Use Of 3D CT Research Articles

Current Concepts in the Measurement of Glenohumeral Bone Loss.

The extent of glenohumeral bone loss seen in anterior shoulder dislocations plays a major role in guiding surgical management of these patients. The need for accurate and reliable preoperative assessment of bone loss on imaging studies is therefore of paramount importance to orthopedic surgeons. This article will focus on the tools that are available to clinicians for quantifying glenoid bone loss with a focus on emerging trends and research in order to describe current practices. Recent evidence supports the use of 3D CT as the most optimal method for quantifying bone loss on the glenoid and humerus. New trends in the use of 3D and ZTE MRI represent exciting alternatives to CT imaging, although they are not widely used and require further investigation. Contemporary thinking surrounding the glenoid track concept and the symbiotic relationship between glenoid and humeral bone loss on shoulder stability has transformed our understanding of these lesions and has inspired a new focus of study for radiologists and orthopedist alike. Although a number of different advanced imaging modalities are utilized to detect and quantify glenohumeral bone loss in practice, the current literature supports 3D CT imaging to provide the most reliable and accurate assessments. The emergence of the glenoid track concept for glenoid and humeral head bone loss has inspired a new area of study for researchers that presents exciting opportunities for the development of a deeper understanding of glenohumeral instability in the future. Ultimately, however, the heterogeneity of literature, which speaks to the diverse practices that exist across the world, limits any firm conclusions from being drawn.

How does computed tomography inform our understanding of shoulder kinematics? A structured review.

The objective of this structured review was to review how computed tomography (CT) scanning has been used to measure the kinematics of the shoulder. A literature search was conducted using Evidence-based Medicine Reviews (Embase) and PubMed. In total, 29 articles were included in the data extraction process. Forty percent of the studies evaluated healthy participants' shoulder kinematics. The glenohumeral joint was the most studied, followed by the scapulothoracic, acromioclavicular, and sternoclavicular joints. Three-dimensional computed tomography (3DCT) and 3DCT with biplane fluoroscopy are the two primary imaging techniques that have been used to measure shoulder joints' motion under different conditions. Finally, many discrepancies in the reporting of the examined motions were found. Different authors used different perspectives and planes to report similar motions, which results in confusion and misunderstanding of the actual examined motion. The use of 3DCT has been widely used in the examination of shoulder kinematics in a variety of populations with varying methods employed. Future work is needed to extend these methodologies to include more diverse populations, to examine the shoulder complex as a whole, and to standardize their reporting of motion examined to make study to study comparisons possible.

Intra- and inter-observer reliability assessment of widely used classifications and the “Ten-segment classification” of tibial plateau fractures

BackgroundTen-segment classification provides a different approach to the evaluation of tibial plateau fractures. The purpose of this study was to assess the intra- and inter-observer reliability of three widely used classification systems (Schatzker, Arbeitsgemeinschaft für Osteosynthesefragen (AO/OTA), and the updated three-column concept (uTCC)) with ten-segment classification in two-dimensional computed tomography (2D-CT) and three-dimensional computed tomography (3D-CT). MethodNinety 2D-CT and 3D-CT scans of patients with tibial plateau fractures were included in this retrospective cohort study. The included data were independently classified by six observers of different years of seniority and were independently observed and classified again after eight weeks. Inter-observer and intra-observer reliability of the four fracture classifications made by the six observers was analyzed using the kappa statistic. Kappa values were interpreted according to the categorical rating by Landis and Koch. ResultsWhen the inter-observer reliability was based on 2D-CT/3D-CT analysis, the mean Kappa values for the Schatzker, AO/OTA, uTCC, and ten-segment classification were 0.64/0.66, 0.56/0.59, 0.53/0.65, and 0.60/0.73, respectively. When intra-observer reliability was based on 2D-CT/3D-CT, the mean Kappa values for the Schatzker, AO/OTA, uTCC, and ten-segment classification were 0.68/0.83, 0.69/0.83, 0.74/0.85, and 0.80/0.91, respectively. ConclusionsThe use of 3D-CT is important for the reliable diagnosis and recognition of tibial plateau fracture features compared to 2D-CT. When using 3D-CT, ten-segment classification showed high intra- and inter-observer agreement.

CORR Insights®: 3D-printed Handheld Models Do Not Improve Recognition of Specific Characteristics and Patterns of Three-part and Four-part Proximal Humerus Fractures.

