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1.
J Pers Med ; 14(4)2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38673028

ABSTRACT

The aim of this study was to evaluate treatment of osteoid osteomas using bipolar radiofrequency ablation (RFA) and patients' quality of life before and after therapy. We retrospectively evaluated patients who underwent bipolar RFA of osteoid osteomas between 2001 and 2016. We assessed patients' symptoms before and after treatment (four weeks after treatment and long-term) using a questionnaire including severity and quality of pain on a 10-point scale (1 = no pain, 10 = severe pain), motion restrictions, pain-related sleep disorders, and necessary pain medication. In addition, we evaluated technical success, complications, hospitalization length, and patients' satisfaction with treatment. This study included 62 patients (43 [69.4%] males, 26.2 ± 13.2 years). Average nidus size was 5.7 ± 2.6 mm. The rate of technical success was 100%. All RFAs were performed without any complications. One patient showed a recurrence, resulting in a recurrence rate of 1.6%, which was successfully treated by another session of RFA. Average hospitalization length was 1.5 ± 0.5 days. A total of 36 patients (58.1%) participated in the questionnaire, reporting an average pain severity of 8.2 ± 1.6 before RFA compared to 3.4 ± 3.0 four weeks after and an average of 2.1 ± 2.3, 6.6 years after therapy, (both p < 0.001). After therapy, 31 (86.1%) patients had no pain. The majority of patients (n = 34, 94.4%) had reduced or absent motion restriction after therapy (p < 0.001). Patient satisfaction rate was 91.7%. In conclusion, bipolar RFA is a safe and effective treatment modality for osteoid osteomas and improves quality of life by reducing pain severity and motion restrictions.

2.
J Appl Clin Med Phys ; 24(2): e13860, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36565180

ABSTRACT

This prospective study sought to evaluate potential savings of radiation dose to medical staff using real-time dosimetry coupled with visual radiation dose feedback during angiographic interventions. For this purpose, we analyzed a total of 214 angiographic examinations that consisted of chemoembolizations and several other types of therapeutic interventions. The Unfors RaySafe i2 dosimeter was worn by the interventionalist at chest height over the lead protection. A total of 110 interventions were performed with real-time radiation dosimetry allowing the interventionalist to react upon higher x-ray exposure and 104 examinations served as the comparative group without real-time radiation monitoring. By using the real-time display during interventions, the overall mean operator radiation dose decreased from 3.67 (IQR, 0.95-23.01) to 2.36 µSv (IQR, 0.52-12.66) (-36%; p = 0.032) at simultaneously reduced operator exposure time by 4.5 min (p = 0.071). Dividing interventions into chemoembolizations and other types of therapeutic interventions, radiation dose decreased from 1.31 (IQR, 0.46-3.62) to 0.95 µSv (IQR, 0.53-3.11) and from 24.39 (IQR, 12.14-63.0) to 10.37 µSv (IQR, 0.85-36.84), respectively, using live-screen dosimetry (p ≤ 0.005). Radiation dose reductions were also observed for the participating assistants, indicating that they could also benefit from real-time visual feedback dosimetry during interventions (-30%; p = 0.039). Integration of real-time dosimetry into clinical processes might be useful in reducing occupational radiation exposure time during angiographic interventions. The real-time visual feedback raised the awareness of interventionalists and their assistants to the potential danger of prolonged radiation exposure leading to the adoption of radiation-sparing practices. Therefore, it might create a safer environment for the medical staff by keeping the applied radiation exposure as low as possible.


Subject(s)
Occupational Exposure , Radiation Exposure , Radiation Injuries , Humans , Radiation Dosage , Prospective Studies , Feedback, Sensory , Radiometry , Radiation Injuries/prevention & control , Radiation Exposure/prevention & control , Occupational Exposure/prevention & control , Radiography, Interventional , Fluoroscopy
3.
NMR Biomed ; 36(2): e4828, 2023 02.
Article in English | MEDLINE | ID: mdl-36082477

