MR Diffusion-Weighted Imaging in Evaluating Immediate HIFU Treatment Response of Uterine Fibroids.

BACKGROUND: Nowadays, High Intensity Focused Ultrasound (HIFU) is a common surgery option for the treatment of uterine fibroids in China, the immediate response of which is clinically evaluated using Contrast Enhanced (CE) imaging. However, the injection of gadolinium with its potential adverse effect is of concern in CE and therefore, it deserves efforts to find a better imaging method without the need for contrast agent injection for this task. OBJECTIVE: To assess the role of diffusion-weighted imaging (DWI) in evaluating the immediate therapeutic response of HIFU treatment for uterine fibroids in comparison with CE. METHODS: 68 patients with 74 uterine fibroids receiving HIFU treatment were enrolled, and immediate treatment response was assessed using post-surgical DWI images. Semi-quantitative ordinal ablation quality grading and quantitative nonperfusion volume (NPV) measurement based on DWI and CE imaging were determined by two experienced radiologists. Agreement of ablation quality grading between DWI and CE was assessed using the weighted kappa coefficient, while intraobserver, interobserver and interprotocol agreements of NPV measurements within and between DWI and CE were evaluated using the intraclass correlation (ICC) and Bland-Altman analysis. RESULTS: Grading of immediate HIFU treatment response showed a moderate agreement between DWI and CE (weighted kappa = 0.446, p < 0.001). NPV measured in 65 fibroids with DWI of Grade 3~5 showed very high ICCs for the intraobserver and interobserver agreement within DWI and CE (all ICC > 0.980, p < 0.001) and also for the interprotocol agreement between DWI and CE (ICC = 0.976, p < 0.001). CONCLUSION: DWI could provide satisfactory ablation quality grading, and reliable NPV quantification results to assess immediate therapeutic responses of HIFU treatment for uterine fibroids in most cases, which suggests that non-contrast enhanced DWI might be potentially used as a more costeffective and convenient method in a large proportion of patients for this task replacing CE imaging.

Ultrasonographic pathological grading of prostate cancer using automatic region-based Gleason grading network.

The Gleason scoring system is a reliable method for quantifying the aggressiveness of prostate cancer, which provides an important reference value for clinical assessment on therapeutic strategies. However, to the best of our knowledge, no study has been done on the pathological grading of prostate cancer from single ultrasound images. In this work, a novel Automatic Region-based Gleason Grading (ARGG) network for prostate cancer based on deep learning is proposed. ARGG consists of two stages: (1) a region labeling object detection (RLOD) network is designed to label the prostate cancer lesion region; (2) a Gleason grading network (GNet) is proposed for pathological grading of prostate ultrasound images. In RLOD, a new feature fusion structure Skip-connected Feature Pyramid Network (CFPN) is proposed as an auxiliary branch for extracting features and enhancing the fusion of high-level features and low-level features, which helps to detect the small lesion and extract the image detail information. In GNet, we designed a synchronized pulse enhancement module (SPEM) based on pulse-coupled neural networks for enhancing the results of RLOD detection and used as training samples, and then fed the enhanced results and the original ones into the channel attention classification network (CACN), which introduces an attention mechanism to benefit the prediction of cancer grading. Experimental performance on the dataset of prostate ultrasound images collected from hospitals shows that the proposed Gleason grading model outperforms the manual diagnosis by physicians with a precision of 0.830. In addition, we have evaluated the lesions detection performance of RLOD, which achieves a mean Dice metric of 0.815.

[Dandelion clock-like sign on CT for diagnose of COVID-19].

