Multi-band whole-body diffusion-weighted imaging with inversion recovery fat saturation: Effects of respiratory compensation.

PURPOSE: To prospectively compare artefacts and image quality in testicular stage I cancer patients using different combinations of breathing schemes and Multi-band (MB) in whole-body DWIBS at 1.5 T.Diffusion-Weighted whole-body Imaging with Background body signal Suppression (DWIBS) using inversion recovery (IR) fat saturation is a cornerstone in oncologic whole-body MRI, but implementation is restrained by long acquisition times. The new Multi-Band (MB) technique reduces scan time which can be reinvested in respiratory compensation. METHODS: Thirty testicular cancer stage I patients were included. Three variations of whole-body DWIBS were tested: Standard free Breathing (FB)-DWIBS, FB-MB-DWIBS and Respiratory triggered (RT)-MB-DWIBS. Artefacts and image quality of b = 800 s/mm2 images were evaluated using a Likert scale. No pathology was revealed. SNR was calculated in a healthy volunteer. RESULTS: RT-MB-DWIBS was rated significantly better than FB-DWIBS in the thorax (p < 0.001) and abdomen (p < 0.001), but not in the pelvis (p = 0.569). FB-MB-DWIBS was ranked significantly lower than both FB-DWIBS (p < 0.001) and RT-MB-DWIBS (p < 0.001) at all locations. However, FB-MB-DWIBS was scanned in half the time without being less than "satisfactory". Few artefacts were encountered. SNR was similar for low-intensity tissues, but the SNR in high-intensity and respiratory-prone tissue (spleen) was slightly lower for FB-DWIBS than the other sequences. CONCLUSION: Images produced by the sequences were similar. MB enables the use of respiratory trigger or can be used to produce very fast free-breathing DWI with acceptable image quality.

Fat fractions from high-resolution 3D radial Dixon MRI for predicting metastatic axillary lymph nodes in breast cancer patients.

PURPOSE: To assess diagnostic performance of fat fractions (FF) from high-resolution 3D radial Dixon MRI for differentiating metastatic and non-metastatic axillary lymph nodes in breast cancer patients. METHOD: High-resolution 3D radial Dixon MRI was prospectively performed on 1.5 T in 70 biopsy-verified breast cancer patients. 35 patients were available for analysis with histopathologic and imaging data. FF images were calculated as fat / in-phase. Two radiologists measured lymph node FF and assessed morphological features in one ipsilateral and one contralateral lymph node in consensus. Diagnostic performance of lymph node FF and morphological criteria were compared using histopathology as reference. RESULTS: 22 patients had metastatic axillary lymph nodes. Mean lymph node FF were 0.20 ±â€¯0.073, 0.31 ±â€¯0.079, and 0.34 ±â€¯0.15 (metastatic, non-metastatic ipsi- and non-metastatic contralateral lymph nodes, respectively). Metastatic lymph node FF were significantly lower than non-metastatic ipsi- (p <  0.001) and contralateral lymph nodes (p <  0.001). Area under the receiver operating characteristics curve for lymph node FF was 0.80 compared to 0.76 for morphological criteria (p =  0.29). Lymph node FF yielded sensitivity 0.91, specificity 0.69, positive predictive value (PPV) 0.83, and negative predictive value (NPV) 0.82, while morphological criteria yielded sensitivity 0.91, specificity 0.62, PPV 0.80, and NPV 0.80 (p =  0.71). Combining lymph node FF and morphological criteria increased diagnostic performance with sensitivity 1.00, specificity 0.67, PPV 0.86, NPV 1.00, and AUC 0.83. CONCLUSIONS: Lymph node FF from high-resolution 3D Dixon images are a promising quantitative indicator of metastases in axillary lymph nodes.

Simultaneous multislice diffusion-weighted imaging with short tau inversion recovery fat suppression in bone-metastasizing breast cancer.

