ObjectiveThe purpose of this study was to investigate retrospectively the clinical procedural performance of CT-guided needle biopsy for retroperitoneal lesions.Materials and MethodsCT-guided needle biopsy was performed in 74 consecutive patients (M:F = 44:30; mean age, 59.7 years) with retroperitoneal lesions between April 1998 and June 2009. The target lesion ranged from 1.5 to 12.5 cm in size. The biopsy access path ranged from 3.5 to 11.5 cm in depth. A biopsy specimen was obtained using an 18-gauge core needle under a CT or CT-fluoroscopy guidance and with the patient under local anesthesia. The histopathological diagnoses from the biopsies were obtained. The diagnostic confirmation of the subtype of lymphoma was evaluated.ResultsSatisfactory biopsy samples were obtained in 73 (99%) of 74 patients and a pathological diagnosis was made in 70 (95%) of 74 patients. Sixty three lesions were malignant (45 lymphomas, nine primary tumors, nine lymph node metastases) and seven were benign. The subtype of lymphoma was specified in 43 (96%) of 45 patients who were diagnosed with lymphoma. Analysis of the value of CT-guided biopsy in this series indicated 63 true positives, zero false positive, six true negatives and five false negatives. This test had a sensitivity of 93%, a specificity of 100% and an accuracy of 93%. No major complications were seen and minor complications were noted in seven patients (five with local hematomas, two with transient pain at the puncture site).ConclusionCT-guided needle biopsy for retroperitoneal lesions is highly practical and useful, and particularly for determining the subtypes in patients with lymphoma.

Dual-phase 3D CTA using 16-MDCT clearly revealed individual arteries and veins around the stomach before laparoscopic gastrectomy. The fused image of 3D CT arteriography and venography during a single breath-hold enabled the simultaneous assessment of arteries and veins before laparoscopic gastrectomy.

The MDCT was effective for evaluation of local invasion and lymph nodes metastasis of colorectal cancer and mesenteric vascular variations before laparoscopic surgery.

Laparoscopic colorectal surgery has been attracting attention for its capacity to improve the quality of life (QOL) of patients. However, there are disadvantages to this approach, namely, it is difficult to obtain an image of the entire view of the operative field, and organs and lesions cannot be manipulated directly by the surgeon during surgery. For this reason, it takes a relatively large amount of time to ligate vessel, which can vary between patients. Furthermore, vessels and organs can be damaged during lymph nodes dissection under laparoscopic guidance, leading to heavy bleeding that prevents the surgeon from having access to a good view of the operative field. Then, to assess preoperatively the vascular anatomy, we carried out multiphase, contrast-enhanced examinations using multidetector-row CT (MDCT) on patients with colorectal cancer, and prepared the fused image of 3D images of arteries, veins, the colorectum, organs, and tumor. We called the utilization of 3D imaging virtual CT colectomy, which contributed to rapid and safe manipulation of the origins of the arteries and the veins, as well as lymph nodes dissection, without incurring injury to the involved arteries and veins.

ABSTRACT. The ability of short injection duration of contrast material to reduce the total injection volume in 64-detector row CT coronary angiography was investigated. 45 patients were divided into three groups: (i) those receiving 0.8 ml kg -1 of contrast material (350 mgI ml -1 ) injected with a fixed duration of 14 s (Group A; n516); (ii) those receiving 0.8 ml kg -1 of contrast material injected with a fixed duration of 10 s (Group B; n515); and (iii) those receiving 0.7 ml kg -1 of contrast material injected with a fixed duration of 10 s (Group C; n514). All patients then received 20 ml of saline. Contrast densities of the ascending aorta and proximal and distal coronary arteries were assessed where vessel diameters were .2.0 mm. The mean enhancement value in the ascending aorta for Group B was significantly higher than that for Groups A and C (p,0.05), whereas there was no significant difference between Groups A and C. All enhancement values in the coronary arteries were higher than 250 Hounsfield units. The mean enhancement value for each coronary artery in Group B was significantly higher than that for Group A (p,0.05), whereas there was no significant difference between Groups A and C. In conclusion, a short injection duration allows a reduction in the total volume of contrast material from 0.8 ml kg -1 to 0.7 ml kg -1 while a steady contrast enhancement is maintained in the ascending aorta and coronary arteries. CT coronary angiography has become a standard tool for the non-invasive assessment of coronary arteries in the past few years [1][2][3][4]. In particular, the improved spatial and temporal resolution and short data acquisition period of 64-detector row CT has led to a further improvement in image quality [5].In CT coronary angiography, high and consistent vascular enhancement is a prerequisite for sufficient evaluation [6][7][8][9]. As the coronary arteries are branches of the ascending aorta, enhancement of the ascending aorta plays a major role in the enhancement of the coronary arteries. Recently, it has been reported that aortic enhancement is closely related to injection duration when the contrast material dose is determined according to patient weight, and that a shorter injection duration contributes to higher aortic enhancement [10,11]. To our knowledge, only a few studies have evaluated the optimal dose of contrast material on the basis of patient weight for a steady vessel enhancement in coronary CT examinations [9]. The purpose of this study is to investigate, on the basis of patient weight, whether it is possible to decrease the total injection volume of contrast material by shortening injection duration while maintaining adequate coronary vessel enhancement in 64-detector row CT coronary angiography. Methods and materials PatientsThis study was performed according to the principles of the Declaration of Helsinki and approved by our institutional review board. Informed consent was obtained from all patients before the CT examination. Patients were recruited from June 2007 to August...