CORR Insights®: 3D-printed Handheld Models Do Not Improve Recognition of Specific Characteristics and Patterns of Three-part and Four-part Proximal Humerus Fractures.

Do Rotation and Measurement Methods Affect Reliability of Anterior Cruciate Ligament Tunnel Position on 3D Reconstructed Computed Tomography?

Background:The literature has seldom investigated the anterior cruciate ligament (ACL) tunnel position while considering the effect of rotation of 3-dimensional computed tomography (3D-CT) images during measurements.Hypothesis:We hypothesized that (1) measurement of the ACL tunnel position in the femur and tibia through use of 3D-CT is considerably influenced by rotation of the 3D model and (2) there exists a reliable measurement method for ACL tunnel position least affected by rotation.Study Design:Controlled laboratory study.Methods:The 3D-CT images of 30 randomly selected patients who underwent single-bundle ACL reconstruction were retrospectively reviewed. For femoral tunnel assessments, rectangular reference frames were used that involved the highest point of the intercondylar notch and outer margins of the lateral femoral condyle (method 1), the highest point of the intercondylar notch and outer margins of the lateral wall of the intercondylar notch (method 2), and the lowest point of the intercondylar notch and outer margins of the lateral femoral condyle (method 3). For tibial tunnel assessments, rectangular reference frames with the cortical outline at the articular surface of the tibia (method A) and the cortical outline of the proximal tibia (method B) were used. For both femoral and tibial assessments, the tunnel positions at 5°, 10°, and 15° of rotation of the 3D model were compared with that at a neutral position.Results:The values measured by methods 1 and 3 showed significant differences at greater than 5° of rotation compared with the value at the neutral position, whereas method 2 showed relatively consistent results. However, the values measured with both methods A and B showed significant differences at greater than 5° of rotation compared with the value at the neutral position.Conclusion:The tunnel position on 3D-CT images was significantly influenced by rotation during measurements. For femoral tunnel position, measurement with a reference frame using the lateral wall of the intercondylar notch (method 2) was the least affected by rotation, with relatively consistent results.Clinical Relevance:This study demonstrates that measurement using the lateral wall of the intercondylar notch might be a consistent and reliable method for evaluating the ACL femoral tunnel position considering the effect of 3D-CT image rotation during measurements. However, both methods to measure tibial tunnel position described in this study were similarly affected by rotation.

The Effectiveness of 3-D Computed Tomography in the Evaluation of Penile Deformities in Patients With Peyronie's Disease: A Pilot Study.

BackgroundAnatomic and functional evaluation of the penis before treatment is very important in the choice of treatment in patients with Peyronie’s disease (PD).AimTo compare 3 different methods for the evaluation of the penile deformity, including auto-photography, combined intracavernous injection stimulation test (CIS), and 3-dimensional computed tomography (3D CT) during artificial penile erection in patients with PD.MethodsPretreatment penile deformities of patients with PD were compared with those detected with auto-photography, using goniometer after intracavernosal vasoactive agent, and 3D CT correlations among these 3 methods were investigated.Main Outcome MeasuresAssessments of penile curvature with auto-photography, CIS, and 3D CT.ResultsThe mean age of 36 patients who were included in the study was 58 ± 8.25 (36–72) years, and the mean time since the onset of the disease was 25 ± 24 months (2–144). Degrees of penile curvatures measured using auto-photography, CIS, and CT were determined as 24° (0°–80°), 40° (0°–90°), and 34° (0°–80°), respectively. When general correlation analysis was performed to evaluate the penile curvatures of all patients using 3 methods, a moderate correlation between auto-photography and both CIS (r = 0.72, P < .001) and 3D CT (r = 0.56, P < .001) was detected, whereas a strong correlation was noticed between CIS and 3D CT (r = 0.78, P < .001). When the correlation analysis between patients with and without ED was examined, a statistically significant decrease in the strength of correlation between CIS and auto-photography in patients with ED (0.629 vs 0.925, P < .05), however, was detected without any statistically significant difference in patients without ED (0.694 vs 0.813, P > .05).ConclusionThe superiority of 3D CT over auto-photography and its strong correlation with CIS in most parameters have been demonstrated. However, it was found that CT did not give more information than the evaluation with CIS. Current limitations and cost increases limit the use of 3D CT in the assessment of PD.Özmez A, Ortac M, Cevik G, et al. The Effectiveness of 3-D Computed Tomography in the Evaluation of Penile Deformities in Patients With Peyronie's Disease: A Pilot Study. Sex Med 2019;7:311–317.