PURPOSE: To compare image quality and ADC values of simultaneous multislice diffusion-weighted imaging (mb-DWI) with that of conventional DWI (c-DWI) using short tau inversion recovery fat saturation (STIR) in women with bone-metastasizing breast cancer. METHOD: c-DWI and mb-DWI were acquired at 1.5 T in 23 breast cancer patients from skull base to mid thighs. mb-DWI was compared to c-DWI in terms of subjective image quality, artefacts and bone metastasis lesion conspicuity assessed on a 5-point Likert scale. ADC values of different organs as well as bone metastasis ADC values were compared between c-DWI and mb-DWI. RESULTS: mb-DWI reduced scan time by 48 % compared with c-DWI (1 min 58 s vs. 3 min 45 s per station). mb-DWI provided similar subjective image quality (3.8 vs. 3.7, p = 0.70), number of artefacts (50 vs. 56), severity of these (4.6 vs. 4.7, p = 0.11), and lesion conspicuity (4.2 vs. 4.4, p = 0.31) compared to c-DWI. mb-DWI showed lower mean ADC values in liver (0.5 × 10-3 mm2/s vs. 0.7 × 10-3 mm2/s, p = 0.002) and erector spine muscle (1.3 × 10-3 mm2/s vs. 1.5 × 10-3 mm2/s, p < 0.001). Bone metastasis ADC values from mb-DWI were 6.4 % lower than c-DWI (95 % confidence interval: 5.4%-7.4%, p < 0.001). CONCLUSIONS: mb-DWI provides similar subjective image quality to c-DWI with the same level of artefacts. Although bone metastasis ADC values were lower, mb-DWI can substantially reduce scan times of whole-body DWI in women with bone-metastasizing breast cancer.

Diagnostic accuracy of CE-CT, MRI and FDG PET/CT for detecting colorectal cancer liver metastases in patients considered eligible for hepatic resection and/or local ablation.

PURPOSE: To compare the diagnostic performance of contrast-enhanced computed tomography (CE-CT), magnetic resonance imaging (MRI) and combined fluorodeoxyglucose/positron emission tomography/computed tomography (FDG-PET/CT) for detection of colorectal liver metastases (CRLM) in patients eligible for local treatment. MATERIALS AND METHODS: This health-research ethics-committee-approved prospective consecutive diagnostic accuracy study, with written informed consent, included 80 cases (76 patients, four participating twice) between 29 June 2015 and 7 February 2017. Prior chemotherapy or local treatment did not exclude participation. Combined FDG-PET/CT including CE-CT and MRI was performed within 0-3 days shortly before local treatment. CE-CT and MRI images were read independently by two readers for each modality. The combined FDG-PET/CT images were read independently by two pairs of readers. A composite reference standard was used. Sensitivities, specificities and area under the receiver operating characteristic curves (AUCROC) were calculated and compared. RESULTS: In total, 260 CRLMs were confirmed. The MRI readers had significantly higher per-lesion sensitivity (85.9% and 83.8%) than both CE-CT readers (69.1% and 62.3%) and both PET/CT reader pairs (72.0% and 72.1%) (p<0.001). There were no significant differences in per-lesion specificity. MRI readers had significantly higher AUCROC (0.92 and 0.88) than both CE-CT readers (0.80 and 0.82) (p≤0.001). AUCROC for MR reader 1 was higher than that of both PET/CT reader pairs (0.83 and 0.84) (p≤0.0001). CONCLUSION: MRI performed significantly better than both CE-CT and combined FDG-PET/CT for detection of CRLM in consecutive patients eligible for local treatment irrespective of prior chemotherapy or local treatment. KEY POINTS: • Patients eligible for local treatment of colorectal liver-metastases require optimal imaging. • In 80 consecutive patients, MRI had superior per lesion diagnostic performance. • Findings were independent of prior treatment and type of planned local treatment. • Equally, MRI had superior diagnostic performance on per segment basis.

