Is CT angiography sufficient for prediction of resectability of periampullary neoplasms?

The optimal preoperative evaluation of periampullary neoplasms remains controversial. The aim of this study was to analyze the accuracy of helical computed tomography (CT) and CT angiography with three-dimensional reconstruction in predicting resectability. Between March 1996 and May 1999, a total of 100 patients with periampullary neoplasms were prospectively staged by helical CT and CT angiography with three-dimensional reconstruction. Vascular involvement was graded from 0 to 4, with grade 0 representing no vascular involvement and grade 4 total encasement of either the superior mesenteric vein or artery. Patients with grade 4 lesions were considered unresectable. Sixty-eight patients underwent surgical exploration with intent to perform a pancreaticoduodenectomy. Forty-four lesions were grade 0, five were grade 1, eight were grade 2, and 11 were grade 3. Resectability for grades 0 to 3 was 96%, l00%, 50%, and 9%, respectively, for an overall resectability rate of 76%. Resectability in patients with vascular encroachment (grade 2) is usually determined by the extent of local disease rather than the presence of extrapancreatic disease. Resection is rarely possible in patients with evidence of vascular encasement (grade 3). Additional imaging modalities such as diagnostic laparoscopy are superfluous in patients with no evidence of local vascular involvement on CT angiography (grades 0 and 1) because of the high resectability rate and infrequency of unsuspected distant metastatic deposits.     

Application of CT 3D reconstruction in diagnosingatlantoaxial subluxation

To evaluate and compare the diagnosticvalue in atlantoaxial subluxation by CT three-dimensional(3D) reconstruction.     

Accuracy of FDG-PET–CT in the Diagnostic Work-up of Vascular Prosthetic Graft Infection

ObjectivesTo investigate the diagnostic accuracy of fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) compared with computed tomography (CT) scanning and added value of fused FDG-PET–CT in diagnosing vascular prosthetic graft infection.DesignProspective cohort study with retrospective analysis.MaterialsTwenty five patients with clinically suspected vascular prosthetic infection underwent CT and FDG-PET scanning.MethodsTwo nuclear medicine physicians assessed the FDG-PET scans; all CT scans were assessed by two radiologists. Fused FDG-PET/CT were judged by the radiologist and the nuclear medicine physician. The concordance between CT and FDG-PET and the inter-observer agreement between the different readers were investigated.ResultsFifteen patients had a proven infection by culture. Single FDG-PET had the best results (sensitivity 93%, specificity 70%, positive predictive value 82% and negative predictive value 88%). For CT, these values were 56%, 57%, 60% and 58%, respectively. Fused CT and FDG-PET imaging also showed high sensitivity and specificity rates and high positive and negative values. Inter-observer agreement for FDG-PET analysis was excellent (kappa = 1.00) and moderate for CT and fused FDG-PET–CT analysis (0.63 and 0.66, respectively).ConclusionFDG-PET scanning showed a better diagnostic accuracy than CT for the detection of vascular prosthetic infection. This study suggests that FDG-PET provides a useful tool in the work-up for diagnosis of vascular prosthetic graft infection.     

Value of multidetector spiral CT in diagnosis of acute thoracolumbar spinal fracture and fracture-dislocation

Objective: To investigate the diagnostic value of multidetector spiral CT (MSCT) in acute thoracolumbar spinal fracture and fracture-dislocation. Methods: CT imaging files of 152 consecutive traumatic patients with thoracolumbar fractures were retrospectively reviewed. MSCT scannings were performed with a collimation of 3-5 mm and a pitch of 5.5. The postprocessing included sagittal and coronal multiplannar reconstruction, and 3-D reconstruction. Results: There were 88 cases of compression fracture, 54 cases of burst fracture and 10 cases of fracture-dislocation. Transverse images of MSCT could visualize all fractures directly and determine whether spinal canal was intact. Postprocessing image was helpful in depicting the displacement of fragment and orientation of dislocation. Conclusions. MSCT plays an important role in diagnosis and management of acute thoracolumhar spinal fracture and fracture-dislocation.     

CT and MRI diagnosis of acute traumatic hepatic rupture： analysis of ten cases

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Preoperative Staging of Patients with Liver Metastases of Colorectal Carcinoma. Does PET/CT Really Add Something to Multidetector CT?

Purpose  

This study was designed to determine prospectively whether the systematic use of PET/CT associated with conventional techniques could improve the accuracy of staging in patients with liver metastases of colorectal carcinoma. We also assessed the impact on the therapeutic strategy.     

Abdominal splenosis： CT and MRI features of 2 cases

Splenosis is ectopic autotransplantation of splenic tissue after splenic trauma or surgery. 1 The most frequent locations are the surface of visceral peritoneum and parietal peritoneum. Liver and retroperitoneum are rarely involved. 1,2 We present here 2 cases of splenosis involving the liver and retroperitoneum with clinical information, imaging findings, and literature review.     

