Sonography of the common bile duct: value of the right anterior oblique view.

The common hepatic and proximal common bile ducts (common duct) lie anteriorly and generally to the right of the portal vein in the porta hepatis. This constant anatomic relationship can be used to demonstrate the common duct and to differentiate it from the portal vein by gray scale ultrasonography. The patient is scanned longitudinally from the right anterior abdominal wall with the ultrasound beam directed posteromedially until two tubular structures are demonstrated in the porta hepatis. The more anterior tubular structure in this projection is the common duct. If the common duct is less than 3 mm in diameter, it may not be clearly delineated. In these cases the absence of common duct dilatation can be inferred. The usefulness of this view for detecting common duct dilatation was evaluated in a series of 101 consecutive cases proven by surgery, autopsy, or cholangiography. The overall accuracy was 96% (four false negative studies; no false positives). We conclude that sonography should be the imaging procedure of choice for suspected extrahepatic biliary obstruction if the serum bilirubin level precludes intravenous cholangiography.     

Multiple-hospital survey of ejection-fraction variability using a cardiac phantom

A dynamic cardiac phantom was used to provide identical input data at 11 different nuclear medicine laboratories throughout the Philadelphia area, and the variability in the resulting calculations of ejection fraction (EF) was assessed. The variability observed between different operators using the same computer system averaged 3 EF units, which was similar to that between different observers using different types of computers. In the range of low ejection fractions, however, there was a suggestion that EFs calculated with an MDS computer were slightly lower than those from a DEC computer.     

右前头足斜位和正位显示门静脉的对比研究

目的评价右前头足斜位(RACCO)和正位显示门静脉的临床价值.材料与方法31例均以7ml/s的速度经肠系膜上动脉(27例)或脾动脉(4例)注入76%泛影葡胺25ml行间接门静脉造影,先行正位门静脉摄影,再行RACCO位摄影,然后对所得图像进行存储、分析.结果图像综合分析表明,RACCO位像好于正位像者20例(占64.5%),RACCO位像等于正位像者7例(占23.3%),RACCO位像差于正位像者4例(占13.2%).末稍分支分析表明RACCO位像显示的远端分支明显好于正位像(占87%).结论RACCO位对门静脉主干及其分支的显示明显优于正位.     

Right anterior caudo-cranial oblique (RACCO) view of portal branches

The right caudocranial oblique (RACCO) view which is obtained by tilting the image intensifier 25 degrees caudally and 30 degrees to the right while the patients lie in supine position is proposed for improved depiction of the portal venous system. Transarterial portography with digital subtraction angiography was performed in the RACCO and posteroanterior (PA) views in 32 patients. Comparison of the two views revealed that the RACCO view was superior to the PA view of the left main branch in 25 patients (78%) and of the right posterior lobe branch in 24 (75%) patients. Visibility of more distal portal branches, however, did not always improve by RACCO view. RACCO view will be useful for the evaluation of portal systems of primary and secondary hepatic neoplasms as a special view following portogram in PA projection when more detailed information is necessary on proximal portal branches.     

MRI analysis of the attachment of the anteromedial and posterolateral bundles of anterior cruciate ligament using coronal oblique images

Purpose

The purpose of this study was to evaluate the course of the anteromedial bundle (AMB) and the posterolateral bundle (PLB) of the anterior cruciate ligament (ACL) with magnetic resonance imaging (MRI) in order to clarify the relationship between the bundles and surrounding anatomic landmarks.

Methods

Eighty-eight knees with intact ACLs were included in this study. MRI coronal oblique images were obtained with the knee in extension and used to assess the following characteristics of the AMB and PLB: (1) course of the ligament, (2) location of the tibial attachment, and (3) femoral attachment and geometry of the lateral femoral condyle inner wall.

Results

In terms of the tibial attachment, the AMB was confluent with the apex of the medial intercondylar ridge (MIR) in all cases. Sixty-five PLBs (74%) inserted into the region between the apex and the slope of the MIR. The resident’s ridge was detected in 91% of the knees in the AMB image, whereas the ridge was clearly visualized in only 17% of the knees in the PLB image. A bony eminence was observed at the inner articular margin of the lateral femoral condyle in the PLB image.

Conclusion

In terms of the tibial attachment, the AMB was confluent with the apex of the medial intercondylar ridge in all cases. Most of the PLBs attached to the region between the apex and the slope of the MIR. Because the bone tunnel location influences clearance between the grafts and the surrounding tissues, these results should be considered during anatomic double-bundle ACL reconstruction.

Level of evidence

Study of nonconsecutive patients without a universally applied gold standard, Level III.

