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Objective: To assess the technical results of CT fluoroscopy-guided, radiofrequency-induced vertebral augmentation (StabiliT®) in terms of vertebral height restoration and polymethylmethacrylate (PMMA) leakages, occurring in 25 individual patients with vertebral compression fractures and osteolysis.Materials and Methods: From 07/2010 to 08/2011, 25 patients (16 women, nine men; age 71 ± 14; range 41-89) with painful vertebral compression fractures due to osteoporosis (n = 19), metastases (n = 2) or multiple myeloma (n = 4) underwent vertebral augmentation with a radiofrequency-activated, high-viscosity polymethylmethacrylate (PMMA) bone cement (StabiliT® Vertebral Augmentation system; DFINE Europe GmbH, Mannheim) under local anesthesia. Thirty-four vertebrae (Th5-L5) were treated in 27 sessions under CT fluoroscopy guidance (128-row CT, Somatom Definition AS, Siemens, Erlangen) using a unilateral access and a cavity-creating osteotome prior to remote-controlled, hydraulically driven cement injection. 1/2/3 levels were treated in 21/5/1 session(s). Vertebral height change in the midsagittal plane (anterior, midvertebral, posterior endplate distance) and PMMA leaks were retrospectively evaluated using the postinterventional CT.Results: All patients were successfully treated in the first session. Mean (MV ± SD) procedure time and amount of injected PMMA were 56 ± 14 min and 4.5 ± 1.4 ml, respectively. Mean anterior/midvertebral/posterior height gain was +7.1/+9.7/+0.4%. Small local vertebral leaks were observed in 18/34 vertebrae (53%) without any clinical sequelae. No major complications occurred.Conclusions: CT fluoroscopy-guided, RF-induced vertebral augmentation with a high-viscosity bone cement (StabiliT®) was safe and technically successful in all patients. Using a hydraulic cement injection technique, a moderate restoration of anterior and midvertebral height was seen while the system was not markedly superior to standard vertebroplasty regarding the frequency of minor asymptomatic PMMA leaks. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to determine the success and complication rates of radiofrequency ablation (RFA) in treatment of osteoid osteoma (OO) and duration of pain relief. Furthermore value of bone biopsy prior to the RFA was evaluated. Materials and Methods: Within 61 months 39 patients (23 male, 16 female, 7-53 years, mean 18.7 years, median 17 years) suffering from osteoid osteoma were treated. Lesions were located in femur (n=20), tibia (n=10), spine (n=5), humerus (n=1), radius (n=1), talus (n=1) and pelvis (n=1). In children, RFA was performed under general anaesthesia, in adults conscious sedation was preferred. In 29 of 39 (74%) lesion biopsies were obtained. Cooling of skin was performed in OOs located in bones with minor soft tissue covering (tibia, radius) and saline flushing via an additional needle was performed if the OO was adjacent to nerval structures. Primary success rate, complications, symptom-free interval, follow-up and biopsy results were evaluated. Results: Within observation period (1-61 months; median: 32 months) 38 of 39 patients were successfully treated and had no more complaints. In 3 of 38 patients relapse occurred after 1, 14 and 32 months and RFA was repeated. Two major complications (broken drill, infection) and 2 minor complications (hematoma, prolonged pain) were observed. Biopsy was able to prove diagnosis in 14 of 29 (48%) cases. Conclusions: Biopsy prior to treatment is not mandatory due to a remarkable amount of false negative findings in clinically and morphologically unambiguous cases of OO. RFA is a highly effective, efficient, minimally invasive and safe method for the treatment of OO. [ABSTRACT FROM AUTHOR]

Background: Unfractionated heparin (UFH) bolus is occasionally administered during endovascular treatment (EVT) to reduce thrombotic complications in acute ischemic stroke patients. However, the MR CLEAN-MED trial showed an increase in symptomatic intracranial hemorrhages (sICH) and a non-significant shift towards worse functional outcome with UFH administration. We aimed to analyze the impact of periprocedural UFH bolus in a real-world setting in anterior (ACS) and posterior circulation stroke (PCS) patients., Methods: We analyzed data from the German Stroke Registry-Endovascular Treatment using propensity score matching. Primary outcome was the modified Rankin Scale at 3 months, and secondary outcome measures included mortality, angiographic outcomes, post-EVT National Institute of Health Stroke Scale scores and ICH at 24 hours., Results: Among 13,082 patients, 7948 with ACS (UFH bolus use in 15%) and 841 with PCS (UFH bolus use in 16.3%) were included in the propensity score matching analysis. Applying MR CLEAN-MED study criteria, UFH bolus was associated with worse functional outcomes (odds ratio [OR] 1.44; 95% CI 1.06-1.96). Analyzing all ACS and PCS patients, UFH bolus did not provide any net benefit. In ACS patients treated with intravenous thrombolysis (IVT), UFH bolus use was associated with worse functional outcomes (OR 2.40; 95% CI 1.34 to 5.06)., Conclusion: Our findings show transferability of the MR CLEAN-MED results into a real-world setting, confirming a negative effect of periprocedural UFH on functional outcome in this subgroup of patients. Considering all ACS and PCS patients, periprocedural UFH did not provide a net benefit and appears to be harmful, particularly in IVT-treated patients., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Evaluation of the effectiveness of CT-guided drainage (CTD) placement in managing symptomatic postoperative fluid collections in liver transplant patients. The assessment included technical success, clinical outcomes, and the occurrence of complications during the peri-interventional period., Methods: Analysis spanned the years 2005 to 2020 and involved 91 drain placement sessions in 50 patients using percutaneous transabdominal or transhepatic access. Criteria for technical success (TS) included (a) achieving adequate drainage of the fluid collection and (b) the absence of peri-interventional complications necessitating minor or prolonged hospitalization. Clinical success (CS) was characterized by (a) a reduction or normalization of inflammatory blood parameters within 30 days after CTD placement and (b) the absence of a need for surgical revision within 60 days after the intervention. Inflammatory markers in terms of C-reactive protein (CRP), leukocyte count and interleukin-6, were evaluated. The dose length product (DLP) for various intervention steps was calculated., Results: The TS rate was 93.4%. CS rates were 64.3% for CRP, 77.8% for leukocytes, and 54.5% for interleukin-6. Median time until successful decrease was 5.0 days for CRP and 3.0 days for leukocytes and interleukin-6. Surgical revision was not necessary in 94.0% of the cases. During the second half of the observation period, there was a trend ( p = 0.328) towards a lower DLP for the entire intervention procedure (median: years 2013 to 2020: 623.0 mGy·cm vs. years 2005 to 2012: 811.5 mGy·cm). DLP for the CT fluoroscopy component was significantly ( p = 0.001) lower in the later period (median: years 2013 to 2020: 31.0 mGy·cm vs. years 2005 to 2012: 80.5 mGy·cm)., Conclusions: The TS rate of CT-guided drainage (CTD) placement was notably high. The CS rate ranged from fair to good. The reduction in radiation exposure over time can be attributed to advancements in CT technology and the growing expertise of interventional radiologists.

