[Clinical Application of "Three-Low" Technique Combined with Artificial Intelligence Iterative Reconstruction Algorithm in Aortic CT Angiography].

Objective: To explore the application value of the "three-low" technique (low radiation dose, low contrast agent dosage and low contrast agent flow rate) combined with artificial intelligence iterative reconstruction (AIIR) in aortic CT angiography (CTA). Methods: A total of 33 patients who underwent aortic CTA were prospectively enrolled. Based on the time of their follow-up examinations, the imaging data were divided into Group A and Group B, with Group A being the control group (100 kV, 0.8 mL/kg, 5 mL/s) and Group B being the "three-low" technique group (70 kV, 0.5 mL/kg, 3 mL/s). In group A, the images were reconstructed by Karl iterative algorithm. Group B was divided into B1 and B2 subgroups, with their images being reconstructed by Karl iterative algorithm and AIIR, respectively. The CT and SD values of the ascending aorta, descending aorta, abdominal aorta, left common iliac artery and right common iliac artery were measured, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The subjective scoring of image quality was performed. The radiation dose parameters were documented. Results: Differences in the CT value, SD value, SNR and CNR of the three groups were statistically significant ( P<0.001). The CT value, SNR and CNR of group B2 were significantly higher than those of group B1, while the SD value of group B2 was significantly lower than that of group B1 ( P<0.017). There was no significant difference between the CT values of group A and those of group B2 ( P>0.017). The SD values, SNR and CNR in group B2 were better than those in group A ( P>0.017). There was significant difference in the subjective evaluation of image quality among the three groups ( P<0.05), but there was no significant difference between group A and group B2 ( P>0.017). The radiation dose and contrast medium dosage in group B decreased 84.14% and 37.08%, respectively, compared with those of group A. Conclusion: With the "three-low" technique combined with AIIR algorithm, the image quality of aortic CTA obtained is comparable to that of conventional dose scanning, while the radiation dose, contrast agent dosage and contrast agent flow rate of patients are significantly reduced.

Appendicolith appendicitis: should we be operating sooner? A retrospective cohort study.

INTRODUCTION: Evidence suggests that delaying an appendicectomy for up to 24 hours does not increase the risk of complicated appendicitis. Appendicoliths are a risk factor for perforation. No study has explored the temporal relationship between appendicolith presence and time to perforation. In this retrospective cohort study, we hypothesise that the presence of an appendicolith confirmed on preoperative computerised tomography scan (pCT) leads to a shorter time to complicated appendicitis. METHODS: We undertook a retrospective single-centre study of patients admitted between 2018 and 2020. Inclusion criteria included: age ≥18 years, appendicitis confirmed on histopathology following an operation and a pCT scan. Complicated appendicitis was defined intraoperatively as an appendicular abscess, gangrenous or perforated appendix. RESULTS: Some 310 patients were included in the study. Forty-five per cent presented with complicated appendicitis (n = 138). Appendicoliths were present in 79 (25.5%) patients. Multivariate logistic regression identified an appendicolith as a significant risk factor for perforation (odds ratio 3.50, 95% confidence interval [CI] 1.16-10.59; p = 0.027). Within the first 12 hours of admission, patients with an appendicolith accounted for a significantly greater proportion of those with complicated appendicitis intraoperatively compared with those without (56.7% vs 43.3%, respectively; p = 0.003). Within 12 hours of admission, those with an appendicolith were 2.05 times more likely to suffer from complicated appendicitis than those without (95% CI 1.28-3.29). CONCLUSIONS: Patients with an appendicolith appendicitis should be considered for an early appendicectomy. Future large-scale multicentre prospective studies are required to explore this further, perhaps informing future guidelines.

Risk stratification of 2- to 5-cm gastric stromal tumors based on clinical and computed tomography manifestations.

