PET/MRI in Endometrial Cancer: Imaging Biomarkers are Associated with Disease Progression and Overall Survival

RATIONALE AND OBJECTIVES

To evaluate the association between positron emission tomography (PET)/magnetic resonance imaging (MRI) biomarkers and survival outcomes in patients with endometrial cancer.

MATERIALS AND METHODS

Between April 2014 and April 2016, 88 patients with newly diagnosed endometrial cancer participated this prospective study and underwent [18F] fluorodeoxyglucose PET/MRI. Sixty-nine patients with measurable tumors on PET/MRI were included in the image analysis. Imaging biomarkers included the minimum and mean apparent diffusion coefficients (ADCmin and ADCmean), maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumors. The log-rank test and Cox proportional hazards model were used to assess the relationship between imaging biomarkers and survival.

RESULTS

After a median follow-up of 80 months, 15 (22%) patients had tumor progression and six (9%) patients died. The results of ADCmin, ADCmean, and SUVmax did not show a significant association with progression-free survival (PFS) and overall survival (OS). Significantly shorter PFS was noted in patients with primary tumors with higher MTV (P < 0.001) and TLG (P < 0.001). Significantly shorter OS was also noted in patients with primary tumors with higher MTV (P = 0.048) and TLG (P = 0.034). In the multivariate analysis, MTV was an independent predictor of PFS (hazard ratio = 10.84, P = 0.033).

CONCLUSION

PET/MRI biomarkers, particularly MTV and TLG, are associated with PFS and OS in patients with endometrial cancer. MTV was an independent predictor of PFS.

Validation of the Efficacy of Ultrasound Speckle Tracking in Measuring Tendon Gliding After Finger Flexor Tendon Repair

OBJECTIVE

Restricted tendon gliding is commonly observed in patients after finger flexor tendon (FFT) repair. The study described here was aimed at quantifying the amount of FFT gliding to evaluate the recovery of post-operative tendons using a 2-D radiofrequency (RF)-based ultrasound speckle tracking algorithm (UST).

METHODS

Ex vivo uniaxial tensile testing of porcine flexor tendons and in vivo isometric testing of human FFT were implemented to verify the efficacy of UST beforehand. The verified UST was then applied to the patients after FFT repair to compare tendon gliding between affected and healthy sides and to investigate its correlation with the joint range of motion (ROM).

RESULTS

Excellent validity was confirmed with the average R2 value of 0.98, mean absolute error of 0.15 ± 0.08 mm and mean absolute percentage error of 5.19 ± 2.43% between results from UST and ex vivo testing. The test-retest reliability was verified with good agreement of ICC (0.90). The affected side exhibited less gliding (p = 0.001) and smaller active ROM (p = 0.002) than the healthy side. Meanwhile, a significant correlation between tendon gliding and passive ROM was found only on the healthy side (ρ = 0.711, p = 0.009).

CONCLUSION

The present study provides a promising protocol to evaluate post-operative tendon recovery by quantifying the amount of FFT gliding with a validated UST. FFT gliding in patients with different levels of ROM restriction should be further explored for categorizing the severity of tendon adhesion.

Ultrasound characteristics of soft tissues near sacroiliac joints and in the lumbar region of patients with ankylosing spondylitis

AIMS

To investigate the musculoskeletal morphomechanical properties (i.e., the thickness and elastic modulus) and the total count of power Doppler signals near the sacroiliac joints in patients with ankylosing spondylitis (AS) and non-AS individuals.

MATERIAL AND METHODS

Twenty participants with AS [median age (interquartile range): 31.7 (11.04) years] and 19 controls [36.3 (10.5) years] with no AS history were recruited. Bilateral ultrasound image acquisition was performed, including the short posterior sacroiliac ligament, interosseous sacroiliac ligament, long posterior sacroiliac ligament, iliolumbar ligament, proximal piriformis muscle, and sacrotuberous ligament. The intraclass correlation coefficients (ICC) of ultrasound parameters, laboratory test results of human leukocyte antigen B27, C-reactive protein, and erythrocyte sedimentation rate, and self-reported physical and disease activity scores were also obtained.

RESULTS

The ligaments and piriformis muscle were thicker and stiffer (greater elastic modulus) in participants with AS than in non-AS participants (all p<0.01). The measurements showed good or excellent reliability (all ICC(3,1) >0.85). The numbers of power Doppler signals detected in the iliolumbar ligament, proximal piriformis muscle, and sacrotuberous ligament were higher in participants with AS than in non-AS participants (all p<0.001). A correlation was identified between disease duration and the elastic modulus of the piriformis muscle (r=0.640, p=0.003).

CONCLUSION

We conclude that the ligaments and proximal piriformis muscle of AS participants have increased thickness, elastic modulus, and power Doppler signal than those of non-AS individuals. These reliable findings may serve as potential markers for the early diagnosis of AS and for assessing medication effects.

Kinematic magnetic resonance imaging for the evaluation of active motion of the mandibular condyle in patients with temporomandibular joint disorders

PURPOSE

To explore the mandibular condylar movements in patients with temporomandibular joint (TMJ) disorders using kinematic magnetic resonance imaging (MRI).

METHODS

We retrospectively recruited patients who were clinically diagnosed with internal derangement of the TMJ and referred to our center for MRI examination. The TMJ discs were categorized into normal disc (ND), anteriorly displaced disc (ADD), and disc with destruction (DD) groups using static images obtained in the closed-mouth view. The difference between the "open-mouth" and "closed-mouth" views on kinematic MRI was used to calculate the condylar translation and rotation. Two radiologists consensually performed the image readings and measurements. One-way analysis of variance and chi-squared test were used to compare the variables in the three groups. Pearson's correlation and general linear models were used to evaluate the correlation and differences between condylar translation and rotation in the three groups.

RESULTS

This study included 98 TMJs from 54 patients. Twenty-six, 49, and 23 TMJs were classified as ND, ADD, and DD, respectively. Condylar rotation and translation demonstrated a significant correlation in all TMJs examined (r = 0.635, p < 0.001), with similar coefficients for all groups. The mean condylar translation in the ND group was greater than that in the ADD and DD groups (ND versus ADD: p = 0.003; ND versus DD: p = 0.002). However, the change in condylar rotation was not affected by the disc status (ND as reference; DD∗condylar translation: coefficient = 0.341, p = 0.332; ADD∗condylar translation: coefficient = -0.100, p = 0.696).

CONCLUSIONS

Kinematic MRI studies revealed that TMJ condylar translation was correlated with its rotation for all disc statuses.

Predictors of changes in preoperative tumor stage between dynamic computed tomography and gadoxetate disodium-enhanced magnetic resonance imaging for hepatocellular carcinoma

BACKGROUND/PURPOSE

Gadoxetate disodium-enhanced magnetic resonance imaging (EOB-MRI) has a higher diagnostic accuracy for hepatocellular carcinoma (HCC) than computed tomography (CT). However, indications for performing EOB-MRI after dynamic CT are not well defined. Therefore, we investigated the clinical factors associated with changes in the preoperative tumor stage between dynamic CT and EOB-MRI.

METHODS

A prospective cohort was conducted from January 2014 to December 2017. 156 adult patients with clinical suspicion of HCC before liver resection were enrolled and we retrospectively reviewed the images. The tumor staging was evaluated by dynamic CT and then EOB-MRI subsequently according to the TNM staging system. The changes in tumor stage between two modalities were identified, and the associated clinical factors were analyzed.

RESULTS

A total of 99 patients were analyzed after excluding 57 patients. 20 patients (20.2%) had changes in tumor stage between dynamic CT and EOB-MRI. The change occurred only in early stage (T1 and T2 lesions) based on dynamic CT initially. Furthermore, in univariate and multivariate analyses, albumin-bilirubin (ALBI) grade 2 and log alpha-fetoprotein (AFP) levels were associated with changes in tumor staging by EOB-MRI than those without (50% vs. 9.9%, p < 0.001 and 2.04 ± 1.35 vs. 1.40 ± 1.16, p = 0.038, respectively). Patients with changes in tumor stage also exhibited higher 1-year recurrence rate and shorter recurrence-free survival.

CONCLUSION

Changes in preoperative tumor stage between dynamic CT and EOB-MRI were associated with CT-defined early stage, ALBI grades, higher log AFP levels, and early recurrence.

Muscle Microcirculatory Responses to Incremental Exercises Are Correlated with Peak Oxygen Uptake in Individuals With and Without Type 2 Diabetes Mellitus

Background: The role of impaired oxygen extraction on peak oxygen uptake (V̇O_2peak) has been extensively studied using noninvasive and indirect methods in both diabetic patients and healthy participants. Methods: A total of 22 participants with type 2 diabetes mellitus [T2DM; median (range) age: 60 (47-70) years] and 22 controls [58 (52-69) years] with no history of diabetes were recruited (reference no. 201812135RINB). Subjects performed an exhaustive incremental exercise and were evaluated using a gas analyzer and near-infrared spectroscopy (NIRS) to determine V̇O_2peak and changes in muscle oxygenation (SmO₂) in the vastus lateralis, respectively. Measurements were taken at rest, warm-up, a period during exercise when SmO₂ reached a minimum saturation plateau, and recovery. The microcirculatory responses of the vastus lateralis muscle during incremental exercise in patients with T2DM were compared with those in control individuals, and the correlation between changes in SmO₂ and V̇O_2peak was estimated. Results: The diabetic group demonstrated lower V̇O_2peak, peak workload, peak heart rate, peak minute ventilation (all P < 0.05), and lower SmO₂ during the rest, warm-up, and recovery phases (all P < 0.05) compared with the control group. A correlation was observed between the change in SmO₂ between the warm-up and plateau value and the V̇O_2peak (r = 0.608, P = 0.006). Conclusions: The results obtained in this study using NIRS support the feasibility of directly measuring changes in muscle SmO₂ magnitudes to estimate the contributions of peripheral active muscle to systemic O₂ uptake (V̇O₂) during incremental exercise.