Purpose: Fluoroscopically guided endovascular carotid artery stenting (CAS) of extracranial carotid stenosis (ECS) is a reasonable alternative to carotid endarterectomy in selected patients. Diagnostic reference levels (DRL) for this common neurointervention have not yet been defined and respective literature data are sparse. We provide detailed dosimetrics for useful expansion of the DRL catalogue., Methods: A retrospective single-center study of patients undergoing CAS between 2013 and 2021. We analyzed dose area product (DAP) and fluoroscopy time considering the following parameters: indications for CAS, semielective/elective versus emergency including additional mechanical thrombectomy (MT) in extracranial/intracranial tandem occlusion, etiology of ECS (atherosclerotic vs. radiation-induced), periprocedural features, e.g., number of applied stents, percutaneous transluminal angioplasty (PTA) and MT maneuvers, and dose protocol. Local DRL was defined as 75% percentile of the DAP distribution., Results: A total of 102 patients were included (semielective/elective CAS n = 75, emergency CAS n = 8, CAS + MT n = 19). Total median DAP was 78.2 Gy cm 2 (DRL 117 Gy cm 2 ). Lowest and highest median dosimetry values were documented for semielective/elective CAS and CAS + MT (DAP 49.1 vs. 146.8 Gy cm 2 , fluoroscopy time 27.1 vs. 43.8 min; p < 0.005), respectively. Dosimetrics were significantly lower in patients undergoing 0-1 PTA maneuvers compared to ≥ 2 maneuvers (p < 0.05). Etiology of ECS, number of stents and MT maneuvers had no significant impact on dosimetry values (p > 0.05). A low-dose protocol yielded a 33% reduction of DAP., Conclusion: This CAS study suggests novel local DRLs for both elective and emergency cases with or without intracranial MT. A dedicated low-dose protocol was suitable for substantial reduction of radiation dose., (© 2023. The Author(s).)

Purpose: To assess accuracy, the frequency of hemorrhagic complications and computed tomography (CT) radiation dose parameters in pediatric patients undergoing landmark-guided external ventricular drain (EVD) placement in an emergency setting., Methods: Retrospective analysis comprised 36 EVD placements with subsequent CT control scans in 29 patients (aged 0 to 17 years) in our university hospital from 2008 to 2022. The position of the EVD as well as the presence and extension of bleeding were classified according to previously established grading schemes. Dose length product (DLP), volume-weighted CT dose index (CTDI vol ) and scan length were extracted from the radiation dose reports and compared to the diagnostic reference values (DRLs) issued by the German Federal Office for Radiation Protection., Results: After the initial EVD placement, optimal positioning of the catheter tip into the ipsilateral frontal horn or third ventricle (Grade I), or a functional positioning in the contralateral lateral ventricle or the non-eloquent cortex (Grade II), was achieved in 28 and 8 cases, respectively. In 32 of 36 procedures, no evidence of hemorrhage was present in the control CT scan. Grade 1 (<1 mL) and Grade 2 (≥1 to 15 mL) bleedings were detected after 3 and 1 placement(s), respectively. For control scans after EVD placements, CTDI vol (median [25%; 75% quartile]) was 39.92 [30.80; 45.55] mGy, DLP yielded 475.50 [375.00; 624.75] mGy*cm and the scan length result was 136 [120; 166] mm. Exceedances of the DRL values were observed in 14.5% for CTDI vol , 12.7% for DLP and 65.6% for the scan length. None of these values was in the range requiring a report to the national authorities., Conclusion: Landmark-based emergency EVD placement in pediatric patients yielded an optimal position in most cases already after the initial insertion. Complications in terms of secondary hemorrhages are rare. CT dose levels associated with the intervention are below the reportable threshold of the national DRLs in Germany.

Purpose: To assess the technical (TS) and clinical success (CS) of CT fluoroscopy-guided drainage (CTD) in patients with symptomatic deep pelvic fluid collections following colorectal surgery., Methods: A retrospective analysis (years 2005 to 2020) comprised 43 drain placements in 40 patients undergoing low-dose (10-20 mA tube current) quick-check CTD using a percutaneous transgluteal ( n = 39) or transperineal ( n = 1) access. TS was defined as sufficient drainage of the fluid collection by ≥50% and the absence of complications according to the Cardiovascular and Interventional Radiological Society of Europe (CIRSE). CS comprised the marked reduction of elevated laboratory inflammation parameters by ≥50% under minimally invasive combination therapy (i.v. broad-spectrum antibiotics, drainage) within 30 days after intervention and no surgical revision related to the intervention required., Results: TS was gained in 93.0%. CS was obtained in 83.3% for C-reactive Protein and in 78.6% for Leukocytes. In five patients (12.5%), a reoperation due to an unfavorable clinical outcome was necessary. Total dose length product (DLP) tended to be lower in the second half of the observation period (median: years 2013 to 2020: 544.0 mGy*cm vs. years 2005 to 2012: 735.5 mGy*cm) and was significantly lower for the CT fluoroscopy part (median: years 2013 to 2020: 47.0 mGy*cm vs. years 2005 to 2012: 85.0 mGy*cm)., Conclusions: Given a minor proportion of patients requiring surgical revision due to anastomotic leakage, the CTD of deep pelvic fluid collections is safe and provides an excellent technical and clinical outcome. The reduction of radiation exposition over time can be achieved by both the ongoing development of CT technology and the increased level of interventional radiology (IR) expertise., Competing Interests: The authors declare that they have no conflicts of interest.

To evaluate the technical outcome, clinical success, and safety of low-milliampere CT fluoroscopy (CTF)-guided percutaneous drain (PD) placement in patients with lymphoceles following radical prostatectomy (RP) with pelvic lymph node dissection (LND). This retrospective analysis comprised 65 patients with PD placement in lymphoceles following RP under low-milliampere CTF guidance. Technical and clinical success were evaluated. Complications within a 30-day time interval associated with CTF-guided PD placement were classified according to SIR. Patient radiation exposure was quantified using dose-length products (DLP) of the pre-interventional planning CT scan (DLPpre), of the sum of intra-interventional CT fluoroscopic acquisitions (DLPintra) and of the post-interventional control CT scan (DLPpost). Eighty-nine lymphoceles were detected. Seventy-seven CT-guided interventions were performed, with a total of 92 inserted drains. CTF-guided lymphocele drainage was technically successful in 100% of cases. For all symptomatic patients, improvement in symptoms was reported within 48 h after intervention. Time course of C-reactive protein and Leucocytes within 30 days revealed a statistically significant (p < 0.0001) decrease. Median DLPpre, DLPintra and DLPpost were 431 mGy*cm, 45 mGy*cm and 303 mGy*cm, respectively. Only one minor complication (self-resolving haematoma over the bladder dome; SIR Grade 2) was observed. Low-milliampere CTF-guided drainage is a safe treatment option in patients with lymphoceles following RP with pelvic LND characterized by high technical and good clinical success rates, which provides rapid symptom relief and serves as definite treatment or as a bridging therapy prior to laparoscopic marsupialisation.

