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Objective:To explore the optimal keV value of the virtual monoenergetic image (VMI) for displaying the osteosarcoma by using the dual-layer spectral detector CT and to evaluate its application value in determining the extent of intramedullary invasion of osteosarcoma.Methods:From August 2021 to August 2022, 57 patients with conventional osteosarcoma of long bone confirmed by biopsy in Beijing Jishuitan Hospital, Capital Medical University were retrospectively analyzed. All patients completed dual-layer spectral CT enhanced examination before limb salvage surgery, and tumor segment resection specimens were obtained after surgery. Conventional 120 kVp image and VMI of 40, 50, 60, 70 and 80 keV were obtained by spectral CT examination, and the CT values of tumors, image noise were measured and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the corresponding images were calculated. The objective evaluation among the six groups of images were assessed with the Friedman test, and then determined the optimal keV value. The maximum distance between the intramedullary boundary of osteosarcoma and the adjacent articular surfaces was measured on the best keV VMI and the tumor segment resection specimens. The Wilcoxon signed rank test was used to find the differences and the Spearman correlation analysis was used to evaluate the correlation between the distance measured from the best keV VMI and the specimens.Results:There were significant differences in CT value, image noise, SNR and CNR between 40-80 keV VMI and 120 kVp conventional CT images ( P<0.05). The CT value, SNR and CNR of 40 and 50 keV VMI were better than 120 kVp ( P<0.001). The 50 keV VMI was chosen as the best keV VMI to measure the intramedullary extent of osteosarcoma. The distance measured from 50 keV VMI was 103.9 (80.4, 131.4) mm, while the distance measured from specimens was 113.5 (94.0, 142.0) mm, and the difference was statistically significant ( Z=-5.76, P<0.001). The 50 keV VMI measurements in 51 patients were smaller than the gross specimens, which underestimated the tumor intramedullary extent, with the difference was 11.1 (6.6, 13.8) mm. The Spearman correlation analysis demonstrated a high positive correlation of distance measured on gross specimens with the 50 keV VMI ( r s=0.960, P<0.001). Conclusions:Dual-layer spectral detector CT with 50 keV VMI is the best image to show the limb osteosarcoma. Compared with gross specimens, the distance measured from CT underestimated the intramedullary invasion range of limb osteosarcoma about 10 mm, but the two show a good correlation.
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Objective To determine the prognostic value of maximum standard uptake (SUVmax) of pretreatment 18F-FDG PET-CT in patients with newly diagnosed soft tissue sarcomas (STS).Methods The clinical data of 34 patients with STS undergoing 18F-FDG PET-CT before treatment were analyzed retrospectively.The relationship between SUVmax of PET-CT and prognostic factors was evaluated by MannWhitney' s non-paraetric test and Spearman' s rank correlation test.The prognostic factors were analyzed by univariate and multivariate analysis.Results Among 34 patients, the median SUVmax was 10.3 (1.5-28.2), and the median maximum diameter was 6.7 cm (1.8-17.2 cm) with positively association between them (r =0.389, P =0.028).SUVmax was also associated with pathological grade, AJCC staging and distant metastasis, respectively (all P ＜ 0.05).In univariate analysis, distant metastasis, pathological grade, AJCC staging, and SUVmax were found to be the prognostic factors (all P ＜ 0.05).Multivariate analysis results indicated that only the SUVmax and distant metastasis were the independent unfavorable prognostic factors (both P ＜ 0.05).Conclusions The SUmax of pretreatment 18F-FDG PET-CT is well correlated with prognostic factors, and it can predict the prognosis of patients with STS.