OBJECTIVE: To evaluate the risk stratification of 2- to 5-cm gastric stromal tumors (GSTs) by analyzing their clinical and computed tomography (CT) manifestations with the goal of providing imaging evidence for rational selection of surgical methods. METHODS: This study involved 223 patients with pathologically diagnosed GSTs of 2 to 5 cm in diameter. According to the pathological results and malignant risk category, the patients were divided into a low-risk biological behavior group (very low and low risk) and high-risk biological behavior group (intermediate and high risk). The clinical and CT manifestations were compared between the groups. The chi-square test was used to analyze categorical variables, and the independent-samples t test was used to analyze continuous variables. Multivariate logistic regression and receiver operating characteristic curve analysis were performed for statistically significant variables. RESULTS: The tumor contour, necrosis, surface ulceration, and long diameter were significantly different between the low-risk group and the high-risk group (P < 0.05). Multivariate logistic regression analysis showed that the tumor contour and long diameter were independent risk factors. The area under the curve was 0.82, and the accuracy, sensitivity, and specificity were 0.78, 77.4 %, and 79.7 %, respectively. CONCLUSIONS: The risk associated with 2- to 5-cm GSTs can be preoperatively predicted in an indirect manner through analysis of clinical and CT manifestations, and this model has high diagnostic value.

Treatment of Differentiated Thyroid Cancer and Recurrent Laryngeal Nerve Function with 131 Iodine Based on Positron Emission Tomography/Computed Tomography Image Segmentation Algorithm.

BACKGROUND: Based on the positron emission tomography (PET) computed tomography (CT) image segmentation algorithm, this article explores the application of PET/CT in the recurrence and metastasis of thyroid cancer after differentiated thyroid cancer (DTC). METHODS: In this study, 132 patients with DTC combined with 131I treatment underwent PET/CT whole-body imaging and 131I whole-body scan (131I-WBS), and the serum thyroglobulin (Tg) level was measured at the same time. RESULTS: Among 54 Tg-positive patients, 49 were positive for 131I-WBS and 32 were positive for PET/CT imaging. Of the 15 Tg-negative patients, 131I-WBS and PET/CT imaging were negative. Three patients with 131I-WBS suggesting residual thyroid tumors were all positive in PET/CT examinations; 7 patients with 131I-WBS suggesting lymph node metastasis were all positive in PET/CT examinations, and in 131I, PET/CT imaging in WBS-negative patients showed 6 lung metastases and 3 bone metastases. CONCLUSIONS: PET/CT and 131I scans are similar in the diagnosis of residual thyroid and lymph node metastasis, but PET/CT has more advantages than does the 131I scan in the diagnosis of bone metastasis and lung metastasis. PET/CT can still find other benign and malignant lesions, which is of great value in the restaging of DTC. The imaging effect of WBS lung lesions in older patients is not good. The presence of stripe, calcification, and patch shadows in the lungs is not conducive to the imaging of WBS lung metastases. Lung strips and calcification affect the WBS lung main factors for imaging of metastases.

[CT manifestations of squamous papilloma in adult nose, pharynx and throat].

Objective:Analyze the CT imaging characteristics of squamous papilloma in adult nose pharynx and throat to improve the diagnostic accuracy.Method:Retrospectively analyze clinical data and CT image data in 24 cases of squamous papilloma in adult nose, pharynx and throat, which were confirmed by endoscopic surgical pathology, and summarize CT imaging features including location, shape, enhancement, and its relationship with adjacent tissue, and so on.Result:The patients with squamous papilloma were characterized by diffusing thickening and uniform swelling of the mucosa of nose, pharynx and throat, narrowing near the cavity gap, swallow gap existing, and enhancement scanning manifested mild-to-moderate gradually uniform reinforcement (enhanced CT value with 20-45 HU), when accompanied with malignancy, apparent arterial enhancement (enhanced CT value >45 HU) was observed.Conclusion:The adult patients with papilloma of nose, pharynx and throat has special features in CT image, which can provide more information for clinical diagnosis.

[Computer-assisted anatomical evaluation of the nasal sinuses in 2-3 years old children].