(1) Purpose: To retrospectively assess the technical and clinical outcome of patients with symptomatic postoperative fluid collections after pancreatic surgery, treated with CT-guided drainage (CTD). (2) Methods: 133 eligible patients between 2004 and 2017 were included. We defined technical success as the sufficient drainage of the fluid collection(s) and the absence of peri-interventional complications (minor or major according to SIR criteria). Per definition, clinical success was characterized by normalization of specific blood parameters within 30 days after the intervention or a decrease by at least 50% without requiring additional surgical revision. C-reactive protein (CRP), Leukocytes, Interleukin-6, and Dose length product (DLP) for parts of the intervention were determined. (3) Results: 97.0% of 167 interventions were technically successful. Clinical success was achieved in 87.5% of CRP, in 78.4% of Leukocytes, and in 87.5% of Interleukin-6 assessments. The median of successful decrease was 6 days for CRP, 5 days for Leukocytes, and 2 days for Interleukin-6. No surgical revision was necessary in 93.2%. DLP was significantly lower in the second half of the observation period (total DLP: median 621.5 mGy*cm between 2011-2017 vs. median 944.5 mGy*cm between 2004-2010). (4) Conclusions: Technical success rate of CTD was very high and the clinical success rate was fair to good. Given an elderly and multimorbid patient cohort, CTD can have a temporizing effect in the postoperative period after pancreatic surgery. Reducing the radiation dose over time might reflect developments in CT technology and increased experience of interventional radiologists.

Carotid cavernous fistulas (CCFs) are abnormal connections between the cavernous sinus and the internal and/or external carotid artery. Endovascular therapy is the gold standard treatment. In the current retrospective single-center study we report detailed dosimetrics of all patients with CCFs treated by endovascular coil embolization between January 2012 and August 2021. Procedural and dosimetric data were compared between direct and indirect fistulas according to Barrow et al., and different DSA protocol groups. The local diagnostic reference level (DRL) was defined as the 3rd quartile of the dose distribution. In total, thirty patients met the study criteria. The local DRL was 376.2 Gy cm 2 . The procedural dose area product (DAP) ( p = 0.03) and the number of implanted coils ( p = 0.02) were significantly lower in direct fistulas. The median values for fluoroscopy time (FT) ( p = 0.08) and number of DSA acquisitions ( p = 0.84) were not significantly different between groups. There was a significantly positive correlation between DAP and FT ( p = 0.003). The application of a dedicated low-dose protocol yielded a 32.6% DAP reduction. In conclusion, this study provides novel DRLs for endovascular CCF treatment using detachable coils. The data presented in this work might be used to establish new specific DRLs.

Arterial ischemic stroke in childhood and adolescence is one of the most time-critical emergencies in pediatrics. Nevertheless, it is often diagnosed with a considerable time delay which may be associated with low awareness, the sometimes nonspecific clinical presentation with a wide variety of differential diagnoses, and less established 'acute care structures'. The revascularisation strategies in adult stroke care are also potential and promising treatment options for children, even if available evidence is still limited. In the post-acute phase, the etiological work-up is complex due to the multitude of risk factors to be considered. But it is essential to identify each child's individual risk profile as it determines secondary prevention, risk of recurrence and outcome. Long-term care in a multiprofessional, interdisciplinary team must take into account the bio-psycho-social aspects to integrate the child into its social and educational, and later professional environment., (© 2022. The Author(s).)

Purpose:  Since artificial intelligence is transitioning from an experimental stage to clinical implementation, the aim of our study was to evaluate the performance of a commercial, computer-aided detection algorithm of computed tomography pulmonary angiograms regarding the presence of pulmonary embolism in the emergency room., Materials and Methods:  This retrospective study includes all pulmonary computed tomography angiogram studies performed in a large emergency department over a period of 36 months that were analyzed by two radiologists experienced in emergency radiology to set a reference standard. Original reports and computer-aided detection results were compared regarding the detection of lobar, segmental, and subsegmental pulmonary embolism. All computer-aided detection findings were analyzed concerning the underlying pathology. False-positive findings were correlated to the contrast-to-noise ratio., Results:  Expert reading revealed pulmonary embolism in 182 of 1229 patients (49 % men, 10-97 years) with a total of 504 emboli. The computer-aided detection algorithm reported 3331 findings, including 258 (8 %) true-positive findings and 3073 (92 %) false-positive findings. Computer-aided detection analysis showed a sensitivity of 47 % (95 %CI: 33-61 %) on the lobar level and 50 % (95 %CI 43-56 %) on the subsegmental level. On average, there were 2.25 false-positive findings per study (median 2, range 0-25). There was no significant correlation between the number of false-positive findings and the contrast-to-noise ratio (Spearman's Rank Correlation Coefficient = 0.09). Soft tissue (61.0 %) and pulmonary veins (24.1 %) were the most common underlying reasons for false-positive findings., Conclusion:  Applied to a population at a large emergency room, the tested commercial computer-aided detection algorithm faced relevant performance challenges that need to be addressed in future development projects., Key Points:   · Computed tomography pulmonary angiograms are frequently acquired in emergency radiology.. · Computer-aided detection algorithms (CADs) can support image analysis.. · CADs face challenges regarding false-positive and false-negative findings.. · Radiologists using CADs need to be aware of these limitations.. · Further software improvements are necessary ahead of implementation in the daily routine.., Citation Format: · Müller-Peltzer K, Kretzschmar L, Negrão de Figueiredo G et al. Present Limitations of Artificial Intelligence in the Emergency Setting - Performance Study of a Commercial, Computer-Aided Detection Algorithm for Pulmonary Embolism. Fortschr Röntgenstr 2021; 193: 1436 - 1444., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Purpose: Intracranial lateral dural arteriovenous fistula (LDAVF) represents a specific subtype of cerebrovascular fistulae, harboring a potentially life-threatening risk of brain hemorrhage. Fluoroscopically guided endovascular embolization is the therapeutic gold standard. We provide detailed dosimetry data to suggest novel diagnostic reference levels (DRL)., Methods: Retrospective single-center study of LDAVFs treated between January 2014 and December 2019. Regarding dosimetry, the dose area product (DAP) and fluoroscopy time were analyzed for the following variables: Cognard scale grade, endovascular technique, angiographic outcome, and digital subtraction angiography (DSA) protocol., Results: A total of 70 patients (19 female, median age 65 years) were included. Total median values for DAP and fluoroscopy time were 325 Gy cm 2 (25%/75% percentile: 245/414 Gy cm 2 ) and 110 min (68/142min), respectively. Neither median DAP nor fluoroscopy time were significantly different when comparing low-grade with high-grade LDAVF (Cognard I + IIa versus IIb-V; p > 0.05, each). Transvenous coil embolization yielded the lowest dosimetry values, with significantly lower median values when compared to a combined transarterial/transvenous technique (DAP 290 Gy cm 2 versus 388 Gy cm 2 , p = 0.031; fluoroscopy time 85 min versus 170 min, p = 0.016). A significant positive correlation was found between number of arterial feeders treated by liquid embolization and both DAP (r s  = 0.367; p = 0.010) and fluoroscopy time (rs = 0.295; p = 0.040). Complete LDAVF occlusion was associated with transvenous coiling (p = 0.001). A low-dose DSA protocol yielded a 20% reduction of DAP (p = 0.021)., Conclusion: This LDAVF study suggests several local DRLs which varied substantially dependent on the endovascular technique and DSA protocol., (© 2020. The Author(s).)