Prediction of Mandibular Advancement Device Response Using CPAP Pressure in Different Polysomnographic Phenotypes

OBJECTIVE

Both continuous positive airway pressure (CPAP) pressure and polysomnographic phenotypes have been associated with mandibular advancement device (MAD) treatment response, but the precise relationship has not been fully elucidated. We hypothesized that utilizing CPAP pressure would predict the MAD response in treatment-naïve patients with moderate-severe obstructive sleep apnea (OSA), and the MAD response would be associated with two polysomnographic phenotypes, including sleep stage dependency and positional dependency.

METHODS

OSA treatment-naïve patients with an apnea-hypopnea index (AHI) ≥15/h who declined CPAP treatment and received MAD treatment for 3-6 months were enrolled. The MAD treatment response was defined as 1) residual AHI under MAD (AHI_MAD) <5/h and 2) AHI_MAD <10/h. Logistic regression was applied to identify the association between CPAP pressure and MAD treatment responders. The predictability of the MAD responder status utilizing CPAP pressure was assessed with the area under the receiver operating characteristic (AUROC).

RESULTS

A total of 128 enrolled patients (AHI ≥30/h in 74.2%) were recruited, of whom 119 patients and 80 patients were included for analysis of sleep stage and positional dependency, respectively. REM-predominant OSA had lower AHI than stage-independent OSA, while the supine-predominant phenotype had lower anthropometrics than the nonpositional-dependent phenotype. The response rates for AHI_MAD <5/h and AHI_MAD <10/h were 25.8% and 48.4%, respectively. Lower anthropometrics, baseline AHI, and supine predominance were associated with the responder status, while CPAP pressure was an independent predictor. The AUROCs for the prediction of AHI_MAD <5/h and AHI_MAD <10/h responders were 0.635 and 0.664, respectively. Utilizing a CPAP level >14 cmH₂O as the cutoff to predict criterion 1 and 2 nonresponders, the sensitivity was 93.9% and 95.2%, respectively.

CONCLUSION

In treatment-naïve patients with moderate-severe OSA, the supine-predominant phenotype and lower CPAP pressure were associated with the MAD response, while the sleep stage dependency phenotype was not. Utilization of a CPAP level >14 cmH₂O could be a sensitive measure to identify nonresponders.

Diagnostic Performance of Proton Magnetic Resonance Spectroscopy and 18F-Fluorocholine PET to Differentiate Benign From Malignant Breast Lesions

PURPOSE

The aim of this study was to evaluate the diagnostic performance of the proton magnetic resonance spectroscopy (MRS) and 18F-fluorocholine (FCH) PET for suspicious breast findings on conventional imaging (mammography and breast ultrasound).

METHODS

From September 2012 to December 2015, 37 women with 39 breast lesions on conventional imaging were enrolled and underwent proton MRS and FCH PET. The MRS parameters of choline signal-to-noise ratio (SNR), choline integral (I(cho)), and the PET parameters including SUVmax in the prone (SUV1) and supine (SUV2) positions were analyzed. Receiver operating characteristic curves with the area under the curve, sensitivity, and specificity under the optimal cutoff points for the different parameters were determined.

RESULTS

Twenty-three lesions (59%) were malignant, and 16 (41.0%) were benign. The malignant lesions tended to show significantly higher MRS and PET parameters than benign lesions (choline SNR, P = 0.007; I(cho), P = 0.003; SUV1 and SUV2, P < 0.0001). Fair to moderate correlations were noted between the choline SNR and PET parameters (SUV1, Spearman rank correlation coefficient, ρ = 0.477; SUV2, ρ = 0.483), as well as I(cho) and PET parameters (SUV1, ρ = 0.493; SUV2, ρ = 0.549). The SUV2 showed the highest diagnostic performance (area under the curve, 0.918). Using 2.5 as the optimal cutoff point, the SUV2 yields 89.5% sensitivity and 87.5% specificity for differentiating malignant from benign lesions.

CONCLUSION

The MRS parameters were fairly to moderately correlated with FCH PET parameters, and both could differentiate malignant from benign breast lesions with SUV2 showing best diagnostic performance.

Safety and Efficacy of Kartigen® in Treating Cartilage Defects: A Randomized, Controlled, Phase I Trial

Here, we aimed to investigate the safety and preliminary efficacy of Kartigen^®, a matrix with autologous bone marrow mesenchymal stem cell-derived chondrocyte precursors embedded in atelocollagen. As a surgical graft, Kartigen^® was implanted onto the cartilage defects at the weight-bearing site of the medial femoral condyle of the knee. Fifteen patients were enrolled and stratified into two groups, undergoing either Kartigen^® implantation (n = 10) or microfracture (control group, n = 5). The primary endpoint was to evaluate the safety of Kartigen^® by monitoring the occurrence of adverse events through physician queries, physical examinations, laboratory tests, and radiological analyses for 2 years. There were no infections, inflammations, adhesions, loose body, or tumor formations in the Kartigen^®-implanted knees. The preliminary efficacy was assessed using the International Knee Documentation Committee (IKDC) score, visual analog scale, and second-look arthroscopy. The postoperative IKDC scores of the Kartigen^® group significantly improved in the 16th week (IKDC = 62.1 ± 12.8, p = 0.025), kept increasing in the first year (IKDC = 78.2 ± 15.4, p < 0.005), and remained satisfactory in the second year (IKDC = 73.6 ± 13.8, p < 0.005), compared to the preoperative condition (IKDC = 47.1 ± 17.0), while the postoperative IKDC scores of the control group also achieved significant improvement in the 28th week (IKDC = 68.5 ± 6.1, p = 0.032) versus preoperative state (IKDC = 54.0 ± 9.1). However, the IKDC scores decreased in the first year (IKDC = 63.5 ± 11.6) as well as in the second year (IKDC = 52.6 ± 16.4). Thirteen patients underwent second-look arthroscopy and biopsy one year after the operation. The Kartigen^® group exhibited integration between Kartigen^® and host tissue with a smooth appearance at the recipient site, whereas the microfracture group showed fibrillated surfaces. The histological and immunohistochemical analyses of biopsy specimens demonstrated the columnar structure of articular cartilage and existence of collagen type II and glycosaminoglycan mimic hyaline cartilage. This study indicates that Kartigen^® is safe and effective in treating cartilage defects.

Metabolic Alterations in Pancreatic Cancer Detected by In Vivo 1H-MR Spectroscopy: Correlation with Normal Pancreas, PET Metabolic Activity, Clinical Stages, and Survival Outcome

Objective: To compare the metabolites of in vivo 1H- MRS in pancreatic cancer with normal pancreas, and correlate these metabolites with Positron Emission Tomography (PET) metabolic activity, clinical stages, and survival outcomes. Methods: The prospective study included 58 patients (mean age 62.7 ± 12.1 years, range 34–81 years; 36 men, 22 women) with pathological proof of pancreatic adenocarcinoma, and all of them received 18F-fluorodeoxyglucose (FDG) PET/MRI before treatment. The single-voxel MRS with a point-resolved selective spectroscopy sequence was used to measure metabolites (creatine, Glx (glutamine and glutamate), N-acetylaspartate (NAA), and lipid) of pancreatic cancer and adjacent normal parenchyma, respectively. FDG-PET parameters included SUVmax, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Non-parametric tests were used to evaluate the differences of MRS metabolites between pancreatic cancer and those in normal pancreas, and their correlation with PET parameters and clinical stages. The correlation with progression-free survival (PFS) and overall survival (OS) was measured using the Kaplan–Meier and Cox proportional hazard models. Results: When compared with normal pancreas, the Glx, NAA, and lipid levels were significantly decreased in pancreatic cancer (all p < 0.05). Creatine, Glx, and lipid levels were all inversely correlated with both MTV (rho = −0.405~−0.454) and TLG (rho = −0.331~−0.441). For correlation with clinical stages, lower lipid levels were found in patients with T4 (vs. <T4, p = 0.038) and lower creatine levels were found in N1 (vs. N0, p = 0.019). Regarding survival outcomes, high TNM stage, low creatine, low Glx, and low lipid levels were associated with both poor PFS and OS (all p < 0.05). Additionally, creatine remained an independent factor for PFS and OS after adjusting for age, sex, tumor size, stages, and other metabolites levels. Conclusions: Decreased MRS metabolites in pancreatic cancer were associated with poor survival outcome, and may be used as prognostic image biomarkers for these patients.

