Purpose
We aimed to evaluate the diagnostic performances of quantitative indices obtained from dopamine transporter (DAT) single-photon emission computed tomography (SPECT) and
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...I-metaiodobenzylguanidine (MIBG) scintigraphy for Parkinsonian syndromes (PS) using the classification and regression tree (CART) analysis.
Methods
We retrospectively enrolled 216 patients with or without PS, including 80 without PS (NPS) and 136 with PS 90 Parkinson’s disease (PD), 21 dementia with Lewy bodies (DLB), 16 progressive supranuclear palsy (PSP), and 9 multiple system atrophy (MSA). The striatal binding ratio (SBR), putamen-to-caudate ratio (PCR), and asymmetry index (AI) were calculated using DAT SPECT. The heart-to-mediastinum uptake ratio (H/M) based on the early (H/M Early) and delayed (H/M Delay) images and cardiac washout rate (WR) were calculated from MIBG scintigraphy. The CART analysis was used to establish a diagnostic decision tree model for differentiating PS based on these quantitative indices.
Results
The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87.5, 96.3, 93.3, 92.9, and 93.1 for NPS; 91.1, 78.6, 75.2, 92.5, and 83.8 for PD; 57.1, 95.9, 60.0, 95.4, and 92.1 for DLB; and 50.0, 98.0, 66.7, 96.1, and 94.4 for PSP, respectively. The PCR, WR, H/M (Delay), and SBR indices played important roles in the optimal decision tree model, and their feature importance was 0.61, 0.22, 0.11, and 0.05, respectively.
Conclusion
The quantitative indices showed high diagnostic performances in differentiating NPS, PD, DLB, and PSP, but not MSA. Our findings provide useful guidance on how to apply these quantitative indices in clinical practice.
Currently, no clinical studies have compared the inspiratory and expiratory volumes of unilateral lung or of each lobe among supine, standing, and sitting positions. In this prospective study, 100 ...asymptomatic volunteers underwent both low-radiation-dose conventional (supine position, with arms raised) and upright computed tomography (CT) (standing and sitting positions, with arms down) during inspiration and expiration breath-holds and pulmonary function test (PFT) on the same day. We compared the inspiratory/expiratory lung/lobe volumes on CT in the three positions. The inspiratory and expiratory bilateral upper and lower lobe and lung volumes were significantly higher in the standing/sitting positions than in the supine position (5.3-14.7% increases, all P < 0.001). However, the inspiratory right middle lobe volume remained similar in the three positions (all P > 0.15); the expiratory right middle lobe volume was significantly lower in the standing/sitting positions (16.3/14.1% decrease) than in the supine position (both P < 0.0001). The Pearson's correlation coefficients (r) used to compare the total lung volumes on inspiratory CT in the supine/standing/sitting positions and the total lung capacity on PFT were 0.83/0.93/0.95, respectively. The r values comparing the total lung volumes on expiratory CT in the supine/standing/sitting positions and the functional residual capacity on PFT were 0.83/0.85/0.82, respectively. The r values comparing the total lung volume changes from expiration to inspiration on CT in the supine/standing/sitting positions and the inspiratory capacity on PFT were 0.53/0.62/0.65, respectively. The study results could impact preoperative CT volumetry of the lung in lung cancer patients (before lobectomy) for the prediction of postoperative residual pulmonary function, and could be used as the basis for elucidating undetermined pathological mechanisms. Furthermore, in addition to morphological evaluation of the chest, inspiratory and expiratory upright CT may be used as an alternative tool to predict lung volumes such as total lung capacity, functional residual capacity, and inspiratory capacity in situation in which PFT cannot be performed such as during an infectious disease pandemic, with relatively more accurate predictability compared with conventional supine CT.
Objectives
To investigate the clinical utility of the Vesical Imaging-Reporting and Data System (VI-RADS) by comparing its diagnostic performance for muscle-invasive bladder cancer (MIBC) between ...radiologists and urologists based on multiparametric MRI, including three-dimensional (3D) fast spin-echo (FSE) T2-weighted acquisitions.
Methods
This study included 66 treatment-naïve patients (60 men, 6 women; mean age 74.0 years) with pathologically proven bladder cancer who underwent multiparametric MRI, including 3D FSE T2-weighted imaging, before transurethral bladder tumour resection between January 2010 and November 2018. The MRI scans were categorised according to the five-point VI-RADS score by four independent readers (two board-certified radiologists and board-certified urologists each), blinded to the histopathological findings. The VI-RADS scores were compared with the postoperative histopathological diagnosis. Interobserver agreement was assessed using weighted kappa coefficients. ROC analysis and generalised estimating equations were used to evaluate the diagnostic performance.