Purpose: To retrospectively evaluate the technical and clinical outcome of patients with symptomatic postoperative fluid collections following liver resection treated with CT-guided drainage (CTD)., Methods: 143 suitable patients were examined between 2004 and 2017. Technical success was defined as (a) sufficient drainage of the fluid collection and (b) the non-occurrence of peri-interventional complications requiring surgical treatment with minor or prolonged hospitalization. Clinical success was defined as (a) decreasing or normalization of specific blood parameters within 30 days after intervention and (b) no surgical revision in addition to intervention required. C-reactive protein (CRP), leukocytes and Total Serum Bilirubin (TSB) were assessed. Dose length product (DLP) for the intervention parts was determined., Results: Technical success was achieved in 99.5% of 189 performed interventions. Clinical success was reached in 74% for CRP, in 86.7% for Leukocytes and in 62.1% for TSB. The median of successful decrease was 6.0 days for CRP, 3.5 days for Leukocytes and 5.5 days for TSB. In 90.2%, no surgical revision was necessary. Total DLP was significantly lower in the second half of the observation period (median 536.0 mGy*cm between years 2011 and 2017 vs. median 745.5 mGy*cm between years 2004 and 2010)., Conclusions: Technical success rate of CTD was very high, and clinical success rate was fair to good. Reduction of the radiation dose reflects developments of CT technology and increased experience of the interventional radiologists.

Purpose: We aimed to evaluate technical and clinical success and safety of computed tomography fluoroscopy (CTF)-guided percutaneous pigtail drainage (PPD) placement in patients with infected renal and perirenal fluid collections., Methods: This retrospective analysis comprised 44 patients (52.27% men; age, 57.1±18.5 years) undergoing low-milliampere (10-20 mA) CTF-guided PPD placement in 61 sessions under local anesthesia from August 2005 to November 2016. Infected fluid collections (n=71) included infected renal cysts (12.68%), renal and perirenal abscesses due to comorbidities (23.94%), or fluid collections after renal surgery or urological intervention (63.38%). Technical success was defined as PPD placement with consecutive fluid aspiration, clinical success as normalization or marked improvement of clinical symptoms (e.g., flank pain, fever) and inflammatory parameters (leukocyte count, C-reactive protein) after minimally invasive combination therapy (intravenous broad-spectrum antibiotics and drainage). Complications were classified according to the CIRSE classification., Results: Overall, 73 single lumen PPD (7.5-12 F) were utilized (1 PPD per session, 69.86%; 2 PPD per session, 15.07%). In 4 cases, PPD could not be inserted into the fluid collection (4.11%) or could not be aspirated (1.37%), yielding overall 94.5% primary technical success. Mean duration of functioning PPD before removal was 10.9 days. Adverse events within 30 days comprised PPD failure (2.27%) or secondary dislocation (Grade 3, 11.36%) and one death (Grade 6, unrelated to intervention, 2.27%). Additional invasive measures after primary CTF-guided PPD were required in 5 patients (nephrectomy 6.82%, partial nephrectomy 2.27%, surgical drainage 2.27%). Thus, clinical success using only minimally invasive measures was achieved in 39 of 44 patients (88.64%)., Conclusion: Given a minor proportion of patients requiring surgical revision, combined antibiotics and CTF-guided PPD of infected renal and perirenal fluid collections provides an excellent technical and clinical outcome.

Purpose: To evaluate technical outcome, diagnostic yield and safety of computed tomographic fluoroscopy-guided percutaneous core needle biopsies in patients with mediastinal masses., Methods: Overall, 155 CT fluoroscopy-guided mediastinal core needle biopsies, performed from March 2010 to June 2020 were included. Size of lesion, size of needle, access path, number of success, number of biopsies per session, diagnostic yield, patient's position, effective dose, rate of complications, tumor localization, size of tumor and histopathological diagnosis were considered. Post-interventional CT was performed, and patients observed for any complications. Complications were classified per the Society of Interventional Radiology (SIR)., Results: 148 patients (age, 54.7 ± 18.2) underwent 155 CT-fluoroscopy-guided percutaneous biopsies with tumors in the anterior (114; 73.5%), middle (17; 11%) and posterior (24; 15.5%) mediastinum, of which 152 (98%) were technically successful. For placement of the biopsy needle, in 82 (52.9%) procedures a parasternal trajectory was chosen, in 36 (23.3%) a paravertebral access, in 20 (12.9%) through the lateral intercostal space and in 17 (11%) the thoracic anterior midline, respectively. A total of 136 (89.5%) of the biopsies were considered adequate for a specific histopathologic analysis. Total DLP (dose-length product) was 575.7 ± 488.8 mGy*cm. Mean lesion size was 6.0 ± 3.3 cm. Neoplastic pathology was diagnosed in 115 (75.7%) biopsies and 35 (23%) biopsy samples showed no evidence of malignancy. Minor complications were observed in 18 (11.6%) procedures and major pneumothorax requiring drainage insertion in 3 interventions (1.9%)., Conclusion: CT fluoroscopy-guided percutaneous core needle biopsy of mediastinal masses is an effective and safe procedure for the initial assessment of patients with mediastinal tumors.

Objectives: Modern endovascular treatment of unruptured intracranial aneurysms (UIAs) demands for observance of diagnostic reference levels (DRLs). The national DRL (250 Gy cm 2 ) is only defined for coiling. We provide dosimetric data for the following procedures: coiling, flow diverter (FD), Woven EndoBridge (WEB), combined techniques., Methods: A retrospective single-centre study of saccular UIAs treated between 2015 and 2019. Regarding dosimetric analysis, the parameters dose area product (DAP) and fluoroscopy time were investigated for the following variables: endovascular technique, aneurysm location, DSA protocol, aneurysm size, and patient age., Results: Eighty-seven patients (59 females, mean age 54 years) were included. Total mean and median DAP (Gy cm 2 ) were 119 ± 73 (89-149) and 94 (73; 130) for coiling, 128 ± 53 (106-151) and 134 (80; 176) for FD, 128 ± 56 (102-153) and 118 (90; 176) for WEB, and 165 ± 102 (110-219) and 131 (98; 209) for combined techniques (p > .05). Regarding the aneurysm location, neither DAP nor fluoroscopy time was significantly different (p > .05). The lowest and highest fluoroscopy times were recorded for WEB and combined techniques, respectively (median 26 and 94 min; p < .001). A low-dose protocol yielded a 43% reduction of DAP (p < .001). Significantly positive correlations were found between DAP and both aneurysm size (r = .320, p = .003) and patient age (r = .214, p = .046)., Conclusions: This UIA study establishes novel local DRLs for modern endovascular techniques such as FD and WEB. A low-dose protocol yielded a significant reduction of radiation dose., Key Points: • This paper establishes local diagnostic reference levels for modern endovascular treatment techniques of unruptured intracranial aneurysms, including flow diverter stenting and Woven EndoBridge device. • Dose area product was not significantly different between endovascular techniques and aneurysm locations, but associated with aneurysm size and patient age. • A low-dose protocol yielded a significant reduction of dose area product and is particularly useful when applying materials with a high radiopacity (e.g. platinum coils).

