Simulation of clipping position for cerebral aneurysms using three-dimensional computed tomography angiography

A novel method for the simulation of the clipping position for cerebral aneurysms based on three-dimensional computed tomography (3D CT) angiography was evaluated. Rotating the regional 3D CT angiography images including the aneurysm provided the virtual intraoperative views of 36 cerebral aneurysms that were eligible for clipping through a pterional approach with a perpendicularly applied straight clip. The cut-along-trace function of the 3D CT workstation was used to simulate the clipping position. The presence or absence of aneurysm remnants was preoperatively evaluated by observing the clipping simulation image. Intraoperative endoscopy and postoperative cerebral angiography were routinely performed to confirm the completeness of obliterations. Nineteen of 21 aneurysms for which complete obliteration was preoperatively expected were confirmed to have no aneurysm remnant. Nine of 15 aneurysms which were expected to have aneurysm remnant were confirmed to persist. The clipping simulation images could correctly predict aneurysm remnant after the initial clipping with a sensitivity of 90.5% and specificity of 60%. The present simulation method can predict aneurysm remnants and improve the likelihood of complete obliteration by clipping.     

Renal mass within a horseshoe kidney: preoperative evaluation with three-dimensional helical computed tomography

Tumors arising within a horseshoe kidney are uncommon and may be difficult to characterize. We report a case of transitional cell carcinoma in a horseshoe kidney. Although several conventional imaging techniques were used to define the mass, each provided limited information. Recent advances in computer technology permit radiologic imaging to provide detailed examination of the horseshoe kidney with a single study. We describe the use of three-dimensional multislice helical computed tomography as the preferred modality to clarify the suspected neoplasm, vasculature, and collecting system of a horseshoe kidney. High-quality anatomic characterization will certainly enhance the opportunity for nephron-sparing surgery within this population.     

Accurate preoperative estimation of liver-graft volumetry using three-dimensional computed tomography

BACKGROUND: The aim of this study was to clarify the value of three-dimensional computed-tomography (3D-CT) volumetry for size matching in living-donor liver transplantation (LDLT). METHODS: 3D-CT volumetry was applied to 25 donors who underwent hepatectomy for a living relative needing an orthotopic liver transplantation. Fifteen patients underwent extended left lobectomy, one patient an extended left lateral lobectomy, and nine patients right lobectomy. 3D-CT imaging was performed with the workstation ZIO M900 (Zio Software Inc., Tokyo, Japan). The estimated volume of the grafts in two-dimensional (2D) and 3D images were compared, and an error ratio was calculated. RESULTS: 3D-CT imaging revealed the anatomy of the hepatic vein bifurcation and the shape of the graft. The error ratio was 12.8+/-2.3% in 3D, compared with 19.4+/-2.5% in 2D. As such, 3D-CT volumetry appears to be more exact than conventional 2D-CT volumetry, but volumetry by 3D-CT still produces an error ratio of approximately 13%. The weight transition of the rats' livers under preservation in University of Wisconsin (UW) solution indicated that the graft volume seems to decrease during perfusion with UW solution. Mismatch of the cutting line and volume reduction by dehydration (approximately 5% reduction 1 hour after perfusion) seems to cause the error in 3D-CT volumetry. CONCLUSIONS: Three-dimensional CT volumetry is useful for size matching in cases of living-related orthotopic liver transplantation.     

A case of extravasation from a cerebral aneurysm during 3-dimensional computed tomography angiography

BACKGROUND: Reports of rebleeding from an aneurysm during 3D-CTA are rare because this imaging method is not widely available. In previous cases, rebleeding of the aneurysm presented with certain imaging features, which were cap-like, corkscrew-like, ribbon-like, and nebulous areas of enhancement. We had a patient whose aneurysm had reruptured during 3D-CTA. This is the sixth report. CASE DESCRIPTION: The patient came to our hospital with SAH. A 3D-CTA showed a pooling of contrast medium in the temporal parenchyma and an aneurysm with an irregular bleb at the bifurcation of the right MCA. The aneurysm with bleb seemed to have a daughter aneurysm and a granddaughter aneurysm, which attached on the daughter aneurysm. We diagnosed rerupture during 3D-CTA because of a clear difference between the initial CT scan and those used as source data for 3D-CTA. Intraoperatively, we confirmed that a part of the aneurysm invaginated into the temporal lobe and that the possible granddaughter aneurysm was a clot on the daughter aneurysm. The intraparenchymal hematoma was attached to this clot. CONCLUSIONS: We report a patient with rerupture of a cerebral aneurysm during 3D-CTA showing new pattern in the image. When extravasation of blood occurs into the brain parenchyma, 3D-CTA clearly demonstrates its extent because there is little attenuation by CSF. In such cases, extravasated blood can form both a small mass that mimics a granddaughter aneurysm and a pooling of contrast medium.     