     

Angiographic assessment of the right hepatic artery for encasement by hilar cholangiocarcinoma: Comparison between antero-posterior and right anterior oblique projections

Purpose: To evaluate the usefulness of right anterior oblique (RAO) arteriography for evaluating encasement of the right hepatic artery (RHA) by hilar cholangiocarcinoma. Methods: Celiac arteriography was performed in both the antero-posterior (AP) and RAO projection in ten patients with cholangiocarcinoma. The lengths of the arteries between the bifurcation of the anterior and posterior branch of the liver and the following points were measured: (a) the bifurcation of the left and right hepatic artery (AP-LR), (b) the bifurcation of the proper hepatic artery and the gastroduodenal artery (AP-PG). Additionally, image quality in investigating the invasion of the RHA was evaluated. Results: On the AP images, the average lengths of AP-LR and AP-PG were 24.5 ± 5.1 mm and 30.0 ± 4.9 mm, respectively. On RAO images, the lengths were 28.2 ± 4.6 mm and 32.7 ± 4.8 mm, respectively. Every length was different between the two projections (p < 0.01). In 6 of 10 patients with hilar cholangiocarcinoma, images in RAO projections were superior to AP images for evaluation of encasement. Conclusion: We conclude that angiography obtained in the RAO projection yields images that are superior to those obtained in the conventional AP projection for assessment of RHA encasement.     

Gated cardiac scanning: canine studies.

Retrospective electrocardiograph gating of data from a rotating detector fan beam computed tomography system was employed to produce end systolic and end diastolic images of the beating heart in a series of normal and experimentally infarcted canines. The gating window was typically less than 20% of the cardiac cycle, and the gated images showed superior spatial resolution compared with ungated images of the same cross section. Comparison of the scans of the normal and of the infarcted animals shows abnormal contrast enhancement of the myocardium in the region of the infarct, and the gating studies demonstrate dyskinetic behavior of the infarct zone.     

Value of combined assessment of global and segmental ventricular contraction with right anterior oblique ECG-gated first-pass and left anterior oblique equilibrium radionuclide ventriculography

A semi-automated, variable-region-of-interest method of analysis was used to measure both global and segmental left ventricular (LV) and global right ventricular (RV) contraction with ECG-gated first-pass and equilibrium radionuclide ventriculography. Normal values were defined in 20 healthy volunteers, and in 24 symptomatic patients, the results were compared with right anterior oblique (RAO) contrast left ventriculography. The global LV ejection fraction (LVEF) obtained by equilibrium imaging in the left anterior oblique (LAO) projection correlated closely with the results obtained by the gated first-pass method in the RAO projection (r=0.95) and those obtained with contrast left ventriculography (r=0.94); furthermore, the interobserver variability was small (r=0.985). The normal values for LVEF obtained using radionuclide techniques and contrast ventriculography did not differ, but with the equilibrium radionuclide method, the RV ejection fraction (RVEF) values were underestimated in comparison to those obtained by the RAO gated first-pass technique. In five patients with localised inferior segmental akinesis at contrast angiography, the RAO first-pass cine display demonstrated a corresponding wall-motion abnormality in all cases, but LAO equilibrium cine displays did so in only one out of five patients. For segmental quantitation of LV contraction, a computer programme defined the ventricular edge, divided the RAO LV images into five segments and determined both the segmental area contraction (SAC) and the counts-based segmental ejection fraction (SEF). Radionuclide SAC measurements correlated very strongly with SEF measurements (r=0.94–0.99). Both radionuclide SAC and radionuclide SEF correlated well with contrast angiographic SAC, except in the inferobasal segment. Mean radionuclide SAC (29%) for the five segments did not differ from mean contrast SAC (29%). This combined protocol enables rapid and accurate biventricular assessment of global and segmental contraction. Significant diagnostic value exists in combining these two acquisition protocols in specific clinical situations.     

Value of combined assessment of global and segmental ventricular contraction with right anterior oblique ECG-gated first-pass and left anterior oblique equilibrium radionuclide ventriculography

A semi-automated, variable-region-of-interest method of analysis was used to measure both global and segmental left ventricular (LV) and global right ventricular (RV) contraction with ECG-gated first-pass and equilibrium radionuclide ventriculography. Normal values were defined in 20 healthy volunteers, and in 24 symptomatic patients, the results were compared with right anterior oblique (RAO) contrast left ventriculography. The global LV ejection fraction (LVEF) obtained by equilibrium imaging in the left anterior oblique (LAO) projection correlated closely with the results obtained by the gated first-pass method in the RAO projection (r = 0.95) and those obtained with contrast left ventriculography (r = 0.94); furthermore, the interobserver variability was small (r = 0.985). The normal values for LVEF obtained using radionuclide techniques and contrast ventriculography did not differ, but with the equilibrium radionuclide method, the RV ejection fraction (RVEF) values were underestimated in comparison to those obtained by the RAO gated first-pass technique. In five patients with localised inferior segmental akinesis at contrast angiography, the RAO first-pass cine display demonstrated a corresponding wall-motion abnormality in all cases, but LAO equilibrium cine displays did so in only one out of five patients. For segmental quantitation of LV contraction, a computer programme defined the ventricular edge, divided the RAO LV images into five segments and determined both the segmental area contraction (SAC) and the counts-based segmental ejection fraction (SEF). Radionuclide SAC measurements correlated very strongly with SEF measurements (r = 0.94-0.99). Both radionuclide SAC and radionuclide SEF correlated well with contrast angiographic SAC, except in the inferobasal segment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Gated right ventricular studies using krypton-81m: comparison with first-pass studies using gold-195m

