ABSTRACT
Objective@#To investigate the image quality of ultralow-dose CT (ULDCT) of the chest reconstructed using a cycle-consistent generative adversarial network (CycleGAN)-based deep learning method in the evaluation of pulmonary tuberculosis. @*Materials and Methods@#Between June 2019 and November 2019, 103 patients (mean age, 40.8 ± 13.6 years; 61 men and 42 women) with pulmonary tuberculosis were prospectively enrolled to undergo standard-dose CT (120 kVp with automated exposure control), followed immediately by ULDCT (80 kVp and 10 mAs). The images of the two successive scans were used to train the CycleGAN framework for image-to-image translation. The denoising efficacy of the CycleGAN algorithm was compared with that of hybrid and model-based iterative reconstruction. Repeated-measures analysis of variance and Wilcoxon signedrank test were performed to compare the objective measurements and the subjective image quality scores, respectively. @*Results@#With the optimized CycleGAN denoising model, using the ULDCT images as input, the peak signal-to-noise ratio and structural similarity index improved by 2.0 dB and 0.21, respectively. The CycleGAN-generated denoised ULDCT images typically provided satisfactory image quality for optimal visibility of anatomic structures and pathological findings, with a lower level of image noise (mean ± standard deviation [SD], 19.5 ± 3.0 Hounsfield unit [HU]) than that of the hybrid (66.3 ± 10.5 HU, p 0.908). The CycleGAN-generated images showed the highest contrast-to-noise ratios for the pulmonary lesions, followed by the model-based and hybrid iterative reconstruction. The mean effective radiation dose of ULDCT was 0.12 mSv with a mean 93.9% reduction compared to standard-dose CT. @*Conclusion@#The optimized CycleGAN technique may allow the synthesis of diagnostically acceptable images from ULDCT of the chest for the evaluation of pulmonary tuberculosis.
ABSTRACT
Objective@#To investigate the image quality of ultralow-dose CT (ULDCT) of the chest reconstructed using a cycle-consistent generative adversarial network (CycleGAN)-based deep learning method in the evaluation of pulmonary tuberculosis. @*Materials and Methods@#Between June 2019 and November 2019, 103 patients (mean age, 40.8 ± 13.6 years; 61 men and 42 women) with pulmonary tuberculosis were prospectively enrolled to undergo standard-dose CT (120 kVp with automated exposure control), followed immediately by ULDCT (80 kVp and 10 mAs). The images of the two successive scans were used to train the CycleGAN framework for image-to-image translation. The denoising efficacy of the CycleGAN algorithm was compared with that of hybrid and model-based iterative reconstruction. Repeated-measures analysis of variance and Wilcoxon signedrank test were performed to compare the objective measurements and the subjective image quality scores, respectively. @*Results@#With the optimized CycleGAN denoising model, using the ULDCT images as input, the peak signal-to-noise ratio and structural similarity index improved by 2.0 dB and 0.21, respectively. The CycleGAN-generated denoised ULDCT images typically provided satisfactory image quality for optimal visibility of anatomic structures and pathological findings, with a lower level of image noise (mean ± standard deviation [SD], 19.5 ± 3.0 Hounsfield unit [HU]) than that of the hybrid (66.3 ± 10.5 HU, p 0.908). The CycleGAN-generated images showed the highest contrast-to-noise ratios for the pulmonary lesions, followed by the model-based and hybrid iterative reconstruction. The mean effective radiation dose of ULDCT was 0.12 mSv with a mean 93.9% reduction compared to standard-dose CT. @*Conclusion@#The optimized CycleGAN technique may allow the synthesis of diagnostically acceptable images from ULDCT of the chest for the evaluation of pulmonary tuberculosis.