ABSTRACT

Whole-body magnetic resonance imaging (MRI) has become increasingly popular in oncology. However, the long acquisition time might hamper its widespread application. We sought to assess and compare free-breathing sequences with conventional breath-hold examinations in whole-body MRI using an automated workflow process. This prospective study consisted of 20 volunteers and six patients with a variety of pathologies who had undergone whole-body 1.5-T MRI that included T1-weighted radial and Dixon volumetric interpolated breath-hold examination sequences. Free-breathing sequences were operated by using an automated user interface. Image quality, diagnostic confidence, and image noise were evaluated by two experienced radiologists. Additionally, signal-to-noise ratio was measured. Diagnostic performance for the overall detection of pathologies was assessed using the area under the receiver operating characteristics curve (AUC). Study participants were asked to rate their examination experiences in a satisfaction survey. MR free-breathing scans were rated as at least equivalent to conventional MR scans in more than 92% of cases, showing high overall diagnostic accuracy (95% [95% CI 92-100]) and performance (AUC 0.971, 95% CI 0.942-0.988; p < 0.0001) for the assessment of pathologies at simultaneously reduced examination times (25 ± 2 vs. 32 ± 3 min; p < 0.0001). Interrater agreement was excellent for both free-breathing (Ï° = 0.96 [95% CI 0.88-1.00]) and conventional scans (Ï° = 0.93 [95% CI 0.84-1.00]). Qualitative and quantitative assessment for image quality, image noise, and diagnostic confidence did not differ between the two types of MR image acquisition (all p > 0.05). Scores for patient satisfaction were significantly better for free-breathing compared with breath-hold examinations (p = 0.0145), including significant correlations for the grade of noise (r = 0.79, p < 0.0001), tightness (r = 0.71, p < 0.0001), and physical fatigue (r = 0.52, p = 0.0065). In summary, free-breathing whole-body MRI in tandem with an automated user interface yielded similar diagnostic performance at equivalent image quality and shorter acquisition times compared to conventional breath-hold sequences.


Subject(s)
Image Interpretation, Computer-Assisted , Magnetic Resonance Imaging , Humans , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Prospective Studies , Whole Body Imaging , Workflow
4.
Eur J Radiol Open ; 9: 100427, 2022.
Article in English | MEDLINE | ID: mdl-35757233

ABSTRACT

Purpose: To assess the diagnostic precision of three different workstations for measuring thoracic aortic aneurysms (TAAs) in vivo and ex vivo using either pre-interventional computed tomography angiography scans (CTA) or a specifically designed phantom model. Methods: This retrospective study included 23 patients with confirmed TAA on routinely performed CTAs. In addition to phantom tube diameters, one experienced blinded radiologist evaluated the dimensions of TAAs on three different workstations in two separate rounds. Precision was assessed by calculating measurement errors. In addition, correlation analysis was performed using Pearson correlation. Results: Measurements acquired at the Siemens workstation deviated by 3.54% (range, 2.78-4.03%; p = 0.14) from the true size, those at General Electric by 4.05% (range, 1.46-7.09%; p < 0.0001), and at TeraRecon by 4.86% (range, 3.22-6.45%; p < 0.0001). Accordingly, Siemens provided the most precise workstation at simultaneously most fluctuating values (scattering of 4.46%). TeraRecon had the smallest fluctuation (scattering of 2.83%), but the largest deviation from the true size of the phantom. The workstation from General Electric showed a scattering of 2.94%. The highest overall correlation between the 1st and 2nd rounds was observed with measurements from Siemens (r = 0.898), followed by TeraRecon (r = 0.799), and General Electric (r = 0.703). Repetition of measurements reduced processing times by 40% when using General Electric, by 20% with Siemens, and by 18% with TeraRecon. Conclusions: In conclusion, all three workstations facilitated precise assessment of dimensions in the majority of cases at simultaneously high reproducibility, ensuring accurate pre-interventional planning of thoracic endovascular aortic repair.

5.
Cancers (Basel) ; 13(9)2021 Apr 28.
Article in English | MEDLINE | ID: mdl-33924810

ABSTRACT

BACKGROUND AND AIMS: Systemic treatment with sorafenib has been the standard of care (SOC) in patients with advanced Barcelona Clinic Liver Cancer (BCLC) stage C hepatocellular carcinoma (HCC) for more than a decade. TACE has been reported to allow better local tumor control in selected patients with BCLC stage C HCC. METHODS: A retrospective analysis of patients with BCLC stage C HCC that were treated with sorafenib and TACE was conducted; they were compared to BCLC stage C patients treated either with TACE or sorafenib in the same period of time outside a clinical trial. RESULTS: A total of 201 patients with BCLC stage C were identified, who were treated with either sorafenib and TACE (group A; n = 54), sorafenib (group B; n = 82) or TACE (group C; n = 65). No significant difference in baseline characteristics was observed. Time to progression was 7.0 months (95% CI: 4.3-9.7), 4.1 months (95% CI: 3.6-4.7) and 5.0 months (95% CI: 2.9-7.1) in groups A, B and C, respectively, and overall survival was 16.5 months (95% CI: 15.0-18.1), 8.4 months (95% CI: 6.0-10.8) and 10.5 months (95% CI: 7.5-13.6), respectively (group A vs. group B: p < 0.001; group A vs. group C: p = 0.0023). Adverse events of grade 3/4 occurred in 34% of patients in group A. CONCLUSIONS: Although sorafenib is a SOC in patients with BCLC stage C HCC, TACE is frequently used as an additional locoregional treatment in selected patients. This combined approach resulted in a significant overall survival benefit in selected patients, although randomized trials have not yet proven this benefit.

