The SSD Technique Applied in Spiral CT Diagnosis of Breast Carcinoma / 实用放射学杂志

Objective Identify CT signs of breast cancer and evaluate the value of the shaded-surface display technique in spiral CT diagnosis of breast cancer.Material:33 cases of breast cancer were analysed.Methods All of patients underwent spiral CT contrast enhanced scans in SSD technique.Results The CT appearances of breast cancer were round or irregular mass,spiculated border,duct retraction,involved coopers lignment,microcalcification,deformed adipose space and axillary lymph nodes contained metastases.Conclusion The SSD technique has proved to be of great value in spiral CT diagnoses and differential diagnoses of breast cancer.

The Clinical Usefulness of Spiral CT Angiography in the Diagnosis of Pulmonary Thromboembolism / 결핵

BACKGROUND: Pulmonary thromboembolism(PTE) is a life threatening disease that needs early diagnosis. Spiral CT angiography depict thromboemboli in the central pulmonary vessels with greater than 90% sensitivity and specificity, which approaches the results of pulmonary angiography in the Prospective Investigation of Pulmonary value(clinical utility) of the spiral CT angiography with 2D image (multiplanar reformation) and 3D images(Shaded surface display, Minimal intensity projection) in the pulmonary thromboembolism. METHODS: We retrospectively analysed spiral CT angiography and prlmonary angiography, lung scan and clinical recordings of 20 patients who had PTE diagnosed by spiral CT angiography(n=19 cases) or pulmonary angiography(n=1 case) from September 1997 to August 1998. Among 20 patients who had underwent spiral CT angiography, 14 patients could be performed lung perfusion scan at the same time. We analyzed the vascular and parenchymal change in spiral CT angiogram. RESULTS: Anatomical distribution of PTE was as follows : 1) left lung(n=103) < right lung(n=129), 2) upper and middle(or lingular) lobe(n=101) < lower lobe(n=116), 3) proximal < distal but 5th order in lower lobe was decreased in distribution. Spiral CT angiography could allow accurate demonstration of 19/20 cases(95%) PTE in our study. Spiral CT angiography could demonstrate acute PTE in 16 patients and chronic PTE in 3 patients. Spiral CT angiography could also showed the combined lung parenchymal lesions(Infarction(n=9 cases), atelectasis(n=4 cases), pleural effusion(n=6 cases)). CONCLUSIONS: Spiral CT angiography with 2D image (multiplanar reformation) and 3D images(shaded surface display, minimal intensity projection) is a noninvasive diagnostic tool in the pulmonary thromboembolism. This method had several advantages; 1) It was showed the distribution of pulmonary embolism in total lung field. 2) It had high sensitivity in diagnosis of pulmonary embolism. 3) It discriminated between acute and chronic PTE. 4) It was showed the associated disease such as lung infarction, atelectasis, pleural effusion. 5) It was correlated with scintigraphic findings.

Three-dimensional CT Imaging in the Evaluation of Craniosynostosis

Technical advances in computer image analysis have made possible three-dimensional(3D) surface Informations of anatomic structures from contiguous axial CT slices. We have recently utilized this 3D CT reconstruction with spiral CT scanner in 6 consecutive patients with primary or secondary craniosynostosis to assess the presence and extent of synostosis, associated calvarial deformity and to facilitate surgical planning of the craniectomy site. High resolution 3-mm contiguous CT sections were obtained and 3D shaded-surface reconstruction image generated after reformation at 2-mm interval. In each case 3D CT demonstrated the exact extent of synostosis, and in 3 cases it was confirmed by surgical inspection. 3D CT images facilitated surgical planning by precisely localizing the proper site for craniectomy. Three-dimensional CT with shaded-surface display may be a useful adjunct to imaging and surgical planning in the patients with craniosynostosis, as well as a useful follow-up imaging study during observation or after surgery.

Comparative Analysis of MIP & SSD Imaged in Diagnosis of intracranial Aneurysms

There is an increasing tendency to use three dimentional computed tomographic angiography(CTA) in diagnosis of intracranial aneurysm. The authors have planned to get a better CTA image through comparing of the maximum intensity projection(MIP) and shaded surface display(SSD) techniques. Eighteen patients were evaluated who had been studied with conventional cerebral angiography(CCA), CTA and received aneurysmal surgery, all together. Original spiral CT images were studied with helical CT scanner with 120ml of non-ionic contrast material, 3ml/sec injection rate, 1mm collimation and 1mm reconstruction interval. MIP and SSD images of CTA were reconstructed with diting by using a standard processing algorithm of volume rendering technique and three dimensional technique. There were 3 cases(12%) of false negatives in both MIP and SSD images among the ottal 25 cases of saccular aneurysms. There were 2 cases(8%) of false positives in SSD images that were actually negative for aneurysm in MIP and CCA. Our results have demonstrated that CTA is a quick, reliable and relatively simple diagnostic tool or screening of intracranial aneurysms, and superior to CCA in evaluating configuration, direction and its associated vascular anatomy. The MIP image was better to reveal vasospasm, calcification, neck shape and adjacent vascular anatomy. On the other hand, the SSD image showed higher false positive rate due to pseudo-saccular fusion and superior to glance over the external configuration and for planning of surgery.

Comparative Analysis of MIP & SSD Imaged in Diagnosis of intracranial Aneurysms

There is an increasing tendency to use three dimentional computed tomographic angiography(CTA) in diagnosis of intracranial aneurysm. The authors have planned to get a better CTA image through comparing of the maximum intensity projection(MIP) and shaded surface display(SSD) techniques. Eighteen patients were evaluated who had been studied with conventional cerebral angiography(CCA), CTA and received aneurysmal surgery, all together. Original spiral CT images were studied with helical CT scanner with 120ml of non-ionic contrast material, 3ml/sec injection rate, 1mm collimation and 1mm reconstruction interval. MIP and SSD images of CTA were reconstructed with diting by using a standard processing algorithm of volume rendering technique and three dimensional technique. There were 3 cases(12%) of false negatives in both MIP and SSD images among the ottal 25 cases of saccular aneurysms. There were 2 cases(8%) of false positives in SSD images that were actually negative for aneurysm in MIP and CCA. Our results have demonstrated that CTA is a quick, reliable and relatively simple diagnostic tool or screening of intracranial aneurysms, and superior to CCA in evaluating configuration, direction and its associated vascular anatomy. The MIP image was better to reveal vasospasm, calcification, neck shape and adjacent vascular anatomy. On the other hand, the SSD image showed higher false positive rate due to pseudo-saccular fusion and superior to glance over the external configuration and for planning of surgery.