ABSTRACT
Objective To explore the CT features and pathology of intrapulmonary lymph nodes (IPLNs), so as to improve the understanding and diagnosis of IPLNs. Methods A total of 38 patients (49 IPLNs) who were confirmed by the surgery and pathology were retrospectively analyzed, including 21 males and 17 females with a mean age of (56±8) years. All the patients underwent MSCT scan and 1.0 mm thin layer reconstruction before surgery. Double-blind method was used to analyze CT signs and the corresponding histopathological changes were compared. Results (1) Location: all IPLNs were located below the level of tracheal carina with 17 were on the left lung, and 32 were on the right lung. (2) Shape: 34 IPLNs were round, 15 were triangular or prism and so on. (3) Size: the maximum diameter of IPLNs ranged from 0.26 to 1.28 cm (0.66±0.23 cm), of which 45 cases were≤1.0 cm. (4) Quantity: 28 IPLNs were solitary and 10 were multiple. (5) Density: All 48 IPLNs were solid nodules with a median CT value of 43 HU (range from 19 to 106 HU), and there were no calcification, vacuoles and air bronchial signs were showed. (6) Margin and pleura: all the 48 IPLNs boundaries were clear and smooth, and 45 pieces were less than 1.0 cm from the pleura, of which 20 were close to the pleura or inter-lobar fissure. (7) Other: no"satellite focal", pleural depression syndrome, and vascular bundle sign were showed;22 peripheral fine lines of IPLNs were visible. (8) Pathology: IPLNs were dark brown or gray-black nodules with well-defined borders, coated, tough, hard, and carbon deposition could be seen in most cases. Conclusion IPLNs are benign nodules in the lung, which have certain CT features and typical pathological changes. Based on the CT performance and characteristics, it is helpful to make correct diagnosis of IPLNs before operation.
ABSTRACT
Objective To explore the application value of histogram quantitative analysis based on diffusion kurtosis imaging (DKI) in detecting prostate cancer (PCa) and assessing tumor aggressiveness. Methods One hundred and twenty patients were retrospectively enrolled in Zhongnan Hospital of Wuhan University from November 2014 to November 2016,with diagnosis confirmed by prostate biopsy,definitive Gleason score(GS) results and prostate MRI examinations. There were 90 tumor foci in 67 prostate cancer patients, including 23 cases with GS≤6 (37 tumor foci), 7 GS 3+4=7(7 tumor foci), 3 GS 4+3=7(3 tumor foci).Thirty four cases who were with GS≥8(43 tumor foci)were divided into low-grade PCa(37 GS≤6)and high-grade PCa(53 GS≥7).Fifty three patients were diagnosed with benign prostatic hyperplasia(BPH).All patients underwent conventional prostate MRI examination and multi b value DKI examination. The apparent diffusion coefficient(Dapp)corrected by non-Gaussian model,apparent kurtosis coefficient(Kapp)and ADC value were obtained for histogram analysis.Student's t test was executed to compare the differences of ADCs,Dappand Kappvalues between prostate cancer(PCa)and BPH,low-grade PCa and high-grade PCa.ROC curves were used to evaluate the diagnostic value of ADCs,Dappand Kappvalues in differentiating PCa from BPH and differentiating high-grade PCa from low-grade PCa. Pearson correlation was used to assess the correlations between the histogram quantitative parameters of ADCs,Dappand Kappvalues and Gleason score. Results Except skew of Kapp, the other histogram quantitative parameters of Kappbetween PCa and BPH were statistically significant (all P<0.05). Except the skew of Kapp, the other histogram quantitative parameters of Kappbetween low-grade PCa and high-grade PCa were statistically significant(all P<0.05).The median,mean and standard deviation of ADC,Dappand Kapphave good diagnostic value in detecting PCa from BPH and differing high-grade PCa from low-grade PCa.The area under ROC curve was ranging from 0.558 to 0.985.There were moderate to high correlations between median,mean of ADC(r=-0.701 and-0.676, respectively),median,mean of Dapp(r=-0.712 and-0.701,respectively),median,standard deviation,and kurtosis of Kapp(r=0.458,0.516 and-0.528,respectively)and Gleason score(all P<0.05).Conclusion The DKI parameters combined with histogram quantitative analysis is helpful in detecting prostate cancer and assessing tumor aggressiveness.