7.
Minim Invasive Ther Allied Technol ; 28(6): 373-380, 2019 Dec.
Article in English | MEDLINE | ID: mdl-30428741

ABSTRACT

Purpose: To assess the accuracy and time requirements of image-guided percutaneous K-wire insertion in the spine using an advanced robot assistance device for needle guidance and to demonstrate a radiation-free workflow for the physician. Material and methods: A planning CT-scan was acquired of a cadaver specimen and analyzed using a 3D-interventional software integrated in the robotic device. The optimal needle path was simulated and the needle holder of the robot was used for guidance during K-wire insertion. Twenty-four K-wires were inserted percutaneously in a transpedicular approach in the following vertebrae: thoracic (T) 2, 7-12 and lumbar (L) 1-5. A post-procedural CT scan was performed to analyze the accuracy of the K-wire insertion. Results: All procedures were carried out without any perforation of the pedicle wall. The mean duration of planning the intervention path was 2:54 ± 2:22 min, mean positioning time was 2:04 ± 0:42 min and the mean time for K-wire insertion was 2:13 ± 0:54 min. In total, the average intervention time was 7:10 ± 3:06 min per pedicle. Compared to the planning, the K-wire position showed a mean deviation of 0.5 mm in the vertical-axis and 1.2 mm in the horizontal-axis. The average intervention path length was 8.1 cm. Conclusion: Our findings show a high accuracy in robot-assisted K-wire insertion during spinal interventions without any exposure of the operator to radiation.


Subject(s)
Lumbar Vertebrae/surgery , Robotics , Tomography, X-Ray Computed , Bone Wires , Humans , Surgery, Computer-Assisted/methods
8.
Rofo ; 190(6): 513-520, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29763951

ABSTRACT

PURPOSE: This study was carried out to investigate the impact of abdominal dynamic four-dimensional CT angiography (4D-CTA) for guiding transarterial chemoembolization (TACE) on the amount of contrast material used, operator radiation exposure, catheter consumption, and diagnostic confidence. MATERIALS AND METHODS: Written consent was waived for this IRB-approved retrospective study. 29 patients (20 men; mean age: 65.7 ±â€Š11.5 years) with malignant liver lesions underwent 4D-CTA, prior to initial TACE. Time-resolved volume-rendering technique (VRT), maximum-intensity projection (MIP), and multiplanar reconstruction (MPR) series were reconstructed, enabling a direct selective catheterization of the tumor-supplying artery without prior conventional digital subtraction angiography (DSA). 29 patients (16 men; mean age: 69.4 ±â€Š13.9) who underwent traditional TACE served as the control group. The amount of administered contrast media, operator radiation exposure, and catheter consumption during TACE were compared. Two radiologists assessed diagnostic confidence in the exclusion of portal vein thrombosis. RESULTS: 4D-CTA TACE resulted in a significant reduction in the amount of contrast media used, compared to traditional TACE (-61.0 ml/ -66.3 % intra-arterial, -12.8 ml/ -13.8 % overall; P < 0.001). The dose-area product indicating operator radiation exposure during intervention was reduced by 50.5 % (P < 0.001), and 0.7 fewer catheters on average were used (P = 0.063), while 4D-CTA data was available to guide TACE. Diagnostic confidence in the exclusion of portal vein thrombosis was significantly enhanced by 4D-CTA, compared to traditional DSA images (scores, 3.9 and 2.4, respectively; P < 0.001). CONCLUSION: Dynamic 4D-CTA enables TACE with a substantially reduced amount of contrast material, decreases operator radiation exposure, and increases diagnostic confidence in the exclusion of portal vein thrombosis. KEY POINTS: · 4D-CTA prior to TACE decreases the amount of utilized contrast material.. · The intra-arterial fraction of contrast media can be reduced by two-thirds.. · The risk of CIN may be decreased by means of 4D-CTA TACE.. · Operator radiation exposure is lower using 4D-CTA for guiding TACE.. · 4D-CTA portography allows for a higher diagnostic confidence than conventional DSA images.. CITATION FORMAT: · Albrecht MH, Vogl TJ, Wichmann JL et al. Dynamic 4D-CT Angiography for Guiding Transarterial Chemoembolization: Impact on the Reduction of Contrast Material, Operator Radiation Exposure, Catheter Consumption, and Diagnostic Confidence. Fortschr Röntgenstr 2018; 190: 513 - 520.


