Method For Treatment Monitoring Research Articles

Inhomogeneity detection within a head-sized phantom using tracking of charged nuclear fragments in ion beam therapy

Objective.The highly conformal carbon-ion radiotherapy is associated with an increased sensitivity of the dose distributions to internal changes in the patient during the treatment course. Hence, monitoring methodologies capable of detecting such changes are of vital importance. We established experimental setup conditions to address the sensitivity of a monitoring approach based on secondary-fragment tracking for detecting clinically motivated air cavity dimensions in a homogeneous head-sized PMMA phantom in 40 mm depth.Approach.The air cavities were positioned within the entrance channel of a treatment field of 50 mm diameter at three lateral positions. The measured secondary-fragment emission profiles were compared to a reference measurement without cavities. The experiments were conducted at the Heidelberg Ion-Beam Therapy Center in Germany at typical doses and dose rates.Main results.Significances above a detectability threshold of 2σfor the larger cavities (20 mm diameter and 4 mm thickness, and 20 mm diameter and 2 mm thickness) across the entire treatment field. The smallest cavity of 10 mm diameter and 2 mm thickness, which is on the lower limit of clinical interest, could not be detected at any position. We also demonstrated that it is feasible to reconstruct the lateral position of the cavity on average within 2.8 mm, once the cavity is detected. This is sufficient for the clinicians to estimate medical effects of such a cavity and to decide about the need for a control imaging CT.Significance.This investigation defines well-controlled reference conditions for the evaluation of the performance of any kind of treatment monitoring method and its capability to detect internal changes within head-sized objects. Four air cavities with volumes between 0.31 cm3and 1.26 cm3were narrowed down around the detectability threshold of this secondary-fragment-based monitoring method.

Magnetic Resonance Imaging of Focused Ultrasound Radiation Force Strain Fields for Discrimination of Solid and Liquid Phases.

Focused ultrasound (FUS) has become a non-invasive option for some surgical procedures, including tumor ablation and thalamotomy. Extension of magnetic resonance (MR) imaging-guided focused ultrasound for ablation of slowly perfused cerebrovascular lesions requires a novel treatment monitoring method that does not rely on thermometry or high-frequency Doppler methods. The goal of this study was to evaluate the sensitivity and specificity of strain estimates based on MR acoustic radiation force imaging (MR-ARFI) for differentiation of solids and liquids. Strain fields were estimated in gelatin-based tissue-mimicking focused ultrasound phantoms on the basis of apparent displacement fields measured by MR-ARFI. MR-ARFI and diffusion-weighted imaging (DWI) measurements were made before and after FUS-induced heating to evaluate the performance of displacement, strain and apparent diffusion coefficient (ADC) measurements for the discrimination of solid and liquid phases. As revealed by receiver operating characteristic analyses, axial normal strain and shear strain components performed significantly better than axial displacement measurements alone when predicting whether a gelatin had melted. Additional measurements must be made to estimate certain strain components, so this trade-off must be considered when developing clinical strategies. ADC had the best overall performance, but DWI is vulnerable to signal dropouts and susceptibility artifacts near cerebrovascular lesions, so this metric may have limited clinical applicability. Strain components based on MR-ARFI apparent displacement measurements perform better than apparent displacement measurements alone at discriminating between solids and liquids. These methods are applicable to FUS treatment monitoring and evaluation of mechanical tissue properties in vivo.

Machine learning-based somatic variant calling in cell-free DNA of metastatic breast cancer patients using large NGS panels

Next generation sequencing of cell-free DNA (cfDNA) is a promising method for treatment monitoring and therapy selection in metastatic breast cancer (MBC). However, distinguishing tumor-specific variants from sequencing artefacts and germline variation with low false discovery rate is challenging when using large targeted sequencing panels covering many tumor suppressor genes. To address this, we built a machine learning model to remove false positive variant calls and augmented it with additional filters to ensure selection of tumor-derived variants. We used cfDNA of 70 MBC patients profiled with both the small targeted Oncomine breast panel (Thermofisher) and the much larger Qiaseq Human Breast Cancer Panel (Qiagen). The model was trained on the panels’ common regions using Oncomine hotspot mutations as ground truth. Applied to Qiaseq data, it achieved 35% sensitivity and 36% precision, outperforming basic filtering. For 20 patients we used germline DNA to filter for somatic variants and obtained 245 variants in total, while our model found seven variants, of which six were also detected using the germline strategy. In ten tumor-free individuals, our method detected in total one (potentially germline) variant, in contrast to 521 variants detected without our model. These results indicate that our model largely detects somatic variants.

