Tomography Angiography For Preoperative Evaluation Research Articles

Utilization of three-dimensional fusion images with high-resolution computed tomography angiography for preoperative evaluation of microvascular decompression: patient series.

High-resolution computed tomography (CT), outfitted with a 0.25-mm detector, has superior capability for identifying microscopic anatomical structures compared to conventional CT. This study describes the use of high-resolution computed tomography angiography (CTA) for preoperative microvascular decompression (MVD) assessment and explores the potential effectiveness of three-dimensional (3D) image fusion with magnetic resonance imaging (MRI) by comparing it with traditional imaging methods. Four patients who had undergone preoperative high-resolution CTA and MRI for MVD at Osaka University Hospital between December 2020 and March 2022 were included in this study. The 3D-reconstructed images and intraoperative findings were compared. One patient underwent conventional CTA, thus allowing for a comparison between high-resolution and conventional CTA in terms of radiation exposure and vascular delineation. Preoperative simulations reflected the intraoperative findings for all cases; small vessel compression of the nerve was identified preoperatively in two cases. Compared with conventional CTA, high-resolution CTA showed superior vascular delineation with no significant change in radiation exposure. The use of high-resolution CTA with reconstructed 3D fusion images can help to simulate prior MVD. Knowing the location of the nerves and blood vessels can perioperatively guide neurosurgeons.

The superiority of 256-slice spiral computed tomography angiography for preoperative evaluation of surrounding arteries in patients with gastric cancer.

ObjectiveTo evaluate the utilization of 256-slice spiral computed tomography (CT) angiography in preoperative assessment of perigastric vascular anatomy in patients with gastric cancer.MethodsIn this study, 80 gastric cancer patients were included. The medical procedure of 256-slice spiral CT angiography was performed on each of these patients consecutively. Thereafter, these patients were subjected to surgical treatment in our hospital. The techniques of volume rendering (VR) and maximum intensity projection (MIP) were used to image reconstruction of arteries around the stomach.ResultsBoth VR and MIP were applied to reconstruct the images of perigastric arteries. The results indicated that VR imaging was inferior to MIP in determining the variant small artery anatomy around the greater curvature and fundus. The respective rates of imaging produced by VR and MIP for left gastroepiploic artery, short gastric artery, and posterior gastric artery, were 32.50% versus 100%, 16.25% versus 87.50%, and 3.75% versus 25.00%, respectively. According to Hiatt’s classification, 75 out of 240 cases were abnormal types, among which we found Type II in 30 cases, Type III in 33 cases, Type IV in three cases, Type V in six cases, and Type VI in only three cases. There was no significant difference for total and every single variation type, between our group and Hiatt’s group (P>0.05).ConclusionThe 256-slice spiral CT angiography can be regarded as an effective and accurate diagnostic modality for preoperative assessing anatomical arterial variations in gastric cancer; MIP was superior to VR at identifying variations of some small artery, whereas VR was better than MIP at showing anatomical arterial variations due to its three-dimensional effect.

Noncontrast-Enhanced Magnetic Resonance Versus Computed Tomography Angiography in Preoperative Evaluation of Potential Living Renal Donors

Living renal donors undergo an extensive examination program. These examinations should be as safe, gentle, and patient friendly as possible. To compare computed tomography angiography (CTA) and an extensive magnetic resonance imaging (MRI) protocol without contrast agents to observations from nephrectomy in living renal donors and to evaluate whether noncontrast-enhanced MRI can replace CTA for vessel assessment in living renal donors. CTA and MRI results were compared to observations from nephrectomy, which served as the reference standard. Fifty-one potential kidney donors underwent imaging, and 31 donated a kidney. Comparisons in sensitivity, specificity, and accuracy were made with respect to the number of arteries, early branching, and the number of veins. Agreement was assessed using Cohen's kappa. The exact McNemar's test was used to test for statistically significant differences. In the assessment of more than one renal artery, the sensitivity and specificity of MRI and CTA were high and in perfect agreement compared to observations from surgery. The results for both MRI and CTA were as follows: (sensitivity 100%/specificity100%/accuracy 100%/Kappa = 1/P = 1). When comparing the ability to test for early branching we found, MRI: (sensitivity 33%/specificity 100%/accuracy 87%/Kappa = 0.45/P = 1) and CTA: (sensitivity 50%/specificity 100%/accuracy 90%/Kappa = 0.62/P = 1). When used to depict supernumerary veins, we found MRI: (sensitivity60%/specifivity100%/accuracy 93%/Kappa = 0.72/P = 1), whereas CTA showed: (sensitivity 40%/specificity 96%/accuracy 87% Kappa = 0.43/P = 1). In conclusion, an optimized MRI protocol that includes noncontrast-enhanced magnetic resonance angiography can be substituted for CTA for preoperative assessment of the renal vessels before living donor nephrectomy.

