the mean number of packs found. RESULTS: Thirty-one patients were positively identified as body packers with an average of 13 packs (min: n = 1, max: n = 58, total: n = 390); seven patients were not concealing drug packets. X-ray images were taken of 24 patients prior to CT, thus allowing a direct comparison between the two methods. The correct diagnosis was made in 42%, in 33% the radiologists were uncertain, and in 25% of drug packets were either not or wrongly identified. X-ray imaging had a positive predictive value of 20% with a negative predictive value of 81%. A total of 55 CT examinations were performed on all patients with a mean effective dose of 2 mSv (low dose) versus 9.3 mSv (standard dose). The visibility of packets on low-dose CT images compared to high-dose CT was not reduced: the radiologists identified 385 and 381 of the packets, respectively, with no difference regarding the examination technique (p = 0.24 and p = 0.253, respectively). The radiodensity of all drug-filled packets at CT ranged from 26-292 HU (mean 181.2 HU). CONCLUSION: X-ray imaging of supposed body packers leads to a significant risk of diagnostic errors and additional need for CT. Instead, a single abdominal low-dose CT examination will deliver the correct diagnoses in most cases, leading to safe clinical management of the suspects.

[Surgical treatment of scapholunate ligament injuries: clinical and radiological results]. / Operative Therapie bei skapholunären Bandverletzungen: Klinische und radiologische Ergebnisse.

BACKGROUND: The purpose of this work was to retrospectively evaluate clinical and radiological results after surgical treatment for scapholunate ligament ruptures. MATERIALS AND METHODS: Measurements of range of motion, strength, and angles, as well as postoperative score assessments were performed in 32 patients. RESULTS: The average mobility in the operated wrist was 52° for flexion, extension 57°, radial 24°, ulnar deviation 31° and forearm rotation outward 88° and inward 89°. The recovery of force was 89% compared with the healthy hand. It showed an average skapholunar angle of 63°, a radioulnar angle of 22° and an average carpal height according to Nattrass of 1.49. Our patients rated the operation result with a median DASH score of 11 points (range 0-70.8 points). The median objective Mayo Wrist Score was 80 points (range 45-100 points). CONCLUSION: Surgical treatment of scapholunate ligament rupture, especially against the background of carpal collapse, is a very satisfactory method with very good results in the objective function and strength, and a high level of patient satisfaction.

MR-guided laser-induced thermotherapy (LITT) in patients with liver metastases of uveal melanoma.

PURPOSE: Evaluation of the local tumour control rate and survival data for magnetic resonance (MR) imaging-guided laser ablation of uveal malignant melanoma liver metastases by using laser-induced interstitial thermotherapy (LITT). MATERIALS AND METHODS: The LITT was performed in 18 patients with liver metastases (n = 44) from uveal malignant melanoma. All patients tolerated this intervention well. With the Kaplan-Meier method, the survival rates were calculated. Indications for the procedure were defined for patients with no more than five metastases, none of which were larger than 5 cm in diameter: The Indication for LITT treatment were recurrent liver metastases after partial liver resection (22%), locally non-resectable tumours (17%) or metastases in both liver lobes (61%). RESULTS: The mean survival rate for all treated patients was 3.6 years (95% CI: 2.19, 5.06). We started the calculation on the date of diagnosis of the metastases treated with LITT. The median survival was 1.83 years; 1-year survival, 88%; 3-year survival 47%, 5-year survival 17%. Calculated after the first LITT treatment the median survival was 2.8 years (95% CI: 1.0, 5.0). 10 patients were treated by transarterial chemoembolization before LITT. CONCLUSION: MR-guided LITT treatment shows a high local tumour control and survival rates in patients with liver metastases of uveal malignant melanoma.

Hepatic arterial infusion with irinotecan in patients with liver metastases of colorectal cancer: results of an extended phase I study.

BACKGROUND: To define the maximum tolerated dose (MTD) tolerability and efficacy of intra-arterial chemotherapy with irinotecan in patients with liver metastases of colorectal carcinoma (CRC). METHODS: Superselective intra-arterial irinotecan was applied on days 1, 14, 28 and 42. The initial dose was 140 mg/m² with escalation in the subsequent patient group to 160 mg/m². The final protocol toxicity evaluation was 260 mg/m². Patients required histologically proven disease and adequate bone marrow, liver and renal function, no extrahepatic metastasis and a life expectancy >12 weeks. results: Thirty-three patients were enrolled (median age 65, range 49-78 years). On dose level VI (240 mg/m²), 1 case of dose-limiting toxicity (DLT) (granulocytopenia) was observed, leading to an enlarged cohort of 6 patients. As no additional DLT was detected on this level, an escalation to level VII was performed. On the dose level of 260 mg/m², irinotecan DLTs were observed, resulting in the termination of escalation and the declaration of dose level VI as MTD. Imaging follow-up with Response Evaluation Criteria in Solid Tumors (RECIST) criteria revealed a complete response in 1 patient, stable disease in 31 patients, and progressed disease in 1 patient. The median time to progression was 4.7 months, the median overall survival 15.6 months. CONCLUSION: The method of intra-arterial chemotherapy with irinotecan is well tolerated and shows promising local response rates in liver metastases of CRC.