ABSTRACT
Objective@#To explore the feasibility and the value of CT enterography (CTE) in the quantitative evaluation of Crohn's disease (CD).@*Methods@#Retrospectively analyzed 49 patients diagnosed as CD by clinical, enteroscopy, pathology, and imaging from April 2016 to June 2017 in Zhongnan Hospital of Wuhan University. All patients underwent routine enteroscopy and standardized CTE. The interval between the two examinations was less than 2 weeks. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were measured at intervals. The ESR ranged from 2.0 to 97.0 mm/1 h, with an average of (30.6±26.5) mm/1 h, CRP from 0.3 to 143.3 mg/L, and a median of 27.7 mg/L. CD patients were classified into inactive, mild and moderate-severe according to Crohn's disease simplified endoscopic activity score(SES-CD) after enteroscopy. CTE evaluated the site of lesion, the thickness and enhanced patterns of the most severe lesions of the bowel wall, mural enhanced CT value in the portal vein phase, ΔCT value, stenosis, perienteric inflammation, mesenteric hypervascularity (comb sign), enlarged lymph nodes, abdominal abscesses, fistulas, etc. The Chi-square test was used to compare the differences of enhanced patterns among different groups. ANOVA (Analysis of Variance) was used to compare the differences in bowel wall thickness, plain CT values, mural enhanced CT value in the portal vein phase and ΔCT values among different groups. The correlation between CTE parameters and SES-CD or laboratory data was analyzed by Pearson (normal distribution data) or Spearman (skewed distribution data).@*Results@#SES-CD ranged from 1 to 15, with an average of 5.1±2.6. Among 49 cases, 13 were inactive, 19 were mild, and 17 were moderate-severe. There were 25 cases of intestinal obstruction or stenosis, including 24 cases in the active group and 1 case in the non-active group, and the difference was statistically significant (χ2=13.3, P<0.01). The short diameter of lymph nodes was more than 10 mm in 7 patients, all of them were active patients; 32 cases were mesenteric hypervascularity, manifested as "comb sign" , among them, 28 cases were active and 4 cases were non-active, and the difference was statistically significant (χ2=9.3, P<0.01). Perienteric inflammation was manifested in 30 cases, including 27 cases in the active group and 3 cases in the non-active group, and the difference was statistically significant (χ2=10.8, P<0.01). The enhanced patterns of thickened bowel wall in the non-active was dominated by C and D types, while A and B types was mainly in the active group, and the difference was statistically significant (P<0.05); There were significant differences in bowel wall thickness, mural enhanced CT value in the portal vein phase and ΔCT values between different groups (P<0.05), however, the difference of plain CT values between different groups was not significant (P>0.05). Bowel wall thickness, mural enhanced CT value in the portal vein phase and ΔCT values were all moderately correlated with SES-CD (r were 0.564, 0.585, 0.533, respectively; P all <0.01). Bowel wall thickness was positively correlated with ESR and CRP(r were 0.542, 0.452, respectively; P all <0.01). Mural enhanced CT value in the portal vein phase and ΔCT values were not correlated with ESR or CRP (P>0.05).@*Conclusion@#The bowel wall thickness, mural enhanced CT value in the portal vein phase and the ΔCT value can be used to accurately assess the activity of CD lesions.
ABSTRACT
Objective To investigate the recent effect and safety of magnetic resonance guided focused ultrasound (MRgFUS) for treating uterine fibroids with a Meta analysis. Methods Such databases as Cochrane Library,PubMed,EMbase, CBM,CNKI,CQVIP and Wanfang were searched from their establishment. After thestudy selected, assessment and data extraction conducted by two reviewers independently, Meta-analysis were performed by using the Comprehensive Meta-analysis V2 software. The volume of non-perfusion ratio (NPVR), fibroid shrinkage, clinical symptom severity (SSS score) and adverse reactions were analyzed.Results Nighteen retrieved articles were included, with a total of 1 549 patients. The results of Meta-analysis showed that:(1)nonperfused volume ratio (NPVR),Mean=57.1%(95%CI 45.0% —69.2%).(2)Percentage of FBs shrinkage:mean=31.4% (95% CI 29.2% —33.6%).(3)Symptom severity score (SSS):baseline mean=51.00(95%CI 41.61—60.40),3 months mean=32.50 (95%CI 25.90—39.10),6 months mean=28.62(95%CI(23.57—33.66),12 months mean=24.46(95%CI 15.44—33.49), the average of the severity score of the patient symptoms had a tendency to reduce.(4)The degree of adverse reactions were mild and could relieve itself, there was fewer serious adverse reactions. Conclusions The current evidence indicates that MRgFUS in treatment of uterine fibroidsis reliable and safe. MRgFUS can significantly reduce the volume and the symptom severity score ofthe patients.