Geometrical dimensions of the lower lumbar vertebrae – analysis of data from digitised CT images

The precise dimensions of the lumbar vertebrae and discs are critical for the production of appropriate spinal implants. Unfortunately, existing databases of vertebral and intervertebral dimensions are limited either in accuracy, study population or parameters recorded. The objective of this study is to provide a large and accurate database of lumbar spinal characteristics from 126 digitised computed tomographic (CT) images, reviewed using the Picture Archiving Communication System (PACS) coupled with its internal measuring instrumentation. These CT images were obtained from patients with low back pain attending the spinal clinic at the Hammersmith Hospitals NHS Trust. Measurements of various aspects of vertebral dimensions and geometry were recorded, including vertebral and intervertebral disc height. The results from this study indicated that the depth and width of the vertebral endplate increased from the third to the fifth lumbar vertebra. Anterior vertebral height remained the same from the third to the fifth vertebra, but the posterior vertebral height decreased. Mean disc height in the lower lumbar segments was 11.6 ± 1.8 mm for the L3/4 disc, 11.3 ± 2.1 mm for the L4/5, and 10.7 ± 2.1 mm for the L5/S1 level. The average circumference of the lower endplate of the fourth lumbar vertebra was 141 mm and the average surface area was 1492 mm². An increasing pedicle width from a mean of 9.6 ± 2.2 mm at L3 through to 16.2 ± 2.8 mm at L5 was noted. A comprehensive database of vertebral and intervertebral dimensions was generated from 378 lumbar vertebrae from 126 patients measured with a precise digital technique. These results are invaluable in establishing an anthropometric model of the human lumbar spine, and provide useful data for anatomical research. In addition this is important information for the scientific planning of spinal surgery and for the design of spinal implants. Received: 9 November 1998 Revised: 14 January 2000 Accepted: 26 January 2000     

Value of Multidetector Row CT in the Assessment of Longitudinal Extension of Cholangiocarcinoma—Correlation Between MDCT and Microscopic Findings

Background  A few authors have reported the value of multidetector row CT (MDCT) for evaluating the longitudinal extent of cholangiocarcinoma. They have not focused on CT attenuation of a tumor and actual tumor extent along the bile ducts. We designed the present study to analyze attenuation. Methods  Between January 2003 and July 2005, 113 consecutive patients with cholangiocarcinoma underwent a surgical resection following MDCT. Of these MDCT studies, 73 (perihilar cholangiocarcinoma, n = 62; middle and distal cholangiocarcinoma, n = 11) were suitable for analysis, and the patients were enrolled in the study. Patients were divided according to tumor hypoattenuation and hyperattenuation on MDCT. Histologic differentiation, desmoplastic reaction, and vascular density were microscopically compared with the tumor attenuation to differentiate the characteristics of the attenuation. The extent of cancer along the bile duct diagnosed by MDCT was compared with the actual extent determined by the microscopic findings. Results  Hyperattenuated tumor was observed in 40 patients. There was no difference in histologic differentiation, desmoplastic reaction, or vascular density between the hyperattenuated and hypoattenuated cholangiocarcinomas. Neither the proximal nor the distal borders between the normal and thickened bile duct wall could be determined in the 33 patients with hypoattenuated tumor; in contrast, an accurate assessment of extent of tumor was obtained in 76% of the proximal borders and 82% of the distal borders in the 40 patients with hyperattenuated tumor. Conclusions  Although the cause of the difference between the hyperattenuated and hypoattenuated cholangiocarcinoma still is unclear, MDCT can be an alternative to direct cholangiography in selected patients with hyperattenuated cholangiocarcinoma.     

Is There a Benefit of Frequent CT Follow-up After EVAR?

ObjectiveImaging follow-up (FU) after endovascular aneurysm repair (EVAR) is usually performed by periodic contrast-enhanced computed tomography (CT) scans. This study aims to evaluate the effectiveness of CT-FU after EVAR.MethodsIn this study, 279 of 304 consecutive patients (261 male, aged 74 years (interquartile range (IQR): 70–79 years) with a median abdominal aortic aneurysm (AAA) diameter of 58 mm (IQR: 53–67 mm)) underwent at least one of the yearly CT scans and plain abdominal films after EVAR. All patients received Zenith stent-grafts for non-ruptured AAAs at a single institution. Patients were considered asymptomatic when a re-intervention was done solely due to an imaging FU finding. The data were prospectively entered in a computer database and retrospectively analysed.ResultsAs a follow-up, 1167 CT scans were performed at a median of 54 months (IQR: 34–74 months) after EVAR. Twenty-seven patients exhibited postoperative AAA expansion (a 5-year expansion-free rate of 88 ± 2%), and 57 patients underwent 78 postoperative re-interventions with a 5-year secondary success rate of 91 ± 2%. Of the 279 patients, 26 (9.3%) undergoing imaging FU benefitted from the yearly CT scans, since they had re-interventions based on asymptomatic imaging findings: AAA diameter expansion with or without endoleaks (n = 18), kink in the stent-graft limbs (n = 4), endoleak type III due to stent-graft limb separation without simultaneous AAA expansion (n = 2), isolated common iliac artery expansion (n = 1) and superior mesenteric artery malperfusion due to partial coverage by the stent-graft fabric (n = 1).ConclusionsLess than 10% of the patients benefit from the yearly CT-FU after EVAR. Only one re-intervention due to partial coverage of a branch by the stent-graft would have been delayed if routine FU had been based on simple diameter measurements and plain abdominal radiograph. This suggests that less-frequent CT is sufficient in the majority of patients, which may simplify the FU protocol, reduce radiation exposure and the total costs of EVAR. Contrast-enhanced CT scans continue, nevertheless, to be critical when re-interventions are planned.     