Lumbar Disc Herniation Automatic Detection in Magnetic Resonance Imaging Based on Deep Learning

Background: Lumbar disc herniation (LDH) is among the most common causes of lower back pain and sciatica. The causes of LDH have not been fully elucidated but most likely involve a complex combination of mechanical and biological processes. Magnetic resonance imaging (MRI) is a tool most frequently used for LDH because it can show abnormal soft tissue areas around the spine. Deep learning models may be trained to recognize images with high speed and accuracy to diagnose LDH. Although the deep learning model requires huge numbers of image datasets to train and establish the best model, this study processed enhanced medical image features for training the small-scale deep learning dataset. Methods: We propose automatic detection to assist the initial LDH exam for lower back pain. The subjects were between 20 and 65 years old with at least 6 months of work experience. The deep learning method employed the YOLOv3 model to train and detect small object changes such as LDH on MRI. The dataset images were processed and combined with labeling and annotation from the radiologist's diagnosis record. Results: Our method proves the possibility of using deep learning with a small-scale dataset with limited medical images. The highest mean average precision (mAP) was 92.4% at 550 images with data augmentation (550-aug), and the YOLOv3 LDH training was 100% with the best average precision at 550-aug among all datasets. This study used data augmentation to prevent under- or overfitting in an object detection model that was trained with the small-scale dataset. Conclusions: The data augmentation technique plays a crucial role in YOLOv3 training and detection results. This method displays a high possibility for rapid initial tests and auto-detection for a limited clinical dataset.

Iodized oil computed tomography versus ultrasound-guided radiofrequency ablation for early hepatocellular carcinoma

BACKGROUND AND PURPOSE

Radiofrequency ablation (RFA) is the standard of care for early stage hepatocellular carcinoma (HCC). However, the clinical outcomes of iodized oil computed tomography (IoCT) versus ultrasound (US)-guided RFA for HCC remain unclear.

METHODS

We retrospectively analyzed consecutive treatment-naïve patients who received curative RFA for HCC within Milan criteria from January 2016 to December 2018. Patients who underwent either IoCT-guided RFA (IoCT group) or US-guided RFA (US group) were included. Various clinical factors, including tumor location, were adjusted with a 1:1 propensity score matching. Subsequently, the cumulative incidence rates for recurrence and hazard ratios for survival were calculated.

RESULTS

We included 184 (37.9%) and 301 (62.1%) patients who received IoCT- and US-guided RFA, respectively. Before propensity score matching, IoCT guidance was significantly associated with multiple tumors, higher body mass index, lower albumin level, and tumors located at S8. After matching, the 1-, 2-, and 3-year local tumor progression rates of the IoCT group were significantly lower than those of the US group (4.4%, 6.9%, and 7.5% vs. 14.4%, 16.3%, and 16.3%, respectively, at p = 0.002, 0.009, and 0.016, respectively). In univariate analyses and multivariate analyses that adjusted for clinical and tumor location-related parameters, the IoCT group had better recurrence-free survival (hazard ratio = 0.581, 95% confidence interval 0.375-0.899) than those with US guidance but not overall survival.

CONCLUSION

IoCT-guided RFA had a lower local tumor progression rate and better recurrence-free survival than did US-guided RFA for HCC within the Milan criteria. CT-guide RFA is a safe and effective alternative to US-guided with similar overall survival. IoCT-guided RFA might have a better local tumor control than US-guided. IoCT-guided RFA may be more suitable for male patients, aged < 70 years, a single tumor measuring 2-5 cm, and a tumor located at the subdiaphragmatic/subcardiac region.

An international expert opinion statement on the utility of PET/MR for imaging of skeletal metastases

BACKGROUND

MR is an important imaging modality for evaluating musculoskeletal malignancies owing to its high soft tissue contrast and its ability to acquire multiparametric information. PET provides quantitative molecular and physiologic information and is a critical tool in the diagnosis and staging of several malignancies. PET/MR, which can take advantage of its constituent modalities, is uniquely suited for evaluating skeletal metastases. We reviewed the current evidence of PET/MR in assessing for skeletal metastases and provided recommendations for its use.

METHODS

We searched for the peer reviewed literature related to the usage of PET/MR in the settings of osseous metastases. In addition, expert opinions, practices, and protocols of major research institutions performing research on PET/MR of skeletal metastases were considered.

RESULTS

Peer-reviewed published literature was included. Nuclear medicine and radiology experts, including those from 13 major PET/MR centers, shared the gained expertise on PET/MR use for evaluating skeletal metastases and contributed to a consensus expert opinion statement. [18F]-FDG and non [18F]-FDG PET/MR may provide key advantages over PET/CT in the evaluation for osseous metastases in several primary malignancies.

CONCLUSION

PET/MR should be considered for staging of malignancies where there is a high likelihood of osseous metastatic disease based on the characteristics of the primary malignancy, hight clinical suspicious and in case, where the presence of osseous metastases will have an impact on patient management. Appropriate choice of tumor-specific radiopharmaceuticals, as well as stringent adherence to PET and MR protocols, should be employed.

Prediction of Lumbar Disc Bulging and Protrusion by Anthropometric Factors and Disc Morphology

The relationship between reduced disc height and disc bulging and/or protrusion has been controversial. The purposes of this study were to examine the relationship between disc morphology and disc bulging and protrusion and to establish a model for predicting disc bulging and protrusion. This is a retrospective study. A total of 452 MRI scans from a spine study were analysed, 210 (46.5%) were men. Logistic regression analysis was applied to identify the association between anthropometric factors, disc morphology factors, and outcome. Model 1 was constructed using anthropometric variables to investigate the capacity for predicting outcomes. Model 2 was constructed using anthropometric and disc morphology variables. Age, body weight, body height, disc height, and disc depth were significantly associated with outcome. The area under the curve (AUC) statistics of Model 2 were significantly better than those of Model 1 at the L3-L4 and L4-L5 levels but not at the L5-S1 level. The results showed an association between disc morphology and disc bulging and/or protrusion at the L3-L4, L4-L5, and L5-S1 levels. The model utilizing both anthropometric factors and disc morphology factors had a better capacity to predict disc bulging and/or protrusion compared with the model using only anthropometric factors.

PET/MRI in Cervical Cancer: Associations Between Imaging Biomarkers and Tumor Stage, Disease Progression, and Overall Survival

BACKGROUND

Positron emission tomography (PET)/MRI biomarkers have been shown to have prognostic significance in patients with cervical cancer. Their associations with progression-free survival (PFS) and overall survival (OS) merit further investigation.

PURPOSE

To evaluate the association between PET/MRI biomarkers and tumor stage, PFS, and OS in patients with cervical cancer.

STUDY TYPE

Prospective cohort study.

POPULATION

In all, 54 patients with newly diagnosed cervical cancer and measurable tumors (>1 cm) were included in the image analysis.

FIELD STRENGTH/SEQUENCE

3.0T integrated PET/MRI including diffusion-weighted echo-planar imaging (b = 50 and 1000 s/mm² ) and [18F]fluorodeoxyglucose PET.

ASSESSMENT

Two radiologists measured the minimum and mean apparent diffusion coefficient (ADC_min and ADC_mean ), maximum standardized uptake value (SUV_max ), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumors.

STATISTICAL TESTS

A Mann-Whitney U-test was used to evaluate the association between the imaging biomarkers and tumor stage. A Cox proportional hazards model was used to assess the relationships between the imaging biomarkers and survival.

RESULTS

In advanced tumors (T ≥ 1b2, M1, stage ≥ IB3), ADC_min was significantly lower and MTV, TLG, MTV/ADC_min , and TLG/ADC_min were significantly higher (P values between <0.001 and 0.036). In N1 tumors, ADC_min was significantly lower and MTV and MTV/ADC_min were significantly higher (P values between 0.005 and 0.016). In survival analysis, SUV_max was an independent predictor of PFS (hazard ratio [HR] = 4.57, P < 0.05), and ADC_min was an independent predictor of OS (HR = 0.02, P < 0.05). In subgroup analysis of patients with different stages, MTV/ADC_min was a predictor of PFS in stage I disease (P = 0.003), ADC_min (P = 0.038), and MTV (P = 0.020) in stage II, SUV_max (P = 0.006), and TLG (P = 0.006) in stage IV; and ADC_min was a predictor of OS in stage III disease (P = 0.008).

DATA CONCLUSION

PET/MRI biomarkers of cervical cancer are associated with tumor stage and survival. SUV_max and ADC_min are independent predictors of PFS and OS, respectively.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: 3.

Total skeletal, psoas and rectus abdominis muscle mass as prognostic factors for patients with advanced hepatocellular carcinoma

PURPOSE

We investigated whether low skeletal muscle mass (LSMM) defined according to different muscle groups on computed tomography (CT) scans are predictive factors of survival for advanced hepatocellular carcinoma (HCC).

METHODS

In this retrospective study, we analyzed patients who received sorafenib therapy for advanced HCC in a prospective patient cohort between 2007 and 2012. The total skeletal muscle (TSM), paraspinal muscle (PS), psoas muscle (PM), rectus abdominis (RA), and abdominal wall (AW) muscle areas were evaluated using a single CT slice at the third lumbar vertebra before treatment. LSMM was determined according to the TSM, PS, PM, RA and AW indices, which was calculated as the parameters divided by the square of the body height.

RESULTS

We enrolled 137 patients. Women had significantly lower TSM index than men did (p < .001). Among men, the optimal cut points of the TSM, PM and RA indices for LSMM diagnosis were 39.1, 8.3 and 2.9 cm²/m², respectively. Patients with LSMM defined by TSM (median 5.1 vs. 8.0 months, p = .007), PM (5.8 vs. 11.8 months, p < .001), and RA (7.2 vs. 8.1 months, p = .003) indices exhibited poorer overall survival than patients without LSMM. After adjusting for clinical variables, TSM (hazard ratio [HR]: 2.122, 95% confidence interval [CI]: 1.134-3.971) and PM (HR: 1.730, 95% CI: 1.058-2.828) indices-defined LSMM remained independent predictors for poor OS, but RA index-defined LSMM did not.