Results
Forty-nine (74.2%) and 17 (25.8%) tumours were confirmed to be non-MIBC and MIBC, respectively, based on pathological examination. The interobserver agreement was good-to-excellent between all pairs of readers (range, 0.73–0.91). The urologists’ sensitivity/specificity values for DCE-MRI VI-RADS scores were significantly lower than those of radiologists. No significant differences were observed for the overall VI-RADS score. The AUC for the overall VI-RADS score was 0.94, 0.92, 0.89, and 0.87 for radiologists 1 and 2 and urologists 1 and 2, respectively.
Conclusions
The VI-RADS score, based on multiparametric MRI including 3D FSE T2-weighted acquisitions, can be useful for radiologists and urologists to determine the bladder cancer muscle invasion status preoperatively.
Key Points
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VI-RADS (using multiparametric MRI including 3D FSE T2-weighted acquisitions) achieves good to excellent interobserver agreement and has similar diagnostic performance for detecting muscle invasion by both radiologists and urologists.
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The diagnostic performance of the overall VI-RADS score is high for both radiologists and urologists, particularly due to the dominant effect of diffusion-weighted imaging on the overall VI-RADS score.
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The sensitivity and specificity values of the T2WI VI-RADS scores for four readers in our study (using 3D FSE T2-weighted acquisitions) were similar (with slightly higher specificity values) to previously published results (using 2D FSE T2-weighted acquisitions).
We aimed to use upright computed tomography (CT) to depict posture-related changes in the brain tissue under normal gravity. Thirty-two asymptomatic volunteers underwent upright CT in the sitting ...position and conventional CT in the supine position on the same day. We compared the shift of the pineal body, cerebellar tonsil, the length of pituitary stalk, optic nerve sheath area and perimeter (ONSA and ONSP, respectively), and lateral ventricular volume between the supine and sitting positions. We also compared shape changes of the cerebrospinal fluid (CSF) spaces at different sites between both positions. In the sitting position, the pineal body shifted 0.68 ± 0.27 mm in the ventral direction and 0.76 ± 0.24 mm in the caudal direction, the length of pituitary stalk decreased by 1.23 ± 0.71 mm, the cerebellar tonsil descended by 2.10 ± 0.86 mm, the right ONSA decreased by 15.21 ± 6.54%, the left ONSA decreased by 15.30 ± 7.37%, the right ONSP decreased by 8.52 ± 3.91%, the left ONSP decreased by 8.20 ± 4.38%, and the lateral ventricular volume decreased by 5.07 ± 3.24% (all P < 0.001). We also observed changes in the shape of CSF spaces with changes in posture. We concluded that the intracranial structure of healthy subjects and volume of ventricles changed according to posture on Earth.
Abstract Objectives This study sought to clarify the incidence and predictors of hypoattenuated leaflet thickening (HALT) and mid-term outcomes after transcatheter aortic valve replacement. ...Background HALT detected on multidetector computed tomography (MDCT) scanning raised concerns about possible subclinical leaflet thrombosis. Methods We studied 70 of 100 consecutive patients from a single-center registry who underwent implantation with the Edwards SAPIEN-XT device. MDCT results, echocardiographic data, and laboratory findings obtained at the 6-month and 1-year follow-ups were analyzed. Results Of 70 patients, MDCT scans revealed HALT in 1 patient (1.4%) at discharge, 7 (10.0%) at 6 months, and 10 (14.3%) at 1 year post–transcatheter aortic valve replacement cumulatively. The degree of leaflet immobility correlated with the HALT area on 4-dimensional MDCT (r = 0.68) on the basis of data from 10 patients. HALT was associated with male sex (70% vs. 25%; p = 0.008) and larger sinus of Valsalva (31.0 ± 2.0 mm vs. 28.6 ± 2.6 mm; p = 0.005). HALT was found in 3 of 49 patients with a 23-mm bioprosthesis and in 7 of 21 patients with a 26-mm bioprosthesis (6.1% vs. 33.3%; p = 0.006). D-dimer levels were significantly increased in the HALT group at the 6-month (2.3 μg/ml interquartile range (IQR): 2.1 to 6.1 μg/ml vs. 1.1 μg/ml IQR: 0.8 to 2.2 μg/ml; p = 0.002) and 1-year (2.7 μg/ml IQR: 1.7 to 4.8 μg/ml vs. 1.2 μg/ml IQR: 0.9 to 2.1 μg/ml; p = 0.006) follow-ups, despite no differences at discharge. The pressure gradient was decreased in the HALT group at the 1-year follow-up (8.3 ± 0.8 mm Hg vs. 11.1 ± 4.9 mm Hg; p = 0.005). After detecting HALT, additional anticoagulation therapy was not administered. Clinical outcomes, including all-cause mortality (0% vs. 1.7%; p = 1.00) and stroke (0% vs. 0%; p = 1.00), were similar between the groups. Conclusions HALT with reduced leaflet motion was not rare but usually subclinical. Valve hemodynamics and mid-term outcomes were uneventful even without additional anticoagulant therapy in our limited number of cases. Male sex, larger sinus and bioprosthesis size, and elevated D-dimer levels during follow-up were associated with this phenomenon.