Is it necessary to dissect the lymph nodes around an abnormal hepatic artery in D2 lymphadenectomy for gastric cancer?

Surgical resection remains the principal treatment for advanced gastric cancer. However, one of the difficulties in radical D2 lymphadenectomy is the identification of the vascular abnormalities around the stomach, especially abnormal hepatic artery. The hepatic artery arising from the superior mesenteric artery shows great variations, and whether or not the lymphatic tissues around the abnormal artery should be dissected is still controversial. Eighty-six gastric cancer patients who underwent radical D2 lymphadenectomy by the same surgeon in our department in the past 2 years were included in this study. All patients underwent multislice spiral computed tomography angiography for preoperative evaluation of the abnormal hepatic artery arising from the superior mesenteric artery. Postoperative immunohistochemistry of the lymphoid tissues around the abnormal hepatic artery was performed using CK20 and CEA antibodies to determine the occurrence of lymph node micrometastasis around the abnormal artery. In our study, we found 14 cases with an abnormal hepatic artery arising from the superior mesenteric artery. The hepatic artery ran in front of the pancreas in 1 case and behind the pancreas in 13 cases. Immunohistochemical analyses revealed no micrometastasis in the lymphoid tissues surrounding the abnormal artery. Abnormal hepatic arteries arising from the superior mesenteric artery can be classified into pre-pancreas and post-pancreas types. Lymph nodes around the abnormal artery may not need to be dissected in radical D2 lymphadenectomy.

Value of 64-slice spiral computed tomography angiography in preoperative evaluation of spinal vascular intervention

Objective To investigate the value of 64-slice spiral computed tomography(CT)angiography in preoperative evaluation of spinal vascular intervention.Methods Seventeen patients with segmental injury of the spinal cord underwent the enhanced 64-slice CT scan of the spine.Thin-slice reconstruction was done,with the slice thickness of 0.625 mm and interval of 0.625 mm.The data were transferred to the work station ADW4.2 in DICM format.Image postprocessing technologies such as volume rendering(VR),maximum intensity projection(MIP)and multi-planar reformat(MPR)were used to conduct three-dimensional reconstruction and analyze the anatomical characteristics of radiculomedullary artery.Results Radiculomedullary artery could be found in the thoracolumbar segment of 16 patients(16/17,94%).Among them,one artery(1/17,6%)went into the vertebral canal through the left intervertebral foramen of T4/5,two(2/17,12%)through the left intervertebral foramen of T10/11,one (1/17,6%)through the left intervertebral foramen of T11/12,four(4/17,24%)through the left intervertebral foramen of L1/2,two(2/17,12%)through the left intervertebral foramen of L2/3,two (2/17,12%)through the right intervertebral foramen of T11/12,two(2/17,12%)through the right intervertebral foramen of T12/L1,two(2/17,12%)through the right foramen of L2/3 andl0(10/17,59%)through the left intervertebral foramen.Either CT scan or DSA examination found no radiculomedullary artery in one patient.All the above findings were in accordance with the results of DSA examination.Conclusions Spiral 64-slice CT scan can provide significant preoperative evaluation information for spinal vascular intervention,for it can accurately and visually show the anatomical features of the radiculomedullary artery such as open position,flow tendency,caliber size and spatial relationship with the surrounding vessels. Key words: Tomography,X-ray computed; Radiography interventional,blood vessels; Spinal cord injuries

Selective intra-arterial 3-dimensional computed tomography angiography for preoperative evaluation of nephron-sparing surgery.

To evaluate selective intra-arterial 3-dimensional computed tomography (3D-CT) angiography as a tool for the preoperative evaluation of nephron-sparing surgery (NSS). Twenty-three patients with renal cell carcinoma indicating NSS underwent selective intrarenal 3D-CT angiography. The time-lapse dual-phase technique was used for simultaneous vascular and urographic visualization. The 3D images were created by the shaded volume-rendering method. The CT attenuation of target structures was measured for quantitative evaluation. The 3D images were visually evaluated for the renal artery, vein, and collecting system using a grading system. Results were statistically analyzed. The 3D-CT angiography depicted the intrarenal branches of the renal artery and vein and the whole collecting system in most patients. Visualization of the renal artery was significantly correlated to its CT attenuation. Visualization of the renal vein was correlated to its CT attenuation adjusted by the surrounding renal parenchyma. Selective intra-arterial 3D-CT angiography allows the detailed visualization of intrarenal structures.