Preoperative computed tomography scanning and arthroscopy in predicting outcome after lateral retinacular release.

We initiated a study to look at preoperative, flexed-knee, midpatellar computed tomography (CT) scans and intraoperative arthroscopic findings of lateral patellar articular degeneration in predicting the results after lateral retinacular release for failed nonoperative treatment of anterior knee pain. Twenty patients with 30 painful knees underwent preoperative flexed-knee, midpatellar CT scans that were retrospectively classified by the method of Fulkerson into normal alignment, lateral subluxation, lateral patellar tilt, and combined tilt and subluxation. Arthroscopy was performed before open lateral release. The lateral facet of the patella was graded as either minimal changes (Outerbridge I or II) or advanced (Outerbridge III or IV) changes. Patients were followed for a minimum of 2 years and graded on a standard patellofemoral rating scale. Only 22 of 30 knees that were thought to be clinically malaligned, actually were malaligned by CT scan; eight CT scans were interpreted as normal. The results were further stratified into group A (CT-documented tilt, minimal facet changes), group B (CT-documented tilt, advanced facet changes), and group C (normal CT). Ninety-two percent of group A were rated good or excellent. Twenty-two percent of Group B rated good/excellent, 33% fair, 44% poor. Only 13% of group C rated good (one patient). Based on the results of the study, we recommend lateral release for anterior knee patients with CT-proven patellar tilt who have not responded to conservative treatment and have minimal facet changes with minimal or no subluxation. Lateral retinacular release should not be offered as a treatment to the patient with a normally aligned patella because poor results will most likely result.     

The outcome of computed tomography in patients with acute renal colic from a low-volume hospital

Objective To assess the interobserver variability of unenhanced helical computed tomography (UHCT) in patients with acute renal colic admitted into a low-volume hospital. Materials and methods All admissions with acute renal colic between August 2002 and February 2004 (18 months) were registered. A total of 133 CT scans were performed on patients suspected of having a stone in the urinary tract (<24 h after admission). All records were subsequently evaluated, the acute CT scans were re-evaluated by a radiological specialist. Interobserver agreements were assessed by means of Kappa analysis. Results A total of 133 consecutive patients met the criteria for inclusion, of whom 62 were women and 71 were men. A total of 67 stones in 53 patients were identified. The variability of the radiological diagnosis (doctors under training and one consultant) was calculated, and the Kappa values were +0.66 and +0.69 for stones on the right and left side, respectively. The Kappa values for stones in ureter and the kidney were +0.79 and +0.52, respectively. In addition to stone disease, there were additional diagnoses in 30 patients (23%), out of whom seven had a malignant tumor. Conclusion In a low-volume hospital with fewer than 100 procedures a year, we found the UHCT method to be safe and reliable with a good interobserver agreement and Kappa value.     

Supratentorial dynamic computed tomography for the diagnosis of vertebrobasilar ischemic stroke

Dynamic computed tomography (CT) is an established method for the evaluation of perfusion in acute ischemic stroke, but is not frequently used to assess infratentorial ischemia. Eleven patients with vertebrobasilar ischemia underwent dynamic CT on admission and/or during the follow-up period. The time of appearance (TA) and time to peak (TTP) were mapped and differences in TA (deltaTA) and TTP (deltaTTP) between the bilateral middle cerebral artery and posterior cerebral artery (PCA) territories were calculated. Conventional angiography and brain imaging including CT and magnetic resonance imaging were also performed. The TA and TTP maps obtained within 48 hours after onset exhibited time delay in eight of nine patients in the bilateral PCA territories. deltaTA and deltaTTP were greater in patients with stenosis or occlusion of the bilateral vertebral arteries or the basilar artery, and in patients without collateral circulation via the posterior communicating arteries than in control subjects. Furthermore, TA and TTP normalized dramatically in patients with recanalization of the arteries. deltaTA and deltaTTP were also normalized. deltaTA and deltaTTP were negatively correlated with the time from onset to examination. Dynamic CT can provide important information in patients with vertebrobasilar ischemic stroke, and may allow the diagnosis of acute ischemia and monitoring of the course.     

Respiratory muscle assessment in predicting extubation outcome in patients with stroke

BackgroundPatients with cerebral infarction often present impaired consciousness and unsatisfactory extubation. We aimed to assess the respiratory mechanics components that might be associated with the success of extubation in stroke patients.MethodsTwenty consecutive patients with stroke who needed mechanical ventilation support were enrolled. The maximal inspiratory pressure, gastric and the esophageal pressure (Pdi/Pdimax), minute volume, respiratory rate, static compliance, airway resistance, rapid shallow breathing index (RSBI), inspiratory time/total respiratory cycle (Ti/Ttot), and PaO₂/FiO₂ were measured.ResultsThe group who presented success to the extubation process presented 12.5±2.2=days in mechanical ventilation and the group who failed presented 13.1±2=days. The mean Ti/Ttot and Pdi/Pdimax for the failure group were 0.4±0.08 (0.36–0.44) and 0.5±0.7 (0.43–0.56), respectively. The Ti/Ttot ratio was 0.37±0.05 (0.34–0.41; P=.0008) and the Pdi/Pdimax was 0.25±0.05 for the success group (0.21–0.28; P<.0001). A correlation was found between Pdi/Pdimax ratio and the RSBI (r=0.55; P=.009) and PaO₂/FiO₂ (r=?0.59; P=.005). Patients who presented a high RSBI (OR, 3.66; P=.004) and Pdi (OR, 7.3; P=.002), and low PaO₂/FIO₂ (OR, 4.09; P=.007), Pdi/Pdimax (OR, 4.12; P=.002) and Raw (OR, 3.0; P=.02) developed mechanical ventilation extubation failure.ConclusionMuscular fatigue index is an important predicting variable to the extubation process in prolonged mechanical ventilation of stroke patients.     