CONCLUSION

LSMM defined by TSM and PM indices are independent predictors of poor prognosis for advanced HCC.

Long-term growth and bone development in children of HBV-infected mothers with and without fetal exposure to tenofovir disoproxil fumarate

BACKGROUND & AIMS

Tenofovir disoproxil fumarate (TDF) is the preferred treatment to prevent maternal transmission of HBV, owing to its efficacy and safety. However, data are lacking on the long-term safety outcomes in children following fetal exposure to TDF.

METHODS

Children participating in a prospective, multisite trial of maternal TDF treatment during late pregnancy were recruited for follow-up visits once a year. Growth parameters, serum biochemistry, HBV serology, and bone mineral density (BMD) by dual-energy x-ray absorptiometery scan were measured.

RESULTS

One hundred and twenty-eight children, 71 in the TDF and 57 in the control group, completed 255 follow-up visits at the age of 2 to 7 (median, 4.08) years. No differences in z-scores for weight-for-age (0.26 ± 0.90 vs. 0.22 ± 0.99, p = 0.481), z-scores for height-for-age (0.20 ± 1.02 vs. 0.25 ± 0.98, p = 0.812), and estimated glomerular filtration rate (169.12 ± 50.48 vs. 169.06 ± 34.46 ml/min/1.73m², p = 0.479) were detected. After adjustment for age, sex and HBV status by multiple linear regression, children in the TDF and control group had comparable levels of serum calcium, phosphorus, bone-specific alkaline phosphatase, calcidiol and BMD of lumbar spines (0.55 ± 0.01 vs. 0.57 ± 0.01 g/cm², p = 0.159) and left hip (0.56 ± 0.01 vs. 0.56 ± 0.01 g/cm², p = 0.926).

CONCLUSIONS

Children of HBV-infected mothers who did or did not receive tenofovir disoproxil fumarate treatment during late pregnancy had comparable long-term growth, renal function, and bone development up to 6-7 years after delivery.

CLINICAL TRIAL NUMBER

NCT01312012 (ClinicalTrials.gov) LAY SUMMARY: Currently there are insufficient long-term safety data in children born to mothers who took antiviral agents during pregnancy to prevent mother-to-infant transmission of hepatitis B virus (HBV). In this study, we found that children of HBV-infected mothers who did or did not receive tenofovir disoproxil fumarate treatment during late pregnancy had comparable long-term growth, renal function, and bone development up to 6-7 years after delivery.

Intravoxel Incoherent Motion Diffusion-weighted MRI of Infiltrated Marrow for Predicting Overall Survival in Newly Diagnosed Acute Myeloid Leukemia

Background Acute myeloid leukemia (AML) features relatively low overall survival (OS). Intravoxel incoherent motion (IVIM) diffusion-weighted MRI separates tissue microcapillary perfusion and diffusivity and may have potential for helping to assess prognosis in infiltrated marrow disease apart from solid tumor. Thus, a study of overall survival would contribute to clarifying the value of IVIM for assessing long-term prognosis in AML. Purpose To determine whether the IVIM-derived parameters of infiltrated bone marrow may be associated with OS in newly diagnosed AML. Materials and Methods This prospective study enrolled participants with newly diagnosed AML between July 2014 to March 2016 consecutively. Participants underwent MRI of the lumbar spine by using an IVIM sequence. Participant clinical characteristics and OS were collected. The median of follow-up period was 20 months (range, 1-56 months). The IVIM parameters (pseudoperfusion fraction, f; diffusion coefficient, D; and pseudodiffusion coefficient, D*) were obtained. A nonparametric log-rank test was used to identify the threshold of IVIM parameters for OS. Univariable Kaplan-Meier and multivariable Cox proportional hazards regression analyses were performed to investigate prognostic significance of possible indicators. Results Fifty-three participants (mean age, 42 years ± 17; 30 men) were evaluated. Nonparametric log-rank test results showed that the thresholds of f and D values for OS were 31.0% and 0.2 × 10^-3 mm²/sec, respectively. Univariable analyses indicated that high f value (>31.0%) and low D value (≤0.2 × 10^-3 mm²/sec) were associated with shorter OS (P = .003 and .01, respectively). An f value greater than 31.0% (hazard ratio, 2.4; 95% confidence interval: 1.0, 5.6; P = .046) was associated with OS, independent of clinical confounders (age, karyotype, and white blood cell counts) in a multivariable analysis. Conclusion Pseudoperfusion fraction and diffusion coefficient from intravoxel incoherent motion diffusion-weighted MRI may be viable prognosis predictors of newly diagnosed acute myeloid leukemia. © RSNA, 2020.

Total skeletal, psoas, and rectus abdominis muscle mass as prognostic factors for patients with advanced hepatocellular carcinoma

568

Background: We investigated whether low skeletal muscle mass (LSMM) defined according to different muscle groups on computed tomography (CT) scans could predict prognosis of advanced hepatocellular carcinoma (HCC). Methods: We analyzed patients who received first-line sorafenib treatment for advanced HCC in a prospective patient cohort between 2007 and 2012. The muscels areas of total skeletal muscle (TSM), paraspinal muscle (PS), psoas muscle (PM), rectus abdominis (RA), and abdominal wall (AW) were evaluated using a single CT slice at the third lumbar vertebra before treatment. LSMM was determined according to the TSM, PS, PM, RA and AW indices, which was calculated as the parameters divided by the square of the body height. Results: We enrolled 137 patients, with a mean age of 57.5 years; 120 were male and 17 were female. Liver disease etiology was hepatitis B virus in 94 (68.6%) patients and hepatitis C virus in 28 (20.4%) patients. All patients had Child–Pugh class A liver reserve. Women had significantly lower TSM index than men did ( p < .001). Among men, the optimal cut points of the TSM, PM and RA indices for LSMM diagnosis were 39.1, 8.3 and 2.9 cm2/m2, respectively. Patients with LSMM exhibited poorer overall survival than patients without LSMM, whether LSMM was defined by TSM index (median 5.1 vs. 8.0 months, p = 0.007), PM index (median 5.8 vs. 11.8 months, p < 0.001), or RA index (median 7.2 vs. 8.1 months, p = 0.003). After adjusting for clinical variables including underweight, age, tumor extent, and performance status, LSMM defined by TSM index (hazard ratio [HR]: 2.123, 95% confidence interval [CI]: 1.124-4.010, p = 0.020), PM index (HR: 1.855, 95% CI: 1.163-2.959, p = 0.009), or RA index (HR: 1.650, 95% CI: 1.004-2.710, p = 0.048) remained independent predictors for poor OS. Conclusions: LSMM defined by TSM, PM and RA indices are independent predictors for poor prognosis of advanced HCC, even after adjusted for body weight.

Intramyocellular Lipids, Insulin Resistance, and Functional Performance in Patients with Severe Obstructive Sleep Apnea

PURPOSE

An increasing number of studies have linked the severity of obstructive sleep apnea (OSA) with metabolic dysfunction. However, little is known about the lipid compartments (intramyocellular [IMCL] and extramyocellular [EMCL] lipids) inside the musculature in these patients. The present study was designed to investigate the IMCL and EMCL, biochemical data, and functional performance in patients with severe OSA, and to examine the correlations between intramuscular lipid contents and test variables.

PARTICIPANTS AND METHODS

Twenty patients with severe OSA (apnea-hypopnea index [AHI]: ≥30/h; body mass index [BMI]: 26.05±2.92) and 20 age- and BMI-matched controls (AHI <5/h) were enrolled. Proton magnetic resonance spectroscopy was used to measure the IMCL and EMCL of the right vastus lateralis muscle. Biochemical data, including levels of fasting plasma glucose, insulin, lipid profiles, and high-sensitivity C-reactive protein (hsCRP), were measured. Insulin resistance index (IR) was calculated using the homeostasis model assessment method. Performance tests included a cardiopulmonary exercise test and knee extension strength and endurance measurements.

RESULTS

Patients with severe OSA had significantly (P<0.05) lower values of IMCL (14.1±5.4 AU) and EMCL (10.3±5.8 AU) compared to the control group (25.2±17.6 AU and 14.3±11.1 AU, respectively). Patients with severe OSA had significantly higher hsCRP, IR, and dyslipidemia compared with controls (all P<0.05). Furthermore, IMCL was negatively correlated with AHI, cumulative time with nocturnal pulse oximetric saturation lower than 90% (TSpO₂<90%) (ρ=-0.35, P<0.05), IR (ρ=-0.40, P<0.05), glucose (ρ=-0.33, P<0.05), and insulin (ρ=-0.36, P<0.05), and positively correlated with lowest oximetric saturation (ρ=0.33, P<0.01).

CONCLUSION

Skeletal muscle dysfunction and metabolic abnormalities were observed in patients with OSA that did not have obesity. IMCL was positively correlated with aerobic capacity and muscular performance, but negatively correlated with AHI and IR. Large-scale clinical trials are required to explore the complicated mechanism among OSA, intramuscular metabolism, and insulin action.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00813852.

Imaging biomarkers from multiparametric magnetic resonance imaging are associated with survival outcomes in patients with brain metastases from breast cancer

OBJECTIVES

The aim of this study is to investigate the correlation of survival outcomes with imaging biomarkers from multiparametric magnetic resonance imaging (MRI) in patients with brain metastases from breast cancer (BMBC).