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Objective To investigate the morphologic features of Bachmann bundle (BB) and its vascular supply on dual-source CT coronary angiography(DSCTCA) in healthy volunteers and patients with coronary artery lesion (CAL). Methods Clinical histories, electrocardiograms (ECGs), and images of DSCTCA of 106 patients ( CAL group) and 100 healthy volunteers ( Control group) were reviewed. All 106 patients underwent conventional coronary angiography ( CCA ). The Gensini scoring system was used to assess the results of CCA. The patients were divided into three groups according to their Gensini scores. The length, width and superoinferior diameter, CT value, and vascular supply of BB were studied. Rank sum test for continuous variables and Chi-square test for categorical variables were used in statistical analysis.Results ( 1 ) BB visualization rate of control group was higher than CAL group [86.0% (86/100) vs 51.9%(55/106), x2 = 27.726, P ＜ 0.01]. The higher the Gensini score of CAL subgroup, the lower the visualization rate of its BB [80.0% ( 28/35 ), 55.6% ( 20/36 ), 20.0% ( 7/35 ), x2 = 25.530, P ＜ 0.01].(2)The median of measurements of length,width and superoinferior diameter of control and CAL group were 13.0 vs 13.8,5.0 vs 5.2 and 5.9 vs 6.2 mm, respectively ( P ＞ 0.05 ). (3) The CT value of the BB region in control group( median :42.6 HU ) was higher than that of CAL group( median: 13.0 HU) ( Z = - 7.061, P ＜0.01). The CT values of BB regions in patients with nonvisualized BB (median: -16.0 HU) were lower. The CT values of the BB regions in CAL group were negatively-correlated with Gensini scores( median:19.0) (r = -0.553, P ＜0.01 ). (4)The blood supply of BB and BB region was provided by right sinuatrial node artery ( SNA, 58.7%, 121/206 ), left SNA ( 35.9%, 74/206 ) or both SNAs ( 5.3%, 11/206 ).Conclusions DSCTCA could can show the anatomical characteristics of BB and its arterial supply. The serious the degree of CAL , the lower the BB display rate, and the higher the abnormal ECG incidence,which indicate that the occurrence of BB lesions is probably related to ischemia.
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Objective To systematically assess the diagnostic performance of CTA for lower extremity peripheral arterial disease (PAD) using a Meta analysis method. Methods Studies were located through electronic searching of the PubMed, EBSCO, Springer, Ovid, CNKI, Cochrane library (from the date of establishment of the databases to October 2009 ). Bibliographies of the retrieved articles were also checked. All the studies concerning the diagnosis of PAD using CTA had been searched and reviewed, and the studies with the DSA as the gold standard were adopted as eligible. Subsequently, the characteristics of the included articles were appraised and extracted. Data on accuracy of included studies were extracted for further heterogeneity exploring, statistical pooling and SROC ( summary receiver operating characteristics)analyzing using the Meta Disc 1.4 software. Results Totally 24 studies met the inclusion criteria with a total of 1096 patients. The heterogeneity was found in these studies. The pooled accuracy indicators like sensitivity, specificity, and diagnostic odds ratio (DOR) were 0.95 ( 95% CI:0.94-0.95 ), 0.96 ( 95% CI:0.95-0.96), and 471.13 (95% CI:242. 92-913.71 ), respectively. The area under of SROC curve was 0.9888 and the Q index was 0.9555. Subgroup analysis demonstrated significant difference on diagnostic performance for various CT slices (P ＜ 0.05 ). Conclusion CTA can be regarded as an effective and feasible method for PAD diagnosis and screening, based on the results of this systematic review. However,more rigorous evaluations of CTA in patients with critical limb ischemia are needed.
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Objective To study the CT findings of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma. Methods The CT examinations of 12 patients with pathologically proven pulmonary MALT lymphoma were reviewed retrospectively. Evaluated imaging findings included number, distribution,shape, attenuation and other associated findings of each lesion were evaluated. Results Thirty-two pulmonary lesions, including consolidations, masses, nodules and lesions with ground glass attenuation,were identified in 12 patients. Multiple lesions were founded in 10 of 12 patients and solitary lesion in 2 patients. Multiple lesions found in one lung in 2 patients, and multiple lesions found in both lungs in 8 patients. Ten cases demonstrated 21 consolidation lesions with air bronchogram, and one of the ten cases demonstrated two lesions with airway dilatation. Three cases demonstrated 5 masses or nodular lesions, 3 of these 5 lesions showed air bronchogram. Two cases demonstrated 6 ground glass attenuation lesions. One case showed mediastinal and hilar lymphadenopathy. Conclusion Pulmonary MALT lymphoma usually appears as multiple bilateral consolidations, masses, nodules with air bronchogram or lesions with groundglass attenuation at CT imaging. The imaging findings described above and with an indolent clinical course may suggest the diagnosis of pulmonary MALT lymphoma.