Purpose:  To observe the technical and clinical outcome as well as safety of CT fluoroscopy-guided drain placement in the multimodal clinical complication management of superinfected gastric leakage after sleeve gastrectomy., Materials and Methods:  All consecutive patients who underwent CT fluoroscopy-guided drain placement to treat superinfected postoperative leakage after sleeve gastrectomy in our department between 2007 and 2014 were included in this retrospective study. All interventions were performed on a 16- or 128-row CT scanner under intermittent CT fluoroscopy guidance (15-25 mAs, 120 kV). The technical and clinical success rates as well as complications, additional therapies and patient radiation dose were analyzed., Results:  14 patients (mean age: 43.8 ± 11.3 years, mean BMI: 52.9 ± 13.5, 7 women) who underwent a total of 31 CT fluoroscopy-guided drain placement procedures were included. 30 of 31 interventions (96.8 %) were technically successful. 7 patients underwent more than one intervention due to drain obstruction or secondary dislocation or as further treatment. During and after the intervention no procedure-associated complications occurred. In all patients, inflammation parameters decreased within days after the CT-guided intervention. The total interventional dose length product (DLP) was 1561 ± 1035 mGy*cm., Conclusion:  CT fluoroscopy-guided drain placement has been shown to be a safe minimally invasive procedure that rarely leads to complications for treating superinfected gastric leakage occurring after sleeve gastrectomy. We assume that operative revisions in a high-risk patient group can be avoided using this procedure., Key Points:   · CT fluoroscopy-guided drain placement in obese - often medically highly complex - patients is a technically feasible procedure.. · Multimodal treatment (CT intervention, endoscopy and surgery) is required to successfully treat gastric leakage after bariatric surgery.. · High-risk surgery might be avoided by the CT-guided drain placement.., Citation Format: · Schwarz J, Strobl FF, Paprottka PM et al. CT Fluoroscopy-Guided Drain Placement to Treat Infected Gastric Leakage after Sleeve Gastrectomy: Technical and Clinical Outcome of 31 Procedures. Fortschr Röntgenstr 2020; 192: 163 - 170., Competing Interests: The authors declare that they have no conflict of interest., (© Georg Thieme Verlag KG Stuttgart · New York.)

In this third-generation dual-source CT (DSCT) study, we retrospectively investigated radiation dose and image quality of portal-venous high-pitch emergency CT in 60 patients (28 female, mean age 56 years) with a body mass index (BMI) ≥ 30 kg/m 2 . Patients were dichotomized in groups A (median BMI 31.5 kg/m 2 ; n = 33) and B (36.8 kg/m 2 ; n = 27). Volumetric CT dose index (CTDI vol ), size-specific dose estimate (SSDE), dose length product (DLP) and effective dose (ED) were assessed. Contrast-to-noise ratio (CNR) and dose-independent figure-of-merit (FOM) CNR were calculated. Subjective image quality was assessed using a five-point scale. Mean values of CTDI vol , SSDE as well as normalized DLP and ED were 7.6 ± 1.8 mGy, 8.0 ± 1.8 mGy, 304 ± 74 mGy * cm and 5.2 ± 1.3 mSv for group A, and 12.6 ± 3.7 mGy, 11.0 ± 2.6 mGy, 521 ± 157 mGy * cm and 8.9 ± 2.7 mSv for group B (p < 0.001). CNR of the liver and spleen as well as each calculated FOM CNR were significantly higher in group A (p < 0.001). Subjective image quality was good in both groups. In conclusion, third-generation abdominal high-pitch emergency DSCT yields good image quality in obese patients. Radiation dose increases in patients with a BMI > 36.8 kg/m 2 .

Objectives: Intraoperative CT (iCT) angiography of the brain with stereotactic frames is an integral part of navigated neurosurgery. Validated data regarding radiation dose and image quality in these special examinations are not available. We therefore investigated two iCT protocols in this IRB-approved study., Methods: Retrospective analysis of patients, who received a cerebral stereotactic iCT angiography on a 128 slice CT scanner between February 2016 and December 2017. In group A, automated tube current modulation (ATCM; reference value 410 mAs) and automated tube voltage selection (reference value 120 kV) were enabled, and only examinations with a selected voltage of 120 kV were included. In group B, fixed parameters were applied (300 mAs, 120 kV). Radiation dose was measured by assessing the volumetric CT dose index (CTDI vol ), dose length product (DLP) and effective dose (ED). Signal-to-noise ratio (SNR) and image noise were assessed for objective image quality, visibility of arteries and grey-white differentiation for subjective image quality., Results: Two hundred patients (n = 100 in each group) were included. In group A, median selected tube current was 643 mAs (group B, 300 mAs; p < 0.001). Median values of CTDI vol , DLP and ED were 91.54 mGy, 1561 mGy cm and 2.97 mSv in group A, and 43.15 mGy, 769 mGy cm and 1.46 mSv in group B (p < 0.001). Image quality did not significantly differ between groups (p > 0.05)., Conclusions: ATCM yielded disproportionally high radiation dose due to substantial tube current increase at the frame level, while image quality did not improve. Thus, ATCM should preferentially be disabled., Key Points: • Automated tube current modulation (ATCM) yields disproportionally high radiation dose in intraoperative CT angiography of the brain with stereotactic head frames. • ATCM does not improve overall image quality in these special examinations. • ATCM is not yet optimised for CT angiography of the brain with major extracorporeal foreign materials within the scan range.