Design and performance evaluation of a slit-slat camera for 2D prompt gamma imaging in proton therapy monitoring: A Monte Carlo simulation study.

We investigated the design of a prompt gamma camera for real-time dose delivery verification and the partial mitigation of range uncertainties. A slit slat (SS) camera was optimized using the trade-off between the signal-to-noise ratio and spatial resolution. Then, using the GATE Monte Carlo package, the camera performances were estimated by means of target shifts, beam position quantification, changing the camera distance from the beam, and air cavity inserting. A homogeneous PMMA phantom and the air gaps induced PMMA phantom were used. The air gaps ranged from 5mm to 30mm by 5mm increments were positioned in the middle of the beam range. To reduce the simulation time, phase space scoring was used. The batch method with five realizations was used for stochastic error calculations. The system's detection efficiency was PGs/proton) for a 10 × 20 cm2 detector (source-to-collimator distance=15.0cm). Axial and transaxial resolutions were 23mm and 18mm, respectively. The SS camera estimated the range as 69.0±3.4 (relative stochastic error 1-sigma is 5%) and 67.6±1.8mm (2.6%) for the real range of 67.0mm for 107 and 108 protons of 100 MeV, respectively. Considering 160 MeV, these values are 155.5±3.1 (2%) and 152.2±2.0mm (1.3%) for the real range of 152.0mm for 107 and 108 protons, respectively. Considering phantom shift, for a 100 MeV beam, the precision of the quantification (1-sigma) in the axial and lateral phantom shift estimation is 2.6mm and 1mm, respectively. Accordingly, the axial and lateral quantification precisions were 1.3mm and 1mm for a 160 MeV beam, respectively. Furthermore, the quantification of an air gap formulated as , where and gapreal are the estimated and real air gap, respectively. The precision of the air gap quantification is 1.6mm (1 sigma). Moreover, 2D PG images show the trajectory of the proton beam through the phantom. The proposed slit-slat imaging systems can potentially provide a real-time, in-vivo, and non-invasive treatment monitoring method for proton therapy.

Vitamin D and anti-infectious immunity. Choice of diagnostic and treatment monitoring method of vitamin D deficiency

Vitamin D and anti-infectious immunity. Choice of diagnostic and treatment monitoring method of vitamin D deficiency

Realization of electrical signal monitoring of metal surface modification by means of low-temperature plasma treatment

The paper shows good prospects of modifying the working surfaces of metal products by low-temperature plasma treatment. We suggest a treatment monitoring method based on the recording of signals that arise in the electrical circuit of the processing unit and present the results of this approach realization. The study substantiates the expediency, assesses possibility, and shows the efficiency of controlling the low-temperature plasma modification based on the correction of its operating parameters according to monitoring data.

Parallel serial assessment of somatic mutation and methylation profile from circulating tumor DNA predicts treatment response and impending disease progression in osimertinib-treated lung adenocarcinoma patients.