Background
Because cancers of hollow organs such as the esophagus are hard to detect even by the expert physician, it is important to establish diagnostic systems to support physicians and increase ...the accuracy of diagnosis. In recent years, deep learning-based artificial intelligence (AI) technology has been employed for medical image recognition. However, no optimal CT diagnostic system employing deep learning technology has been attempted and established for esophageal cancer so far.
Purpose
To establish an AI-based diagnostic system for esophageal cancer from CT images.
Materials and methods
In this single-center, retrospective cohort study, 457 patients with primary esophageal cancer referred to our division between 2005 and 2018 were enrolled. We fine-tuned VGG16, an image recognition model of deep learning convolutional neural network (CNN), for the detection of esophageal cancer. We evaluated the diagnostic accuracy of the CNN using a test data set including 46 cancerous CT images and 100 non-cancerous images and compared it to that of two radiologists.
Results
Pre-treatment esophageal cancer stages of the patients included in the test data set were clinical T1 (12 patients), clinical T2 (9 patients), clinical T3 (20 patients), and clinical T4 (5 patients). The CNN-based system showed a diagnostic accuracy of 84.2%,
F
value of 0.742, sensitivity of 71.7%, and specificity of 90.0%.
Conclusions
Our AI-based diagnostic system succeeded in detecting esophageal cancer with high accuracy. More training with vast datasets collected from multiples centers would lead to even higher diagnostic accuracy and aid better decision making.
The modified total Sharp score (mTSS) is often used as an evaluation index for joint destruction caused by rheumatoid arthritis. In this study, special findings (ankylosis, subluxation, and ...dislocation) are detected to estimate the efficacy of mTSS by using deep neural networks (DNNs). The proposed method detects and classifies finger joint regions using an ensemble mechanism. This integrates multiple DNN detection models, specifically single shot multibox detectors, using different training data for each special finding. For the learning phase, we prepared a total of 260 hand X-ray images, in which proximal interphalangeal (PIP) and metacarpophalangeal (MP) joints were annotated with mTSS by skilled rheumatologists and radiologists. We evaluated our model using five-fold cross-validation. The proposed model produced a higher detection accuracy, recall, precision, specificity, F-value, and intersection over union than individual detection models for both ankylosis and subluxation detection, with a detection rate above 99.8% for the MP and PIP joint regions. Our future research will aim at the development of an automatic diagnosis system that uses the proposed mTSS model to estimate the erosion and joint space narrowing score.
Angiomyolipoma is the most common benign solid renal neoplasm observed in clinical practice. Once thought to be a hamartoma and almost always diagnosed by the imaged-based detection of fat, ...angiomyolipomas are now known to consist of a heterogeneous group of neoplasms. Although all are considered perivascular epithelioid cell tumors, many display different pathology, imaging features, and clinical behavior. The importance of understanding this group of neoplasms is emphasized by the fact that many types of angiomyolipoma contain little to no fat, and despite being benign, sometimes escape a pre-operative diagnosis. These types of angiomyolipomas can all be considered when encountering a renal mass that is both hyperattenuating relative to renal parenchyma on unenhanced CT and T2-hypointense, features that reflect their predominant smooth muscle component. We review recent developments and provide a radiological classification of angiomyolipomas that helps physicians understand the various types and learn how to both diagnose and manage them.
We propose a wrist joint subluxation/ankylosis classification model for an automatic radiographic scoring system for X-ray images. In managing rheumatoid arthritis, the evaluation of joint ...destruction is important. The modified total Sharp score (mTSS), which is conventionally used to evaluate joint destruction of the hands and feet, should ideally be automated because the required time depends on the skill of the evaluator, and there is variability between evaluators. Since joint subluxation and ankylosis are given a large score in mTSS, we aimed to estimate subluxation and ankylosis using a deep neural network as a first step in developing an automatic radiographic scoring system for joint destruction. We randomly extracted 216 hand X-ray images from an electronic medical record system for the learning experiments. These images were acquired from patients who visited the rheumatology department of Keio University Hospital in 2015. Using our newly developed annotation tool, well-trained rheumatologists and radiologists labeled the mTSS to the wrist, metacarpal phalangeal joints, and proximal interphalangeal joints included in the images. We identified 21 X-ray images containing one or more subluxation joints and 42 X-ray images with ankylosis. To predict subluxation/ankylosis, we conducted five-fold cross-validation with deep neural network models: AlexNet, ResNet, DenseNet, and Vision Transformer. The best performance on wrist subluxation/ankylosis classification was as follows: accuracy, precision, recall, F1 value, and AUC were 0.97±0.01/0.89±0.04, 0.92±0.12/0.77±0.15, 0.77±0.16/0.71±0.13, 0.82±0.11/0.72±0.09, and 0.92±0.08/0.85±0.07, respectively. The classification model based on a deep neural network was trained with a relatively small dataset; however, it showed good accuracy. In conclusion, we provided data collection and model training schemes for mTSS prediction and showed an important contribution to building an automated scoring system.
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