Contrast-enhanced computed tomography scanning of the postoperative spine

A prospective study of contrast-enhanced computed tomography (CT) scanning was undertaken for 17 levels previously operated upon in the lumbosacral spine in 14 patients. All levels with prior operations were scanned before and after the administration of intravenous contrast medium. A standardized technique for contrast enhancement using high doses of intravenous contrast medium was employed and a specialized technique for measuring enhancement with corrections for scan artifacts was used. Results indicated that measurable contrast enhancement occurred in 16 of 17 postoperative scars up to 12 years after surgery. Enhanced scans provided more accurate delineation of the size and margins of postoperative scarring than precontrast scans. No instances of enhancement of normal disk or recurrent herniated disk were observed. In six instances recurrent herniated disks were predicted on the basis of contrast-enhanced CT scans and subsequently confirmed at reoperation. Contrast-enhanced CT scans meticulously performed appear to permit differentiation between scarring and disk herniation in patients with recurring symptoms after operations for lumbosacral disk disease.     

Accuracy of computed tomography in predicting appendiceal perforation

Background

Some surgeons use nonoperative management with or without interval appendectomy for patients who present with perforated appendicitis. These strategies depend on accurately delineating perforation by computed tomography (CT). Since 2005, our institution has used an evidence-based definition for perforation as a hole in the appendix or fecalith in the abdomen. This has been shown to clearly separate those with a high risk of abscess from those without. To quantify the ability of CT to identify which patients would meet these criteria for perforation, we tested 6 surgeons and 2 radiologists who evaluated blinded CT scans.

Methods

A junior and senior surgical residents, 2 staff interventional radiologists, and 4 attending pediatric surgeons with 3 to 30 years of experience reviewed 200 CT scans of pediatric patients who had undergone a laparoscopic appendectomy. All CT scans were reviewed electronically, and the reviewers were blinded to the results, outcome, and intraoperative findings. None of the patients had a well-formed abscess on CT. The reviewers were asked to decide only on perforated or nonperforated appendicitis according to our intraoperative definition. Clinical admission data were reviewed and compared between groups.

Results

In total, the reviewers were correct 72% of the time with an overall sensitivity of 62% and a specificity of 81%. The overall positive predictive value was 67%, and the negative predictive value was 77%.

Conclusions

This study shows that in the absence of a well-formed abscess, the triage of patient care based on a preoperative diagnosis of perforation from CT may be imprudent and subject a portion of the population to an unnecessarily prolonged course of care.     

The use of preoperative computed tomography scanning in total hip arthroplasty

Computed tomography (CT) scanning is a useful tool in many areas of orthopedics. This prospective study reviews the authors' experience with CT scans in 73 patients studied prior to total hip arthroplasty. The CT scan is valuable in the primary total hip arthroplasty if the radiograph suggests medial, posterior, or superior acetabular wall defects. In some instances, bone grafting or other special procedures are required for the reconstruction of these defects. In the present study, preoperative CT identified an abnormality in 18 cases with deficient acetabular walls, while plain radiographs identified only six of these difficulties. Although important information for planning revision total hip arthroplasties was noted in this series, CT scans are indicated primarily in instances of suspected acetabular wall defects.     

The value of perfusion computed tomography in predicting clinically relevant vasospasm in patients with aneurysmal subarachnoid hemorrhage

Delayed cerebral ischemia remains a severe potential complication of aneurysmal subarachnoid hemorrhage (SAH) possibly leading to death and disability. We evaluated a semiquantitative and visual analysis of perfusion computed tomography (PCT) as a predictor of clinically relevant vasospasm (CRV) in patients with aneurysmal SAH. Thirty-eight patients with aneurysmal SAH were analyzed yielding 145 PCT scans. PCT, clinical examination, and transcranial Doppler ultrasound (TCD) were performed on days 3, 7, 10, and 14 after hemorrhage. Cerebral blood flow, cerebral blood volume, and time to peak (TTP) were analyzed semiquantitatively using six regions of interest, and visually for signs of cerebral hypoperfusion. CRV was defined as secondary cerebral infarction (CI) seen on cranial computed tomography scans and/or delayed neurological deterioration (DND). CI occurred in 13 (34.2 %) and DND in 11 patients (28.9 %). With TCD as pretest, TTP had a sensitivity of 90 % and a specificity of 72 % (cutoff value, 0.963) as predictor for CI. TTP’s sensitivity as predictor for DND was 90 % with a specificity of 61.1 % (cutoff value, 0.983). Visual analysis of TTP showed a negative predictive value of 100 % with a positive predictive value of 52 %. TTP is a sensitive and specific perfusion parameter in predicting CI in patients with SAH. Its use in the clinical setting may optimize the early treatment of patients at risk for vasospasm before the onset of clinical deterioration, especially when applying TCD as pretest. Further investigation in a larger patient population is required.     