Circulating tumor DNA (ctDNA) harboring tumor-specific genetic and epigenetic aberrations allows for early detection and real-time monitoring of tumor dynamics. In this study, we aimed to evaluate the potential of parallel serial assessment of somatic mutation and methylation profile in monitoring the response to osimertinib of epidermal growth factor receptor (EGFR) T790M-positive advanced lung adenocarcinoma patients. Parallel somatic mutation and DNA methylation profiling was performed on a total of 85 longitudinal plasma samples obtained from 8 stage IV osimertinib-treated EGFR T790M-positive lung adenocarcinoma patients. Our results revealed a significant correlation between the by-patient methylation level with the maximum allele fraction (maxAF, P=0.0002). The methylation levels were significantly higher in the plasma samples of patients with detectable somatic mutations than patients without somatic mutations (P=0.0003) and healthy controls (P=0.0018). Moreover, analysis of both the DNA methylation level and maxAF revealed four trends of treatment response. Collectively, the decrease in methylation level and maxAF reflected treatment efficacy, while the gradual increase reflected impending disease progression (PD). Elevated methylation levels and maxAF were observed in 6 and 5 patients in an average lead-time of 3.0 and 1.9 months, respectively, prior to evaluation of PD using radiological imaging. DNA methylation profiling has the potential to predict disease relapse prior to evaluation through radiological modalities, suggesting that serial assessment of methylation level in combination with somatic mutation profiling are reliable methods for treatment monitoring. These methods should thus be incorporated with imaging modalities for a more comprehensive work-up of treatment response, particularly for patients treated with targeted therapies.

Parallel Serial Assessment of Somatic Mutation and Methylation Profile from Circulating Tumor DNA Predicts Treatment Response and Impending Disease Progression in Osimertinib-Treated Lung Adenocarcinoma Patients

Background: Circulating tumor DNA (ctDNA) harboring tumor-specific genetic and epigenetic aberrations allows for early detection and real-time monitoring of tumor dynamics. In this study, we aimed to evaluate the potential of parallel serial assessment of somatic mutation and methylation profile in monitoring the response to osimertinib of EGFR T790M-positive advanced lung adenocarcinoma patients. Methods: Parallel somatic mutation and DNA methylation profiling was performed on a total of 85 longitudinal plasma samples obtained from eight stage IV osimertinib-treated EGFR T790M-positive lung adenocarcinoma patients. Findings: Our results revealed significant correlation between the by-patient methylation level with the maximum allele fraction (maxAF, P=0.0002). The methylation levels were significantly higher in the plasma samples of patients with detectable somatic mutations than patients without somatic mutations (P=0.0003) and healthy controls (P=0.0018). Moreover, analysis of both DNA methylation level and maxAF revealed four trends of treatment response. Collectively, the decrease in methylation level and maxAF reflected treatment efficacy, while the gradual increase reflected impending disease progression. Elevated methylation levels and maxAF were observed in six and five patients in an average lead-time of 3.0 and 1.9 months, respectively, prior to evaluation of disease progression using radiological imaging. Interpretation: DNA methylation profiling has the potential to predict disease relapse prior to being evaluated thru radiological modalities, suggesting that serial assessment of methylation level in combination with somatic mutation profiling are reliable methods for treatment monitoring and should be incorporated with imaging modalities for a more comprehensive work-up of treatment response, particularly for patients treated with targeted therapies. Funding Statement: This work was supported by grants from the National Natural Science Foundation of China (grant number 81772471 to S.Xia), Double First-Class University Plan funding of 2016 from Tongji Medical College, Huazhong University of Science and Technology (grant number 5001540022 to S.Xia) and Qinghai Science and Technology Department Funding (grant number 2017-ZJ-709 to S. Xia). Declaration of Interests: J.Ye, A.Lizaso, J.Su, H.Han-Zhang and S. Chuai are employees of Burning Rock Biotech. The other authors declare no potential conflicts of interest. Ethics Approval Statement: This study was performed according to the Helsinki Declaration of 1964 and its current amendments. The study protocol has been approved by the Ethics Committee of Huazhong University of Science and Technology (approval number: 2015L01374/2015L01373). Written informed consent was provided by all the patients included in the study.

The translational science of hodgkin lymphoma.