Subject(s)
Catheters , Chemoembolization, Therapeutic , Four-Dimensional Computed Tomography , Occupational Exposure/prevention & control , Radiation Exposure/prevention & control , Radiography, Interventional , Aged , Aged, 80 and over , Bile Duct Neoplasms/blood supply , Bile Duct Neoplasms/diagnostic imaging , Bile Duct Neoplasms/therapy , Carcinoma, Hepatocellular/blood supply , Carcinoma, Hepatocellular/diagnostic imaging , Carcinoma, Hepatocellular/therapy , Cholangiocarcinoma/blood supply , Cholangiocarcinoma/diagnostic imaging , Cholangiocarcinoma/therapy , Cohort Studies , Computed Tomography Angiography , Contrast Media/administration & dosage , Equipment Failure , Female , Humans , Liver Neoplasms/blood supply , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/secondary , Liver Neoplasms/therapy , Male , Middle Aged , Retrospective Studies , Triiodobenzoic Acids/administration & dosage
9.
Pancreas ; 46(8): 1039-1045, 2017 09.
Article in English | MEDLINE | ID: mdl-28796138

ABSTRACT

OBJECTIVES: Choosing the best treatment option at the optimal point of time for patients with walled-off necrosis (WON) is crucial. We aimed to identify imaging parameters and clinical findings predicting the need of necrosectomy in patients with WON. METHODS: All patients with endoscopically diagnosed WON and pseudocyst were retrospectively identified. Post hoc analysis of pre-interventional contrast-enhanced computed tomography was performed for factors predicting the need of necrosectomy. RESULTS: Sixty-five patients were included in this study. Forty patients (61.5%) were diagnosed with pseudocyst and 25 patients (38.5%) with WON. Patients with WON mostly had acute pancreatitis with biliary cause compared with more chronic pancreatitis and toxic cause in pseudocyst group (P = 0.002 and P = 0.004, respectively). Logistic regression revealed diabetes as a risk factor for WON. Computed tomography scans revealed 4.62% (n = 3) patients as false positive and 24.6% (n = 16) as false negative findings for WON. Reduced perfusion and detection of solid findings were independent risk factors for WON. CONCLUSIONS: Computed tomography scans are of low diagnostic yield when needed to predict treatment of patients with pancreatic cysts. Reduced pancreatic perfusion and solid findings seem to be a risk factor for WON, whereas patients with diabetes seem to be at higher risk of developing WON.


Subject(s)
Endoscopy/methods , Pancreatitis/diagnostic imaging , Tomography, X-Ray Computed/methods , Abscess/diagnostic imaging , Abscess/etiology , Abscess/surgery , Acute Disease , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Necrosis/diagnostic imaging , Necrosis/etiology , Necrosis/surgery , Pancreatitis/complications , Pancreatitis/surgery , Predictive Value of Tests , Prognosis , Retrospective Studies , Risk Factors , Treatment Outcome , Young Adult
10.
World J Clin Oncol ; 8(4): 343-350, 2017 Aug 10.
Article in English | MEDLINE | ID: mdl-28848701

ABSTRACT

AIM: To evaluate the clinical value and efficiency of trans-arterial chemoperfusion (TACP) in patients with liver metastases from breast cancer (BC) and colorectal cancer (CRC). METHODS: We treated 36 patients with liver metastases of BC (n = 19, 19 females) and CRC (n = 17; 8 females, 9 males) with repeated TACP. The treatment interval was 4 wk. TACP was performed with gemcitabine (1000 mg/m2) and mitomycin (10 mg/m2), administered within 1 h after positioning the catheter tip in the hepatic artery. Before treatment, the size, location, tumour volume, vascularization and number of liver tumours were evaluated using magnetic resonance imaging (MRI). Tumour response was evaluated according to the Response Evaluation Criteria in Solid Tumors guidelines. RESULTS: TACP using gemcitabine and mitomycin for metastases from CRC and BC was performed without any serious side effects. The follow-up MRI showed a therapeutic response in 84.2% of the BC patients - stable disease 47.4% and partial response 36.8%. A progression was seen in 15.8%. CRC patients showed a therapeutic response in 52.9% of cases. A progression of the disease was documented in 47.1% of the patients with CRC. These data show that TACP in patients with liver metastases of BC leads to a significantly better therapeutic response compared with CRC patients (P = 0.042). The median survival time was 13.2 mo for the BC patients, which is significantly longer than for CRC patients at 9.3 mo (P = 0.001). CONCLUSION: TACP for liver metastases of BC appears to be a safe and effective palliative treatment with improved outcomes in comparison to patients with CRC.