METHODS

This study was approved by the institutional review board. Twenty-two patients with BMBC who underwent treatment involving bevacizumab on day 1, etoposide on days 2-4, and cisplatin on day 2 in 21-day cycles were prospectively enrolled for a phase II study. Three brain MRIs were performed: before the treatment, on day 1, and on day 21. Eight imaging biomarkers were derived from dynamic contrast-enhanced MRI (Peak, IAUC₆₀, K^trans, k_ep, v_e), diffusion-weighted imaging [apparent diffusion coefficient (ADC)], and MR spectroscopy (choline/N-acetylaspartate and choline/creatine ratios). The relative changes (Δ) in these biomarkers were correlated with the central nervous system (CNS)-specific progression-free survival (PFS) and overall survival (OS) using the Kaplan-Meier and Cox proportional hazard models.

RESULTS

There were no significant differences in the survival outcomes as per the changes in the biomarkers on day 1. On day 21, those with a low ΔK^trans (p = 0.024) or ΔADC (p = 0.053) reduction had shorter CNS-specific PFS; further, those with a low ΔPeak (p = 0.012) or ΔIAUC₆₀ (p = 0.04) reduction had shorter OS compared with those with high reductions. In multivariate analyses, ΔK^trans and ΔPeak were independent prognostic factors for CNS-specific PFS and OS, respectively, after controlling for age, size, hormone receptors, and performance status.

CONCLUSIONS

Multiparametric MRI may help predict the survival outcomes in patients with BMBC.

KEY POINTS

• Decreased angiogenesis after chemotherapy on day 21 indicated good survival outcome. • ΔK ^trans was an independent prognostic factors for CNS-specific PFS. • ΔPeak was an independent prognostic factors for OS. • Multiparametric MRI helps clinicians to assess patients with BMBC. • High-risk patients may benefit from more intensive follow-up or treatment strategies.

Multiparametric PET/MR imaging biomarkers are associated with overall survival in patients with pancreatic cancer

PURPOSE

To correlate the overall survival (OS) with the imaging biomarkers of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), diffusion-weighted imaging (DWI), magnetic resonance spectroscopy, and glucose metabolic activity derived from integrated fluorine 18 fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET)/MRI in patients with pancreatic cancer.

METHODS

This prospective study was approved by the institutional review board and informed consent was obtained from all participants. Sixty-three consecutive patients (mean age, 62.7 ± 12 y; men/women, 40/23) with pancreatic cancer underwent PET/MRI before treatment. The imaging biomarkers were comprised of DCE-MRI parameters (peak, IAUC ₆₀ , K ^trans , k _ep , v _e ), the minimum apparent diffusion coefficient (ADC_min), choline level, standardized uptake values, metabolic tumor volume, and total lesion glycolysis (TLG) of the tumors. The relationships between these imaging biomarkers with OS were evaluated with the Kaplan-Meier and Cox proportional hazard models.

RESULTS

Seventeen (27%) patients received curative surgery, with the median follow-up duration being 638 days. Univariate analysis showed that patients at a low TNM stage (≦3, P = 0.041), high peak (P = 0.006), high ADC_min (P = 0.002) and low TLG (P = 0.01) had better OS. Moreover, high TLG/peak ratio was associated with poor OS (P = 0.016). Multivariate analysis indicated that ADC_min (P = 0.011) and TLG/peak ratio (P = 0.006) were independent predictors of OS after adjustment for age, gender, tumor size, and TNM stage. The TLG/peak ratio was an independent predictor of OS in a subgroup of patients who did not receive curative surgery (P = 0.013).

CONCLUSION

The flow-metabolism mismatch reflected by the TLG/peak ratio may better predict OS than other imaging biomarkers from PET/MRI in pancreatic cancer patients.

Comparing Western and Eastern criteria for sarcopenia and their association with survival in patients with pancreatic cancer

BACKGROUND & AIMS

Sarcopenia and cachexia are associated with pancreatic cancer and serve as important adverse prognostic factors. Body composition can be analyzed by routine computed tomography (CT) for cancer staging and has been used to study many types of cancer. The CT measurements are robust, but the diagnostic criteria for sarcopenia vary among different studies. Age, sex and race are important factors that affect muscle and fat masses. This study aimed to analyze the effect of different sarcopenia diagnostic criteria on the prognosis of patients with pancreatic cancer.

METHODS

Patients with newly diagnosed pancreatic cancer at National Taiwan University Hospital between October 2013 and October 2016 were retrospectively reviewed in this study. Body composition was assessed using cross-sectional CT images to calculate the total skeletal muscle (TSM) index. The concordance and interobserver variability of the TSM measurements were evaluated using both the Western criteria and the Eastern criteria. Kaplan-Meier analyses and the Cox proportional hazard ratio with two different diagnostic criteria for sarcopenia were used to compare the effect on overall survival (OS).

RESULTS

A total of 146 patients with pancreatic cancer were enrolled. The TSM index measured by the Western institute was highly correlated with that measured by the Eastern institute (r = 0.953, p < 0.001). The prevalence of sarcopenia in the patient group at baseline was 66.4% (97/146) by the Western criteria and 11.0% (16/146) by the Eastern criteria, and only low agreement was found between the Western and Eastern criteria (Kappa value = 0.028, p = 0.149). Patients who were sarcopenic by the Western criteria showed no significant difference in OS versus those who were not sarcopenic (p = 0.807). However, patients who were sarcopenic by the Eastern criteria showed a significant difference in OS versus those who were not sarcopenic in a univariate analysis (p = 0.008) and multivariate analysis after adjustment for AJCC stage (p = 0.014).

CONCLUSIONS

Our study demonstrates that different diagnostic criteria may result in different diagnoses and that sarcopenia is an important poor prognostic factor for pancreatic cancer when appropriate diagnostic criteria are selected.

Early perfusion changes within 1 week of systemic treatment measured by dynamic contrast-enhanced MRI may predict survival in patients with advanced hepatocellular carcinoma

OBJECTIVES

To correlate early changes in the parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) within 1 week of systemic therapy with overall survival (OS) in patients with advanced hepatocellular carcinoma (HCC).

METHODS

Eighty-nine patients with advanced HCC underwent DCE-MRI before and within 1 week following systemic therapy. The relative changes of six DCE-MRI parameters (Peak, Slope, AUC, Ktrans, Kep and Ve) of the tumours were correlated with OS using the Kaplan-Meier model and the double-sided log-rank test.

RESULTS

All patients died and the median survival was 174 days. Among the six DCE-MRI parameters, reductions in Peak, AUC, and Ktrans, were significantly correlated with one another. In addition, patients with a high Peak reduction following treatment had longer OS (P = 0.023) compared with those with a low Peak reduction. In multivariate analysis, a high Peak reduction was an independent favourable prognostic factor in all patients [hazard ratio (HR), 0.622; P = 0.038] after controlling for age, sex, treatment methods, tumour size and stage, and Eastern Cooperative Oncology Group performance status.

CONCLUSIONS

Early perfusion changes within 1 week following systemic therapy measured by DCE-MRI may aid in the prediction of the clinical outcome in patients with advanced HCC.

KEY POINTS

• DCE-MRI is helpful to evaluate perfusion changes of HCC after systemic treatment. • Early perfusion changes within 1 week after treatment may predict overall survival. • High Peak reduction was an independent favourable prognostic factor after systemic treatment.

Breath-hold spin echosequence for assessing liver iron content

OBJECTIVE

To compare a multiple breath-hold, multiecho, multiplanar spin-echo (BHMEMPSE) magnetic resonance (MR) sequence with a TR of 300ms with a traditional multiecho, multiplanar spin-echo (MEMPSE) MR sequence for assessing liver iron content.

MATERIALS AND METHODS

This study was approved by the institutional review board; informed consent was waived. Liver R2 measurement was derived from the mono-exponential model by BHMEMPSE and MEMPSE MR sequences of a 1.5T MR machine in 30 thalassemia patients (9men, 21women, aged 27.7±6.8years). Hepatic iron contents were estimated using Ferriscan in all patients. The inter- and intra-observer agreement of the 2 MR sequences was also evaluated.

RESULTS

MEMPSE R2 values significantly correlated with Ferriscan iron content values (r=0.895, p<0.001) and serum ferritin concentration (r=0.661, p<0.001). BHMEMPSE R2 values significantly correlated with Ferriscan values (r=0.914, p<0.001) and serum ferritin concentration (r=0.608, p<0.001). The distribution of MEMPSE R2 values against BHMEMPSE R2 values revealed an excellent linear relationship (r=0.978, p<0.001). The inter- and intra-observer agreement of the 2 MR sequences was excellent, with an interclass correlation coefficient exceeding 0.9. The distribution of Ferriscan against BHMEMPSE R2 values revealed a curvilinear relationship (r=0.935, p<0.001).

CONCLUSIONS

The BHMEMPSE sequence exhibited comparable estimation for assessing liver iron content, comparable repeatability and a shorter acquisition time compared with the MEMPSE sequence. The BHMEMPSE sequence can serve as an adjunctive sequence to assess liver iron content.

A pilot study to determine the timing and effect of bevacizumab on vascular normalization of metastatic brain tumors in breast cancer

Background

To determine the appropriate time of concomitant chemotherapy administration after antiangiogenic treatment, we investigated the timing and effect of bevacizumab administration on vascular normalization of metastatic brain tumors in breast cancer patients.