Purpose: We aimed to assess the safety and technical outcome of computed tomography (CT) fluoroscopy-guided osteoplasty with or without prior percutaneous radiofrequency ablation (RFA) in patients with painful osteolyses., Methods: We performed a retrospective analysis of 29 patients with painful extraspinal and spinal osteolyses (16 women, 13 men; 63.1±14.4 years) who underwent CT fluoroscopy-guided osteoplasty (10-20 mAs tube current) with or without RFA (26 and 14 lesions, respectively), in 33 consecutive procedures from 2002 to 2016. Technical success was defined as at least one complete RFA cycle and subsequent polymethyl metacrylate (PMMA) bone cement injection covering ≥75% of longest diameter of extraspinal osteolysis on axial plane or of distance between vertebral endplates. Procedure-related complications within 30 days and dose-length-product (DLP) were also evaluated., Results: Osteolyses were located in the pelvis (acetabulum, n=10; iliac bone, n=4), spine (thoracic, n=6; lumbar, n=5; sacral, n=8), long bones (femur, n=3; tibia, n=1), sternum (n=2) and glenoid (n=1). Mean size of the treated osteolysis was 4.0±1.2 cm (range, 1.9-6.9 cm). Of 40 osteolyses, 31 (77.5%) abutted neighboring risk structures (spinal canal or neuroforamen, n=18; neighboring joint, n=11; other, n=8). Mean number of RFA electrode positions and complete ablation cycles was 1.5±0.9 and 2.1±1.7, respectively. Mean PMMA filling volume was 7.7±5.7 mL (range, 2-30 mL). Small asymptomatic PMMA leakages were observed in 15 lesions (37.5%). Mean total DLP was 850±653 mGy*cm. Six minor complications were observed, without any major complications., Conclusion: CT fluoroscopy-guided percutaneous osteoplasty with or without concomitant RFA for the treatment of painful extraspinal and spinal osteolyses can be performed with a low complication rate and high technical success.

Background In unclear pancreatic lesions, a tissue sample can confirm or exclude the suspected diagnosis and help to provide an optimal treatment strategy to each patient. To date only one small study reported on the outcome of computed tomography (CT) fluoroscopy-guided biopsies of the pancreas. Purpose To evaluate technical success and diagnostic rate of all CT fluoroscopy-guided core biopsies of the pancreas performed in a single university center during a 10-year period. Material and Methods In this retrospective study we included all patients who underwent a CT fluoroscopy-guided biopsy of a pancreatic mass at our comprehensive cancer center between 2005 and 2014. All interventions were performed under local anesthesia on a 16-row or 128-row CT scanner. Technical success and diagnostic rates as well as complications and effective patient radiation dose were analyzed. Results One hundred and one patients (54 women; mean age, 63.9 ± 12.6 years) underwent a total of 104 CT fluoroscopy-guided biopsies of the pancreas. Ninety-eight of 104 interventions (94.2%) could be performed with technical success and at least one tissue sample could be obtained. In 88 of these 98 samples, a definitive pathological diagnosis, consistent with clinical success could be achieved (89.8%). Overall 19 minor and three major complications occurred during the intra- or 30-day post-interventional period and all other interventions could be performed without complications; there was no death attributable to the intervention. Conclusion CT fluoroscopy-guided biopsy of pancreatic lesions is an effective procedure characterized by a low major complication and a high diagnostic rate.

Objectives: Our aim was to provide further evidence for the efficacy/safety of radioembolization using yttrium-90-resin microspheres for unresectable chemorefractory liver metastases from colorectal cancer (mCRC)., Methods: We followed 104 consecutively treated patients until death. Overall survival (OS) was calculated from the day of the first radioembolization procedure. Response was defined by changes in tumour volume as defined by Response Evaluation Criteria in Solid Tumours (RECIST) v1.0 and/or a ≥30 % reduction in serum carcinoembryonic antigen (CEA) at 3 months., Results: Survival varied between 23 months in patients who had a complete response to prior chemotherapy and 13 months in patients with a partial response or stable disease. Median OS also significantly improved (from 5.8 months to 17.1 months) if response durability to radioembolization extended beyond 6 months. Patients with a positive trend in CEA serum levels (≥30 % reduction) at 3 months post-radioembolization also had a survival advantage compared with those who did not: 15.0 vs 6.7 months. Radioembolization was well tolerated. Grade 3 increases in bilirubin were reported in 5.0 % of patients at 3 months postprocedure., Conclusions: After multiple chemotherapies, many patients still have a good performance status and are eligible for radioembolization. This single procedure can achieve meaningful survivals and is generally well tolerated., Key Points: • After multiple chemotherapies, many patients are still eligible for radioembolization (RE). • RE can achieve meaningful survival in patients with chemorefractory liver-predominant metastatic colorectal cancer (mCRC). • Tumour responsiveness to prior systemic treatments is a significant determinant of overall survival (OS) after RE. • Radioembolization in patients with a good performance status is generally well tolerated.

Purpose: The aim of this study was to evaluate the clinical and functional outcomes in patients who underwent selective interventional embolization of renal pseudoaneurysms or arteriovenous fistulas at our center., Materials and Methods: Our retrospective analysis included all consecutive patients who received selective transcatheter embolization of renal pseudoaneurysms or arteriovenous fistulas after partial nephrectomy in our department from January, 2003 to September, 2013. The technical and clinical success rate and functional outcome of every procedure was collected and analyzed. Furthermore, the change in renal parenchymal volume before and after embolization was determined in a subgroup., Results: A total of 1425 patients underwent partial nephrectomy at our hospital. Of these, 39 (2.7 %) were identified with a pseudoaneurysm or an arteriovenous fistula after partial nephrectomy. The diagnosis of the vascular lesions was made by means of biphasic CT or CEUS. Technical success by means of selective microcoil embolization was achieved in all 39 patients (100 %). Clinical success, defined as no need for further operation or nephrectomy during follow-up, was achieved in 35 of 39 patients (85.7 %). Renal function, as measured by eGFR before and after the intervention, did not change significantly. However, a mean loss of parenchymal volume of 25.2 % was observed in a subgroup. No major or minor complications were attributable to the embolization procedure., Conclusion: Transcatheter embolization is a promising method for treating vascular complications which may occur after partial nephrectomy. We confirm the high success rate of this technique while discussing renal functional outcomes and potential safety aspects., Key Points: Arterial pseudoaneurysms and arteriovenous fistulas are rare but severe complications after partial nephrectomy. Selective microcoil embolization is a safe and effective kidney-preserving procedure for treating these complications. Embolization leads to a significant loss of renal parenchymal volume but not to a loss of renal function., (© Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: This study was designed to assess technical success and complications in patients with high-risk soft tissue sarcomas undergoing CT fluoroscopy-guided closed-tip catheter placement before treatment with combined chemotherapy and regional hyperthermia., Materials and Methods: This retrospective study comprised all patients referred for insertion of closed-tip catheters for the introduction of thermometry probes before regional hyperthermia treatment at a single university centre from 2010 to 2015. Catheter placements were performed under local anaesthesia and intermittent CT fluoroscopy guidance. Technical success, complication rate, duration of catheter insertion and dose-length product (DLP) were analysed. Technical success was defined as intratumoural catheter placement suitable for subsequent thermometry., Results: A total of 35 procedures were performed on 35 patients (22 men, 13 women). In 34 out of 35 interventions catheters were inserted successfully; in one patient catheter placement was not feasible. No intra-interventional complications occurred. In six patients post-interventional complications were observed - two major (one abscess formation and one severe catheter dislocation) and four minor complications. Technical failure was observed in 11.4% of patients, especially catheter kinking. A total of 55 catheters were placed, with a mean number of 1.7 ± 0.7 per patient. Mean total DLP was 723.2 ± 355.9 mGy*cm., Conclusion: CT fluoroscopy-guided closed-tip catheter placement into high-risk soft tissue sarcomas was characterised by high technical success and relatively low complication rate. While major complications were rarely observed, catheter-kinking preventing successful thermometry represented the most frequent technical failure.