11.
Radiol Manage ; 39(1): 17-21, 2017 Jan.
Article in English | MEDLINE | ID: mdl-30725545

ABSTRACT

The purpose of this work was a cost analysis for the acquisition of two new MRI devices in a university hospital. The costs of a classical exchange (new purchase) were compared to those of a system upgrade. Taking the local circumstances into account, up to $121,000 could be saved with. the system upgrade for one MRI system compared to a classic exchange. Upgrades of the 1.5 and 3 Tesla systems were performed within 15 working days without any problems or restrictions. The number of examinations per day could be increased from 13.4 to 16.2 using the 1.5T system and from 14.1 to 15.9 using the 3T. The upgrade possibility of an old MRI device represents an economically attractive approach, which allows access to the latest state-of-the-art MRI technology while respecting the limited economic resources of the department.


Subject(s)
Capital Expenditures/statistics & numerical data , Financial Management, Hospital/methods , Magnetic Resonance Imaging/instrumentation , Costs and Cost Analysis , Efficiency, Organizational , Germany , Hospital Design and Construction , Humans , Organizational Case Studies
12.
Eur J Radiol ; 86: 26-32, 2017 Jan.
Article in English | MEDLINE | ID: mdl-28027757

ABSTRACT

PURPOSE: To compare free-breathing radial VIBE with moderate undersampling (us-radial-VIBE) with a standard breathhold T1-weighted volumetric interpolated sequence (3D GRE VIBE) in patients unable to suspend respiration during dynamic liver examination. MATERIAL AND METHODS: 23 consecutive patients underwent dynamic liver MR examination using the free-breathing us-radial-VIBE sequence as part of their oncologic follow-up. All patients were eligible for the free-breathing protocol due to severe respiratory artifacts at the planning or precontrast sequences. The us-radial-VIBE acquisitions were compared to the patients last staging liver MRI including a standard breathhold 3D GRE VIBE. For an objective image evaluation, signal intensity (SI), image noise (IN), signal-to-noise ratio (SNR) and contrast-enhancement ratio (CER) were compared. Representative image quality parameters, including typical artifacts were independently, retrospectively and blindly scored by four readers. RESULTS: Us-radial-VIBE had significant lower SNR (p<0.0001) and higher IN (p<0.0001), whereas SI did not differ (p=0.62). Temporal resolution assessed with CER in the arterial phase showed higher values for us-radial-VIBE (p=0.028). Subjective image quality parameters received generally slightly higher scores for 3D GRE VIBE. In a smaller subgroup comprising patients with severe respiratory artifacts also at reference breathhold 3D GRE VIBE examination, us-radial-VIBE showed significantly higher image quality scores. Furthermore, there were generally more severe respiratory artifacts in 3D GRE VIBE, whereas streaking was characteristic in almost all us-radial-VIBE acquisitions but did not affect diagnostic validity. CONCLUSION: Free-breathing dynamic liver imaging using us-radial-VIBE delivers accurate temporal resolution, low motion artifact susceptibility and good image quality and represents a promising alternative in patients unable to suspend respiration.


Subject(s)
Liver Neoplasms/diagnosis , Magnetic Resonance Imaging/methods , Artifacts , Breath Holding , Contrast Media , Feasibility Studies , Female , Humans , Image Enhancement/methods , Imaging, Three-Dimensional/methods , Male , Middle Aged , Motion , Respiration , Retrospective Studies , Signal-To-Noise Ratio
13.
Radiol Med ; 122(3): 194-203, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27896570

