Virtual monochromatic images (VMI) that reconstructed on dual-energy computed tomography (DECT) have further application prospects in radiotherapy, and there is still a lack of clinical dose verification. In this study, GE Revolution CT scanner was used to perform conventional imaging and gemstone spectral imaging on the simulated head and body phantom. The CT images were imported to radiotherapy treatment planning system (TPS), and the same treatment plans were transplanted to compare the CT value and the dose distribution. The results show that the VMI can be imported into TPS for CT value-relative electron density conversion and dose calculation. Compared to conventional images, the VMI varies from 70 to 140 keV, has little difference in dose distribution of 6 MV photon treatment plan.
Electrons ; Phantoms, Imaging ; Tomography Scanners, X-Ray Computed ; Tomography, X-Ray Computed

To explore the effect and experience of quality control circle(QCC) in quality control testing for CT scanners, the quality control circle group was set up to determine the theme of quality control circle, and the causes of the failure of the quality control testing for CT scanners were analyzed, then the corresponding corrective measures were formulated and carried out. After the activity of the quality control circle, the qualified rate of CT quality control testing in the second level 2nd Class of public hospitals and private hospitals in Shanghai increased from 40.6% to 86.1%. By conducting quality control circle activities, we found the problems existed in the quality control testing of CT scanners, and put forward many corresponding corrective measures and solutions which finally improved the qualified rate of CT quality control testing.
China ; Quality Control ; Tomography Scanners, X-Ray Computed ; standards ; Tomography, X-Ray Computed

OBJECTIVE: To determine imaging features that may separate adamantinomatous and papillary variants of craniopharyngiomas given that tumors with adamantinomatous signature features are associated with higher recurrence rates, morbidity, and mortality. We specifically reviewed calcification on CT, T1 bright signal intensity, and cystic change on T2 weighted images for differentiating these two types. METHODS: We retrospectively reviewed the MRI and CT studies in 38 consecutive patients with pathologically proven craniopharyngiomas between January 2004 and February 2014 for the presence of calcification on CT scans, bright signal intensity on T1 weighted images, and cystic change on T2 weighted images. RESULTS: Of the 38 craniopharyngiomas, 30 were adamantinomatous type and 8 were papillary type. On CT scans, calcification was present in 25 of 38 tumors. All calcified tumors were adamantinomatous type. Twenty four of 38 tumors had bright signal intensity on T1 weighted images. Of these 24 tumors, 22 (91.7%) were adamantinomatous and 2 were papillary type. Cystic change on T2 weighted images was noted in 37 of 38 tumors; only 1 tumor with papillary type did not show cystic change. CONCLUSION: T1 bright signal intensity and calcification on CT scans uniformly favor the adamantinomatous type over papillary type of craniopharyngioma in children. However, these findings are more variable in adults where calcification and T1 bright signal intensity occur in 70.6% and 58.8% respectively of adult adamantinomatous types of craniopharyngiomas.
Adult ; Child ; Craniopharyngioma* ; Humans ; Magnetic Resonance Imaging ; Mortality ; Recurrence ; Retrospective Studies ; Tomography Scanners, X-Ray Computed ; Tomography, X-Ray Computed

Histiocytosis, Langerhans-Cell ; diagnosis ; genetics ; Humans ; MAP Kinase Kinase 1 ; genetics ; Male ; Mutation ; Proto-Oncogene Proteins B-raf ; genetics ; Smoking Cessation ; Tomography Scanners, X-Ray Computed

OBJECTIVES: This work was a comparative study that aimed to find a proper method for accurately segmenting persistent ground glass nodules (GGN) in thin-section computed tomography (CT) images after detecting them. METHODS: To do this, we first applied five types of semi-automatic segmentation methods (i.e., level-set-based active contour model, localized region-based active contour model, seeded region growing, K-means clustering, and fuzzy C-means clustering) to preprocessed GGN images, respectively. Then, to measure the similarities, we calculated the Dice coefficient of the segmented area using each semiautomatic method with the result of the manually segmented area by two radiologists. RESULTS: Comparison experiments were performed using 40 persistent GGNs. In our experiment, the mean Dice coefficient for each semiautomatic segmentation tool with manually segmented area was 0.808 for the level-set-based active contour model, 0.8001 for the localized region-based active contour model, 0.629 for seeded region growing, 0.7953 for K-means clustering, and 0.7999 for fuzzy C-means clustering, respectively. CONCLUSIONS: The level-set-based active contour model algorithm showed the best performance, which was most similar to the result of manual segmentation by two radiologists. From the differentiation between the normal parenchyma and the nodule, it was also the most efficient. Effective segmentation methods will be essential for the development of computer-aided diagnosis systems for more accurate early diagnosis and prognosis of lung cancer in thin-section CT images.
Diagnosis ; Diagnosis, Computer-Assisted ; Early Diagnosis ; Glass* ; Image Processing, Computer-Assisted ; Lung ; Lung Neoplasms ; Methods* ; Prognosis ; Solitary Pulmonary Nodule ; Tomography Scanners, X-Ray Computed ; Tomography, X-Ray Computed*

OBJECTIVETo investigate the protective effects of a Chinese herbal formula, taikong yangxin prescription (TKYXP) against bone deterioration in a hindlimb unloaded (tail-suspension) rat model.

METHODSThirty-two male Sprague-Dawley rats were divided into 4 groups: tail-suspension group fed with 2.5 g•kg(-1)•day(-1) of TKYXP extract (high dose), tail-suspension group fed with 1.25 g•kg(-1)•day(-1) (low dose), tail-suspended group treated with water placebo (placebo control group) and non tail-suspended group. The effects of TKYXP on bone were assessed using peripheral quantitative computed tomography (pQCT), microcomputerized tomography (micro-CT) and three-point bending biomechanical test on the femur in vivo.