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Objective To quantitatively analyze the image quality of megavoltage cone-beam CT (MVCBCT) under different scanning conditions to provide reference in clinical applications. Methods Si-emens ONCOR linear accelerator with MVCBCT was used to scan the phantom under different conditions. The image quality was evaluated in terms of image noise, uniformity, spatial resolution, contrast resolution, the number of Monitor Units(MUs) used in imaging,and the size of the reconstruction matrix. The comparison of the image quality between MVCBCT and conventional simulator CT was also analyzed. Results The image noise was decreased with the increase of the number of MUs. The uniformity index showed that the system u-niformity was weakly dependent on MU numbers or the size of the reconstruction matrix. Except for the ima-ges with 5 MUs,all other images had the spatial resolution of 0.4 lp/mm with a reconstruction matrix of 256 ×256. Better low contrast resolution was achieved by using more MUs. For typical pelvis and head-and-neck patients,the imaging dose at the center was 0.8 cGy/MU and 0.7 cGy/MU, respectively,and the maxi-mum dose was about 1.2 cGy/MU. For typical abdomen patients,the image maximum dose and center dose was 1.3 cGy/MU and 0.7 cGy/MU,respectively. Conclusions The image quality of MVCBCT is inferior to the conventional kilo-voltage CT. However,with the optimization of the parameters in imaging,we can a-chieve sufficient image contrast in the bone,air and some soft-tissue structures with low imaging dose to pa-tients. Such images can be used for IGRT.
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Objective To study the clinicopathological characteristics of hepatobiliary cystic neoplasms(cystadenoma and cystadenocarcinoma)in order to improve its diagnostic and therapeutic accuracy.Methods A retrospective analysis was done on the clinical materials of 9 cases of cystic biliary tumors hospitalized in the People's Hospital of Rizhao City from May 1993 to May 2007.All cases were confirmed by operation and pathologic biopsy.Results Six cases were biliary cystadenoma with muhilocular cyst.The other three cases were biliary cystadenocarcinoma,two with single cyst and one with multilocular cyst.Of the three cystadenocarcinorna,two cases had mural nodules and one case had papillary excrescences and cystic wall thickening.Irregular thickening of internal sept.was shown in the multilocular cyst cases.Two had calcification.Enhancement of the wall.internal septa and nlasses were seen in all the malignant tumors on CT scans. Metastatic lymph node was found in one cage. Conclusion There were no special clinical characteristics in difierentiation between hiliary cystadenoma and cystadenocarcinoma. Single cyst, mural nodules and papillary excrescences,irregular thickening of cystic wall and internal septa,coarse calcification and metastatic lymph node increase the likelihood of the diagnosis of the malignant tumors.But the diagnostic differentiation between cystadenoma and cystadenocarcinoma depends on pathology.
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We aimed to compare the CT findings of nontuberculous mycobacterial pulmonary diseases caused by Mycobacterium avium-intracellulare complex (MAC) and Mycobacterium abscessus. Two chest radiologists analyzed retrospectively the thin-section CT findings of 51 patients with MAC and 36 with M. abscessus infection in terms of patterns and forms of lung lesions. No significant difference was found between MAC and M. abscessus infection in the presence of small nodules, tree-in-bud pattern, and bronchiectasis. However, lobar volume decrease (p=0.001), nodule (p=0.018), airspace consolidation (p=0.047) and thin-walled cavity (p=0.009) were more frequently observed in MAC infection. The upper lobe cavitary form was more frequent in the MAC (19 of 51 patients, 37%) group than M. abscessus (5 of 36, 14%) (p=0.029), whereas the nodular bronchiectatic form was more frequent in the M. abscessus group ([29 of 36, 81%] vs. [27 of 51, 53%] in MAC) (p=0.012). In conclusion, there is considerable overlap in common CT findings of MAC and M. abscessus pulmonary infection; however, lobar volume loss, nodule, airspace consolidation, and thin-walled cavity are more frequently seen in MAC than M. abscessus infection.