Kohdennettu ultraääni avaa uusia hoitomahdollisuuksia

Valtaosa Suomessa hoidetuista on ollut gynekologisia potilaita

High-intensity focused ultrasound therapy in the uterine fibroid: a clinical case study of poor heating efficacy

A clinical case study of high-intensity focused ultrasound (HIFU) treatment in the uterine fibroid was conducted. During the therapy, poor heating efficacy was observed which could be attributed to several factors such as the local perfusion rate, patient-specific anatomy or changes in acoustic parameters of the ultrasound field. In order to determine the cause of the diminished heating, perfusion analyses and ultrasound simulations were conducted using the magnetic resonance imaging (MRI) data from the treatment. The perfusion analysis showed high local perfusion rate in the myoma (301.0 +- 25.6 mL/100 g/min) compared to the surrounding myometrium (233.8 +- 16.2 mL/100 g/min). The ultrasound simulations did not show large differences in the focal point shape or the acoustic pressure (2.07 +- 0.06 MPa) when tilting the transducer. However, a small shift (-2.2 +- 1.3 mm) in the axial location of the focal point was observed. The main causes for the diminished heating were likely the high local perfusion and ultrasound attenuation due to the deep location of the myoma.Comment: Conference Proceedin

A new breast tomosynthesis imaging method : Continuous Sync-and-Shoot - technical feasibility and initial experience

Background Digital breast tomosynthesis (DBT) is gaining popularity in breast imaging. There are several different technical approaches for conducting DBT imaging. Purpose To determine optimal imaging parameters, test patient friendliness, evaluate the initial diagnostic performance, and describe diagnostic advances possible with the new Continuous Sync-and-Shoot method. Material and Methods Thirty-six surgical breast specimens were imaged with digital mammography (DM) and a prototype of a DBT system (Planmed Oy, Helsinki, Finland). We tested the patient friendliness of the sync-and-shoot movement without radiation exposure in eight volunteers. Different imaging parameters were tested with 20 specimens to identify the optimal combination: angular range 30 degrees, 40 degrees, and 60 degrees; pixel binning; Rhodium (Rh) and Silver (Ag) filtrations; and different kV and mAs values. Two breast radiologists evaluated 16 DM and DBT image pairs and rated six different image properties. Imaging modalities were compared with paired t-test. Results The Continuous Sync-and-Shoot method produced diagnostically valid images. Five out of eight volunteers felt no/minimal discomfort, three experienced mild discomfort from the tilting movement of the detector, with the motion being barely recognized. The combination of 30 degrees, Ag filtering, and 2 x 2 pixel binning produced the best image quality at an acceptable dose level. DBT was significantly better in all six evaluated properties (P <0.05). Mean Dose(DBT)/Dose(DM) ratio was 1.22 (SD = 0.42). Conclusion The evaluated imaging method is feasible for imaging and analysing surgical breast specimens and DBT is significantly better than DM in image evaluation.Peer reviewe

Magnetic resonance imaging-guided biopsies in children

Background: Magnetic resonance imaging (MRI) is used far less as an imaging-guided method for percutaneous biopsies than computed tomography (CT) and ultrasound (US), despite its imaging benefits, particularly in children.Purpose: To evaluate the feasibility, accuracy and safety of MRI-guided biopsies in paediatric patient population.Material and Methods: The retrospective study included 57 consecutive paediatric patients (Results: The overall diagnostic accuracy of histologic biopsy was 0.94, with sensitivity 0.82, specificity 1.00, positive predictive value (PPV) 1.00 and negative predictive value (NPV) 0.92. In histological bone biopsies, diagnostic accuracy was 0.96, with sensitivity 0.86, specificity 1.00, PPV 1.00 and NPV 0.94. The FNAB sample diagnosis was associated with the histological diagnosis in 79% of cases. There were no major primary complications and only a few late complications. After biopsy, 83% of the children were ambulatory in 6 h. Anti-inflammatory drugs and paracetamol provided satisfactory pain relief in 96% of the patients after biopsy. Most outpatients (71%) were discharged from hospital either on the same day or 1 day later.Conclusion: MRI is a technically feasible, accurate and safe guidance tool for performing percutaneous biopsies in children.</p