Hodgkin Lymphoma (HL) is an unusual B-cell lymphoma because the malignant cells exist as a minority population in a densely cellular microenvironment. The microenvironment is comprised predominately of inflammatory and immune cells with fibrosis in some cases. There are multiple dysregulated signalling pathways that sustain HL within this microenvironment, such as the Nuclear factor-κB and Janus kinase/signal transducers and activators of transcription pathways. Advances in genomic medicine have enabled a better characterisation of the rare tumour cells and improved our understanding of the signalling mechanisms that exist between the malignant cell and its microenvironment. Current therapy for HL produces excellent clinical outcomes in most younger patients. However, problems with current treatment approaches include poorer outcomes in the elderly, toxicity of highly-effective combination chemotherapy regimens and relapse in high-risk patients. Better understanding of disease biology aids in upfront prognostication of patients, defines new methods for treatment monitoring and assists in the recognition of novel targets for therapy. Biology-driven therapies, including anti-CD30 antibody conjugates, cellular immunotherapies and immune modulation, particularly with checkpoint inhibitors, have changed treatment algorithms for relapsed/refractory patients. Future challenges exist in incorporating immune-based therapies earlier in treatment algorithms to reduce toxicity and prevent relapse for patients with HL.

Real-Time HIFU Treatment Monitoring Using Pulse Inversion Ultrasonic Imaging

Real-time monitoring of high-intensity focused ultrasound (HIFU) surgery is essential for safe and accurate treatment. However, ultrasound imaging is difficult to use for treatment monitoring during HIFU surgery because of the high intensity of the HIFU echoes that are received by an imaging transducer. Here, we propose a real-time HIFU treatment monitoring method based on pulse inversion of imaging ultrasound; an imaging transducer fires ultrasound twice in 0° and 180° phases for one scanline while HIFUs of the same phase are transmitted in synchronization with the ultrasound transmission for imaging. By doing so, HIFU interferences can be eliminated after subtracting the two sets of the signals received by the imaging transducer. This function was implemented in a commercial research ultrasound scanner, and its performance was evaluated using the excised bovine liver. The experimental results demonstrated that the proposed method allowed ultrasound images to clearly show the echogenicity change induced by HIFU in the excised bovine liver. Additionally, it was confirmed that the moving velocity of the organs in the abdomen due to respiration does not affect the performance of the proposed method. Based on the experimental results, we believe that the proposed method can be used for real-time HIFU surgery monitoring that is a pivotal function for maximized treatment efficacy.

ASCO 2018 NSCLC highlights-combination therapy is key.

SummaryNon-small cell lung cancer (NSCLC) treatment was booming at this year’s ASCO 2018 meeting as several well-performed phase III trials with practice-changing potential were presented. Thereby immune checkpoint blockade (ICB) consolidated its major role in the treatment of NSCLC patients without genetic alterations and extended its use by showing impressive data on ICB combination therapies (mainly combined with chemotherapy). Furthermore the role of predictive biomarkers for ICB therapy (Programmed death-ligand 1 [PD-L1] expression, tumor mutational burden [TMB] testing and others) have been further developed and blood-based tests were presented with promising data revealing the potential of this minimally invasive method for treatment monitoring and guidance in the future. Nevertheless the best biomarker is still elusive and future research is ongoing and might be a multimodal approach combining different modalities. No major studies concerning new genetic alterations or innovative targets were presented and the focus in genetic driven NSCLC was the evaluation of combinational approaches (e.g. in epidermal growth factor receptor [EGFR] mutation positve patients, EGFR tyrosine kinase inhibitor [TKI] plus anti-angiogenic agent or chemotherapy backbone). The presented results showed some benefit for the combinational approach; however toxicity might be an issue and further validation is necessary. Summarizing, ASCO 2018 showed that combinational approaches will be the future standard treatment in NSCLC and that biomarker identification is more heterogeneous and complex than anticipated, but presented next generation techniques may pave the way to a more personalized cancer therapy.

A method for treatment monitoring using circulating tumour DNA in cancer patients without targetable mutations.