Methods

Eight patients who participated in a phase II trial for breast cancer-induced refractory brain metastases were enrolled and subjected to 4 dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) examinations that evaluated Peak, Slope, iAUC₆₀, and Ktrans before and after treatment. The treatment comprised bevacizumab on Day 1, etoposide on Days 2–4, and cisplatin on Day 2 in a 21-day cycle for a maximum of 6 cycles. DCE-MRI was performed before treatment and at 1 h, 24 h, and 21 days after bevacizumab administration.

Results

Values of the 4 DCE-MRI parameters reduced after bevacizumab administration. Compared with baseline values, the mean reductions at 1 and 24 h were −12.8 and −24.7 % for Peak, −46.6 and −65.8 % for Slope, −27.9 and −55.5 % for iAUC₆₀, and −46.6 and −63.9 % for Ktrans, respectively (all P < .05). The differences in the 1 and 24 h mean reductions were significant (all P < .05) for all the parameters. The generalized estimating equation linear regression analyses of the 4 DCE-MRI parameters revealed that vascular normalization peaked 24 h after bevacizumab administration.

Conclusion

Bevacizumab induced vascular normalization of brain metastases in humans at 1 and 24 h after administration, and the effect was significantly higher at 24 h than at 1 h.

Trial registration

ClinicalTrials.gov, identifier NCT01281696, registered prospectively on December 24, 2010

Dynamic upper airway collapse observed from sleep MRI: BMI-matched severe and mild OSA patients

Dynamic magnetic resonance imaging (MRI) allows real-time characterization of upper airway collapse in sleeping subjects with obstructive sleep apnea (OSA). The aim of our study was to use sleep MRI to compare differences in upper airway collapse sites between BMI-matched subjects with mild OSA and severe OSA. This is a prospective, nested case-control study using dynamic sleep MRI to compare 15 severe OSA subjects (AHI >40) and 15 mild OSA (AHI <10) subjects, who were matched for BMI. Upper airway imaging was performed on sleeping subjects in a 3.0 T MRI scanner. Sleep MRI movies were used by blinded reviewers to identify retropalatal (RP), retroglossal (RG), and lateral pharyngeal wall (LPW) airway collapse. Mean AHI in the severe OSA group was 70.3 ± 23 events/h, and in the mild group was 7.8 ± 1 events/h (p < 0.001). All mild and severe OSA subjects demonstrated retropalatal airway collapse. Eighty percent in the mild group showed single-level RP collapse (p < 0.001). All subjects in the severe group showed multi-level collapse: RP + LPW (n = 9), RP + RG + LPW (n = 6). All severe OSA subjects showed LPW collapse, as compared with three subjects in the mild group (p < 0.001). LPW collapse was positively associated with AHI in simple regression analysis (β = 51.8, p < 0.001). In conclusion, severe OSA patients present with more lateral pharyngeal wall collapse as compared to BMI-matched mild OSA patients.

Dynamic Contrast-enhanced MR Imaging of Advanced Hepatocellular Carcinoma: Comparison with the Liver Parenchyma and Correlation with the Survival of Patients Receiving Systemic Therapy

Purpose To retrospectively compare the perfusion parameters of advanced hepatocellular carcinoma (HCC) measured with dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging with surrounding liver parenchyma to determine the relationship between these parameters and uncensored overall survival (OS). Materials and Methods This retrospective study had institutional review board approval, and informed consent was waived. DCE MR imaging was performed in 92 patients with advanced HCC before systemic treatment was administered (19 patients received a placebo). Three semiquantitative (peak, slope, and area under the gadolinium concentration-time curve [AUC]) and six quantitative (arterial fraction, arterial flow, portal flow, total blood flow, distribution volume, and mean transit time) parameters were calculated by placing regions of interest in the largest area of the tumor and background liver parenchyma. The DCE MR imaging parameters between the tumor and normal liver were compared with paired Wilcoxon test. By using the Cox proportional hazards model for univariate and multivariate analyses, the association of DCE MR imaging parameters and OS was investigated. Results HCC demonstrated significantly higher peak, slope, AUC, arterial fraction, and arterial flow but lower portal flow, distribution volume, and mean transit time than did the background liver (all P < .05). Patients with high peak in the tumor had longer OS (P = .005) than did those with low peak. Cox multivariate analysis identified peak as an independent predictor of OS (P = .032) after adjusting for age, sex, treatment, tumor size, and portal vein thrombosis. Conclusion DCE MR imaging parameters can be used to differentiate advanced HCC from the background liver, and peak, a semiquantitative parameter, is associated with outcome in patients with advanced HCC before systemic therapy. ^© RSNA, 2016 An earlier incorrect version of this article appeared online. This article was corrected on July 22, 2016.

Safety of gadobutrol in over 23,000 patients: the GARDIAN study, a global multicentre, prospective, non-interventional study

OBJECTIVES

To investigate the safety and tolerability of gadobutrol at the recommended dose in patients requiring contrast-enhanced magnetic resonance imaging/angiography (MRI/MRA) in the routine setting.

METHODS

GARDIAN prospectively enrolled 23,708 patients undergoing routine gadobutrol-enhanced MRI/MRA for approved indications at 272 study centres in Europe, Asia, North America, and Africa and monitored for adverse events.

RESULTS

Median gadobutrol dose was 0.11 mmol/kg body weight. The overall incidence of adverse drug reactions (ADRs) was 0.7 % (n = 170 patients), with similar incidences in patients with renal impairment or cardiac disease, from different geographic regions and in different gadobutrol dose groups. Patients at risk for contrast media reaction had an ADR incidence of 2.5 %. Five patients (0.02 %) experienced serious adverse events, four were drug-related. One patient experienced a fatal anaphylactoid shock, assessed to be related to injection of gadobutrol. The contrast quality of gadobutrol-enhanced images was rated by treating physicians as good or excellent in 97 % cases, with similar ratings in all patient subgroups and indications.

CONCLUSIONS

The GARDIAN study shows that gadobutrol at the recommended dose is well tolerated across a large, diverse patient population.

KEY POINTS

• Gadobutrol at recommended dose shows low rates of adverse drug reactions • Gadobutrol demonstrates a uniform safety profile across diverse patient groups • Gadobutrol provides excellent contrast quality in routine practice.

Static craniofacial measurements and dynamic airway collapse patterns associated with severe obstructive sleep apnoea: a sleep MRI study

OBJECTIVES

Using sleep MRI, we aimed to identify static craniofacial measurements and dynamic upper airway collapse patterns associated with severe obstructive sleep apnoea (OSA) during natural sleep in age and BMI-matched patients.

DESIGN

Nested case-control study.

SETTING

Sleep MRI images (3.0 Tesla scanner) and synchronised acoustic recording were used to observe patterns of dynamic airway collapse in subjects with mild and severe OSA. Midsagittal images were also used for static craniofacial measurements.

PARTICIPANTS

Fifteen male subjects with severe OSA (mean AHI 70.3 ± 23 events/h) were matched by age and BMI to 15 subjects with mild OSA (mean AHI 7.8 ± 1.4 events/h). Subjects were selected from a consecutive sleep MRI study cohort.

MAIN OUTCOME MEASURES

Static craniofacial measurements selected a priori included measurements that represent maxillomandibular relationships and airway morphology. Axial, sagittal and coronal views of the airway were rated for dynamic collapse at retropalatal, retroglossal and lateral pharyngeal wall regions by blinded reviewers. Bivariate analysis was used to correlate measures associated with severity of OSA using AHI. Statistical significance was set at P < 0.01.

RESULTS

Lateral pharyngeal wall collapse from dynamic sleep MRI (β = 51.8, P < 0.001) and upper airway length from static MRI images (β = 27.2, P < 0.001) positively correlated with severity of OSA.

CONCLUSIONS

Lateral pharyngeal wall collapse and upper airway length are significantly associated with severe OSA based on sleep MRI. Assessment of these markers can be readily translated to routine clinical practice, and their identification may direct targeted surgical treatment.

Novel Imaging Diagnosis for Hepatocellular Carcinoma: Consensus from the 5th Asia-Pacific Primary Liver Cancer Expert Meeting (APPLE 2014)

Current novel imaging techniques in the diagnosis of hepatocellular carcinoma (HCC), with the latest evidence in this field, was discussed at the Asia-Pacific Primary Liver Cancer Expert (APPLE) meeting held in Taipei, Taiwan, in July 2014. Based on their expertise in a specific area of research, the novel imaging group comprised 12 participants from Japan, South Korea, Taiwan, and China and it included 10 abdominal radiologists, one hepatologist, and one pathologist. The expert participants discussed topics related to HCC imaging that were divided into four categories: (i) detection method, (ii) diagnostic method, (iii) evaluation method, and (iv) functional method. Consensus was reached on 10 statements; specific comments on each statement were provided to explain the rationale for the voting results and to suggest future research directions.

Assessing hepatic fibrosis: comparing the intravoxel incoherent motion in MRI with acoustic radiation force impulse imaging in US

OBJECTIVES

This study compared the diagnostic performance of intravoxel incoherent motion (IVIM) in magnetic resonance imaging (MRI) and acoustic radiation force impulse imaging (ARFI) in ultrasound (US) for liver fibrosis (LF) evaluation.

METHODS

A total of 49 patients scheduled for liver surgery were recruited. LF in the non-tumorous liver parenchyma at the right lobe was estimated using a slow diffusion coefficient, fast diffusion coefficient (D fast), perfusion fraction (f) of the IVIM parameters, the total apparent diffusion coefficient of conventional diffusion-weighted imaging and the shear wave velocity (Vs) of ARFI. LF was graded using the Metavir scoring system on histological examination. The Spearman rank correlation coefficient for correlation and analysis of variance was used for determining difference. The diagnostic performance was compared using receiver operating characteristic curve analysis.