RESULTSTKYXP had a significant protective effect against bone loss induced by tail-suspension on day 28, as shown in the reduction in bone mineral density (BMD) loss, preservation of bone micro-architecture and biomechanical strength. The administration ofhigh dose TKYXP could significantly reduce the total BMD loss by 4.8% and 8.0% at the femur and tibia regions, respectively, compared with the placebo control group (P<0.01) on day 28. Its bone protective effect on the femur was further substantiated by the increases of the trabecular BMD (by 6.6%), bone volume fraction (by 20.9%), trabecular number (by 9.5%) and thickness (by 11.9%) as compared with the placebo control group.

CONCLUSIONTKYXP may protect the bone under weightless influence from gradual structural deterioration in the tail-suspension model.

Animals ; Biomechanical Phenomena ; drug effects ; Bone Density ; drug effects ; Bone and Bones ; diagnostic imaging ; drug effects ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Femur ; Male ; Rats ; Rats, Sprague-Dawley ; Tibia ; Tomography Scanners, X-Ray Computed ; Weightlessness ; X-Ray Microtomography

OBJECTIVE: To report the possible malignant transformation of primary sinonasal ameloblastoma into sinonasal ameloblastic carcinoma.

METHODS
Design: Case Report

Setting: Tertiary Public University Hospital

Patient: One

RESULT: A 50-year-old woman with a previous diagnosis of sinonasal ameloblastoma reported recurrence of symptoms of right-sided nasal obstruction and epistaxis two years after endoscopic sinus surgery. Clinical examination, CT scans and subsequent total maxillectomy with orbital exenteration revealed a left intranasal mass with maxillary, ethmoid and orbital floor extension and pulmonary and hepatic metastases.  Histopathologic findings of palisading columnar epithelium with reverse polarity with malignant features were consistent with ameloblastic carcinoma. Despite subsequent cycles of chemotherapy, the patient died two years after surgery. To the best of our knowledge, there have been no published reports of a primary sinonasal ameloblastoma with malignant transformation in the English literature.

CONCLUSION: Ameloblastic carcinoma is a rare neoplasm which may arise de novo or from malignant transformation of an ameloblastoma. Because ameloblastoma is commonly encountered in our setting, clinicians should be aware of this possibility and closely follow their patients accordingly.

Human ; Female ; Middle Aged ; Carcinoma ; Ameloblastoma ; neoplasm ; Tomography Scanners, X-Ray Computed

This young adult man presented to ENT clinic with a complaint of left facial weakness and persistent left retro-auricular pain. High resolution CT of the mastoids was performed following clinical assessment. In this case, there is extensive sclerotic bony expansion with a ground-glass appearance involving the left zygoma, sphenoid and petrous temporal bone. The bony expansion is centred on the medullary bone and has an abrupt zonal transition (Figure 1). The bone involvement encompasses almost complete bony stenosis of the left external auditory meatus down to 1-2mm with consequential fluid in the external auditory canal and middle ears (Figure 2). The bony expansion involves both the tympanic and mastoid segments of the facial canal which are stenosed. The ossicular chain remains intact. The left mastoid air cells are under-pneumatised and completely occupied by fluid.
Human ; Male ; Young Adult ; Facial Paralysis ; Mastoiditis ; Tomography Scanners, X-Ray Computed

The primary objectives of this retrospective study were to determine the cancer detection rate of PET/CT in this institution and to compare the sensitivity and specificity of low-dose PET/CT to that of PET with high-dose CT. Three hundred sixty-seven (367) patients with unremarkable history, family history of cancer, symptoms or abnormal diagnostic tests, and with follow-up studies were included. PET/CT and histopathology results were noted. Individual and overall cancer detection rates, as well as sensitivities and specificities for each subgroup, were computed. Overall cancer detection rates was 22.3%, for low-dose PET/CT was 17.9%, and for high-dose PET/CT was 24.4%. Using the chi squared test of independence, no statistically significant difference was found between the calculated sensitivities and specificities of low- and high-dose PET/CT across all patient groups. Using the Mantel-Haeaszel chi squared test, a statistically significant association between the subindication for malignancy screening and PET/CT results was established with subindications pointing to a higher suspicion for malignancy having a higher probability of detecting a malignancy. Therefore, high-dose PET/CT as a screening test would be advised for high-risk patients and low-dose PET/CT would be recommended because of its similar accuracy but lower radiation exposure.

Human ; Male ; Female ; Aged 80 and over ; Aged ; Middle Aged ; Adult ; Young Adult ; Adolescent ; Child ; Positron-Emission Tomography ; Tomography Scanners, X-Ray Computed ; neoplasms-diagnosis ; False Positive Reactions ; False Negative Reactions

Transcatheter closure of atrial septal defects has become a popular procedure. The availability of a preprocedural imaging study is crucial for a safe and successful closure. Both the anatomy and morphology of the defect should be precisely evaluated before the procedure. Three-dimensional (3D) echocardiography and cardiac computed tomography are helpful for understanding the morphology of a defect, which is important because different defect morphologies could variously impact the results. During the procedure, real-time 3D echocardiography can be used to guide an accurate closure. The safety and efficiency of transcatheter closures of atrial septal defects could be improved through the use of detailed imaging studies.
Echocardiography ; Echocardiography, Three-Dimensional ; Heart Septal Defects, Atrial* ; Tomography Scanners, X-Ray Computed ; Vascular Access Devices