Do CT scans aid assessment of distal tibial physeal fractures?

Distal tibial physeal fractures are the second most common growth plate injury and the most common cause of growth arrest and deformity. This study assesses the accuracy of pre-operative planning for placement of the screws in these fractures using either standard radiographs or CT scans. We studied 62 consecutive physeal fractures over a period of four years. An outline of a single cut of the CT scan was used for each patient. An ideal position for the screw was determined as being perpendicular to and at the midpoint of the fracture. The difference in entry point and direction of the screw between the ideal and the observers' assessments were compared using the paired Student's t-test. There was a statistically significant improvement (p < 0.0001) in the accuracy of the point of insertion and the direction of the screw on the pre-operative plan when CT scans were used rather than plain radiographs. We would, therefore, recommend that CT scans are routinely used in the pre-operative assessment and treatment of distal tibial physeal fractures.     

Reliability of the 8?Week Time Point for Single Assessment of Midcarpal Fusion by CT Scan

High rates of nonunion have recently been reported for midcarpal fusions. Due to curvature and overlap of carpal interfaces, two dimensional films are not reliable in determining union of a midcarpal fusion. Computed tomography is the most reliable radiographic method of evaluating osseous union. Initiating motion as soon as fusion has occurred is a priority with the goal of maximizing final range. Cost control in healthcare makes obtaining serial scans unreasonable. The single optimal time point for a computed tomography scan to determine union of a midcarpal fusion remains to be determined. A prospective protocol selected 8 weeks post operative as the point in time to obtain the single determining scan. Forty-six consecutive midcarpal fusions with scaphoidectomy were retrospectively analyzed for the reliability of this time point. All fusions had achieved union by 8 weeks and only this one scan was clinically necessary to advance the patients on to full range of motion without a splint at that time.     

Spiral CT arthrography of multiplanar reconstruction and virtual arthroscopy technique in diagnosis of knee with internal derangements

To evaluate the values of spiral CTarthrography with multiplanar reconstruction and virtualarthroscopy technique in diagnosis of internal derangementsof the knee.     

Accuracy of helical CT in the detection of pulmonary metastases: is intraoperative palpation still necessary?

Background

Pulmonary metastasectomy is well accepted in patients with isolated metastases from an extrathoracic malignancy. The standard approach involves careful intraoperative palpation of the lungs because more metastases are frequently found than were seen by preoperative conventional computed tomography (CT). Helical CT detects more nodules than conventional CT, raising the question of whether palpation of the lungs is still necessary if helical CT is used.

Methods

Retrospective review was done of medical records of patients undergoing metastasectomy with curative intent at the University of North Carolina (UNC) from 1999 to 2003. During this time at UNC, helical CT was routinely performed using a standardized technique, and all metastasectomy patients underwent manual lung palpation. The primary outcome measure of this study was whether malignant nodules (palpated, resected, and proven histologically) were reliably detected preoperatively by helical CT.

Results

Thirty-four patients were identified who underwent 41 cases of pulmonary metastasectomy with lung palpation. Our analysis revealed that in 22% (9/41), more malignant nodules were found intraoperatively than were detected by helical CT. Of 88 malignant intraparenchymal nodules, 69 were detected by helical CT (sensitivity 78%). Subset analyses of tumor histology, disease-free interval, the presence of a single lesion versus multiple lesions, the interval between the CT and metastasectomy, and the size of the largest lesion were unable to identify a cohort in which lung palpation was no longer needed after preoperative helical CT.

Conclusions

Despite the advent of helical CT, palpation of the lung is necessary if the goal is to resect all detectable disease.     

CT features of high-voltage electric shock-induced liver injury:a case report

Few reports concerning the CT feature of electric shock-induced liver damages have ever been published. This paper presents such a case treated in our Institute.     

Outcomes of type 2 endoleaks detected on venous phase CT arteriography

Purpose

The majority of type 2 endoleaks (T2EL) are identified on computed tomography angiography (CTA) both on arterial and venous phase. There is a subset of T2EL that are demonstrated only on venous phase CTA. This study was done to report the outcomes of T2EL detected only on venous phase CTA.