ABSTRACT
Objective To assess regional cerebrovascular reactivity (CVR) and cognition impairment of subcortical ischemic vascular disease (SIVD). To show whether CVR affects cognitive impairment of SIVD patients. Methods Arterial spin-labeling (ASL) by MR image was applied in measuring regional cerebral blood flow (rCBF) of frontal lobe, temporal lobe, parietal lobe, occipital lobes after 5% CO2 inhalation, and the CVR was demonstrated by increase rate of rCBF in all the subject areas. Results (1)The patients with SIVD had reduced CVR in cortex of frontal lobes, white matter of frontal lobes, temporal lobes and occipital lobes(P < 0.05). (2) CVR in the SIVD patients with cognitive impairment decreased in frontal cortex and white matter when compared with the patients without cognitive impairment(P < 0.01). Conclusion These results showed that CVR decreased significantly in cortical gray matter and white matter in elderly patients with SIVD. Also the reduction of CVR in the frontal cortex and white matter was associated with cognitive impairment.
ABSTRACT
Clinical data and manifestations on muhi-slice spiral CT (MSCT) of 11 patients with disseminated peritoneal adenomucinosis (DPAM) were retrospectively reviewed.The CT manifestations were also compared with surgical and histopathological findings.MSCT findings showed a large amount of gel-like ascites in 9 cases and local cystic masses in 2 cases.Among 9 cases with a large amount ascites,abdominal multiple cystic masses were shown in 5 case,and infiltration of the greater omentum and mesentery in 5 cases.Hepatic scalloping was found in 6 cases ; parenchymal invasion of the liver or spleen were showed in 5 cases; calcification of the cystic masses in 5 cases.Ovary mueinous cystadenoma was presented in 3 female patients.Enlarged lymph nodes and omental cake were not found in all cases.The results indicate that the characteristic MSCT manifestations of DPAM include diffuse gel-like ascites,multiple cystic masses with or without calcification,hepatic scalloping and parenchyma invasion.
ABSTRACT
Objective To explore the mechanism of self-awareness in the heavy smokers(HS)by using regional homogeneity(ReHo)combined with resting-state functional MRI(fMRI).Methods Thirty HS and 31 healthy non-smokers(NS)matched for age and sex underwent a 3.0 T resting-state fMRI.The data were post-processed by SPM 5 and then the ReHo values were calculated by REST software.The ReHo values between the two groups were compared by two-sample t-test.The brain map with significant difference of ReHo value was obtained.Results Compared with that in NS group,the regions with decreased ReHo value included the bilateral precuneus,superior frontal gyrus,medial prefrontal cortex,right angular gyrus,inferior frontal gyrus,inferior occipital gyrus,cerebellum,and left middle frontal gyrus in HS group.The regions of increased ReHo value included the bilateral insula,parahippocampal gyrus,white matter of parietal lobe,pons,left inferior parietal lobule,lingual gyrus,thalamus,inferior orbital gyrus,white matter of temporal-frontal lobe,and cerebellum.The difference was more obvious in the left hemisphere.Conclusions In HS,abnormal ReHo on a resting state which reflects network of smoking addiction.This method may be helpful in understanding the mechanism of self-awareness in HS.