BackgroundThe potentials of circulating tumour DNA (ctDNA) have been studied for non-invasive disease monitoring in patients with targetable mutations. However, the majority of cancer patients harbour no targetable mutations. A workflow including targeted next-generation sequencing (NGS) and droplet digital PCR (ddPCR) could be used for monitoring treatment in these patients. Thus, our aim was to evaluate the workflow for ctDNA monitoring in a cohort of non-small cell lung cancer patients.MethodsForty patients were prospectively included. Plasma samples were collected prior to and during treatment. NGS (Ion AmpliSeq Colon and Lung Cancer panel v2) was performed on ctDNA from pre-treatment samples. The identified mutations were monitored by ddPCR in consecutively collected samples.ResultsMutations were detected in 21 patients. The most commonly mutated genes were TP53 (N=20) and KRAS (N=13). Treatment was discontinued due to non-response in 18 patients. In 16 of these, a simultaneous increase in ctDNA concentration was observed. A twofold ctDNA concentration increase confirmed in a second successive sample predicted non-response on the following imaging in 83% of patients (10/12).ConclusionctDNA monitoring can be used for early detection of non-response in patients without targetable mutations, and therefore could supplement imaging data for treatment monitoring in this subset of patients.

Adjunct use of optical coherence tomography increases the detection of recurrent basal cell carcinoma over clinical and dermoscopic examination alone

BackgroundBasal cell carcinoma (BCC) is a locally destructive form of skin cancer, mainly affecting Caucasians. In the last few years non-surgical treatments of BCC have become widely used and non-invasive methods for treatment monitoring and follow-up are therefore becoming increasingly warranted. The objective of this study was to investigate the utility of adjunct use of non-invasive optical coherence tomography (OCT) imaging for the detection of recurrent BCC over clinical and dermoscopic examination alone, in a real-world setting. MethodsA total of 58 patients, previously treated with curettage and/or MAL-PDT for BCC, were included in the study. The patients were examined clinically and dermoscopically for recurrence by a dermatologist before joining the study. The included patients were then OCT scanned and if the OCT images raised suspicion of recurrent BCC the area was biopsied. ResultsIn 6 cases the clinical examination revealed suspicions recurrent lesions and OCT correctly identified all of these (6/6). In 49 cases the follow-up examinations showed no clinical or dermoscopic signs of recurrence, but in 12.2% (6/49) of these cases the subsequent OCT examination revealed a subclinical recurrent BCC lesion. These were all confirmed by histology. In 3 cases both the clinical and the OCT diagnosis was unclear and recurrent BCC could not be ruled out, but histology showed no sign of malignancy. ConclusionsThese results suggest that the adjunct use of OCT increases the detection rate of recurrent BCC over clinical/dermoscopy examination alone.

High-intensity focused ultrasound monitoring using harmonic motion imaging for focused ultrasound (HMIFU) under boiling or slow denaturation conditions.

Harmonic motion imaging for focused ultrasound (HMIFU) is a recently developed high-intensity focused ultrasound (HIFU) treatment monitoring method that utilizes an amplitude-modulated therapeutic ultrasound beam to induce an oscillatory radiation force at the HIFU focus and estimates the focal tissue displacement to monitor the HIFU thermal treatment. In this study, the performance of HMIFU under acoustic, thermal, and mechanical effects was investigated. The performance of HMIFU was assessed in ex vivo canine liver specimens (n = 13) under slow denaturation or boiling regimes. A passive cavitation detector (PCD) was used to assess the acoustic cavitation activity, and a bare-wire thermocouple was used to monitor the focal temperature change. During lesioning with slow denaturation, high quality displacements (correlation coefficient above 0.97) were observed under minimum cavitation noise, indicating the tissue initial-softening-then- stiffening property change. During HIFU with boiling, HMIFU monitored a consistent change in lesion-to-background displacement contrast (0.46 ± 0.37) despite the presence of strong cavitation noise due to boiling during lesion formation. Therefore, HMIFU effectively monitored softening-then-stiffening during lesioning under slow denaturation, and detected lesioning under boiling with a distinct change in displacement contrast under boiling in the presence of cavitation. In conclusion, HMIFU was shown under both boiling and slow denaturation regimes to be effective in HIFU monitoring and lesioning identification without being significantly affected by cavitation noise.