RESULTS

LF exhibited significant correlation with the three parameters D fast, f, and Vs (r = -0.528, -0.337, and 0.481, respectively, P < 0.05). The D fast values in the F4 group were significantly lower than those in the F0, F1 and F2 groups. D fast exhibited a non-inferior performance for diagnosing all fibrosis grades compared with that of Vs.

CONCLUSIONS

Both IVIM and ARFI provide reliable estimations for the noninvasive assessment of LF.

KEY POINTS

• Liver fibrosis can be diagnosed and graded using noninvasive imaging modalities. • ARFI and IVIM can be incorporated into routine examinations. • IVIM can differentiate liver cirrhosis from none to moderate liver fibrosis. • The diagnostic performances of IVIM and ARFI are equal.

Standardized uptake value and apparent diffusion coefficient of endometrial cancer evaluated with integrated whole-body PET/MR: Correlation with pathological prognostic factors

PURPOSE

To evaluate the correlation between maximum standardized uptake value (SUVmax ) and minimum apparent diffusion coefficient (ADCmin ) of endometrial cancer derived from an integrated positron emission tomography / magnetic resonance (PET/MR) system and to determine their correlation with pathological prognostic factors.

MATERIALS AND METHODS

This prospective study was approved by the Institutional Review Board of the hospital, and informed consent was obtained. Between April and December 2014, 47 consecutive patients with endometrial cancer were enrolled and underwent simultaneous PET/MR examinations before surgery. Thirty-six patients with measurable tumors on PET/MR were included for image analysis. Pearson's correlation coefficient was used to evaluate the correlation between SUVmax and ADCmin of the tumors. The Mann-Whitney U-test was utilized to evaluate relationships between these two imaging biomarkers and pathological prognostic factors.

RESULTS

The mean SUVmax and ADCmin were 14.7 ± 7.1 and 0.48 ± 0.13 × 10(-3) mm(2) /s, respectively. A significant inverse correlation was found between SUVmax and ADCmin (r = -0.53; P = 0.001). SUVmax was significantly higher in tumors with advanced stage, deep myometrial invasion, cervical invasion, lymphovascular space involvement, and lymph node metastasis (P < 0.05). ADCmin was lower in tumors with higher grade, advanced stage, and cervical invasion (P < 0.05). The ratio of SUVmax to ADCmin was higher in tumors with higher grade, advanced stage, deep myometrial invasion, cervical invasion, lymphovascular space involvement, and lymph node metastasis (P < 0.05).

CONCLUSION

SUVmax and ADCmin of endometrial cancer derived from integrated PET/MR are inversely correlated and are associated with pathological prognostic factors.

Bevacizumab preconditioning followed by Etoposide and Cisplatin is highly effective in treating brain metastases of breast cancer progressing from whole-brain radiotherapy

PURPOSE

We hypothesized that a window period between bevacizumab and cytotoxic agents may enhance drug delivery into tumor tissue through bevacizumab-induced vascular normalization in patients with brain metastases of breast cancer (BMBC).

EXPERIMENTAL DESIGN

A single-arm phase II study was conducted in which BMBC patients refractory to whole-brain radiotherapy (WBRT) were enrolled. In a 21-day cycle, patients received bevacizumab (15 mg/kg) on day 1, which, with a 1-day window period, was followed by etoposide (70 mg/m(2)/day; days 2-4) and cisplatin (70 mg/m(2); day 2; BEEP regimen). The BEEP regimen was administered for a maximum of 6 cycles. The primary endpoint was the central nervous system (CNS)-objective response rate according to volumetric response criteria.

RESULTS

A total of 35 patients were enrolled between January 2011 and January 2013. The median age was 54.3 years (range, 33-75); 19 patients (54.3%) had an Eastern Cooperative Oncology Group performance status of 2 or 3. Twenty-seven patients [77.1%; 95% confidence interval (CI), 59.9-89.6] achieved a CNS-objective response, including 13 patients (37.1%) with a ≥80% volumetric reduction of CNS lesions. With a median follow-up of 16.1 months, the median CNS progression-free survival and overall survival times were 7.3 months (95% CI, 6.5-8.1) and 10.5 months (95% CI, 7.8-13.2), respectively. Common grade 3 or 4 toxicities included neutropenia (30.8%) and infection (21.3%).

CONCLUSIONS

By administering bevacizumab 1 day before etoposide and cisplatin, the BEEP regimen appeared highly effective in BMBC refractory to WBRT. Further study of vascular normalization window concept is warranted.

Synchronized imaging and acoustic analysis of the upper airway in patients with sleep-disordered breathing

Progressive narrowing of the upper airway increases airflow resistance and can produce snoring sounds and apnea/hypopnea events associated with sleep-disordered breathing due to airway collapse. Recent studies have shown that acoustic properties during snoring can be altered with anatomic changes at the site of obstruction. To evaluate the instantaneous association between acoustic features of snoring and the anatomic sites of obstruction, a novel method was developed and applied in nine patients to extract the snoring sounds during sleep while performing dynamic magnetic resonance imaging (MRI). The degree of airway narrowing during the snoring events was then quantified by the collapse index (ratio of airway diameter preceding and during the events) and correlated with the synchronized acoustic features. A total of 201 snoring events (102 pure retropalatal and 99 combined retropalatal and retroglossal events) were recorded, and the collapse index as well as the soft tissue vibration time were significantly different between pure retropalatal (collapse index, 2 ± 11%; vibration time, 0.2 ± 0.3 s) and combined (retropalatal and retroglossal) snores (collapse index, 13 ± 7% [P ≤ 0.0001]; vibration time, 1.2 ± 0.7 s [P ≤ 0.0001]). The synchronized dynamic MRI and acoustic recordings successfully characterized the sites of obstruction and established the dynamic relationship between the anatomic site of obstruction and snoring acoustics.

The pilot experience upon surgical ablation of large liver tumor by microwave system with tissue permittivity feedback control mechanism

Background

Microwave ablation (MWA) is used to treat patients with unresectable liver cancer. Our institution applied a novel microwave generator capable of automatically adjusting energy levels based on feedback related to tissue permittivity. This approach is meant to facilitate ablations over larger areas and provide results of greater predictablility. This paper reports on the safety, efficacy, and feasibility of this new system in the treatment of patients with large liver tumors.

Methods

Between July 2012 and December 2012, a total of 23 patients with malignant liver tumors exceeding 4 cm in diameter underwent surgical MWA using a 902–928 MHz generator. The proposed system used a 14-gauge antenna without internal-cooling. Follow up on tumor recurrence was performed using contrast-enhanced computed tomography or magnetic resonance imaging at 1 month and then at 3 month intervals for a period of at least 12 months following ablation.

Results

Among the cancers treated, 10 were primary hepatocellular carcinomas (HCCs) and 13 were metastatic lesions from primary colorectal cancer (CRLM). The mean tumor size was 5.40 cm (range of 4.0-7.0 cm). A total of 18 patients underwent MWA via open surgery, and 5 received laparoscopic MWA. The mean ablation time was 1982 seconds, with a range of 900-3600 seconds, and the median number of ablation sessions was 2.0 (range of 1–4 sessions). The rate of complete ablation, as defined by a total loss of contrast-enhancement one month post-treatment, was 82.6% (19 of 23 patients), and the rate of local recurrence was 26.3% (5 of 19 patients). For tumors with a diameter of 4.0-7.0 cm, the technical success rate of MWA was higher for HCC patients (70%) than for metastatic liver cancer (53.8%) patients; however, the difference was not statistically significant. All patients survived throughout the observation period, and the morbidity rate was 8.6%.

Conclusions

MWA treatment using the proposed system with tissue permittivity feedback control resulted in a high rate of complete ablation and reduced morbidity. This approach proved to be a fast, easy, and effective option for the ablation of large liver cancers, particularly HCCs.

Abstract 2984: Normalization of tumor vasculature by anti-angiogenesis therapy in metastatic tumor: A clinical study to determine the timing and effect

Background: Clinically, combination of anti-angiogenic agents with chemotherapeutic agents demonstrated better antitumor efficacy. Instead of merely effect on vasculature regression, careful use of anti-angiogenic therapy may cause the grossly abnormal structure and function of tumor blood vessels to return to a more normal state. Treatment with anti-angiogenic agents can primarily improve chemotherapy efficacy by normalizing tumor vasculature, decrease the intra-tumor interstitial pressure, thereby leading to a more effective drug delivery. We planned to investigate the timing and effect of tumor vascular normalization in human after the administration of anti-angiogenic agent. It may help determine the appropriate timing of administration of chemotherapeutic agents after anti-angiogenic treatment.

Materials and methods: This study enrolled the last 8 consecutive patients who participated in a phase II trial for treatment of refractory brain metastases from breast cancer (Eur J Can 49:2s, 2013 suppl; abstr 1878). The protocol treatment consists of bevacizumab 15mg/kg on day 1, chemotherapy of etoposide and cisplatin on day 2 (24 hours after administration of bevacizumab), in 21-day cycles. These 8 patients specifically received four dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) examinations. DCE-MRI was performed before treatment, 1 hour after the end of bevacizumab infusion (i.e., 2.5 hours after starting bevacizumab infusion), 24 hours and 21 days after bevacizumab infusion. This study was registered with ClinicalTrials.gov, identifier NCT01281696, and was approved by the ethical review board.