Clinical Implications of Monitoring Circulating Tumor DNA in Patients with Colorectal Cancer.

Purpose: We investigated whether detection of ctDNA after resection of colorectal cancer identifies the patients with the highest risk of relapse and, furthermore, whether longitudinal ctDNA analysis allows early detection of relapse and informs about response to intervention.Experimental Design: In this longitudinal cohort study, we used massively parallel sequencing to identify somatic mutations and used these as ctDNA markers to detect minimal residual disease and to monitor changes in tumor burden during a 3-year follow-up period.Results: A total of 45 patients and 371 plasma samples were included. Longitudinal samples from 27 patients revealed ctDNA postoperatively in all relapsing patients (n = 14), but not in any of the nonrelapsing patients. ctDNA detected relapse with an average lead time of 9.4 months compared with CT imaging. Of 21 patients treated for localized disease, six had ctDNA detected within 3 months after surgery. All six later relapsed compared with four of the remaining patients [HR, 37.7; 95% confidence interval (CI), 4.2-335.5; P < 0.001]. The ability of a 3-month ctDNA analysis to predict relapse was confirmed in 23 liver metastasis patients (HR 4.9; 95% CI, 1.5-15.7; P = 0.007). Changes in ctDNA levels induced by relapse intervention (n = 19) showed good agreement with changes in tumor volume (κ = 0.41; Spearman ρ = 0.4).Conclusions: Postoperative ctDNA detection provides evidence of residual disease and identifies patients at very high risk of relapse. Longitudinal surveillance enables early detection of relapse and informs about response to intervention. These observations have implications for the postoperative management of colorectal cancer patients. Clin Cancer Res; 23(18); 5437-45. ©2017 AACR.

Comparison of four MRI protocols for detection of extrahepatic colorectal cancer metastases.

PURPOSE: To compare three magnetic resonance imaging (MRI) protocols containing diffusion-weighted imaging with background suppression (DWIBS) and one traditional protocol for detecting extrahepatic colorectal cancer metastases. MATERIALS AND METHODS: Thirty patients with extrahepatic colorectal cancer metastases were scanned in three stations from the skull base to the upper thighs using a 1.5T MRI system with six different MRI sequences; transverse and coronal T2 -weighted (T2 W) turbo spin-echo (TSE), coronal short tau inversion recovery (STIR), 3D T1 W TSE, DWIBS, and a contrast-enhanced T1 W 3D gradient echo (GRE) sequence. The six sequences were used to build four hypothetical MRI interpretive sets which were read by two readers in consensus, blinded to prior imaging. Lesions were categorized into 13 anatomic regions. Fluorodeoxyglucose / positron emission tomography / computed tomography (FDG-PET/CT) read with full access to prior imaging and clinical records was used as the reference standard. Sensitivity, specificity, and false discovery rate (FDR) were calculated as appropriate and receiver operating characteristic (ROC) curves were constructed. RESULTS: In all, 177 malignant lesions were detected by FDG-PET/CT and distributed in 92 out of 390 scanned anatomic regions. The sensitivity was statistically higher in two out of three sets incorporating DWIBS on a per-lesion basis (66.7%, 63.3%, and 66.7% vs. 57.6%) (P = 0.01, P = 0.11, and P = 0.01, respectively) and in all sets incorporating DWIBS on a per-region basis (75.0%, 75.0%, and 77.2 vs. 66.3%) (P = 0.04, P = 0.04, and P = 0.01, respectively). There was no difference in specificity, FDR, or AUCROC . There was no difference between sets containing DWIBS irrespective of the use of a contrast-enhanced sequence. CONCLUSION: MRI sets containing DWIBS had superior sensitivity. This sensitivity was retained when omitting a contrast-enhanced sequence. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1619-1630.

Black or white coffee before anaesthesia?: A randomised crossover trial.