Thiamine transporter-2 deficiency: outcome and treatment monitoring.

BackgroundThe clinical characteristics distinguishing treatable thiamine transporter-2 deficiency (ThTR2) due to SLC19A3 genetic defects from the other devastating causes of Leigh syndrome are sparse.MethodsWe report the clinical follow-up after thiamine and biotin supplementation in four children with ThTR2 deficiency presenting with Leigh and biotin-thiamine-responsive basal ganglia disease phenotypes. We established whole-blood thiamine reference values in 106 non-neurological affected children and monitored thiamine levels in SLC19A3 patients after the initiation of treatment. We compared our results with those of 69 patients with ThTR2 deficiency after a review of the literature.ResultsAt diagnosis, the patients were aged 1 month to 17 years, and all of them showed signs of acute encephalopathy, generalized dystonia, and brain lesions affecting the dorsal striatum and medial thalami. One patient died of septicemia, while the remaining patients evidenced clinical and radiological improvements shortly after the initiation of thiamine. Upon follow-up, the patients received a combination of thiamine (10–40 mg/kg/day) and biotin (1–2 mg/kg/day) and remained stable with residual dystonia and speech difficulties. After establishing reference values for the different age groups, whole-blood thiamine quantification was a useful method for treatment monitoring.ConclusionsThTR2 deficiency is a reversible cause of acute dystonia and Leigh encephalopathy in the pediatric years. Brain lesions affecting the dorsal striatum and medial thalami may be useful in the differential diagnosis of other causes of Leigh syndrome. Further studies are needed to validate the therapeutic doses of thiamine and how to monitor them in these patients.

Large-scale resting state network correlates of cognitive impairment in Parkinson's disease and related dopaminergic deficits.

Cognitive impairment is a common non-motor feature of Parkinson's disease (PD). Understanding the neural mechanisms of this deficit is crucial for the development of efficient methods for treatment monitoring and augmentation of cognitive functions in PD patients. The current study aimed to investigate resting state fMRI correlates of cognitive impairment in PD from a large-scale network perspective, and to assess the impact of dopamine deficiency on these networks. Thirty PD patients with resting state fMRI were included from the Parkinson's Progression Marker Initiative (PPMI) database. Eighteen patients from this sample were also scanned with 123I-FP-CIT SPECT. A standardized neuropsychological battery was administered, evaluating verbal memory, visuospatial, and executive cognitive domains. Image preprocessing was performed using an SPM8-based workflow, obtaining time-series from 90 regions-of-interest (ROIs) defined from the AAL brain atlas. The Brain Connectivity Toolbox (BCT) was used to extract nodal strength from all ROIs, and modularity of the cognitive circuitry determined using the meta-analytical software Neurosynth. Brain-behavior covariance patterns between cognitive functions and nodal strength were estimated using Partial Least Squares. Extracted latent variable (LV) scores were matched with the performances in the three cognitive domains (memory, visuospatial, and executive) and striatal dopamine transporter binding ratios (SBR) using linear modeling. Finally, influence of nigrostriatal dopaminergic deficiency on the modularity of the “cognitive network” was analyzed. For the range of deficits studied, better executive performance was associated with increased dorsal fronto-parietal cortical processing and inhibited subcortical and primary sensory involvement. This profile was also characterized by a relative preservation of nigrostriatal dopaminergic function. The profile associated with better memory performance correlated with increased prefronto-limbic processing, and was not associated with presynaptic striatal dopamine uptake. SBR ratios were negatively correlated with modularity of the “cognitive network,” suggesting integrative effects of the preserved nigrostriatal dopamine system on this circuitry.