ABSTRACT

OBJECTIVE: Purpose of our study was to demonstrate the feasibility and limitations of acoustic noise reduction in a standard clinical MRI protocol for abdominal imaging. METHODS: Acoustic noise and image quality were assessed in 17 patients for a standard liver imaging protocol including TSE and GRE sequences and compared to quiet optimizations as described by Heismann et al. Two blinded readers scored artifacts, the delineation of the abdominal organs and level of diagnostic confidence. Means of the sound level measurements, the ratings and the measurement of SNR and CNR were compared. RESULTS: Significant reduction of acoustic noise was measured for T2 TSE (-30.7%), T2 HASTE (-22.6%) and less difference for T1 DIXON (-4.7%) and T1 FLASH (-2.7%). SNR and CNR were lower for quiet T2 TSE (-18.0%, -23.1%) and T2 HASTE (-46.2%, -37.7%) and higher for T1 DIXON (+32.0%, +24.4%). Inter-rater correlation was k = 0.987 with p < 0.001. CONCLUSIONS: Although sequence-based noise optimizations faces problems in T1 FLASH and DIXON sequences, there is an important acoustic benefit in T2 TSE and T2 HASTE sequences, which goes along with a maintained image quality and diagnostic confidence.


Subject(s)
Abdomen/diagnostic imaging , Artifacts , Loudness Perception , Magnetic Resonance Imaging/methods , Noise/prevention & control , Algorithms , Feasibility Studies , Female , Humans , Liver/diagnostic imaging , Magnetic Resonance Imaging/standards , Male , Middle Aged
14.
Visc Med ; 32(2): 116-20, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27413729

ABSTRACT

BACKGROUND: Hepatocellular carcinoma (HCC) is a frequent complication of liver cirrhosis. Worldwide, HCC is one of the most common cancers, with a rising incidence. METHODS: A selective literature search was conducted, taking into account current studies, reviews, meta-analyses, and guidelines. RESULTS: The diagnosis is established either non-invasively by dynamic imaging, showing a typical contrast enhancement and wash-out, or histopathologically. Pathological diagnosis of HCC is recommended for all atypical nodules in patients with cirrhosis and for those in non-cirrhotic patients. Tumor therapy as well as treatment of the underlying chronic liver disease and/or preservation of liver function are important for the management of patients with HCC. Standard stage-adapted treatments are based on the widely applied Barcelona Clinic Liver Cancer staging system including liver resection and transplantation, interventional treatments such as thermal ablation and transarterial therapies, and systemic treatment with the tyrosine kinase inhibitor sorafenib. After failure of sorafenib, anti-angiogenic drugs, MET inhibitors, and immunotherapeutics are currently under advanced clinical investigation. CONCLUSION: Treatment of HCC is multidisciplinary and therefore requires a close cooperation between various disciplines such as hepatology, visceral surgery, radiology, and oncology to achieve the best outcome depending on the tumor stage and degree of liver function impairment.

15.
Int J Hyperthermia ; 32(7): 757-64, 2016 11.
Article in English | MEDLINE | ID: mdl-27436220

ABSTRACT

PURPOSE: Computed tomography (CT) and ultrasound-guided microwave ablations (MWA) are part of the established treatment of liver tumours. In spite of its potential advantages, magnetic resonance (MR) monitoring of MWA did not enter clinical practice because of the lack of compatible devices. The purpose of the current study was to prove the feasibility of real-time qualitative MR monitoring using a new MR-compatible MWA device. MATERIAL AND METHODS: We performed 27 MWA experiments with different durations (5, 10 and 15 min) on an ex vivo bovine liver model using a MR-compatible MWA device. We compared the diameters of the ablation zone as depicted on three T1-based sequences to those of the macroscopic specimen. The volume and the sphericity index of the macroscopic ablation area were calculated in order to characterise the device. Ablation pattern and artefacts on the three sequences were also taken into account. RESULTS: We obtained high-quality real-time images using all three sequences. The diameters as depicted on the MR sequences slightly overestimated the macroscopic ablation area but correlated significantly in all cases (p < 0.05). VIBE provided the best correlation for both short-axis diameter (r = 0.96) and long-axis diameter (r = 0.87), whereas starVIBE (r = 0.85; r = 0.72) and FLASH (r = 0.75; r = 0.84) correlated slightly less. Significantly more severe noise artefacts were observed on starVIBE compared to FLASH and VIBE sequences (p < 0.0001). CONCLUSION: The current ex vivo liver model experiment suggests that real-time qualitative MR monitoring of MWA is feasible. Further research using in vivo and human models are recommended.