Intraoperative PEEP-ventilation during PMMA-injection for augmented pedicle screws: improvement of leakage rate in spinal surgery.

BACKGROUND: Within the last two decades the use of polymethylmethacrylate (PMMA) in the treatment of osteoporotic vertebral fractures has been established widely. Several techniques of cement application in spinal surgery have been described. Besides classical vertebroplasty, kyphoplasty and related techniques that reinforce stability of the fractured vertebral body itself, augmentation of pedicle screws became an issue in the past 10 years. Aim of this technique is strengthening of the implant-bone-interface and the prevention of loosening and failure of posterior instrumentation in limited bone quality due to osteoporosis. PMMA use in spinal surgery always bears the risk of cement leakage and cement embolism. There are only few publications dealing with cement leakage in pedicle screw augmentation. We examined our cohort concerning incidence and type of leakage in comparison to the literature. In particular, we evaluated a possible role of intrathoracic pressure during cementation procedure. PATIENTS AND METHODS: In this retrospective study 42 patients were included. Mean age was 74 (57-89) years. 311 fenestrated, augmented screws were analyzed postoperatively concerning leakage and subsequent pulmonary embolism of cement particles. Overall, there was a leakage rate of 38.3 %, and 28.6 % of patients showed pulmonary embolism of PMMA. During surgery, patients were in part ventilated with a positive end-expiratory pressure (PEEP) of 15 cmH2O during cement injection. These individuals showed significantly less leakage locally as well as less PMMA-emboli in the pulmonary circulation in contrast to patients ventilated without increased PEEP. CONCLUSION: PEEP elevation during administration of PMMA via fenestrated pedicle screws is reducing the leakage rate in spinal surgery. These beneficial effects warrant further evaluation in prospective studies.

[TEAM®-G (Trauma Evaluation and Management Germany). Serves as a basis for an interdisciplinary training in the emergency room]. / TEAM®-G ("Trauma Evaluation and Management Germany"). Grundlage für ein interdisziplinäres und interprofessionelles Schockraumtraining.

BACKGROUND: The implementation of ATLS® in the daily routine of trauma management in the emergency department is a challenge. This goal cannot be reached by educating ATLS® to a few team members only. In order to enforce the implementation of ATLS® in a level I trauma centre, a generic in-house training was introduced in 2009 with inter-professional integration of all specialists of the trauma team. MATERIALS AND METHODS: The TEAM® course (trauma evaluation and management concept of the American College of Surgeons) was the theoretical basis of the training. This educational program was developed for medical students and multidisciplinary team members. Prior training, a questionnaire for self-assessment was completed by n=84 team members to assess their knowledge about ATLS® principles. The hands-on training time was 90 min. N=10 members of the trauma team worked out three scenarios of multiple injured patients. These were provided as near-reality manikin simulations by a specialist trainer. After the training participants re-evaluated and analysed improvement by the training. Duration of trauma management and the number of missed injuries were analysed one year prior and one year after the training and served as a marker of the process and outcome quality of trauma care. RESULTS: Prior the training, 57% of trainees specified their knowledge related to the ATLS® can be improved. Their expectations were generally satisfied by the training. The mean time of trauma management in the ED could not be reduced one year after the training (36±16 min) compared to one year prior the training (39±18 min), however, the detection of missed injuries (5.6% vs. 3.2%, p<0.05) was significantly diminished after the training. CONCLUSION: Apart form education of ATLS® providers the inauguration of an interdisciplinary and interprofessionel team training may enhance implementation of ATLS- algorithms into daily routine.

First human study in treatment of unresectable liver metastases from colorectal cancer with irinotecan-loaded beads (DEBIRI).

The objective of this pilot clinical study was to assess the safety, technical feasibility, pharmacokinetic (PK) profile and tumour response of DC Bead™ with irinotecan (DEBIRI™) delivered by intra-arterial embolisation for the treatment of metastatic colorectal cancer. Eleven patients with unresectable liver metastases from CRC, tumour burden <30% of liver volume, adequate haematological, liver and renal function, performance status of <2 were included in this study. Patients received up to 4 sessions of TACE with DEBIRI at 3-week intervals. Feasibility of the procedure, safety and tumour response were assessed after each cycle. PK was measured after the first cycle. Patients were followed up to 24 weeks. Only mild to moderate adverse events were observed. DEBIRI is a technically feasibile procedure; no technical complications were observed. Average Cmax for irinotecan and SN-38 was 194 ng/ml and 16.7 ng/ml, respectively, with average t½ of 4.6 h and 12.4 h following administration of DEBIRI. Best overall response during the study showed disease control in 9 patients (2 patients with partial response and 7 with stable disease, overall response rate of 18%). Our study shows that transarterial chemoembolisation with irinotecan-loaded DC beads (DEBIRI) is safe, technically feasible and effective with a good PK profile.