Passive mapping of acoustic sources within the human skull cavity with a hemispherical sparse array using computed tomography-based aberration corrections

Traditionally, the use of ultrasound (US) in the brain has been limited by the skull bone, which presents unique challenges for both transcranial therapy and imaging due to its attenuating and aberrating effects, which become more prevalent at higher US frequencies. On transmit, these skull-induced aberrations can be overcome through the use of large-aperture phased array transducers with appropriate driving frequencies, combined with computed tomography (CT)-based bone morphology and numerical models to derive element driving signals which minimize the distortions. Recently, we have demonstrated in silico that an analogous approach can be performed during beamforming on receive, to allow for passive acoustic imaging over a large region within the skull cavity [Jones et al., Phys. Med. Biol. 58, 4981–5005 (2013)]. We will present preliminary results obtained from applying this technique experimentally with a hemispherical (30 cm diam.) sparse receiver array (128 piezo-ceramic elements, 2.5 mm diam., and 612 kHz center frequency) to image acoustic sources through an ex vivo human skullcap. Images produced using non-invasive CT-based skull corrections will be compared with those obtained through an invasive hydrophone-based correction approach, and with images formed without skull-specific corrections. This technique has promising applications in both cavitation-mediated transcranial focused ultrasound therapies, by providing a method for treatment monitoring and control, as well as in ultrasound angiographic imaging of the brain.

Multi-parametric monitoring and assessment of high-intensity focused ultrasound (HIFU) boiling by harmonic motion imaging for focused ultrasound (HMIFU): an ex vivo feasibility study

Harmonic motion imaging for focused ultrasound (HMIFU) is a recently developed high-intensity focused ultrasound (HIFU) treatment monitoring method with feasibilities demonstrated in vitro and in vivo. Here, a multi-parametric study is performed to investigate both elastic and acoustics-independent viscoelastic tissue changes using the Harmonic Motion Imaging (HMI) displacement, axial compressive strain and change in relative phase shift during high energy HIFU treatment with tissue boiling. Forty three (n = 43) thermal lesions were formed in ex vivo canine liver specimens (n = 28). Two-dimensional (2D) transverse HMI displacement maps were also obtained before and after lesion formation. The same method was repeated in 10 s, 20 s and 30 s HIFU durations at three different acoustic powers of 8, 10, and 11 W, which were selected and verified as treatment parameters capable of inducing boiling using both thermocouple and passive cavitation detection (PCD) measurements. Although a steady decrease in the displacement, compressive strain, and relative change in the focal phase shift (Δϕ) were obtained in numerous cases, indicating an overall increase in relative stiffness, the study outcomes also showed that during boiling, a reverse lesion-to-background displacement contrast was detected, indicating potential change in tissue absorption, geometrical change and/or, mechanical gelatification or pulverization. Following treatment, corresponding 2D HMI displacement images of the thermal lesions also mapped consistent discrepancy in the lesion-to-background displacement contrast. Despite the expectedly chaotic changes in acoustic properties with boiling, the relative change in phase shift showed a consistent decrease, indicating its robustness to monitor biomechanical properties independent of the acoustic property changes throughout the HIFU treatment. In addition, the 2D HMI displacement images confirmed and indicated the increase in the thermal lesion size with treatment duration, which was validated against pathology. In conclusion, multi-parametric HMIFU was shown capable of monitoring and mapping tissue viscoelastic response changes during and after HIFU boiling, some of which were independent of the acoustic parameter changes.

Emerging quantitative magnetic resonance imaging biomarkers of hepatic steatosis

Emerging quantitative magnetic resonance imaging biomarkers of hepatic steatosis

Integration of PET/CT in Current Diagnostic and Response Evaluation Methods in Patients with Tuberculosis.

Tuberculosis is a systemic disease that still affects many people. While pleural involvement is frequently observed in extrapulmonary tuberculosis, multiple skeletal system and articular involvements are quite rare. FDG PET imaging could be a promising diagnostic and treatment monitoring method, especially in complicated cases and if the other methods are inadequate. In this case study, we report a patient who was admitted with suspected malignancy and then diagnosed with tuberculosis pleuritis, lymphadenitis, spondylodiscitis, and sacroiliitis with specific symptoms; the response to anti-tuberculosis therapy was shown using FDG PET/CT.