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Objective To explore the feasibility of electrocardiogram (ECG)-gated coronary artery calcium scoring (CACS) CT scan for attenuation correction of 9gTcm-methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging (MPI) based on a hybrid SPECT/CT scanner.Methods From January 2017 to October 2017,a total of 110 subjects (61 males,49 females;age:(68.4±9.4) years) underwent ECG-gated MPI,ECG-gated CACS CT scan and conventional non-gated cardiac CT scan.The gated and non-gated CT scans were used for attenuation correction of MPI separately,then the relative percentage of radioactive distribution of left ventricular (LV) walls (anterior,lateral,inferior,septal and apex) based on different correction methods were compared,and the influences of CACS CT scan and conventional CT scan on visual assessment for myocardial ischemia were also compared.Paired t test and Kappa test were used to analyze the data.Results The relative radioactive distribution percentages of all LV walls in CACS CT corrected MPI and those in conventional CT corrected MPI were not statistically significant (t values:from-0.782 to 0.456,all P＞0.05).The weighted Kappa values of LV anterior,lateral,inferior,septal and apex from 2 types of corrected images between 2 physicians were 0.864 (95％ CI:0.749-0.979),0.795 (95％ CI:0.717-0.874),0.494(95％ CI:0.076-0.912),0.724(95％ CI:0.321-1.000),0.873 (95％ CI:0.764-0.982),respectively (all P＜0.01).Conclusion ECG-gated CACS CT scan can be used for attenuation correction of 99Tcm-MIBI MPI based on a hybrid SPECT/CT scanner.
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ObjectiveTo explore an individualized abdominal scan protocol with a 64-slice CT scanner.MethodsFrom Sep.2010 to Nov.2010,one hundred consecutive patients,who underwent twice non-contrast-enhanced abdominal CT scans within 3 months,were enrolled in this study.For each patient,the tube current of 274 eff.mAs and 207 eff.mAs were applied respectively in the first and second abdominal scan.The imaging qualities of the two scans were evaluated retrospectively by 3 reviewers.All the individual variants,including height,weight,body mass index (BMI),the maximum transverse diameter,the anteroposterior diameter and the average maximum diameter of abdomen were recorded.A five-point scale was used for grading the image noise of eight organs,including abdominal aorta,portal vein,liver,spleen,gallbladder,pancreas,renal cortex and renal medulla. Diagnostic acceptability of CT images at three anatomic levels,including porta bepatis,pancreas and the upper pole of renal,was also evaluated by using a five-point scale.The noise value of abdominal aorta was defined as the standard deviation (SD) of CT values of aorta at the level of porta hepatis.Scatter diagram and Pearson correlation analysis were used for evaluating the linear relationship between the individual variants and the noise value of abdominal aorta,and multivariate linear regression analysis was used for evaluating the relevance between the individual variants and the noise value of aorta.ResultsIn this patients group,the average height was ( 164.6 ± 7.5 ) cm,the average weight was (64.3 ± 11.0) kg,the BMI was (23.7 ±3.3) kg/m2,the maximum transverse diameter of abdomen was(29.8 ± 2.3 )cm,the anteroposterior diameter of abdomen was (23.1 ± 2.9) cm,and the average maximum diameter of abdomen was ( 26.5 ± 2.5 ) cm.Pearson correlation analysis showed significant positive linear correlation between the noise value of abdominal aorta( 1 1.7 ± 3.0)and patients' weight ( r =0.744,P ＜ 0.01 ),BMI ( r =0.689,P ＜ 0.01 ),the maximum transverse diameter ( r =0.813,P ＜ 0.01 ),the anteroposterior diameter ( r =0.781,P ＜ 0.01 ),the average maximum diameter of the abdomen ( r =0.789,P ＜ 0.01 ) ; however,there was no positive linear correlation between the noise value of abdominal aorta and patients' height ( r =0.292,P ＜ 0.01 ). The maximum transverse diameter of abdomen is greatly related to the noise value of abdominal aorta (Beta =0.487,P ＜0.01 ).For the patient with the maximum transverse diameter of abdomen ranging from 27 to 32 cm,diagnostic acceptability of CT images at the anatomic level of porta hepatis showed statistical significance compared with the patient with the maximal transverse diameter of the abdomen greater than 32 cm or less than 27 cm (P ＜ 0.05 ).Conclusion The tube current of 207 eft.mAs is reasonable for abdominal CT scan for patients with the maximal transverse diameter of the abdomen ranging from 27 to 32 cm.