Subject(s)
Ablation Techniques/methods , Liver/surgery , Magnetic Resonance Imaging/methods , Microwaves/therapeutic use , Animals , Catheter Ablation/methods , Cattle , Humans
16.
Eur J Radiol ; 85(8): 1432-8, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27423684

ABSTRACT

OBJECTIVES: To evaluate the influence of endorectal coil (ERC) regarding spectral quality and diagnostic suitability and diagnostic performance in 3.0T 1H-magnetic resonance spectroscopy imaging (MRSI) compared to 1.5T MRSI. MATERIALS AND METHODS: The study was approved by the Institutional Review Board. MRSI of the prostate was performed on 19 patients at 1.5T with ERC (protocol 1), at 3.0T with a disabled ERC (protocol 2) and at 3.0T with ERC (protocol 3). Age, weight, body size, body-mass-index, prostate volume, time between measurements, diagnostic suitability of spectra, histopathological results after biopsy of cancer suspect lesions (CSL), sensitivity and specificity were evaluated. Signal-to-noise ratio (SNR) was calculated and compared using semiparametrical multiple Conover-comparisons. Correlations between SNR and prostate volume and BMI were indicated using Pearson correlation coefficient. Distribution of SNR was evaluated for prostate quadrants. RESULTS: Diagnostic suitable spectra were achieved in 76 % (protocol 1, 100% in CSL), 32 % (protocol 2, 59% in CSL) and 50 % (protocol 3, 80% in CSL) of the voxels. SNR was significantly higher in protocol 3 compared to protocol 2 and 1 (93,729 vs. 27,836 vs. 32,897, p<0.0001) with significant difference between protocol 2 and 1 (p<0.023). Highest SNR was achieved in the dorsal prostate (protocols 1 and 3; p<0.0001). Sensitivity at 3.0T was higher with use of ERC. Specificity was highest at 1.5T with ERC. CONCLUSION: The ERC improves the diagnostic suitability and the SNR in MRSI at 3.0T. Less voxels at 3.0T with disabled ERC are suitable for diagnosis compared to 1.5T with ERC. MRSI at 3.0T with ERC shows the highest SNR. SNR in dorsal quadrants of the prostate was higher using ERC.


Subject(s)
Image Enhancement/instrumentation , Image Interpretation, Computer-Assisted/instrumentation , Magnetic Resonance Spectroscopy/methods , Prostatic Neoplasms/diagnostic imaging , Aged , Biopsy , Body Mass Index , Humans , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Image Processing, Computer-Assisted/methods , Male , Middle Aged , Prospective Studies , Prostate/diagnostic imaging , Prostate/pathology , Prostatic Neoplasms/pathology , Sensitivity and Specificity , Signal-To-Noise Ratio
17.
Br J Radiol ; 89(1064): 20151060, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27164030

ABSTRACT

The adequate treatment of non-resectable liver metastases from colorectal cancer which are resistant to systemic chemotherapy currently provides a great challenge. The aim is to identify and review key strategies in the treatment of colorectal liver metastases. A search for current literature on the topic of interventional strategies for colorectal metastases was performed in Medline in order to achieve this goal. Studies before 2005 and with <20 patients treated for colorectal metastases were excluded. Transarterial chemoembolization (TACE), transarterial embolization and selective internal radiation therapy (SIRT) were identified as examples of regional strategies for colorectal liver metastases, utilizing the unique blood supply of the liver. Radiofrequency ablation (RFA), microwave ablation (MWA) and cryoablation were selected as examples for currently available ablative techniques. Median survival in the key studies reviewed ranged from 7.7 to 28.6 for TACE, 8.3-12.6 for SIRT, 8.2-53.2 for RFA and 29-43 months for MWA. After review of the literature, it can be concluded that interventional oncologic therapies are a safe and effective method for treating colorectal liver metastases. The use of new chemotherapeutic agents for local therapy and new ablation technologies and techniques may increase patient survival and allows a neoadjuvant therapy setting. In addition, a combination of local therapies may be used to increase effectiveness in the future, which is subject to further research.

18.
Transpl Int ; 29(3): 369-80, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26697811

ABSTRACT

With favourable 5-year survival rates up to 75%, liver transplantation (LT) is the treatment of choice for hepatocellular carcinoma (HCC). Nonetheless, tumour recurrence after LT remains a challenge. The aim of this retrospective study was to develop a predictive score for tumour recurrence after LT by combining clinical parameters with HCC biomarkers (microRNA). A microRNA (miRNA) microarray analysis was used to compare miRNA expression patterns in tissue samples of 40 patients with and without HCC recurrence after LT. In a screening cohort (n = 18), the miRNA analysis identified significant differences in the expression of 13 miRNAs in patients with tumour recurrence. Using the most significant miRNAs in this screening cohort, we could develop a predictive score, which combined the expression levels of miR-214, miR-3187 and the Milan criteria, and we could define low- and high-risk groups for tumour recurrence and death. The above score was evaluated in a second and independent cohort (n = 22). In contrast to the Milan criteria alone, this score was significantly associated with tumour recurrence. Our analysis indicated that the use of a specific miRNA expression pattern in combination with a limited tumour burden as defined by the Milan criteria may lead to a more accurate prediction of tumour recurrence.