Krypton-81m, given by continuous i.v. infusion, has been successfully used for the equilibrium ECG-gated assessment of right ventricular function. We compared gated studies with 81mKr (half-life 13 sec) with first-pass studies using 195mAu (half-life 30.5 sec). Krypton studies analyzed using variable regions of interest (ROIs) led to a significantly higher calculated right ventricular ejection fraction (RVEF) than with a fixed ROI, both with and without background correction. The differences between first-pass studies and gated studies without background correction were significant (p less than 0.01), whereas they were not with background correction. These data suggest that large systematic errors exist in the calculation of RVEF depending on the analysis method and that background correction is important when different techniques are compared.     

高场MRI斜矢状位与斜冠状位扫描在贲门癌术前检查中的应用价值

目的:探讨改进高场MRI斜矢状位与斜冠状位扫描在贲门癌术前检查中的应用价值.方法:回顾性分析69例贲门癌患者的MR I图像资料,MR I检查均采取平行于食管下段长轴的斜矢状位、斜冠状位和标准正矢状位、正冠状位的扫描方法.两位MR I诊断医师采用双盲法根据食管MR I图像评判两种不同扫描方法下距离肿块边缘的食管胸下段及腹...     

Computational cardiac anatomy using MRI.

Ventricular geometry and fiber orientation may undergo global or local remodeling in cardiac disease. However, there are as yet no mathematical and computational methods for quantifying variation of geometry and fiber orientation or the nature of their remodeling in disease. Toward this goal, a landmark and image intensity-based large deformation diffeomorphic metric mapping (LDDMM) method to transform heart geometry into common coordinates for quantification of shape and form was developed. Two automated landmark placement methods for modeling tissue deformations expected in different cardiac pathologies are presented. The transformations, computed using the combined use of landmarks and image intensities, yields high-registration accuracy of heart anatomies even in the presence of significant variation of cardiac shape and form. Once heart anatomies have been registered, properties of tissue geometry and cardiac fiber orientation in corresponding regions of different hearts may be quantified.     

Calculating anterior glenoid bone loss using the Bernageau profile view

Objective

To determine if it is possible to measure glenoid bone loss by using the Bernageau view and to compare it to a 3D?CT scan.

Materials and methods

Fifty healthy subjects with a mean age of 34?±?8?years old and 31 (62?%) male were submitted to the Bernageau view X-ray of both shoulders. Three blinded evaluators measured the distance between the posterior and anterior glenoid rim. Ten patients with multiple episodes of unilateral traumatic anterior shoulder dislocation with a mean age of 34?±?9.1?years old and 90?% male were submitted to the same X-ray technique to determine the percentage of glenoid bone loss. They were also submitted to a bilateral 3D?CT scan to be compared to the radiographs.

Results

In the 50 asymptomatic subjects, the AP distance was 24.48?mm?±?3.32?mm in the left shoulder and 24.82?mm?±?3.16?mm in the right shoulder. Comparing the X-ray study and the 3D?CT scan of the ten patients with multiple episodes, there was no significant statistical difference of the AP normal distance in both methods (p?=?0.646), the AP erosion distance (p?=?0.386), as well as the percentage of bone loss (p?=?0.513). Moreover, the differences between the percentages of bone loss in the X-ray, compared with the 3D CT scan were, on average 2.28?% (range 0 to 6.05?%).

Conclusions

The Bernageau radiographic view is an accurate and reproducible technique for measuring the presence of glenoid erosion, with similar results when compared to the 3D CT scan.     

前交叉韧带斜冠状面薄层解剖断面与MRI表现对照研究

目的对冰冻膝关节前交叉韧带（ACL）斜冠状面薄层解剖断面与正常人膝关节MRI特点进行对照研究，为ACL损伤分级诊断建立基础。方法1例（1只）膝关节标本行斜冠状面MRI确定角度，冰冻后沿斜冠状面1mm层厚铣切，观察ACL薄层解剖特点。选择50名正常人对其ACL进行MR斜冠状面扫描，观察ACL的MRI特点。结果1只膝关节标本的ACL在斜冠状面薄层断面清晰显示其全程走行，清晰地显示ACL前内束与后外束，前内束从股骨髁附着点后上方区自后向外侧及前内侧走行，止于髁间棘附着区前内侧方，后外侧束从股骨髁附着点前下方区，自后外侧及外下走行，止于髁间棘附着区后外侧方。斜冠状面MRI能够显示50名正常人ACL全程，显示率为100％。MRI能够区分ACL前内束与后外束结构，显示前内束自后外侧向前内走行，止于髁间棘附着区前内侧方，后外束自后外侧向外下走行，止于髁间棘附着区后外侧方。MRI显示ACL走行与薄层断面显示的走行一致。结论斜冠状面是观察ACL的最佳方位，临床对怀疑ACL损伤的患者必要时行MR斜冠状面扫描。