Usefulness of Three-Dimensional Computerized Tomographic Volumetry for Determining Split Renal Function in Donors for Living-Related Kidney Transplantation

BackgroundIn living-related kidney transplantation, it is important to spare the superior kidney for the donor if there is a significant difference in split renal function. We have been using renal scintigraphy to decide which kidney to be donated. Recently, we used data regarding kidney volume and maximum area in the frontal plane of the 3-dimensional computerized tomography (3DCT) image of the kidney. We evaluated the validity of these parameters for estimating split renal function. MethodsWe calculated the ratio of right kidney volume (VOL-ratio) and maximum area in the frontal plane of the kidney (AREA-ratio) with the use of 3DCT and examined the correlation between these 2 parameters and the ratio of right kidney estimated renal plasma flow (ERPF-ratio) calculated with the use of technetium-99m mercaptoacetyltriglycine (99mTc-MAG3) renal scintigraphy. Forty-six donors for living-related kidney transplantation were evaluated. Their mean age was 53 years; there were 14 male and 32 female donors. ResultsCorrelation coefficients between VOL-ratio and ERPF-ratio and between AREA-ratio and ERPF-ratio were 0.441 and 0.471, respectively (P = .002; P = .001). Bland-Altman analysis confirmed that the majority of difference scores between VOL-ratio–ERPF-ratio and AREA-ratio–ERPF-ratio were within the 95% confidence interval of the differences. The differences between VOL-ratio–ERPF-ratio and AREA-ratio–ERPF-ratio were (mean ± 1.96SD) 1.17 ± 6.04% and −0.82 ± 6.09%, respectively. It seemed that the distribution of AREA-ratio–ERPF-ratio was less biased than that of VOL-ratio–ERPF-ratio. ConclusionsThe discrepancy between the ratio of kidney volume and the maximum area in the frontal plane of the kidney may have been due to the rotation of the kidney. The ratio of ERPF obtained with the use of renal scintigraphy approximates not only the ratio of kidney volume but also the ratio of maximum area in the frontal plane of the kidney. Thus, our findings suggest that the use of 99mTc-MAG3 renal scintigraphy alone may underestimate the function of a rotated kidney.

The use of 3D-CT in weapon caused impression fractures of the skull, from a forensic radiological point of view

Abstract Objective The aim of this study was to analyze the usefulness of the three-dimensional (3D) volume renderings (VRTs), based on computed tomography (CT) images of the head, to gain more insight in the etiology of impression skull fractures. Materials and methods 3D-CT scans of 12 forensic cases with impression skull fractures after head injury were selected. Ten radiologists were asked to determine the shape of the used object, the amount of blows and the location of the fracture, based on 2D CT images and 3D volume renderings. Afterwards, the results of the assessments were compared with the real shapes of the true object in case. Results In 7 out of 12 cases, the used weapon was a hammer. In 62% of the cases the shape of the used object was determined correctly by the radiologists and in 72% of the cases the amount of blows on the skull was correct. There was no significant difference in results between the forensically experienced and forensically inexperienced radiologists. Conclusion 3D-CT is useful in a forensic setting, to determine the shape of a suspected weapon and the amount of blows. However, assessment of the CT data should always be combined with information about the scene and a profound morphological inspection of the wound.

Prenatal diagnosis of fetal skeletal dysplasia with 3D CT

Clinical use of 3D CT for fetal skeletal malformations is controversial. The purpose of this study was to evaluate the efficacy of fetal 3D CT using three protocols with different radiation doses and through comparing findings between fetal CT and conventional postnatal radiographic skeletal survey. Seventeen fetuses underwent CT for suspected skeletal dysplasia. A relay of three CT protocols with stepwise dose-reduction were used over the study period. The concordance between the CT diagnosis and the final diagnosis was assessed. Ninety-three radiological findings identifiable on radiographs were compared with CT. Fetal CT provided the correct diagnosis in all 17 fetuses, the detectability rate of cardinal findings was 93.5 %. In 59 % of the fetuses an US-based diagnosis was changed prenatally due to CT findings. The estimated fetal radiation dose in the final protocol was 3.4 mSv (50 %) of the initial protocol, and this dose reduction did not result in degraded image quality. The capability of fetal CT to delineate the skeleton was almost the same as that of postnatal skeletal survey. The perinatal management was altered due to these more specific CT findings, which aided in counseling and in the management of the pregnancy.