OBJECTIVE: To explore the value of the "dandelion clock-like" sign on chest CT for diagnosis of SARS-CoV-2-associated pneumonia. METHODS: This retrospective analysis was conducted based on the data of 119 cases from the Department of Fever and the Department of Infection undergoing chest high-resolution CT examinations in Sanshui District People's Hospital between January, 24 and February 10, 2020. The cases with no abnormality on chest CT were excluded. Twenty-three patients were diagnosed to have pneumonia, including 9 with SARS-CoV-2-associated pneumonia and 14 with other types of pneumonia. We comparatively analyzed the CT signs, location of the lesions and the dandelion clock-like sign among different types of pneumonia. RESULTS: Among the 23 patients with pneumonia, 9 (39.1%) had common or severe SARS-CoV-2- associated pneumonia with a positive epidemiological history and corresponding respiratory symptoms. Seven of the SARSCoV-2-associated pneumonia patients had multiple lesions in bilateral lungs, compromising mainly the lung field and the subpleural area and showing patchy, lumpy, and umbrella-shaped ground glass opacity, often accompanied by pulmonary vascular thickening and increased microvessels, interlobular septal thickening and fibrosis and lined with grid-like and small-bubble-like "crazy-paving" patterns. The dandelion clock-like sign was found in all the 9 patients with SARSCoV-2-associated pneumonia, with a total of 46 lesions (60.5%, 76 total lesions); 9 of the lesions presented with a "dandelion clek-like" sign and 37 with a "dandelion seed sign". These signs were not found in the 14 patients with other types of pneumonia. CONCLUSIONS: The dandelion clock-like sign is a common and characteristic chest CT finding in patients with SARS-CoV-2-associated pneumonia, and can help to distinguish SARS-CoV-2-associated pneumonia from other types of pneumonia.

[Changes in shape and signal intensity of high intensity zone in lumbar intervertebral discs on magnetic resonance images: a longitudinal study].

OBJECTIVE: To investigate changes over time in the shape and signal intensity of high intensity zone (HIZ) in the lumbar intervertebral discs on magnetic resonance images in patients with low back pain. METHODS: The imaging data were collected from 27 patients with low back pain, who underwent lumbar magnetic resonance (MR) imaging examinations that identified HIZ lesions and received follow-up MR examinations at least 1.5 years later over the period from January 2009 to January 2017. The initial and follow-up MR T2WI images of the patients were read by two experienced radiologists to categorize the changes in the shape of the HIZ lesions into enlarged, unchanged, shrunk, and disappeared. The volume and signal/cerebrospinal fluid signal intensity (T2/CSF) ratio of the HIZ were measured on sagittal MR images using ImageJ software. RESULTS: Of the 43 HIZ lesions found in the initial examinations, 22 (51.2%) remained unchanged in the follow-up examinations, 10 (21.3%) were enlarged, 9 (20.9%) shrank, and 2 (23.3%) disappeared. The follow-up examinations revealed 4 new HIZ lesions in the intervertebral discs. The volumes of these lesions did not vary significantly in the follow-up examinations (P=0.653), but the T2/CSF ratio was significantly higher in the follow-up than in the initial examinations (P=0.043). CONCLUSIONS: After observation for an average of 3 years and 3 months, most of the HIZ lesions in the lumbar intervertebral discs of the patients with low back pain remained stable in shape, but their signal intensity on MR images increased.

[Magnetic resonance imaging versus DR for whole spine imaging in patients with degenerative spinal disease].

OBJECTIVE: To assess the quality of whole spine images obtained by DR and magnetic resonance imaging (MRI) and analyze the whole spinal imaging sagittal parameters for standing DR and supine MRI. METHODS: Sixty-one patients aged 49.9∓17.6 years with degenerative spinal disease underwent both standing DR and supine MRI of the whole spine from November, 2010 to March, 2016. The image quality was retrospectively reviewed, and the cervical lordosis (CL), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), and sagittal vertical axis (SVA) were measured on the whole spinal lateral DR and middle sagittal MR images. RESULTS: Both the DR and MR whole spine images had a high quality (100%). The CL, TK, LL, SS, and SVA measured were 28.37mnplus;10.91 °, 29.98mnplus;8.96 °, 45.61mnplus;12.46 °, 34.38mnplus;9.05 °, and 17.20mnplus;26.39 mm on DR images and were 24.34mnplus;9.01 °, 21.22mnplus;8.13 °, 41.45mnplus;12.17 °, 37.45mnplus;8.19 °, and 36.51mnplus;12.44mm on MR images, respectively, showing significant differences in the measurements between the two modalities (P=0.000, 0.000, 0.000, 0.001, and 0.007, respectively). The correlation coefficient between DR and MR images for CL, TK, LL, SS, and SVA were 0.69, 0.68, 0.72, 0.51, and 0.27 (P=0.000, 0.000, 0.000, 0.000, and 0.034, respectively). CONCLUSION: Both standing DR and supine MR whole spine imaging can provide high-quality images. The CL, TK, LL, SS, and SVA measured on supine MR whole spine images are correlated with those on standing DR images but differ obviously. Supine MR imaging can not substitute standing DR examinations, and comprehensive assessment of degenerative spinal disease needs the combination of the two imaging techniques.

[Correlation of vertebral body deformity and adjacent disc degeneration in patients with old thoracolumbar compression fractures].