Objective:To analyze the anatomical and developmental characteristics of nasal sinuses in 2-3 years old children.Method:Coronal CT scans of 62 cases (2-3 years old children) were studied with the imaging station. The gasification conditions of the sinuses were identified and measured.Result:The mean of the transverse and vertical diameters for the left side of the maxillary sinuse was (17.51±2.92)mm and (16.63±3.46)mm. Those for the right side were (17.28±2.51)mm and (17.24±3.72)mm. The mean for the left side of the anterior ethmoid sinus were (5.06±1.18)mm and (13.61±2.49)mm. Those for its right side were (5.00±1.45)mm and (13.64±2.30)mm. The mean for the left side of the posterior ethmoid sinus were (7.94±1.72)mm and (12.80±1.78)mm. Those for the right side were (7.88±1.85)mm and (12.64±.96)mm.96.77%(120 sides) of the sphenoid sinuses were developed. The mean for the left side of the sphenoid sinus were (7.38±3.11)mm and (8.67±3.14)mm. Those for the right side were (7.48±2.70)mm and (8.63±2.42)mm. 30.65% (38 sides) of the frontal sinuses were developed.Conclusion:The all nasal sinuses in 2-3 years old children have been already developed. The pneumatization of the frontal sinus was defined in some babies. It can help radiologist make correct diagnosis of paranasal sinuses in children.

[The facial nerve study of multi-slice spiral computed tomography in congenital abnormality of external and middle ear].

Objective:Images of temporal bone are obtained on Siemens 64 slices spiral CT scanner with high resolution scanning to describe the course of facial nerve for better preoperative evaluation of CAEMA.Method:To describe the course of facial nerve on rectangular coordinate system from three silce on HRCT, 29 patients(35 ears) are enrolled in our study in ENT department from November 2005 to March 2007 in the second affiliated hospital of sun yan sen university, who are all diagnosed not acquired deformity but CAEME, associated with no congenital deformity syndromes and no middle ear or mastoid operations before. Patients with bilateral ears deformity are 6, and unilateral ears deformity are 23 (13 right and 10 left) in the study group. The control group is the normal ears of unilateral ear deformity.Result:In the study group, the shortest distance from FN tympanic segment to oval window is shorter than that of the normal group (P< 0.05). In CAEME of unilateral ears the FN mastoid segment displaces anteriorly about 2.7 mm, and in CAEME of bilateral ears displaces 3.0mm, compared with the normal ears (P< 0.05). The deformity degree of auricle has correlations with anteriorly displacement of facial nerve mastoid segment (P< 0.05).Conclusion:The FN mastoid segment is anteriorly displacement in both bilateral and unilateral ear deformity. The deformity degree of auricle has correlations with anteriorly displacement of facial nerve mastoid segment. The lateral displacement of facial nerve doesn't occur usually in CAEME. The shortest distance between oval window and tympanic segment of FN become shorter than normal ears.

Value of 3-dimensional CT virtual anatomy imaging in complex foreign body retrieval from soft tissues.

OBJECTIVE: To investigate the value of 3-dimensional (3D) CT virtual anatomy imaging (VAI) in the complex foreign body (FB) retrieval of the soft tissues. MATERIALS AND METHODS: Four hundred and seventy-five patients with radiopaque FB(s) diagnosed by radiograph underwent contrast-enhanced 3D CT examination. VAI was reconstructed by volume-rendering opacity software, by sliding down the lowest threshold from -600 to 100 HU. The imaging was grouped into three groups: A (axial and multi-planar reformation [MPR] images), B (standard 3D imaging with axial and MPR images), and C (VAI with axial and MPR images). They were analyzed to reveal the type, size, number, location, complications, and the interventional removability of the object, with the comparisons in the management and clinical outcomes on the patient follow-up studies. The data were subjected to chi-square tests, with p value < 0.05 indicating significant statistical difference. RESULTS: The FB shape, size, number, site distribution and vessels around FB, as well as the FB-associated vascular complications and the FB interventional removability were assessed more accurately in Group C than in Group B or Group A (p < 0.005). There was no significant difference in disclosing the type and depth of the FB among the three groups (p > 0.75). On the basis of the 3D CT, especially the enhanced 3D CT VAI, the followings were processed: the recommendation of interventional removal in 286 (60.47%) and non-intervention in 187 (39.53%) of the 473 patients with soft-tissue FB(s); in 352 (56.50%) of the 623 radiopaque FBs patients, 258 (54.55%) patients accurately detected on 3D CT and the successful removal by intervention (343 FBs) or surgery (9 FBs) without any sequela; and 215 (45.45%) patients with 271 FBs lost in the follow-up, with their departure from the hospital. CONCLUSION: The 3D CT, especially 3D enhanced CT VAI, has great incremental value in further diagnosis and management of complex FB extraction from soft tissues.