Preoperative Three-dimensional CT Predicts Intraoperative Findings in Hip Arthroscopy

Currently, plain radiographs and MRI are the standard imaging modalities used for diagnosing femoroacetabular impingement (FAI) and preoperative planning for arthroscopic treatment of FAI. The value of three-dimensional (3D) CT for these purposes is unclear. We therefore determined the reliability of CT assessment of FAI and whether CT findings of hip disease predict arthroscopic findings. We retrospectively assessed the preoperative CT scans of 118 patients who underwent primary hip arthroscopy. Intraoperative findings, including size of the cam lesion, presence of an acetabular labral articular disruption lesion, and one of four types of labral tear were recorded and compared with the retrospectively read CT findings. Agreement analysis between CT and intraoperative detection of FAI yielded kappa values of 0.48 for cam lesions and 0.16 for pincer lesions. Increasing values for the CT-based alpha angle correlated with increasing severity of arthroscopically assessed acetabular labral articular disruption grade. Each pattern of FAI predicted a specific labral tear type. Our data suggest CT has moderate value in predicting mechanically based labral tear patterns, although better parameters for assessment of pincer lesions are needed. Diagnostic assessment of patients with suspected FAI may be improved with use of 3D CT.

Evaluation of ossification of the posterior longitudinal ligament by three-dimensional computed tomography and magnetic resonance imaging

Detection of ossification of the posterior longitudinal ligament (OPLL) of lesions by lateral radiography is sometimes difficult because the lesions are small. Three-dimensional computed tomography (3D CT) imaging has made it possible to detect lesions not been seen by lateral radiography. To evaluate the use of 3D CT in visualizing and classifying OPLL, and the added value of magnetic resonance imaging (MRI) in determining spinal cord compression. Prospective case study in an academic department of orthopedic surgery. Patients with OPLL diagnosed by lateral radiography of the cervical spine from April 2006 to March 2007 were identified. Ossification of the posterior longitudinal ligament visualized lateral radiography was classified according to the existing scheme as continuous, segmental, mixed, or other type. Ossification of the posterior longitudinal ligament visualized by 3D CT was organized into a classification system comprising flat, irregular, or localized types and were compared with the lateral radiographic images. Magnetic resonance imaging was done to determine the extent of spinal cord compression. All 55 patients (35 men and 20 women; median age, 66 years) with OPLL were enrolled. Of these, 41 (75%) had a type of OPLL as visualized by 3D CT that corresponded with only one type of OPLL as visualized by lateral radiography. In 39 (71%) of 55, the areas of the ossified lesions visualized by 3D CT were the same as those visualized by lateral radiography. In the other 16, the lesions were either too small or too unclear to be visualized by lateral radiography. In all cases, 3D CT imaging showed that the transverse width of OPLL was within the bilateral Luschka joints, which was not noted by lateral radiography. In 13 of the 14 subjects who underwent MRI, spinal cord compression was noted at the superior or inferior edges of the ossified lesions that had been seen by 3D CT. Three-dimensional computed tomography visualization of OPLL provided the basis of a classification system, superior to lateral radiography, and provided new information about OPLL. Combining 3D CT with MRI might be useful to provide details about spinal cord compression in OPLL.

A comparison of seminal vesicle size on CT between autosomal dominant polycystic kidney disease (ADPKD) patients and normal subjects

Extrarenal manifestations are common in autosomal dominant polycystic kidney disease (ADPKD). Although seminal vesicles can also be involved in patients with ADPKD, little is known about the size differences of the seminal vesicles between ADPKD patients and normal subjects. To determine whether the size of seminal vesicles in ADPKD patients is larger than that in normal subjects with the use of three-dimensional (3D) CT. Using a retrospective case-control study design, we reviewed the findings of 696 male patients with an age range of 20-69 years who underwent contrast enhanced multi-detector computed tomography (MDCT) imaging of the kidney in our institution from August 2007 to July 2008. A total of 68 male patients with ADPKD comprised the study group. Another 68 age-matched non-ADPKD male patients comprised the control group. The size of bilateral seminal vesicles was assessed by measurement of the short dimension on axial, coronal, and sagittal images by the use of a picture archiving and communication system (PACS). The mean width of seminal vesicles in ADPKD patients was 1.70+/-0.40 cm (axial images), 1.86+/-0.45 cm (coronal), and 1.59+/-0.39 cm (sagittal). For control group subjects, the mean width was 1.53+/-0.29 cm (axial), 1.68+/-0.43 cm (coronal), and 1.48+/-0.31 cm (sagittal). The mean size differences between the ADPKD and control groups for the measured widths on axial and coronal images were statistically significant (P=0.01 and P=0.02, respectively). The width as measured on axial images showed a decrease with age in the control group subjects (linear trend, P=0.005), but no significant decrease was noted in ADPKD patients. The seminal vesicles were demonstrated to be larger in ADPKD patients as compared with normal subjects as determined with the use of 3D CT.