The impact of computed tomography scanning on the child with renal trauma

A six-year experience using computed tomography (CT) in the diagnosis of blunt abdominal trauma was reviewed to assess the impact of CT scanning on a patient with renal injury. Three questions were evaluated: Does the increased sensitivity of the CT scan alter the indications for surgery? Does the CT scan help predict the course and eventual outcome of nonoperative therapy? Are there circumstances when the CT scan is not the most efficient and cost effective method of diagnosis? One hundred seventy six consecutive patients with suspected renal trauma were reviewed. One hundred thirty eight were evaluated by CT scan and IVP, the other 38 by excretory urogram alone. Forty four renal injuries were identified. Four of these patients required urgent surgery and four others required later operation for unsuspected congenital anomalies. The injuries sustained by the other 36 cases resolved without surgery. Each patient has been followed for 1 to 5 years following their trauma, and their status assessed by questionnaire and physical examination. The CT technique provides better definition of the injury upon which to base the decision to operate or to enter the patient into nonoperative management. The extravasation seen on CT scan is frequently exaggerated and should not be an absolute indication for exploration. The scan provides improved follow-up data as to completeness of healing and allows directions to be given to the parents concerning resumption of full physical activities. The patients with asymptomatic posttraumatic hematuria, have in our experience, a very low incidence of intraperitoneal or retroperitoneal injuries. Therefore, these patients do not require the advantages of CT scan and may be screened by the less expensive intravenous pyelogram.     

Rapid-bolus contrast-enhanced dynamic computed tomography in acute pancreatitis: a prospective study.

The purpose of this prospective study was to determine the clinicopathological significance of necrotic areas demonstrated by rapid-bolus contrast-enhanced computed tomography (CT) in patients with biochemically predicted severe pancreatitis. Although CT necrosis occurred significantly more frequently in patients with clinically severe (ten of 12) compared with mild (seven of 20) pancreatitis (P less than 0.025), seven of 17 (41 per cent) patients with CT necrosis developed clinically mild pancreatitis and six of ten (60 per cent) patients with clinically severe pancreatitis and CT necrosis recovered with conservative management. The site and extent of CT necrosis did not correlate with disease severity. Fine-needle aspiration cytology, operative and post-mortem findings and endoscopic retrograde cholangiopancreatography examinations all strongly suggested that CT necrosis represents true pancreatic necrosis. We conclude that the finding of CT necrosis is not in itself an indication for operative intervention, but that rapid-bolus contrast-enhanced dynamic CT greatly facilitates the planning and execution of surgical therapy.     

The role of computed tomography in the management of acute pancreatitis

Sixty-three patients with the clinical diagnosis of acute pancreatitis were submitted to contrast enhanced CT examination. As compared to Ranson's objective clinical parameters, CT grading according to Hill et al. as modified by Balthazar et al. was found to reflect accurately the severity of acute pancreatitis. Evaluation of serial CT examination did not reveal any significant progression in classification during the course of acute pancreatitis. The presence of hypodense areas in the pancreas as a single parameter seems to have a distinct prognostic value. In only one out of five pancreatic abscesses was the presence of gas bubbles observed on CT. It is concluded that contrast enhanced CT has a definite place in the management of acute pancreatitis.     

Computed tomography of the brain in predicting outcome of traumatic intracranial haemorrhage in Malaysian patients

Summary  Head injury is a significant economic, social and medical problem all over the world. Road accidents are the most frequent cause of head injury in Malaysia with highest risk in the young (15 to 24 years old). The associated outcomes include good recovery, possibility of death for the severely injured, which may cause disruption of the lives of their family members. It is important to predict the outcome as it will provide sound information to assist clinicians in Malaysia in providing prognostic information to patients and their families, to assess the effectiveness of different modes of treatment in promoting recovery and to document the significance of head injury as a public health problem.  Results. A total of 103 cases with intracranial haemorrhage i.e. intracerebral haemorrhage, extradural haemorrhage, subdural haemorrhage, intraventricular haemorrhage, haemorrhagic contusion and subarachnoid haemorrhage, following motor vehicle accidents was undertaken to study factors contributing to either good or poor outcome according to the Glasgow Outcome Scale. Patients below 12 years of age were excluded. The end point of the study was taken at 24 months post injury.  The selected variables were incorporated into models generated by logistic regression techniques of multivariate analysis to see the significant predictors of outcome as well as the correlation between the CT findings with GCS.  Conclusion. Significant predictors of outcome were GCS on arrival in the accident emergency department, pupillary reflex and the CT scan findings. The CT predictors of outcome include ICH, EDH, IVH, present of SAH, site of ICH, volumes of EDH and SDH as well as midline shift.