Objective To explore the solution of local water-fat separation swap artifacts(WFS-SA)on nasopharyngeal T1WI-itera-tive decomposition of water and fat with echo asymmetry and least-squares estimation(T1WI-IDEAL)enhanced examination images.Methods Thirty-seven patients with obvious WFS-SA on nasopharyngeal enhanced examination using the A group T1WI-IDEAL param-eters were collected.Scans with modified parameters B,C,and D groups were subsequently performed based on the A group parame-ters.Subjective ratings of image quality were conducted on the four image groups,and the image signal-to-noise ratio(SNR)of the posterior wall of the nasopharynx and medulla oblongata was quantified.The total number of artifact slices(TAS),total artifact area(TAA),and maximum single-slice artifact area(SSAAmax)of the WFS-SA in the four image groups were recorded.The consistency of image quality ratings between the two technologists was analyzed via the intraclass correlation coefficient(ICC),and one-way analysis of variance or rank-sum test was used to compare the SNR,TAS,TAA,and SSAAmax among the four image groups.Results The subjective rating for modified B,C,and D groups of T1WI-IDEAL images by two technologists was deemed satisfactory(ICC=0.721-0.928,P<0.001).Significant variations in image quality ratings were observed among the three groups(H=45.131,P<0.001),with ratings for C and D groups surpass-ing those for B group(P<0.001).The TAS,TAA,and SSAAmax exhibited a decreasing pattern on T1WI-IDEAL images across A,B,C,and D groups,with statistically significant variances observed among all groups(P<0.001).Moreover,the SNR of the medulla oblongata layer in D group displayed a notably higher value compared to A,B groups,with statistically significant distinctions(P<0.001).Conclusion By combining the reduction of the echo train length(ETL)to 2 with the implementation of a double shimming,the occurrence of WFS-SA on nasopharyngeal T1WI-IDEAL enhanced examination images can be minimized and the overall image quality can be enhanced.

Objective To compare and analyze the application value of brain black blood technology three-dimensional BrainVIEW(3D-BrainVIEW)and conventional three-dimensional turbo field echo T1 weighted imaging(3D-TFE T1WI)in brain metastases of lung cancer.Methods A total of 60 patients with pathologically confirmed lung cancer were selected.All patients underwent brain enhanced MRI using 3D-BrainVIEW and 3D-TFE T1WI.The signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of the two groups were compared and analyzed,respectively.The diagnostic efficacy(including number,size,and location)of the two groups of images in detecting brain metastases was evaluated by two experienced radiologists via double-blind method.Results The diagnostic consistency between the two radiologists was excellent[intraclass correlation coefficient(ICC)=0.998,P<0.001].There were significant differences in SNR,CNR,and the number and location of brain metastases between 3D-BrainVIEW sequence and 3D-TFE T1WI sequence(P<0.05),and 3D-BrainVIEW sequence was significantly superior to 3D-TFE T1WI sequence.In addition,the number of brain metastases detected by 3D-Brain VIEW sequence was significantly higher than that detected by 3D-TFE T1WI sequence in lesions with minimum diameter(Dmin)<5 mm(P<0.001).There was no difference in the number of lesions detected by the two sequences in lesions with Dmin>5 mm(P>0.05).Conclusion The SNR and CNR of 3D-Brain VIEW enhanced scan images are significantly higher than those of 3D-TFE T1WI,which has higher detection efficiency for lung cancer brain metastases,and can effectively reduce misdiagnosis caused by microvascular enhance-ment,which has high clinical application value.