ABSTRACT
Objective Global brain atrophy was reported as an important structural change in Alzheimer's disease (AD), while it has been detected in the older person with normal cognitive function. Therefore, this study was aimed at investigating the difference of the neural metabolites in the left hippocampus (HIP) and left frontal cortex (FC) among patients who showed global brain atrophy but with different cognitive function. Methods The 33 patients with global brain atrophy confirmed by MRI scan, underwent a comprehensively clinical and neuropsychological assessment including mini-mental state examination (MMSE), activities of daily living scale (ADL) and clock drawing test(CDT). According to the diagnostic and statistical manual of mental disorders, fourth edition(DSM-Ⅳ) and Mayo clinic rochester(MCR), 14 patients were diagnosed as AD, 9 patients as amnestic mild cognitive impairment(aMCI), and 10 patients as normal cognition. Every person was taken a cerebral proton magnetic resonance spectroscopy(1H-MRS) scan to measure the levels of n-acetylaspartate(NAA), choline(Cho), myo-inositol(MI) and Creatine(Cr) in the left HIP and the left FC. Results While compared with the group with normal cognition, the ratio of NAA/Cr in the AD group reduced 10.2% in the left HIP and 5.3% in the left FC, and the ratio of Cho/Cr increased 17.5% in the left HIP and 16.7% in the left FC, and the ratio of MI/Cr increased 39.5% in the left HIP and 19.2% in the left FC. The ratio of NAA/Cr of the left HIP in the AD group was lower than that in the aMCI group at the decrease rate of 6.4%, while the ratio of NAA/Cr of the left FC was not significantly different between the two groups. The AD group had higher ratios of Cho/Cr at the increase rate of 9.3% in the HIP and 12.3% in the FC, and higher MI/Cr ratios at the increase rate of 30% in the HIP and 17% in the FC than in the aMCI group. The aMCI group showed significantly lower ratio of NAA/Cr at the decrease rate of 4.1% and higher ratio of Cho/Cr at the increase rate of 7.5% in the left HIP than in the normal cognition group. Conclusions Among patients with global brain atrophy, the decrement of ratio of NAA/Cr in the left HIP and the increment of the ratio of Cho/Cr and MI/Cr are predictive of the progress from aMCI to AD. Moreover, the decrement of ratio of NAA/Cr in the left HIP and the increment of the ratio of Cho/Cr are helpful to distinguish the aMCI and the persons with normal cognition.
ABSTRACT
Metabolic characteristics of 39 human brain tumor tissues, including 15 astrocytomas, 13 fibroblastic meningiomas and 11 transitional meningiomas from 39 individual patients, have been studied using high resolution magic-angle spinning (HRMAS) 1H NMR spectroscopy in conjunction with principal component analysis (PCA). With rich metabolite information, 1H NMR spectra showed that the tumor-tissuc metabonome was dominated by lipids, lactate, myo-inositol, ereatine, choline metabolites such as choline, phosphocholine and glycerophosphocholine, amino acids such as alanine, glutamate, glutamine, taurine, N-acetyl-aspartate and glutathione. PCA of the tumor NMR spectra clearly showed metabonomic differences between low-grade astrocytomas and meningiomas whereas such differences were more moderate between fibroblastic and transitional meningiomas. Compared with meningiomas, the low-grade astrocytomas had higher levels of glycerophosphocholine, phosphocholine, myo-inositol and creatine but lower levels of alanine, glutamate, glutamine, glutathione and taurine. The N-acetyl-aspartate level was low but detectable in low-grade astrocytomas whereas it was not detectable in meningiomas. It is concluded that tissue metabonomics technology consisting of HRMAS 1H NMR spectroscopy and multivariate data analysis (MVDA) offers a useful tool (1) for distinguishing different types of brain tumors, (2) for providing the metabolic information for human brain tumors, which are potentially useful for understanding biochemistry of tumor progression.