Purpose: To evaluate the safety of radioembolization (RE) with (90)Yttrium ((90)Y) resin microspheres depending on coiling or no-coiling of aberrant/high-risk vessels., Materials and Methods: Early and late toxicity after 566 RE procedures were analyzed retrospectively in accordance with the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE v3.0). For optimal safety, aberrant vessels were either coil embolized (n = 240/566, coiling group) or a more peripheral position of the catheter tip was chosen to treat right or left liver lobes (n = 326/566, no-coiling group)., Results: Clinically relevant late toxicities (≥ Grade 3) were observed in 1% of our overall cohort. The no-coiling group had significantly less "any" (P = 0.0001) or "clinically relevant" (P = 0.0003) early toxicity. There was no significant difference (P > 0.05) in delayed toxicity in the coiling versus the no-coiling group. No RE-induced liver disease was noted after all 566 procedures., Conclusion: RE with (90)Y resin microspheres is a safe and effective treatment option. Performing RE without coil embolization of aberrant vessels prior to treatment could be an alternative for experienced centers.

Objectives: To assess the technical and clinical results of MRgFUS treatment and factors affecting clinical treatment success., Materials and Methods: A total of 252 women (mean age, 42.1 ± 6.9 years) with uterine fibroids underwent MRgFUS. All patients underwent MRI before treatment. Results were evaluated with respect to post-treatment nonperfused volume (NPV), symptom severity score (SSS), reintervention rate, pregnancy and safety data., Results: NPV ratio was significantly higher in fibroids characterized by low signal intensity in contrast-enhanced T1-weighted fat saturated MR images and in fibroids distant from the spine (>3 cm). NPV ratio was lower in fibroids with septations, with subserosal component and in skin-distant fibroids (p < 0.001). NPV ratio was highly correlated with clinical success: NPV of more than 80 % resulted in clinical success in more than 80 % of patients. Reintervention rate was 12.7 % (mean follow-up time, 19.4 ± 8 months; range, 3-38). Expulsion of fibroids (21 %) was significantly correlated with a high clinical success rate. No severe adverse events were reported., Conclusions: Adequate patient selection and correct treatment techniques, based on the learning curve of this technology, combined with technical advances of the system, lead to higher clinical success rates with low complications rate, comparable to other uterine-sparing treatment options., Key Points: • MRgFUS appears to be a valid alternative to other uterus-preserving therapies • Patient selection is a significant factor in achieving high NPV ratios • MRI screening parameters correlate with the amount of fibroid ablation in MRgFUS • NPV results of more than 80 % correlate with higher clinical success rates.

The purpose of this study was to evaluate the role of diffusion-weighted MR imaging (DW-MRI) in the assessment of treatment response of primary or secondary liver malignancies after stereotactic radiosurgery (SRS) using robotic radiosurgery. All patients who underwent SRS therapy for hepatic malignancies who had pre- and post-interventional MR examinations including DW-MRI at our hospital between 02/2010 and 02/2012 were included. A retrospective analysis of the institutional imaging database identified 13 patients (4 men, 9 women, mean age: 66 years) with a total of 14 primary or secondary liver malignancies. Criteria of tumor response to treatment were a decrease in size and/or loss of contrast enhancement as assessed with respect to RECIST criteria. Mean apparent diffusion coefficient (ADC) values for normal liver parenchyma and hepatic masses in each MR examination were calculated and compared using two-tailed, paired t-test with a significance level of 0.05. Mean ADC values of liver malignancies were 1.10 ± 0.30 x 10(-3) mm(2)/s, 1.48 ± 0.35 x 10(-3) mm(2)/s and 1.56 ± 0.40 x 10(-3) mm(2)/s on pre-interventional, the first post-interventional, and the second post-interventional DW-MRI. There was a significant increase of ADC values between the pre-interventional examination and the first and second post-interventional follow-up exams (p < 0.01 and p = 0.01, respectively). However, there was no statistical difference between the ADC values of the first and second post-interventional MRI. ADC values of normal liver parenchyma did not show significant changes in ADC values during pre- and post-interventional MRI. ADC measurements may allow the evaluation of response to treatment of hepatic malignancies by SRS. ADC values of liver malignancies increase significantly after SRS treatment., (© The Author(s) 2014.)

Purpose: To evaluate technical success, complications, and effective dose in patients undergoing CT fluoroscopy-guided iliosacral screw placement for the fixation of unstable posterior pelvic ring injuries., Materials and Methods: Our retrospective analysis includes all consecutive patients with vertical sacral fractures and/or injury of the iliosacral joint treated with CT fluoroscopy-guided screw placement in our department from 11/2005 to 03/2013. Interventions were carried out under general anesthesia and CT fluoroscopy (10-20 mAs; 120 kV; 16- or 128-row scanner, Siemens Healthcare, Erlangen, Germany). Technical outcome, major and minor complications, and effective patient dose were analyzed., Results: We treated 99 consecutive patients (mean age 53.1 ± 21.7 years, 50 male, 49 female) with posterior pelvic ring instability with CT fluoroscopy-guided screw placement. Intervention was technically successful in all patients (n = 99). No major and one minor local complication occurred (1 %, secondary screw dislocation). General complications included three cases of death (3 %) due to pulmonary embolism (n = 1), hemorrhagic shock (n = 1), or cardiac event (n = 1) during a follow-up period of 30 days. General complications were not related to the intervention. Mean effective patient radiation dose per intervention was 12.28 mSv ± 7.25 mSv. Mean procedural time was 72.1 ± 37.4 min., Conclusions: CT fluoroscopy-guided screw placement for the treatment of posterior pelvic ring instabilities can be performed with high technical success and a low complication rate. This method provides excellent intrainterventional visualization of iliac and sacral bones, as well as the sacral neuroforamina for precise screw placement by applying an acceptable effective patient dose.

Purpose: To evaluate technical outcome and safety of computed tomographic (CT) fluoroscopy-guided percutaneous fiducial marker placement before CyberKnife stereotactic radiosurgery., Materials and Methods: Retrospective analysis was performed of 196 patients (106 men) undergoing CT fluoroscopy-guided fiducial marker placement in 222 consecutive procedures under local anesthesia from March 2006 to February 2012. Technical success was defined as fiducial marker location in the tumor or vicinity suitable for CyberKnife radiosurgery evaluated on postinterventional planning CT. Complications were classified per Society of Interventional Radiology (SIR)., Results: One hundred ninety-six patients (age, 61.5 y ± 13.1) underwent percutaneous placement of 321 fiducial markers (mean per tumor, 1.2 ± 0.5; range, 1-4) in 37 primary tumors and 227 metastases in the thorax (n = 121), abdomen (n = 122), and bone (n = 21). Fiducial marker placement was technically successful in all procedures: intratumoral localization in 193 (60.1%), at tumor margin in 50 (15.6%), and outside of tumor in 78 cases (24.3%; mean distance to marker, 0.4 cm ± 0.6; range, 0-2.9 cm). Complications were observed in 63 placement procedures (28.4%), including minor self-limiting pneumothorax (n = 21; SIR class B) and self-limiting pulmonary hemorrhage (n = 35; SIR class A), and major pneumothorax requiring thoracostomy/drainage insertion (n = 14; SIR class D) and systemic toxicity of local anesthetic drug (n = 1; SIR class D)., Conclusions: CT fluoroscopy-guided percutaneous fiducial marker placement can be performed with high technical success under local anesthesia in various anatomic regions. Although self-limiting in most cases, pneumothorax and pulmonary hemorrhage are frequently observed during fiducial marker implantation into lung tumors., (Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.)