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Objective To investigate MSCT findings of CT features of basal cell adenomas in the parotid gland, and improve its diagnostic value.Methods 12 cases plain and enhanced CT findings of basal cell adenomas in the parotid gland were retrospectively analyzed for their position, numbers, size, shape, edge, density and enhancement features,which were all verified pathologically after surgery.Results (1) There were 4 males and 8 females, of which 7 females were in the age of 50 ～59; (2) There were 14 lesions in 12 cases,11 cases were single and 1 case was unilateral multiple ( 3 lesions) ; (3) 12 lesions were situated in superficial lobe of the parotid gland, and 2 lesions were situated between superficial lobe and deep lobe of the parotid gland; (4) The maximum diameter of all lesions were <3cm,of which 5 lesions were < 1em,and 6 lesions were 1 ～2cm,and 3 lesions were >2cm; (5) The boundary of all lesions were clear;The edge of 13 lesions were smooth and 1lesion was aot smooth; (6) The density of 3 lesions were uniform, of which the diameter of 2 lesions were < 1 cm.There were 4 lesions showed a regular cystic zone in the center,and 7 lesions showed a irregular cystic zone in the center;The area of cystic zone were >50%in 5 lesions; (7)All of 14 lesions were enhanced obviously in enhanced CT scans.Increase of CT values were ≥40HU.Conclusion Single less lesions situated in superficial lobe of parotid gland, with clear boundary, smooth edge, cystic zone in the lesions, and enhanced obviously were the CT features of basal cell adenomas.Recognizing this CT features combined with the patients' gender and age could make for a definite diagnosis.
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Objective To investigate CT features of similar Hexheimer's reaction during initial treatment of active pulmonary tuberculosis. Methods The similar Hexheimer's reaction in 44 patients diagnosed by clinic and follow-up CT scans were retrospectively reviewed by three radiologists. Results During initial treatment of active pulmonary tuberculosis, development of radiographic progression were observed in 57 foci, including 28 pulmonary lesions increased at the site of their original lesion or new opacities elsewhere, ipsilateral or contralateral to the original lesion or both, 10 lesions related to the pleura (pleural effusion, pleural tuberculoma), 15 lymphadeneetasis, 3 thymus reactions, and 1 cardiac pericardium thickening, respectively. These reactions appeared from the 20 days to 3. 5 months, then with continuation of the initial chemotherapy for 1.0-3.0 months, the radiographic response was excellent with the areas of progression and the original lesions demonstrating resolution or improvement. Conclusion The CT appearances of similar Hexheimer's reaction during initial treatment of active tuberculosis are specific to a certainty.
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Objective To compare various CT signs of pancreatic carcinoma (PC) and inflammatory pancreatic mass (IPM), and to study the diagnostic value of these signs for distinguishing two diseases. Methods Eigty-five patients with PC and IPM were proved by surgery, fine needle aspiration or other comprehensive methods. These patients underwent non-enhanced and enhanced CT scans. CT findings were analyzed retrospectively. The occurrance rates of various CT signs in these two diseases were analyzed with Fisher test and were compared with the corresponding clinical and operational results as welL Results Among the 85 patients, 66 patients were proved to have PC, and 19 were proved to have IPM. In PC group,58 were corerectly diagnosed with CT, 3 (4. 5% ) were misdiagnosed, and 5 (7.6%) were omitted. In IPM group, 9 were correctly diagnosed with CT and 10 (52. 6% ) were misdiagnosed. The CT findings were as follows: (1) Pancreatic mass with liver metastases, lymph node metastases, encased celiac arteries, and cancer emboli in portal veins just occurred in PC group. (2) The occurrence rates of mass over 3 cm in diameter, clear boundary, low-density area within the mass, pseudocysts, peripancreatie infiltration, ascites, and slight and moderate pancreatic-bile duct dilation in PC group were 90. 91% (60/66), 15.15% ( 10/66), 54. 55% ( 36/66 ), 10. 61% ( 7/66 ), 4. 55% ( 3/66 ), 22. 73% ( 15/66 ), 24. 24% ( 16/66 ), 45.45% (30/66), and 27. 27% (18/66) respectively, the occurrence rates in IPM group were 94. 74% ( 18/19), 15.79% ( 3/19 ), 52. 63% ( 10/19 ), 15.79% ( 3/19 ), 15. 79% ( 3/19 ), 21.05% (4/19), 31.58% (6/19) ,21.05% (4/19), and 5.26% (1/19) respectively. There was no statistical difference for these CT findings between two groups(P >0. 05). (3) Pancreatic head mass with atrophy of pancreatic body and tail, mass calcification, pancreatic duct-penetrating sign, pancreatic head mass with hypertrophy of pancreatic body and tail, biliary stones with inflammation , and thickening of pre-kidney fascia in PC group were 48.48% ( 32/66 ), 3.03% ( 2/66 ), 1.52% ( 1/66 ), 10. 61% ( 7/66 ), 6. 06% ( 4/66 ) and 3.03% (2/66) respectively, the occurrence rates of those in IPM group were 5. 26% (1/19),47.37% (9/19), 15.79% ( 3/19 ), 84. 21% ( 16/19 ), 36. 84% ( 7/19 ) and 21.05% ( 4/19 ) respectively. There was statistical difference for these CT findings between two groups ( P < 0. 05 ) . Conclusion Accurate evaluation of various CT signs in PC and IPM is of great importance in the diagnosis of the two diseases.