BACKGROUND: In current preoperative fasting guidelines, coffee with milk is still regarded by many as solid food. Evidence on the consequences for gastric volume of adding milk to coffee 2 h before anaesthesia is still weak. OBJECTIVES: The aim of this study was to compare the gastric volume by MRI in healthy volunteers after drinking coffee with and without added milk. DESIGN: A randomised crossover trial where all participants were exposed to three coffee and milk mixtures performed as a noninferiority study with a predefined noninferiority limit of 12 ml. SETTING: Department of Day Surgery and Department of Radiology, Aarhus University Hospital, Aarhus, Denmark. The study was conducted between August 2013 and February 2014. PARTICIPANTS: Total 32 healthy volunteers, aged 18 to 71 years. INTERVENTIONS: The participants fasted for 6 h for solid food, and 2 h before the MRI examination of gastric volume, each participant ingested one of three coffee mixtures: 175 ml coffee, including either 0 or 20 or 50% full fat milk. Each participant was studied by MRI three times separated by a minimum time interval of 2 days. The order of coffee mixture ingested was determined by random allocation. MAIN OUTCOME MEASURE: Gastric volume as measured by MRI. RESULTS: The mean gastric volume for black coffee was 27.8 ml, for coffee with 20% milk 17.9 ml and for coffee with 50% milk 20.6 ml. Compared to black coffee, the gastric volume for 20% milk was significantly decreased with a difference of -10.0 ml (95% confidence interval, -18.2, -1.8), and for 50% milk it was insignificantly decreased, -7.2 ml (95% confidence interval, -17.4, +2.9). The upper confidence interval for the difference in gastric volume between the 'no milk added' group and each 'milk added' group did not reach the noninferiority limit of 12 ml. CONCLUSION: The study provides evidence that adding up to 50% full fat milk to coffee leads to no or only a minimal increase of the gastric volume 2 h later. The results support a liberalisation of policy on the addition of milk to hot drinks before planned anaesthesia. TRIAL REGISTRATION: www.Clinicaltrials.gov identifier: NCT02361632.

Traditional SCORE-based health check fails to identify individuals who develop acute myocardial infarction.

INTRODUCTION: Atherosclerotic cardiovascular disease (CVD), including acute myocardial infarction (AMI), is caused by well-known risk factors. They constitute important therapeutic targets, but their predictive value is disputed. We evaluated the effectiveness of the risk scoring system (SCORE) and thresholds for pharmacotherapy re-commended in the European guidelines on CVD prevention. MATERIAL AND METHODS: The medical records of 605 consecutive patients hospitalized for a first AMI were reviewed. Patients with pre-existing CVD, diabetes, or incomplete information on risk factors were excluded. Those not treated with statin before AMI were risk stratified based on risk factors. A SCORE ≥ 5% or ≥ 10% was considered to qualify for preventive medication in young adults (age ≤ 60 years) or elderly (age > 60 years), respectively. RESULTS: Before AMI, 40 (9%) used statin. Among non-statin users, only five of the 109 young adults had a SCORE ≥ 5%, and 23 of the 284 elderly had a SCORE ≥ 10%. Among women, only three elderly qualified for treatment. More than four times more patients would have qualified for treatment with the high-risk country chart used in 2011. The incremental value of the novel high-density lipoprotein adjusted SCORE charts was limited. CONCLUSION: Few patients admitted with a first AMI used statin. Among non-statin users, SCORE and the recommended thresholds for pharmacotherapy identified no women and less than one out of ten men who untreated were destined for an AMI before 61 years of age. The preventive potential of a traditional risk factor-based health check is limited. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.

An automated in vitro model for the evaluation of ultrasound modalities measuring myocardial deformation.