Although ultrasound and magnetic resonance imaging are competitive imaging modalities for the guidance of needle-based interventions, computed tomography (CT) is the only modality suitable for image-guided interventions in all regions of the body, including the lungs and bone. The ongoing technical development of CT involves accelerated image acquisition, significantly improved spatial resolution, CT scanners with an extended gantry diameter, acceleration of the procedure through joystick control of relevant functions of interventional CT by the interventional radiologist and tube current modulation to protect the hands of the examiner and radiosensitive organs of the patient. CT fluoroscopy can be used as a real-time method (the intervention is monitored under continuous CT fluoroscopy) or as a quick check method (repeated acquisitions of individual CT fluoroscopic images after each change of needle or table position). For the two approaches, multislice CT fluoroscopy (MSCTF) technique with wide detectors is particularly useful because even in the case of needle deviation from the center slice the needle tip is simultaneously visualised in the neighboring slices. With the aid of this technique a precise placement of interventional devices is possible even in angled access routes and in the presence of pronounced respiratory organ movements. As the reduction of CT fluoroscopy time significantly reduces radiation exposure for the patient and staff, the combination of a quick check technique and a low milliampere technique with multislice CT fluoroscopy devices is advantageous.

With respect to monitoring of high intensity focused ultrasound (HIFU), synonym focused ultrasound (FUS) treatment, magnetic resonance imaging (MRI) is characterized by several advantageous properties: the precise definition and morphological characterization of the target area (before and after the intervention), the real-time visualization of the treatment effect by thermal imaging (during the intervention) and in the sense of a stereotactic system, the 3-dimensional localization of the target lesion, planning of the target volume and assessment of the achieved ablation volume (before and during the intervention). Non-enhanced T2-weighted multislice MR images are acquired for planning of the intervention. For temperature monitoring (comprising thermometry and thermodosimetry), the temperature-dependent shift of proton resonance frequency (PRFS) is most frequently employed. This method is independent of the treated tissue type or thermally induced tissue changes and facilitates a relative measurement of the temperature change based on a reference value. Future MRI applications include diffusion-weighted MRI (DWI-MRI; for the intrainterventional estimation of treatment efficacy), dynamic contrast-enhanced MRI (DCE-MRI, for the prediction of the potential and assessment of the treatment effect achieved) and motion-corrected temperature monitoring (referenceless and multibaseline thermometry).

Objectives: The aim of this study was to assess the impact of the advanced technology of the new ExAblate 2100 system (Insightec Ltd, Haifa, Israel) for magnetic resonance imaging (MRI)-guided focused ultrasound surgery on treatment outcomes in patients with symptomatic uterine fibroids, as measured by the nonperfused volume ratio., Materials and Methods: This is a retrospective analysis of 115 women (mean age, 42 years; range, 27-54 years) with symptomatic fibroids who consecutively underwent MRI-guided focused ultrasound treatment in a single center with the new generation ExAblate 2100 system from November 2010 to June 2011. Mean ± SD total volume and number of treated fibroids (per patient) were 89 ± 94 cm and 2.2 ± 1.7, respectively. Patient baseline characteristics were analyzed regarding their impact on the resulting nonperfused volume ratio., Results: Magnetic resonance imaging-guided focused ultrasound treatment was technically successful in 115 of 123 patients (93.5%). In 8 patients, treatment was not possible because of bowel loops in the beam pathway that could not be mitigated (n = 6), patient movement (n = 1), and system malfunction (n = 1). Mean nonperfused volume ratio was 88% ± 15% (range, 38%-100%). Mean applied energy level was 5400 ± 1200 J, and mean number of sonications was 74 ± 27. No major complications occurred. Two cases of first-degree skin burn resolved within 1 week after the intervention. Of the baseline characteristics analyzed, only the planned treatment volume had a statistically significant impact on nonperfused volume ratio., Conclusions: With technological advancement, the outcome of MRI-guided focused ultrasound treatment in terms of the nonperfused volume ratio can be enhanced with a high safety profile, markedly exceeding results reported in previous clinical trials.

Background: Stereotactic radiation therapy is an evolving modality to treat otherwise unresectable liver metastases. In this analysis, two local therapies: 1) single session robotic radiosurgery (RRS) and 2) percutaneous radiofrequency ablation (RFA) were compared in a total of 60 heavily pretreated colorectal cancer patients., Methods: Thirty patients with a total of 35 colorectal liver metastases not qualifying for surgery that were treated in curative intent with RRS were prospectively followed. To compare efficacy of both treatment modalities, patients treated with RFA during the same period of time were matched according to number and size of the treated lesions. Local tumor control, local disease free survival (DFS), and freedom from distant recurrence (FFDR) were analyzed for efficacy. Treatment-related side effects were recorded for comparison., Results: The median diameter of the treated lesions was 33 mm (7-53 mm). Baseline characteristics did not differ significantly between the groups. One- and two-year local control rates showed no significant difference but favored RRS (85% vs. 65% and 80% vs. 61%, respectively). A significantly longer local DFS of patients treated with RRS compared to RFA (34.4 months vs. 6.0 months; p < 0.001) was found. Both, median FFDR (11.4 months for RRS vs. 7.1 months for RFA p = 0.25) and the recurrence rate (67% for RRS and 63% for RFA, p > 0.99) were comparable., Conclusion: Single session RRS is a safe and effective method to treat colorectal liver metastases. In this analysis, a trend towards longer DFS was seen in patients treated with RRS when compared to RFA.

Standard Radiological Methods: High-intensity focused ultrasound (synonyms FUS and HIFU) under magnetic resonance imaging (MRI) guidance (synonyms MRgFUS and MR-HIFU) is a completely non-invasive technology for accurate thermal ablation of a target tissue while neighboring tissues and organs are preserved., Methodical Innovations: The combination of FUS with MRI for planning, (near) real-time monitoring and outcome assessment of treatment markedly enhances the safety of the procedure., Achievements: The MRgFUS procedure is clinically established in particular for the treatment of symptomatic uterine fibroids, followed by palliative ablation of painful bone metastases. Furthermore, promising results have been shown for the treatment of adenomyosis, malignant tumors of the prostate, breast and liver and for various intracranial applications, such as thermal ablation of brain tumors, functional neurosurgery and transient disruption of the blood-brain barrier.