Fiducial markers and their impact on ablation outcome for patients treated with MR-guided transurethral ablation (TULSA): a retrospective technical analysis

Objectives: Fiducial markers improve accuracy in external beam radiation therapy (EBRT) for treatment of prostate cancer (PCa). However, many patients recur after EBRT necessitating additional treatment, such as MR-guided transurethral ultrasound ablation (TULSA). Residual markers may compromise TULSA through ultrasound field distortions and generation of local susceptibility artifacts. The objective was to investigate how markers affect the ablation outcome during clinical TULSA treatments.Subjects and methods: A retrospective analysis was performed on nine patients with radiorecurrent PCa and residual markers who received TULSA. The MR susceptibility artifact was quantified as a function of marker type, size and orientation, in particular for thermometry. The spatial distribution of markers inside the prostate was recorded, and the resulting impact on the thermal dose was measured. The thermal dose measurements were directly compared to the residual enhancing prostatic tissue observed on the immediate and control post-TULSA contrast enhanced (CE) image.Results: Successful thermal dose accumulation to the target boundary occurred for 14/20 (70%) of markers, confirmed with CE imaging. Gold markers situated simultaneously close to the urethra (≤12 mm) and far from the target boundary (≥13 mm) reduced the ultrasound depth of heating. Nitinol markers produced large, hypointense artifacts that disrupted thermometry and compromised treatment. Artifacts from gold markers were less pronounced, but when located near the target boundary, also affected treatment.Conclusion: Marker composition, orientation and location inside the prostate can all potentially impact treatment outcome. Proper patient selection through detailed MRI screening is critical to ensure successful radiorecurrent PCa treatment outcomes with TULSA.</p

Ultrasonographic Assessment of the Normal Femoral Articular Cartilage of the Knee Joint: Comparison with 3D MRI

ObjectiveUltrasonography (US) has a promising role in evaluating the knee joint, but capability to visualize the femoral articular cartilage needs systematic evaluation. We measured the extent of this acoustic window by comparing standardized US images with the corresponding MRI views of the femoral cartilage.DesignTen healthy volunteers without knee pathology underwent systematic US and MRI evaluation of both knees. The femoral cartilage was assessed on the oblique transverse axial plane with US and with 3D MRI. The acoustic window on US was compared to the corresponding views of the femoral sulcus and both condyles on MRI. The mean imaging coverage of the femoral cartilage and the cartilage thickness measurements on US and MRI were compared.ResultsMean imaging coverage of the cartilage of the medial femoral condyle was 66% (range 54%–80%) and on the lateral femoral condyle 37% (range 25%–51%) compared with MRI. Mean cartilage thickness measurement in the femoral sulcus was 3.17 mm with US and 3.61 mm with MRI (14.0% difference). The corresponding measurements in the medial femoral condyle were 1.95 mm with US and 2.35 mm with MRI (21.0% difference), and in the lateral femoral condyle, they were 2.17 mm and 2.73 mm (25.6% difference), respectively.ConclusionTwo-thirds of the articular cartilage of the medial femoral condyle, and one-third in the lateral femoral condyle, can be assessed with US. The cartilage thickness measurements seem to be underestimated by US. These results show promise for the evaluation of the weight-bearing cartilage of the medial femoral condyle with US.</p

Feasibility of apparent diffusion coefficient in predicting the technical outcome of MR-guided high-intensity focused ultrasound treatment of uterine fibroids - a comparison with the Funaki classification

PurposeTo investigate the feasibility of using an apparent diffusion coefficient (ADC) classification in predicting the technical outcome of magnetic resonance imaging-guided high-intensity focused ultrasound (MRgHIFU) treatment of symptomatic uterine fibroids and to compare it to the Funaki classification.Materials and methodsForty-two patients with forty-eight uterine fibroids underwent diffusion-weighted imaging (DWI) before MRgHIFU treatment. The DW images were acquired with five different b-values. Correlations between ADC values and treatment parameters were assessed. Optimal ADC cutoff values were determined to predict technical outcomes, that is, nonperfused volume ratios (NPVr) such that three classification groups were created (NPVr of 80%). Results were compared to the Funaki classification using receiver-operating-characteristic (ROC) curve analysis, with statistical significance being tested with the Chi-square test.ResultsA statistically significant negative correlation (Spearman's rho = -0.31, p-value 80%) and 1800 x 10(-6)mm(2)/s (NPVr 80%), ADC II (NPVr 30-80%) and ADC III (NPVr < 30%). Analysis of the whole model area under the curve resulted in values of 0.79 for the ADC classification (p-value = 0.0007) and 0.62 for the Funaki classification (p-value = 0.0527).ConclusionsLower ADC values prior to treatment correlate with higher NPV ratios. The ADC classification seems to be able to predict the NPV ratio and may even outperform the Funaki classification. Based on these results DWI and ADC maps should be included in the MRI screening protocol