ABSTRACT
Objective To analyze the imaging characteristics of gastric lipoma.Methods The clinical appearances and imaging characteristics such as size,margin,density or intensity,ulceration and so on of gastric lipomas in 13 cases were retrospectively analysed.Results 13 gastric lipomas were all solitary and intracavitary growth,origined from submucosal of every part of stomach.6 gastric lipomas showed submucosal filling defect and soft gastric wall,3 cases with ulcer presenting "bull eye sign" on barium meal.8 gastric lipomas on CT showed variable-size round or oval low-density masses with-50~-120 HU CT value.2 gastric lipomas on MRI were high intensity on T1/T2WI and low intensity on fat supression T2WI.Conclusion X-ray,CT and MRI are of respective value in diagnosing the gastric lipoma.
ABSTRACT
Objective To analyze the DWI characteristics of intracranial epidermoid cyst (ECs),and to evaluate “T2 shine-through” effect. Methods There were 15 cases of ECs confirmed by pathology, in which 3 cases had the residual tumor after surgery. The ADC value was measured in ECs,deep white matter and CSF,and the comparison was made between DWI and FLAIR in showing the tumors. Results (1) The lesions in 15 cases were high intensity on DWI, their ADC value was from 0.80?10 -3mm2/s to 1.23?10 -3mm2/s, the average was (1.05?0.14)?10 -3mm2/s. But the ADC value of deep white matter was from 0.74?10 -3mm2/s to 1.09?10 -3mm2/s, the mean was (0.88?0.09)?10 -3mm2/s. The ADC value of CSF was from 2.98?10 -3mm2/s to 3.78?10 -3mm2/s,the mean was (3.31?0.21)?10 -3mm2/s. The ADC value of ECs was significant lower than that of CSF ( P
ABSTRACT
Objective To explore the imaging characteristics of hepatic primary leiomyoma.Methods The CT and MR imaging findings of three pathologically proven primary leiomyoma of the liver were analyzed,and the correlation between the imaging features and pathological results was analyzed.Two patients underwent CT scanning.Two patients underwent MRI.Results The lesions appeared hypodense in CT images,and with elongated T_1 time and elongated T_2 time in MRI.One lesion was homogenous both in CT and MRI,with significant homogenous enhancement.The other two lesions were inhomogeneous,with inhomogeneous enhancement in one lesion.All the three lesions had the sign of pseudocapsule.Neither hepatic cirrhosis nor venous tumor emboli were present.Pathological examination showed proliferation of spindle- shaped neoplastic cells and hyperplasia of capillary.One tumor had central hyalinization and another tumor had central necrosis.Conclusion Primary leiomyoma of the liver is one kind of hypervascular tumors with pseudocapsule.CT and MR can provide helpful information to the diagnosis.
ABSTRACT
Objective To analyze the features of intracrayze the features of intracranial cystic diseases on ~1H MRS,and to evaluate the applicable value of ~1H MRS.Methods Fifty-two patients were examinated by single voxel ~1H MRS,included Ⅰ-Ⅱ graded astrocytomas(n=8),glioblastomas(n=9),metastasis(n=13),brain abscesses(n=10),epidermoids(n=4),anachnoid cysts(n=5),brain Cysticerciasis(n=3).Results(1)There was only Lac in Ⅰ-Ⅱ graded astrocytomas.But in glioblastomas,as were as all showed Lac,4 cases showed low Cho and NAA and 2 cases Lip.(2) In(13 metastasis) patients,7 cases only presented Lac,6 cases showed Cho,3 cases showed low NAA and(6 ones) Lip.(3) In brain abscesses,all showed Lac,9 cases displayed AA,6 cases showed Ace,5 cases appeared Suc and Ala,2 cases had Lip.(4) Four cases of epidermoid showed Lac,one showed Lip.In(4 arachnoid) cysts,2 cases had low Lac,one showed Lip.Three cases of cysticerciasis showed Lac,Ace,Suc,Ala and no AA,Cho,NAA.Conclusion Lac is the most common resonance peak on ~1H MRS in intracranial cystic diseases and for no diagnostic specificity.AA combined Ace,Suc,and Ala are highly specificity for brain abscess.Ace,Suc and Ala appearance cues the the possible existence of cysticerciasis.~1H MRS is helpful for the qualitative diagnosis of intracranial disease.