Objective To explore the solution of local water-fat separation swap artifacts(WFS-SA)on nasopharyngeal T1WI-itera-tive decomposition of water and fat with echo asymmetry and least-squares estimation(T1WI-IDEAL)enhanced examination images.Methods Thirty-seven patients with obvious WFS-SA on nasopharyngeal enhanced examination using the A group T1WI-IDEAL param-eters were collected.Scans with modified parameters B,C,and D groups were subsequently performed based on the A group parame-ters.Subjective ratings of image quality were conducted on the four image groups,and the image signal-to-noise ratio(SNR)of the posterior wall of the nasopharynx and medulla oblongata was quantified.The total number of artifact slices(TAS),total artifact area(TAA),and maximum single-slice artifact area(SSAAmax)of the WFS-SA in the four image groups were recorded.The consistency of image quality ratings between the two technologists was analyzed via the intraclass correlation coefficient(ICC),and one-way analysis of variance or rank-sum test was used to compare the SNR,TAS,TAA,and SSAAmax among the four image groups.Results The subjective rating for modified B,C,and D groups of T1WI-IDEAL images by two technologists was deemed satisfactory(ICC=0.721-0.928,P<0.001).Significant variations in image quality ratings were observed among the three groups(H=45.131,P<0.001),with ratings for C and D groups surpass-ing those for B group(P<0.001).The TAS,TAA,and SSAAmax exhibited a decreasing pattern on T1WI-IDEAL images across A,B,C,and D groups,with statistically significant variances observed among all groups(P<0.001).Moreover,the SNR of the medulla oblongata layer in D group displayed a notably higher value compared to A,B groups,with statistically significant distinctions(P<0.001).Conclusion By combining the reduction of the echo train length(ETL)to 2 with the implementation of a double shimming,the occurrence of WFS-SA on nasopharyngeal T1WI-IDEAL enhanced examination images can be minimized and the overall image quality can be enhanced.

Objective To compare and analyze the application value of brain black blood technology three-dimensional BrainVIEW(3D-BrainVIEW)and conventional three-dimensional turbo field echo T1 weighted imaging(3D-TFE T1WI)in brain metastases of lung cancer.Methods A total of 60 patients with pathologically confirmed lung cancer were selected.All patients underwent brain enhanced MRI using 3D-BrainVIEW and 3D-TFE T1WI.The signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of the two groups were compared and analyzed,respectively.The diagnostic efficacy(including number,size,and location)of the two groups of images in detecting brain metastases was evaluated by two experienced radiologists via double-blind method.Results The diagnostic consistency between the two radiologists was excellent[intraclass correlation coefficient(ICC)=0.998,P<0.001].There were significant differences in SNR,CNR,and the number and location of brain metastases between 3D-BrainVIEW sequence and 3D-TFE T1WI sequence(P<0.05),and 3D-BrainVIEW sequence was significantly superior to 3D-TFE T1WI sequence.In addition,the number of brain metastases detected by 3D-Brain VIEW sequence was significantly higher than that detected by 3D-TFE T1WI sequence in lesions with minimum diameter(Dmin)<5 mm(P<0.001).There was no difference in the number of lesions detected by the two sequences in lesions with Dmin>5 mm(P>0.05).Conclusion The SNR and CNR of 3D-Brain VIEW enhanced scan images are significantly higher than those of 3D-TFE T1WI,which has higher detection efficiency for lung cancer brain metastases,and can effectively reduce misdiagnosis caused by microvascular enhance-ment,which has high clinical application value.

Objective:To synthesize non-contrast-enhanced CT images from enhanced CT images using deep learning method based on convolutional neural network, and to evaluate the similarity between synthesized non-contrast-enhanced CT images by deep learning(DL-SNCT) and plain CT images considered as gold standard subjectively and objectively, as well as to explore their potential clinical value.Methods:Thirty-four patients who underwent conventional plain scan and enhanced CT scan at the same time were enrolled. Using deep learning model, DL-SNCT images were generated from the enhanced CT images for each patient. With plain CT images as gold standard, the image quality of DL-SNCT images was evaluated subjectively. The evaluation indices included anatomical structure clarity, artifacts, noise level, image structure integrity and image deformation using a 4-point system). Paired t-test was used to compare the difference in CT values of different anatomical parts with different hemodynamics (aorta, kidney, liver parenchyma, gluteus maximus) and different liver diseases with distinct enhancement patterns (liver cancer, liver hemangioma, liver metastasis and liver cyst) between DL-SNCT images and plain CT images. Results:In subjective evaluation, the average scores of DL-SNCT images in artifact, noise, image structure integrity and image distortion were all 4 points, which were consistent with those of plain CT images ( P>0.05). However, the average score of anatomical clarity was slightly lower than that of plain CT images (3.59±0.70 vs. 4) with significant difference ( Z = -2.89, P<0.05). For different anatomical parts, the CT values of aorta and kidney in DL-SNCT images were significantly higher than those in plain CT images ( t=-12.89, -9.58, P<0.05). There was no statistical difference in the CT values of liver parenchyma and gluteus maximus between DL-SNCT images and plain CT images ( P>0.05). For liver lesions with different enhancement patterns, the CT values of liver cancer, liver hemangioma and liver metastasis in DL-SNCT images were significantly higher than those in plain CT images( t=-10.84, -3.42, -3.98, P<0.05). There was no statistical difference in the CT values of liver cysts between DL-SNCT iamges and plain CT images ( P>0.05). Conclusions:The DL-SNCT image quality as well as the CT values of some anatomical structures with simple enhancement patterns is comparable to those of plain CT images considered as gold-standard. For those anatomical structures with variable enhancement and those liver lesions with complex enhancement patterns, there is still vast space for DL-SNCT images to be improved before it can be readily used in clinical practice.