OBJECTIVE: To assess the correlation between vertebral body deformity and degeneration of the adjacent intervertebral discs in patients with old thoracolumbar compression fractures. METHODS: Seventy-one patients who had been conservatively treated after single segment thoracolumbar compression fractures between April, 2011 and May, 2014 were enrolled in this study. Both radiographic and magnetic resonance (MR) images of the thoracolumbar segment were obtained. The involved vertebral body deformity was rated on radiography according to the Genant criterion, and the degeneration of the adjacent cephalic and caudal discs was assessed on MR images using the Oner and Pfirrmann classification schemes, respectively. The relationship between vertebral body deformity and adjacent disc changes was assessed using correlation analysis, and the changes in the adjacent cranial and caudal discs was compared. RESULTS: The Genant classification of the involved vertebral bodies was moderately correlated with Oner morphological scores (r=0.48, P<0.01), but not with the Pfirrmann signal scores of the adjacent cephalic discs or with the Genant or Pfirrmann scores of the adjacent caudal discs (P>0.05). The Oner classification of the adjacent cephalic discs was higher than that of the adjacent caudal discs (P<0.01), but their Pfirrmann classification did not differ significantly. CONCLUSION: The deformity of vertebral body affects the adjacent cephalic discs proportionally but not the adjacent caudal discs.

Establishing a disc degeneration model using computed tomography-guided percutaneous puncture technique in the rabbit.

BACKGROUND: Various animal models have been developed to investigate the complex mechanisms leading to intervertebral disc disorders and to evaluate the different therapeutic options. The needle puncture technique is commonly used to induce intervertebral degeneration in animal models. The present study aimed to establish a rabbit model of intervertebral disc degeneration using a simple, minimally invasive procedure. METHODS AND MATERIALS: The animal model was created in the rabbit using computed tomography-guided percutaneous puncture technology. An 18-gauge needle was used to induce a disc injury with a 5-mm puncture depth. Radiographic, histologic, and biochemical analyses and magnetic resonance imaging were performed to assess the consequent disc degeneration. RESULTS: Significant disc space narrowing was observed as early as 4 wk, and osteophytes were formed at 12 wk after puncture. The magnetic resonance imaging assessment demonstrated a progressive loss of T2-weighted signal intensity at the stabbed discs throughout the 12-wk period. The histologic analysis showed a progressive loss of the normal architecture from 4 wk to the end point. The biochemical assays suggested that the expression of proteoglycan decreased progressively with increasing time. CONCLUSIONS: A simple, but minimally invasive, intervertebral disc degeneration model was established successfully using computed tomography-guided percutaneous puncture technology in the rabbit. The puncture procedure can be performed with minimal damage and handling of the other structures, ensuring a uniform reproducible disc degeneration model.

[Establishment of a rabbit model of lumbar intervertebral disc degeneration via the paraspinal approach].

OBJECTIVE: To establish a rabbit model of intervertebral disc degeneration by puncturing the anulus fibrosus through an approach between the longissimus dorsi muscle and obliquus externus abdominis. METHODS: The L(4/5) and L(5/6) intervetebral discs of 6 New Zealand white rabbits were punctured by an 18-gauge pin in the anterolateral annular fibrosus through an approach between the longissimus dorsi muscle and the obliquus externus abdominis with the right transverse processes of L(5) and L(6) resected; the L(2/3) discs were used as the control without exposure or needle stab, and the L(3/4) discs were subjected to sham operation with the discs exposed but not punctured after resecting the right transverse process of L(4). X-ray and magnetic resonance imaging (MRI) were performed preoperatively and at the 4th week after puncture. At 4 weeks after the operation, histological and immunohistochemical analyses of the discs were carried out. RESULTS: X-ray of the punctured discs at 4 weeks after the operation presented a significant decrease of disc height, osteophytosis formation, and end-plate stiffness; an obvious decrease of signal intensity on T(2)-weighted images was found in the puncture group but not in the control or sham-operated groups. Gross morphological inspection showed atrophy of the nucleus pulposus, which became loose, soft, and fragile with a light yellow color. Histological and immunohistochemical analyses showed a significant decrease of notochordal cells and type II collagen in the nucleus pulposus in the puncture group as compared to the control and sham-operated groups. CONCLUSION: Puncture through the approach between the longissimus dorsi muscle and the obliquus externus abdominis allows the establishment of a reliable animal model for studying intervertebral disc degeneration.