Subject(s)
Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/metabolism , MicroRNAs/metabolism , Neoplasm Recurrence, Local/metabolism , Postoperative Complications/metabolism , Adult , Aged , Biomarkers/metabolism , Carcinoma, Hepatocellular/surgery , Female , Humans , Liver Neoplasms/surgery , Liver Transplantation , Male , Middle Aged , Oligonucleotide Array Sequence Analysis , Retrospective Studies
19.
J Vasc Interv Radiol ; 27(2): 181-7, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26686422

ABSTRACT

PURPOSE: To study long-term changes to the thoracic aorta following thoracic endovascular aortic repair (TEVAR) for treatment of different aortic pathologic conditions. MATERIALS AND METHODS: This retrospective study included 53 consecutive patients (mean age, 58.8 y ± 14; 13 female and 40 male) in whom TEVAR was performed between October 2002 and May 2010. The mean duration of follow-up was 21.1 months (range, 0.5-96 mo). Statistical analysis was performed with the Friedman test and Conover-Iman test. RESULTS: Nineteen patients with aortic aneurysm (group 1), 25 patients with type B dissection (group 2), and 9 patients with other pathologic conditions (group 3) were treated with TEVAR. The mean overall aortic lengths (from the origin of the left subclavian artery to the origin of the celiac trunk) before TEVAR were 271.4 mm, 268.6 mm, and 233.6 mm in groups 1, 2, and 3, respectively. At 12-month follow-up, the lengths were 282.8 mm, 294.4 mm, and 237.5 mm in groups 1, 2, and 3, respectively. The changes in aortic lengths following TEVAR were statistically significant (P < .001). A second intervention was required in 14 patients, and 6 patients died during follow-up. CONCLUSIONS: A significant change in the overall aortic length was observed following TEVAR. The changes in aortic length reached statistical significance after 12 months.


Subject(s)
Aorta, Thoracic/physiopathology , Aorta, Thoracic/surgery , Aortic Diseases/physiopathology , Aortic Diseases/surgery , Endovascular Procedures/methods , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Retrospective Studies
20.
Eur Radiol ; 26(3): 755-63, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26123407

ABSTRACT

PURPOSE: To evaluate feasibility of measuring parenchymal blood volume (PBV) of malignant hepatic tumours using C-arm CT, test the changes in PBV following repeated transarterial chemoembolization (TACE) and correlate these changes with the change in tumour size in MRI. METHODS: 111 patients with liver malignancy were included. Patients underwent MRI and TACE in a 4- to 6-week interval. During intervention C-arm CT was performed. Images were post-processed to generate PBV maps. Blood volume data in C-arm CT and change in size in MRI were evaluated. The correlation between PBV and size was tested using Spearman rank test. RESULTS: Pre-interventional PBV maps showed a mean blood volume of 84.5 ml/1000 ml ± 62.0, follow-up PBV maps after multiple TACE demonstrated 61.1 ml/1000 ml ± 57.5. The change in PBV was statistically significant (p = 0.02). Patients with initial tumour blood volume >100 ml/1000 ml dropped 7.1% in size and 47.2% in blood volume; 50-100 ml/1000 ml dropped 4.6% in size and 25.7% in blood volume; and <50 ml/1000 ml decreased 2.8% in size and increased 82.2% in blood volume. CONCLUSION: PBV measurement of malignant liver tumours using C-arm CT is feasible. Following TACE PBV decreased significantly. Patients with low initial PBV show low local response rates and further increase in blood volume, whereas high initial tumour PBV showed better response to TACE. KEY POINTS: Parenchymal blood volume assessment of malignant hepatic lesions using C-arm CT is feasible. The parenchymal blood volume is reduced significantly following transarterial chemoembolization. Parenchymal blood volume can monitor the response of tumours after transarterial chemoembolization. Although not significant, high initial parenchymal blood volume yields better response to TACE.


Subject(s)
Chemoembolization, Therapeutic/methods , Liver Neoplasms/therapy , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Blood Volume , Blood Volume Determination , Feasibility Studies , Female , Humans , Liver Neoplasms/pathology , Magnetic Resonance Imaging , Male , Middle Aged , Retreatment , Treatment Outcome , Tumor Burden , Young Adult
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