Objective:To investigate the clinical value of magnetic resonance imaging (MRI) plain scan and diffusion weighted imaging (DWI) in the diagnosis of brain metastases.Methods:The MRI plain imaging findings of 105 cases with brain metastases and 103 cases without brain metastases confirmed by enhanced MRI examination and clinical diagnosis were retrospectively analyzed. The comparisons of plain MRI findings including T1 weighted image (T1WI), T2WI, T2/fluid attenuated inversion recovery (T2/FLAIR), DWI and apparent diffusion coefficient (ADC) values were made between brain metastases and non-brain metastases.Results:The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T1WI in the brain metastatic group were 54, 23, 9 and 19, respectively, while the numbers of hypo-intensity and iso-intensity in the non-brain metastatic group were 52 and 51, respectively, with statistically significant difference ( P<0.001). The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T2WI in the brain metastatic group were 1, 9, 72 and 23, respectively, while the numbers of iso-intensity and hyper-intensity in the non-brain metastatic group were 11 and 92, respectively, with statistically significant difference ( P<0.001). The numbers of hypo-intensity, hyper-intensity and heterogeneous signal intensity of DWI in the brain metastatic group were 4, 31 and 65, respectively, while the number of hyper-intensity in the non-brain metastatic group was 4 and others were iso-intensity, respectively, with statistically significant difference ( P<0.001). The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T2WI/FLAIR in the brain metastatic group were 4, 5, 60 and 36, respectively, while all cases in the non-brain metastatic group were hyper-intensity, with statistically significant difference ( P<0.001). The number of lesion accompanied with peripheral edema in the brain metastatic group were 69 cases, significantly higher than 0 cases in the non-brain metastatic group ( P<0.001). The mean ADC value in the brain metastatic group were (0.919±0.019)×10 -3 mm 2/s, significantly lower than (1.098±0.012)×10 -3 mm 2/s of non-brain metastatic group ( P<0.05). Conclusions:For patients with a history of primary malignancy, the MRI plain scan signals of T1WI, T2WI, T2WI/FLAIR and DWI are significantly different between brain metastatic tumor and non-metastatic tumor. The mixed signal, peripheral edema and the restriction of DWI diffusion indicate brain metastases. The combined application of the above parameters can improve the diagnostic efficacy of predicting brain metastases, and contrast enhancement MRI examination should be performed for the confirmation of diagnosis.

Objective:To investigate the clinical value of magnetic resonance imaging (MRI) plain scan and diffusion weighted imaging (DWI) in the diagnosis of brain metastases.Methods:The MRI plain imaging findings of 105 cases with brain metastases and 103 cases without brain metastases confirmed by enhanced MRI examination and clinical diagnosis were retrospectively analyzed. The comparisons of plain MRI findings including T1 weighted image (T1WI), T2WI, T2/fluid attenuated inversion recovery (T2/FLAIR), DWI and apparent diffusion coefficient (ADC) values were made between brain metastases and non-brain metastases.Results:The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T1WI in the brain metastatic group were 54, 23, 9 and 19, respectively, while the numbers of hypo-intensity and iso-intensity in the non-brain metastatic group were 52 and 51, respectively, with statistically significant difference ( P<0.001). The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T2WI in the brain metastatic group were 1, 9, 72 and 23, respectively, while the numbers of iso-intensity and hyper-intensity in the non-brain metastatic group were 11 and 92, respectively, with statistically significant difference ( P<0.001). The numbers of hypo-intensity, hyper-intensity and heterogeneous signal intensity of DWI in the brain metastatic group were 4, 31 and 65, respectively, while the number of hyper-intensity in the non-brain metastatic group was 4 and others were iso-intensity, respectively, with statistically significant difference ( P<0.001). The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T2WI/FLAIR in the brain metastatic group were 4, 5, 60 and 36, respectively, while all cases in the non-brain metastatic group were hyper-intensity, with statistically significant difference ( P<0.001). The number of lesion accompanied with peripheral edema in the brain metastatic group were 69 cases, significantly higher than 0 cases in the non-brain metastatic group ( P<0.001). The mean ADC value in the brain metastatic group were (0.919±0.019)×10 -3 mm 2/s, significantly lower than (1.098±0.012)×10 -3 mm 2/s of non-brain metastatic group ( P<0.05). Conclusions:For patients with a history of primary malignancy, the MRI plain scan signals of T1WI, T2WI, T2WI/FLAIR and DWI are significantly different between brain metastatic tumor and non-metastatic tumor. The mixed signal, peripheral edema and the restriction of DWI diffusion indicate brain metastases. The combined application of the above parameters can improve the diagnostic efficacy of predicting brain metastases, and contrast enhancement MRI examination should be performed for the confirmation of diagnosis.