三维CT重建对关节内骨折分型术前评价的影响

[目的]对比分析分别使用胫骨平台和髋臼骨折的三维CT和二维CT影像资料所得骨折分型结果，来评价三维CT对关节内骨折分型术前评价的影响。[方法]4名骨科主治医生回顾性分析本院28例胫骨平台骨折和19例髋臼骨折病例，分别使用二维CT和三维CT影像资料，对骨折分型做出判断，使用一致性检验来评价关于骨折术前分型的观察者间信度和观察者自身信度。[结果]使用三维CT影像时，对骨折分型判断的观察者间信度和自身信度均提高为极度一致，Kappa系数分别0．945和0．981（胫骨平台骨折）、0．934和0．979（髋臼骨折）。[结论]使用三维CT成像能够提高对胫骨平台骨折和髋臼骨折术前分型的可靠性，三维CT对关节内骨折分型术前评价有很高的应用价值。     

Anomalous V2 of the left pulmonary vein detected using three-dimensional computed tomography in a patient with lung cancer: A case report

We report one of the rare anatomical variations of the pulmonary vein wherein the left V2 drained into the inferior pulmonary vein. A 63-year-old man was referred to our hospital because of an abnormal shadow in the left lower lung field that was noted on chest X-ray. Computed tomography (CT) revealed a tumor in the left lower lobe. A biopsied tumor specimen was diagnosed as an adenocarcinoma, and thus, left lower lobectomy was performed. Preoperative three-dimensional CT revealed that an anomalous V2 of the left lung drained from the superior segment into the inferior pulmonary vein. This variation type was confirmed during thoracoscopic left lower lobectomy. We were able to perform left lower lobectomy with the preservation of the anomalous V2. The postoperative course was uneventful, and the patient was discharged on postoperative day 12. It is important to identify anatomical variations of the pulmonary vein and reliably preserve and process the affected area to prevent postoperative complications.     

Middle cerebral artery atherosclerotic stenosis mimicking a cerebral aneurysm: pitfall in preoperative evaluation of cerebral aneurysms

We report a case of an aneurysm-like finding of MCA with severe atherosclerosis on standard radiological evaluation, which led us to plan surgical clipping. In particular, patients, whose modalities usually performed for preoperative assessment of cerebral aneurysms, such as DSA, 3D CTA and MRA, are insufficient.     

Preoperative airway evaluation using multi-slice three-dimensional computed tomography for a patient with severe tracheal stenosis

A 71-yr-old female with a malignant thyroid tumour was to undergothyroidectomy under general anaesthesia. Preoperative chestx-ray and plain computed tomography (CT) showed severe trachealstenosis. Three-dimensional figures of the trachea and a virtualbronchoscopic movie were obtained from multi-slice CT to evaluatethe stenotic region and to simulate fibroscopic tracheal intubation,respectively. After induction of general anaesthesia with propofol,a tracheal tube was successfully passed through the stenoticregion under the guide of a fibroscope as simulated in the virtualmovie. We conclude that multi-slice CT is useful for preoperativeairway evaluation for patients with stenosis and distortionof the trachea.      

Anomalous pulmonary vein detected using three-dimensional computed tomography in a patient with lung cancer undergoing thoracoscopic lobectomy

Few clinicians are familiar with the anatomy of anomalous pulmonary veins, and studies reporting patients who required right lower lobectomy for lung cancer and who had anomalies of the middle and lower pulmonary veins are even rarer. This report describes the case of a lung cancer patient who had an anomalous lateral part of the middle lobe vein (V4) draining into the right inferior pulmonary vein, which was confirmed by three-dimensional 64-row multidetector computed axial tomography (3D-MDCT) angiography. She was then successfully treated with video-assisted thoracic surgery. The preoperative 3D imaging of the pulmonary vein and artery allowed us to comprehend fully the patient's vascular anatomy before the operation. Thus, we recommend preoperative 3D-MDCT angiography for patients with lung cancer undergoing thoracic surgery, especially video-assisted thoracic surgery.     

An anomalous segmental vein of the left upper lobe of the lung: preoperative identification by three-dimensional computed tomography pulmonary angiography

A number of variations in the pulmonary arteries and veins have been documented, and the information is very important for performing a safe lung resection. This report describes a case of an anomalous segmental vein of the left upper lobe of the lung. The patient was a 75-year old male who was suspected to have lung cancer in the left upper lobe. A contrast-enhanced computed tomography showed a vessel behind the left lower bronchus. A three-dimensional computed tomography angiography demonstrated that it was an anomalous vein for the apicoposterior segment of the left upper lobe of the lung, draining into the left inferior pulmonary vein. The aberrant vein was readily identified during surgery and was divided without injury, and a left upper lobectomy was successfully performed. Aberrant pulmonary veins for the superior segment of the right upper lobe of the lung are rarely observed, and the same kind of anomaly on the left side has not been reported.     