Evaluation of Nonsyndromic Multiple Supernumerary Teeth Using Three-Dimensional Computerized Tomography: A Case Report and Literature Review

The aims of this report are to present a case of nonsyndromic multiple supernumerary teeth and a discussion of the value of three-dimensional computerized tomography (3D CT) for precise radiographic imaging of the anomaly. Multiple supernumerary teeth without any associated syndromes are very rare. Exact radiographic presentations with an associated diagnosis of nonsyndromic multiple supernumerary teeth have not been well published. A young Chinese female patient presented with asymmetrical nonsyndromic multiple supernumerary teeth in the premolar and molar regions of her mouth. A 3D CT was used to evaluate the exact location and orientation of these teeth and to guide the treatment strategy. The use of 3D CT for the evaluation of supernumerary teeth proved to be very useful in determining their size, location, and state of development, as well as their impact on adjacent teeth and tissues in a 15-year-old patient. The 3D CT is a very useful radiological tool to assess nonsyndromic multiple supernumerary teeth.

Patterns of care study for brachytherapy: results of the questionnaire for the years 2002 and 2007 in The Netherlands.

PurposeThe goal of the ESTRO Patterns of Care study for Brachytherapy in Europe (PCBE) 2002 was to develop an aid to analyse brachytherapy practices. A 2nd version of the PCB questionnaire was created for 2007. Data over 2007 were collected at the radiotherapy institutions in The Netherlands and compared with those from 2002. The aim of this study is to describe national brachytherapy practices, to demonstrate trends, and to provide data for rational health care planning.Material and methodsData were collected using a web-based questionnaire. For each centre, a local coordinator, responsible for coordinating the questionnaires and support of the further analysis was assigned. Data from the national cancer incidence registry was used for comparison with the data from the 21 Dutch departments.ResultsThere was a decrease in low-dose rate equipment in parallel to an increase in both pulsed-dose rate and high-dose rate equipment. The use of 3D CT and MR based imaging techniques showed a slow rise. The most common clinical procedures were for prostate, gynaecological, and oesophageal tumours. A large increase (146%) in permanent implant prostate applications using 125I seeds was observed. The numbers of oesophageal and gynaecological treatments remained stable. There is concern on the low numbers of cases treated in some institutions for a few complex treatment sites. For head and neck, anal canal, paediatrics, bladder and eye interventions it ranged from 3-20 patients per year per institution.ConclusionsThe increase in number of patient treated with brachytherapy is in accordance with the increases in cancer incidence. The percentage of all radiotherapy patients treated with brachytherapy (approximately 5%) remained stable. The survey identified certain trends in resources and techniques, as well as areas of expected improvement and possible gain in clinical outcome. Data reported from this survey can be used for further planning of resources, facilities and concentration of a low-volume specialised and complex treatments.

歯顎顔面部ＣＴ画像からの歯の自動抽出

CT is an effective tool for image diagnosis because it enables noninvasive observation of internal organs. In the course of CT, 3D-CT, such as a helical scanning CT and a multi-detector row CT, has been developed. With the use of 3D-CT, organs can be observed from several viewing directions. Even now, however, 3D-CT images are generated by manual procedures to extract objective organs using the threshold method. These procedures waste time and effort. Therefore, development of highly automated and effective extracting techniques has been desired. The region growing (RG) method is one of the effective techniques of extracting internal organs. The conventional RG method, however, has some defects. Extracted regions are strongly affected by the threshold value for segmentation. A break point on a region contour yields a leakage of region. To overcome these defects, we formulated a modified region growing method with edge detection (MRGWED) which combines a three-dimensional region growing technique and an edge detection technique. Using the MRGWED, we tried to extract teeth from dentomaxillofacial 3D-CT image data.