OBJECTIVE: To investigate the CT findings of patients with different clinical types of coronavirus disease 2019 (COVID-19). METHODS: A total of 67 patients diagnosed as COVID-19 by nucleic acid testing were collected and divided into 4 groups according to the clinical stages based on . The CT imaging characteristics were analyzed among patients with different clinical types. RESULTS: Among 67 patients, 3(4.5%) were mild, 35 (52.2%) were moderate, 22 (32.8%) were severe, and 7(10.4%) were critical ill. No significant abnormality in chest CT imaging in mild patients. The 35 cases of moderate type included 3 (8.6%) single lesions, the 22 cases of severe cases included 1 (4.5%) single lesion and the rest cases were with multiple lesions. CT images of moderate patients were mainly manifested by solid plaque shadow and halo sign (18/35, 51.4%); while fibrous strip shadow with ground glass shadow was more frequent in severe cases (7/22, 31.8%). Consolidation shadow as the main lesion was observed in 7 cases, and all of them were severe or critical ill patients. CONCLUSIONS CT images of patients with different clinical types of COVID-19 have characteristic manifestations, and solid shadow may predict severe and critical illness.
Betacoronavirus ; isolation & purification ; Coronavirus Infections ; classification ; diagnostic imaging ; Humans ; Lung ; diagnostic imaging ; Pandemics ; classification ; Pneumonia, Viral ; classification ; diagnostic imaging ; Tomography, X-Ray Computed

OBJECTIVE: To analyze the CT findings of patients with different clinical types of coronavirus disease 2019 (COVID-19). METHODS: A total of 67 patients diagnosed as COVID-19 by nucleic acid testing were included and divided into 4 groups according to the clinical staging based on . The CT imaging characteristics were analyzed among patients with different clinical types. RESULTS: Among 67 patients, 3 (4.5%) were mild cases, 35 (52.2%) were ordinary cases, 22 (32.8%) were severe cases, and 7 (10.4%) were critically ill. There were no abnormal CT findings in mild cases. In 35 ordinary cases, there were single lesions in 3 cases (8.6%) and multiple lesions in 33 cases (91.4%), while in severe case 1 case had single lesion (4.5%) and 21 had multiple lesions (95.5%). CT images of ordinary patients were mainly manifested as solid plaque shadow and halo sign (18/35, 51.4%); while fibrous strip shadow with ground glass shadow was more frequent in severe cases (7/22, 31.8%). Consolidation shadow as the main lesion was observed in 7 cases, and all of them were severe or critical ill patients. CONCLUSIONS CT images in patients with different clinical types of COVID-19 have characteristic manifestations, and solid shadow may predict severe and critical illness.
Betacoronavirus ; Clinical Laboratory Techniques ; Coronavirus Infections ; diagnosis ; diagnostic imaging ; Humans ; Lung ; diagnostic imaging ; pathology ; Pneumonia, Viral ; diagnostic imaging ; pathology ; Severity of Illness Index ; Tomography, X-Ray Computed ; methods

Objective:To explore diagnostic value of dynamic electrocardiogram (DCG) combined esophageal electro‐physiological examination (EEE) for sick sinus syndrome (SSS) .Methods :A total of 74 cases suspecting SSS ,who presented 24h mean heart rate <55 beats/min in DCG ,were selected .After DCG examination ,all subjects received EEE . Diagnostic value of single and combined examinations wereexplored .Results:Compared withthe SSS positive rate of single DCG and single EEE(87.8% ,86.5% ) ,theSSS positive rate ofDCG combined EEE(97.3% ) was sig‐nificantly rose ,P<0.05 both .Conclusion:Dynamic electrocardiogram combined esophageal electrophysiological ex‐amination can evaluate sinus node function from different angles ,which can significantlyincrease SSS diagnose rat .