Venous aneurysm of the cephalic vein: Report of a case

(Received for publication on Mar. 13, 1997; accepted on Sept. 2, 1997)     

Detection of intrahepatic veno-venous shunts by three-dimensional venography using multidetector-row computed tomography during angiography

Purpose

The hepatic vein (HV) can be removed during hepatectomy if there is an effective intrahepatic veno-venous shunt (vv-shunt). We evaluated the efficacy of vv-shunt detection by three-dimensional (3D) venography reconstructed from multidetector-row computed tomography (MDCT) during angiography.

Methods

3D venography was reconstructed using computer software in 88 patients with intrahepatic tumors.

Results

We found that 12 patients had one shunt [4 right hepatic vein (RHV)—middle hepatic vein (MHV) and 12 RHV- inferior right hepatic vein (IRHV)] and 1 patient had 2 shunts (RHV-MHV and -IRHV), confirming a clinically efficient vv-shunt in 14.8 % of the patients. In one patient with an RHV-IRHV shunt, the preserved RHV-IRHV shunt worked well and prevented congestion of the postero-caudal subsegment after central bisegmentectomy with partial resection of the RHV ventral trunk for huge hepatocellular carcinoma (HCC).

Conclusions

Although the vv-shunt detection rate by 3D venography is low, a visualized vv-shunt proved to be efficient. Thus, invasive occlusion venography is avoidable if a vv-shunt is seen on 3D venography.     

Validity of preoperative volumetric analysis of congestion volume in living donor liver transplantation using three-dimensional computed tomography.

Reconstruction of middle hepatic vein (MHV) tributaries is controversial in right-lobe living donor liver transplantation (LDLT). This study aimed to evaluate the appropriateness of reconstructing MHV tributaries by volumetry using 3-dimensional computed tomography (3D-CT). Between November 2003 and January 2005, 42 donor livers (right-lobe graft, n = 25; left-lobe graft, n = 17) were evaluated using this software. The total congestion volume (CV) associated with the MHV tributaries and the inferior right hepatic vein (IRHV), and graft volume (GV) were calculated. In recipients with right-lobe grafts, CV/(right liver volume [RLV]) and (GV - CV)/(standard liver volume [SLV]) were compared between 2 groups: with reconstruction (n = 16) and without reconstruction (n = 9). To evaluate the influence of CV on the remnant right lobe in donors, total bilirubin was compared between 2 groups: high CV (CV > 20%, n = 13) or low CV (CV < or = 20%, n = 4). The mean CV/RLV ratio was 32.3 +/- 17.1% (V5, 15.2 +/- 9.9%; V8, 9.2 +/- 4.1%; and IRHV, 8.5 +/- 11.4%) and the maximum ratio was as high as 80.8%. The mean (GV - CV)/SLV ratio before reconstruction in patients with or without reconstruction resulted in 33.5 +/- 12.8% and 55.4 +/- 12.9%, respectively (P < 0.01). In donors, total bilirubin was significantly high in the high CV group on postoperative day 1 compared with the low CV group (P < 0.05). In conclusion, calculation of CV using 3D-CT software proved to be very useful. We concluded that this evaluation should be an integral part of procedure planning, especially for right-lobe LDLT.     

Morphometric analysis of the peroneal tubercle using a three-dimensional computed tomography model

BackgroundThe peroneal tubercle is a small bony ridge located on the lateral wall on the calcaneus immediately inferior to the lateral malleolus and separates the peroneus brevis and peroneus longus tendons. The size and configuration of the peroneal tubercle has been implicated in the pathogenesis of peroneal tendon tears and tenosynovitis and is the increasing object of clinical interest. However, the morphology of the tubercle is difficult to assess with precision.MethodsWe utilized a new method to evaluate the three-dimensional (3D) geometry of 46 calcanei from 34 consecutive patients; average patient age was 48.0 years who underwent lower extremity computed tomography (CT) for clinical treatment of non-peroneal tubercle-related conditions. The 3D geometries of calcanei were reconstructed by using the computer software to calculate the surface 3D models. To measure the size of the peroneal tubercle, we virtually excised it from the 3D calcaneus model and made a precise measurement of the height.ResultsPeroneal tubercles with measured heights of 1 mm or more were detected in 65% of the feet, with an average tubercle height of 2.59 mm. Peroneal tubercles were larger and more frequent in middle-aged or older than younger patients.