BACKGROUND: Echocardiography is the method of choice when one wishes to examine myocardial function. Qualitative assessment of the 2D grey scale images obtained is subjective, and objective methods are required. Speckle Tracking Ultrasound is an emerging technology, offering an objective mean of quantifying left ventricular wall motion. However, before a new ultrasound technology can be adopted in the clinic, accuracy and reproducibility needs to be investigated. AIM: It was hypothesized that the collection of ultrasound sample data from an in vitro model could be automated. The aim was to optimize an in vitro model to allow for efficient collection of sample data. MATERIAL & METHODS: A tissue-mimicking phantom was made from water, gelatin powder, psyllium fibers and a preservative. Sonomicrometry crystals were molded into the phantom. The solid phantom was mounted in a stable stand and cyclically compressed. Peak strain was then measured by Speckle Tracking Ultrasound and sonomicrometry. RESULTS: We succeeded in automating the acquisition and analysis of sample data. Sample data was collected at a rate of 200 measurement pairs in 30 minutes. We found good agreement between Speckle Tracking Ultrasound and sonomicrometry in the in vitro model. Best agreement was 0.83 ± 0.70%. Worst agreement was -1.13 ± 6.46%. CONCLUSIONS: It has been shown possible to automate a model that can be used for evaluating the in vitro accuracy and precision of ultrasound modalities measuring deformation. Sonomicrometry and Speckle Tracking Ultrasound had acceptable agreement.

Left ventricular longitudinal strain for perioperative cardiac monitoring in aortic aneurysm surgery using transthoracic 2-dimensional echocardiography: a feasibility and repeatability study.

OBJECTIVE: This study investigated perioperative echocardiographic image quality, the feasibility, and intra- and interobserver repeatability of left ventricular longitudinal two-dimensional strain echocardiography (2DSE) in aortic aneurysm surgery. DESIGN: A prospective, descriptive method evaluation. SETTING: A single-center study. PARTICIPANTS: Eighteen patients undergoing elective open infrarenal aortic aneurysm repair. INTERVENTION: No intervention was made. MEASUREMENTS AND MAIN RESULTS: Four echocardiographic examinations were made: E1, preoperatively; E2, within 4 hours after surgery; E3, the first postoperative day; and E4, the second postoperative day. Four-chamber, 2-chamber, and longitudinal axis apical views were achieved. Image quality was scored visually on a scale from 1 to 5 with 5 as the best, and the 2-dimensional strain echocardiography (2DSE) software was applied to measure peak systolic strain. Blinded analyses were performed twice by 1 observer and once by a second observer. Image quality decreased significantly after surgery as compared with the preoperative examination, but 72% of patients had at least 1 image scoring >/=3 through all examinations. The software was able to measure the segmental and global left ventricular peak systolic strain in 80% and 61%, respectively, for the first observer and 71% and 26%, respectively, for the second observer. The coefficients of repeatability for intra- and interobserver measurements were 5.5% and 7.3% for segmental strain and 1.6% and 3.5% for global strain. 2DSE was more feasible and repeatable when echocardiographic images were good. CONCLUSION: Feasibility and repeatability of 2DSE is good but affected by image quality. This study shows that 2DSE can be used in a clinical setting.

Speckle tracking ultrasound is independent of insonation angle and gain: an in vitro investigation of agreement with sonomicrometry.

OBJECTIVE: It has been shown that speckle tracking ultrasound (STU) is capable of measuring peak strain accurately in vitro over a range of compression rates and amplitudes. The aim of this study was to investigate the influence of different angles of insonation with a range of scanner settings. METHODS: A tissue-mimicking phantom was cyclically deformed to imitate the beating heart. With different combinations of scanner settings, strain was measured by STU using sonomicrometry as reference. RESULTS: Over a majority of parameter combinations, speckle tracking measured strain accurately. However, a combination of large echocardiographic image displacements, low frame rates, and small sector depths resulted in increased difference between STU and sonomicrometry. The angle of insonation and gain setting did not affect STU. CONCLUSION: Despite the limitations exhibited by image displacement, frame rate, and sector depth, STU remains a promising technique for angle-independent assessment of strain.