Virtual Three-dimensional Computed Tomography Assessment of the Gastric Pouch Following Laparoscopic Roux-Y Gastric Bypass

The construction of the gastric pouch during surgery is largely based on the prevailing dogma of Roux-Y gastric bypass (RYGB) surgery. The scarce data that exist suggest that the smaller the gastric pouch, the greater the weight loss after surgery. Current estimations of pouch volume have inherent limitations. We describe the use of virtual three-dimensional computed tomography (3D CT) to assess pouch volume in the immediate postoperative period. We performed 3D CT on three patients 1 day after laparoscopic RYGB using a 16-channel multidetector CT scan. Effervescent granules were administered, along with 1 oz of water, orally to achieve gastric pouch distension. Transaxial images were transferred to the 3D workstation (Vitrea, Vital Images, Inc.) and endoluminal views of the gastric pouch were generated with perspective volume rendering. Pouch area was also measured from the standard postoperative upper gastrointestinal (UGI) contrast study. All three patients were female, with a mean preoperative body mass index (BMI) of 43.7 kg/m(2) and a mean age of 44.3 years. Mean pouch height was 4.07 cm, mean pouch width was 3.79 cm, and mean pouch depth was 2.1 cm. The mean calculated pouch volume was 31.6 cm(3). The calculated pouch area using 3D CT was statistically indistinct from the pouch area calculated using the UGI study (15.2 cm(2) vs 16.9 cm(2); p = 0.549.) For the first time, we describe the use of 3D CT to accurately measure postoperative pouch volume. In addition, we were able to confirm the utility of area (postoperative UGI) as an accurate surrogate for pouch volume.

CT-based analysis of malignant tumor volume and localization: a preliminary study

The purpose of this study was to correlate 3D-CT (3D computed tomography) volume measurements of malignant tumors with the response to treatment, and to observe bone invasion in these lesions applying a specific imaging protocol. We analyzed 17 individuals with maxillofacial malignant lesions who were submitted to spiral CT (2D-CT). The original data were transferred to an independent workstation using a 3D volume rendering package software, which was used by two examiners to obtain area and volume measurements of the lesions, independently, three times each, prior to and after treatment. The segmentation protocol was applied for the assessment of bone involvement. The difference between imaging and gold standard values was not considered significant (p > 0.05). Regarding bone invasion, three false-negatives were obtained using MPR-CT (multiplanar reconstruction) and no false-negatives were obtained using the 3D segmentation protocol. The use of 3D-CT may be a differential and important factor for expanding options regarding the localization, dimension, and clarification of lesion components.

Preoperative renal tumor evaluation by three-dimensional magnetic resonance imaging: Staging and detection of multifocality

Objectives To evaluate, retrospectively, the staging accuracy of three-dimensional magnetic resonance imaging (3D-MRI) in our institution as a prelude to a prospective comparison of 3D-MRI and 3D computed tomography (CT) for preoperative planning of partial nephrectomy. In recent years, the use of 3D-CT for preoperative evaluation and surgical planning in patients undergoing nephron-sparing surgery has gained considerable popularity. Methods The images of 26 consecutive patients evaluated by 3D-MRI as part of the preoperative imaging studies for renal tumor were evaluated retrospectively and compared with the surgical pathologic findings to evaluate the ability of 3D-MRI to predict tumor multifocality, tumor stage, collecting system invasion, and venous invasion. Results 3D-MRI accurately predicted tumor multifocality in 1 of 2 cases. Imaging identified five of seven multifocal lesions. Two subcentimeter lesions were missed. Preoperative staging was correct in 29 of 30 lesions (97% accuracy). One T3b tumor was incorrectly staged as T2. Venous invasion was identified in 2 of 3 cases (67% sensitivity), but no false-positive results were seen. 3D-MRI had 100% sensitivity and 88% specificity in the prediction of collecting system invasion. Conclusions The staging accuracy of 3D-MRI appears to be quite good. Given the accuracy of this technique, along with the popularity of 3D imaging before renal surgery, these results provide the impetus for a future study directly comparing 3D-CT with 3D-MRI in the capacity of surgical preoperative planning.

Theoretical use of 3D CT to predict method of patella realignment

Procedures for the treatment of patello-femoral malalignment are grouped into two categories, proximal realignment and distal realignment. However, no clear indications in respect of these realignments have been reported. We have tried to evaluate patello-femoral alignment three-dimensionally using CT. The results lead us to group patients with recurrent patella dislocation into three types. Type 1 comprises patients with normal patello-femoral alignment. Type 2 comprises patients whose patella only deviates laterally and who need proximal realignment. Type 3 comprises patients whose patella and tibial tuberosity both deviate laterally and who need both proximal and distal realignment.

The measurements of acetabular head area index use of 3D-CT

The measurements of acetabular head area index use of 3D-CT