Results: Clinically, all the 8 patients achieved partial remission at central nervous system. All of the 4 DCE-MRI parameters decreased after bevacizumab infusion. Compared to baseline values, the mean reductions at 1 hour and 24 hours were -12.8% and -24.7% for Peak, -46.6% and -65.8% for Slope, -27.9% and -55.5% for iAUC60, -46.6% and -63.9% for Ktrans, respectively (all P values &lt;0.05). The differences between 1 hour and 24 hours reached statistical significance (all P values &lt;0.05) for all the parameters. However, the differences in the mean percentage change between 24 hours and 21 days did not reach significance in any of the four parameters

Conclusion: Normalization of tumor vasculature induced by bevacizumab was clearly demonstrated in brain metastases in human at 1 hour after completion of bevacizumab infusion, but significantly became more obvious at 24 hours after bevacizumab administration.

Citation Format: Yen-Shen Lu, Bang-Bin Chen, Ching-Hung Lin, Wei-Wu Chen, Pei-Fang Wu, Ann-Lii Cheng, Tiffany Ting-Fang Shih. Normalization of tumor vasculature by anti-angiogenesis therapy in metastatic tumor: A clinical study to determine the timing and effect. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2984. doi:10.1158/1538-7445.AM2014-2984

Trends in the utilization of computed tomography and cardiac catheterization among children with congenital heart disease

Background/Purpose

Pediatric cardiac computed tomography (CT) is a noninvasive imaging modality used to clearly demonstrate the anatomical detail of congenital heart diseases. We investigated the impact of cardiac CT on the utilization of cardiac catheterization among children with congenital heart disease.

Methods

The study sample consisted of 2648 cardiac CT and 3814 cardiac catheterization from 1999 to 2009 for congenital heart diseases. Diagnoses were categorized into 11 disease groups. The numbers of examination, according to the different modalities, were compared using temporal trend analyses. The estimated effective radiation doses (mSv) of CT and catheterization were calculated and compared.

Results

The number of CT scans and interventional catheterizations had a slight annual increase of 1.2% and 2.7%, respectively, whereas that of diagnostic catheterization decreased by 6.2% per year. Disease groups fell into two categories according to utilization trend differences between CT and diagnostic catheterization. The increased use of CT reduces the need for diagnostic catheterization in patients with atrioventricular connection disorder, coronary arterial disorder, great vessel disorder, septal disorder, tetralogy of Fallot, and ventriculoarterial connection disorder. Clinicians choose either catheterization or CT, or both examinations, depending on clinical conditions, in patients with semilunar valvular disorder, heterotaxy, myocardial disorder, pericardial disorder, and pulmonary vein disorder. The radiation dose of CT was lower than that of diagnostic cardiac catheterization in all age groups.

Conclusion

The use of noninvasive CT in children with selected heart conditions might reduce the use of diagnostic cardiac catheterization. This may release time and facilities within the catheterization laboratory to meet the increasing demand for cardiac interventions.

Quantification of hepatic steatosis: a comparison of the accuracy among multiple magnetic resonance techniques

BACKGROUND AND AIM

Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are important diagnostic tools for the non-invasive assessment of hepatic steatosis (HS). This study was conducted to compare different magnetic resonance (MR) techniques and correlate the MR findings with histological and intracellular lipid density findings.

METHODS

In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant prospective study, 60 patients scheduled for liver resection were included in this study. Fat fraction in the non-tumorous liver parenchyma was estimated using double-echo MRI, triple-echo MRI (TE-MRI), and MRS. HS was defined by the histologic steatosis percentage (HSP), and intrahepatocellular triglyceride density (IHTGD) of the surgical specimen used as the reference standard. Imaging quantification results were evaluated using Pearson's correlation. Lin's concordance coefficient and Bland-Altman 95% limits of agreement were used to evaluate the concordance of IHTGDs estimated by the three MR techniques. The diagnostic performance was compared using receiver operating characteristic curve analysis.

RESULTS

HS assessed by TE-MRI and MRS had a stronger relationship with HS assessed by HSP and IHTGD. The TE-MRI method had the highest concordance correlation coefficients (ρ = 0.881) and percentage (95%, 57/60) within the Bland-Altman 95% limits of agreement. Receiver operating characteristic curve analysis for diagnosing > 5% HSP showed significantly larger area under the curve (0.9783) for TE-MRI than for double-echo MRI (0.8773, P = 0.0121).

CONCLUSIONS

Among the three MR techniques, TE-MRI and MRS may be the preferred techniques for non-invasive assessment of HS.

DCE-MRI in hepatocellular carcinoma-clinical and therapeutic image biomarker

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) enables tumor vascular physiology to be assessed. Within the tumor tissue, contrast agents (gadolinium chelates) extravasate from intravascular into the extravascular extracellular space (EES), which results in a signal increase on T1-weighted MRI. The rate of contrast agents extravasation to EES in the tumor tissue is determined by vessel leakiness and blood flow. Thus, the signal measured on DCE-MRI represents a combination of permeability and perfusion. The semi-quantitative analysis is based on the calculation of heuristic parameters that can be extracted from signal intensity-time curves. These enhancing curves can also be deconvoluted by mathematical modeling to extract quantitative parameters that may reflect tumor perfusion, vascular volume, vessel permeability and angiogenesis. Because hepatocellular carcinoma (HCC) is a hypervascular tumor, many emerging therapies focused on the inhibition of angiogenesis. DCE-MRI combined with a pharmacokinetic model allows us to produce highly reproducible and reliable parametric maps of quantitative parameters in HCC. Successful therapies change quantitative parameters of DCE-MRI, which may be used as early indicators of tumor response to anti-angiogenesis agents that modulate tumor vasculature. In the setting of clinical trials, DCE-MRI may provide relevant clinical information on the pharmacodynamic and biologic effects of novel drugs, monitor treatment response and predict survival outcome in HCC patients.

Comparison of characteristics and transarterial chemoembolization outcomes in patients with unresectable hepatocellular carcinoma and different viral etiologies

PURPOSE

To determine any differences in patient characteristics and outcomes after transarterial chemoembolization between different viral etiologies of hepatocellular carcinoma (HCC).

METHODS

This retrospective study consisted of 201 patients undergoing first-time transarterial chemoembolization for unresectable HCC from January to December 2009. The patients were divided into four groups: hepatitis B virus (HBV) only (n = 104), hepatitis C virus (HCV) only (n = 63), HBV and HCV (n = 10), and no viral hepatitis (n = 24). The clinical and laboratory data were obtained from electronic medical records, and imaging findings obtained before transarterial chemoembolization were analyzed. Kaplan-Meier analyses were used to assess the impact of HBV or HCV status, clinical characteristics, and imaging results on overall survival.

RESULTS

After a median follow-up of 28.3 months ± 16.2, the 1-, 2-, and 3-year overall survival rates were 74.1%, 59.7%, and 53.2%. Patients with HBV had a significant association with younger age (P = .001), higher male-to-female ratio (P = .003), lower alanine aminotransferase levels (P = .018), higher albumin levels (P = .009), and multifocal tumors at diagnosis (P = .04) compared with patients with HCV. Patients with both HBV and HCV had significantly higher serum bilirubin levels compared with the other groups (P = .002). No significant difference was found in overall survival among the different hepatitis groups (P = .943). Multivariate analysis showed that statistically significant determinants for overall survival were Child-Pugh class (P = .002), Barcelona Clinic Liver Cancer stage (P < .001), tumor size (P < .001), and distribution (P < .001).

CONCLUSIONS

Viral etiology has no correlation with the outcome of patients with HCC undergoing transarterial chemoembolization.

Reference curves for the aortic area by age

RATIONALE AND OBJECTIVES

The aim of this study was to establish reference curves and formulas for aortic cross-sectional area in patients from infancy to young adulthood.

MATERIALS AND METHODS

Patients (aged 2 days to 18.1 years) who underwent electrocardiographically gated cardiac computed tomography between May 2004 and December 2011 were retrospectively examined. These patients were further divided into a group of normal controls (without aortic disease) and a group with coarctation of aorta. In the group of normal controls, the cross-sectional area of the aorta was measured at six locations: the sinotubular junction, distal ascending aorta, proximal arch, distal arch, aortic isthmus, and descending aorta (DAO). Interobserver and intraobserver variability, gender differences, the relationship between aortic cross-sectional areas and age, and the ratio to the DAO were also examined. The area ratio to the DAO was also examined in the group with coarctation of the aorta.

RESULTS

A total of 65 patients and 365 measurable aortic segments were included in the analysis (55 normal controls and 10 patients with coarctation of aorta). Interobserver and intraobserver variability was limited (aside from measurements of the sinotubular junction). There were no gender differences in age and the cross-sectional areas of the different aortic segments. In the group of normal controls, the cross-sectional area of each aortic segment was highly correlated with age (all >0.90, P < .001). The reference curves and formulas for aortic cross-sectional area by age were also determined for further clinical use. In the normal controls, the <95% confidence intervals of the ratios of aortic isthmus to DAO, distal arch to DAO, and proximal arch to DAO were approximately 0.6, 0.8, and 1.0, respectively. In addition, in the group with coarctation, all area ratios of aortic isthmus to DAO were <0.6, which was significantly different from the group of normal controls (P < .001). The area ratios of distal arch to DAO and proximal arch to DAO were also significantly different between two groups (P < .001 for both).

CONCLUSIONS

Measurement of aortic area was reproducible. The established reference curves and formulas and minimal area ratios were convenient for further clinical use.