Feasibility of T2 relaxation time in predicting the technical outcome of MR-guided high-intensity focused ultrasound treatment of uterine fibroids

PurposeThe aim of this study was to assess the feasibility of T2 relaxation time in predicting the immediate technical outcome i.e., nonperfused volume ratio (NPVr) of magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) treatment of symptomatic uterine fibroids and to compare it with existing T2-weighted imaging methods (Funaki classification and scaled signal intensity, SSI).Materials and methods30 patients with 32 uterine fibroids underwent an MRI study including a quantitative T2 relaxation time measurement prior to MRgHIFU treatment. T2 relaxation times were measured with a multi-echo fast imaging-based technique with 16 echoes. The correlation between pretreatment values of the uterine fibroids and treatment outcomes, that is nonperfused volume ratios (NPVr), was assessed with nonparametric statistical measures. T2 relaxation time-based method was compared to existing T2-weighted imaging-based methods using receiver-operating-characteristics (ROC) curve analysis and Chi-square test.ResultsNonparametric measures of association revealed a statistically significant negative correlation between T2 relaxation time values and NPVr. The T2 relaxation time classification (T2 I, T2 II, and T2 III) resulted in the whole model p-value of 0.0019, whereas the Funaki classification resulted in a p-value of 0.56. The T2 relaxation time classification (T2 I and T2 II) achieved a whole model of a p-value of 0.0024, whereas the SSI classification had a p-value of 0.0749.ConclusionsA longer T2 relaxation time of the fibroid prior to treatment correlated with a lower NPVr. Based on our results, the T2 relaxation time classifications seem to outperform the Funaki classification and the SSI method.</p

The role of co-occurring insomnia and mental distress in the association between lumbar disc degeneration and low back pain related disability

Background Lumbar disc degeneration (LDD) is associated with low back pain (LBP). Although both insomnia and mental distress appear to influence the pain experience, their role in the association between LDD and LBP is uncertain. Our objective was to investigate the role of co-occurring insomnia and mental distress in the association between LDD and LBP-related disability. Methods A total of 1080 individuals who had experienced LBP during the previous year underwent 1.5-T lumbar magnetic resonance imaging, responded to questionnaires, and participated in a clinical examination at the age of 47. Full data was available for 843 individuals. The presence of LBP and LBP-related disability (numerical rating scale, range 0-10) were assessed using a questionnaire. LDD was assessed by a Pfirrmann-based sum score (range 0-15, higher values indicating higher LDD). The role of insomnia (according to the five-item Athens Insomnia Scale) and mental distress (according to the Hopkins Symptom Check List-25) in the association between the LDD sum score and LBPrelated disability was analyzed using linear regression with adjustments for sex, smoking, body mass index, education, leisure-time physical activity, occupational physical exposure, Modic changes, and disc herniations. Results A positive association between LDD and LBP-related disability was observed among those with absence of both mental distress and insomnia (adjusted B = 0.132, 95% CI = 0.028-0.236, p = 0.013), and among those with either isolated mental distress (B = 0.345 CI = 0.039-0.650, p = 0.028) or isolated insomnia (B = 0.207, CI = 0.040-0.373, p = 0.015). However, among individuals with co-occurring insomnia and mental distress, the association was not significant (B = -0.093, CI = -0.346-0.161, p = 0.470). Conclusions LDD does not associate with LBP-related disability when insomnia and mental distress co-occur. This finding may be useful when planning treatment and rehabilitation that aim to reduce disability among individuals with LDD and LBP. Future prospective research is warranted.publishedVersionPeer reviewe