CT angiography clot burden score and collateral score: correlation with clinical and radiologic outcomes in acute middle cerebral artery infarct

BACKGROUND AND PURPOSE

Clot extent, location, and collateral integrity are important determinants of outcome in acute stroke. We hypothesized that a novel clot burden score (CBS) and collateral score (CS) are important determinants of clinical and radiologic outcomes and serve as useful additional stroke outcome predictors.

MATERIALS AND METHODS

One hundred twenty-one patients with anterior circulation infarct presenting within 3 hours of stroke onset were reviewed. The Spearman correlation was performed to assess the correlation between CBS and CS and clinical and radiologic outcome measures. Patients were dichotomized by using a 90-day modified Rankin scale (mRS) score. Uni- and multivariate logistic regression models were used to assess variables predicting favorable clinical and radiologic outcomes. Receiver operating characteristic and intraclass correlation coefficient (ICC) analyses were performed. Diagnostic performance of a CBS threshold of >6 was assessed.

RESULTS

There were 85 patients (mean age, 70 +/- 14.5 years). Patients with higher CBS and CS demonstrated smaller pretreatment perfusion defects and final infarct volume and better clinical outcome (all, P < .01). CBS (P = .009) and recanalization (P = .015) independently predicted favorable outcome. A CBS >6 predicted good clinical outcome with an area under the curve of 0.75 (95% confidence interval [CI], 0.65-0.84; P = .0001), sensitivity of 73.0 (95% CI, 55.9-86.2), and specificity of 64.6 (95% CI, 49.5-77.8). The recanalization rate with intravenous recombinant tissue plasminogen activator was higher in patients with CBS >6 (P = .04; odds ratio, 3.2; 95% CI, 1.1-9.4). The ICC was 0.97 (95% CI, 0.95-0.98) and 0.87 (95% CI, 0.80-0.91) for CBS and CS, respectively.

CONCLUSIONS

CBS and CS are useful additional markers predicting clinical and radiologic outcomes.

Analysis of prostate and seminal vesicle motion: implications for treatment planning

PURPOSE

To quantify prostate and seminal vesicle positional changes (target motion) between treatment planning and delivery, and to identify the factors contributing to target motion.

METHODS AND MATERIALS

Thirty patients with adenocarcinoma of the prostate were prospectively evaluated by analyzing two sequential planning computerized tomography (CT) scans (S1, obtained prior to treatment, and S2, obtained during the fourth week of treatment) for each patient. All anatomical volumes of interest (soft tissue and bony) were reconstructed from transverse CT images and projected onto anterior and lateral beam's-eye view projections. Positional changes between S1 and S2 were eliminated by applying a rigid body translation and rotation. Target motion was then measured by recording the positional change between S1 and S2 at the edges (right, left, superior, inferior). Potential correlation of target motion with bladder volume, rectal volume, and rectal diameter changes were evaluated by linear regression analysis.

RESULTS

Neither the prostate nor seminal vesicles remained fixed with respect to bony anatomy between S1 and S2. The distribution of positional changes were generally small (< 0.5 cm), but maximum displacements of 1.5-2.2 cm did occur, particularly in the lateral view. In this study, bladder volume changes between the scans were small and did not correlate with target motion (P = 0.67). Both rectal volume and rectal diameter changes correlated with target motion for both the prostate (p = 0.004 and 0.005, respectively) and seminal vesicles (p < 0.001 and < 0.001, respectively). However, neither the initial rectal volume nor the initial rectal diameter could be used to predict subsequent target motion when evaluated either singly or as part of a multiple regression model.

CONCLUSIONS

Target motion occurs during the course of treatment planning and delivery and should be considered when designing conformal radiation fields. Although the target position at the time of planning CT may differ substantially from the mean treatment position, target motion cannot be predicted by evaluating simply measured parameters from a single scan, or double scan sequence.

Alberta Stroke Program Early CT Scoring of CT perfusion in early stroke visualization and assessment

BACKGROUND AND PURPOSE

Qualitative CT perfusion (CTP) assessment by using the Alberta Stroke Program Early CT Score (ASPECTS) allows rapid calculation of infarct extent for middle cerebral artery infarcts. Published thresholds exist for noncontrast CT (NCCT) ASPECTS, which may distinguish outcome/complication risk, but early ischemic signs are difficult to detect. We hypothesized that different ASPECTS thresholds exist for CTP parameters versus NCCT and that these may be superior at predicting clinical and radiologic outcome in the acute setting.

MATERIALS AND METHODS

Thirty-six baseline acute stroke NCCT and CTP studies within 3 hours of symptoms were blindly reviewed by 3 neuroradiologists, and ASPECTS were assigned. Treatment response was defined as major neurologic improvement when a > or =8-point National Institutes of Health Stroke Scale improvement at 24 hours occurred. Follow-up NCCT ASPECTS and 90-day modified Rankin score (mRS) were radiologic and clinical reference standards. Receiver operating characteristic curves derived optimal thresholds for outcome.

RESULTS

Cerebral blood volume and NCCT ASPECTS had similar radiologic correlations (0.6 and 0.5, respectively) and best predicted infarct size in the absence of major neurologic improvement. A NCCT ASPECT threshold of 7 and a cerebral blood volume threshold of 8 discriminated patients with poor follow-up scans (P < .0002 and P = .0001) and mRS < or =2 (P = .001 and P < .001). Only cerebral blood volume predicted major neurologic improvement (P = .02). Interobserver agreement was substantial (intraclass correlation coefficient, 0.69). Cerebral blood volume ASPECTS sensitivity, specificity, positive predictive value, and negative predictive value for clinical outcome were 60%, 100%, 100%, and 45%, respectively. No patients with cerebral blood volume ASPECTS <8 achieved good clinical outcome.

CONCLUSION

Cerebral blood volume ASPECTS is equivalent to NCCT for predicting radiologic outcome but may have an additional benefit in predicting patients with major neurologic improvement.

Prostate seed implant quality assessment using MR and CT image fusion

PURPOSE

After a seed implant of the prostate, computerized tomography (CT) is ideal for determining seed distribution but soft tissue anatomy is frequently not well visualized. Magnetic resonance (MR) images soft tissue anatomy well but seed visualization is problematic. We describe a method of fusing CT and MR images to exploit the advantages of both of these modalities when assessing the quality of a prostate seed implant.

METHODS AND MATERIALS

Eleven consecutive prostate seed implant patients were imaged with axial MR and CT scans. MR and CT images were fused in three dimensions using the Pinnacle 3.0 version of the ADAC treatment planning system. The urethra and bladder base were used to "line up" MR and CT image sets during image fusion. Alignment was accomplished using translation and rotation in the three ortho-normal planes. Accuracy of image fusion was evaluated by calculating the maximum deviation in millimeters between the center of the urethra on axial MR versus CT images. Implant quality was determined by comparing dosimetric results to previously set parameters.

RESULTS

Image fusion was performed with a high degree of accuracy. When lining up the urethra and base of bladder, the maximum difference in axial position of the urethra between MR and CT averaged 2.5 mm (range 1.3-4.0 mm, SD 0.9 mm). By projecting CT-derived dose distributions over MR images of soft tissue structures, qualitative and quantitative evaluation of implant quality is straightforward.

CONCLUSIONS

The image-fusion process we describe provides a sophisticated way of assessing the quality of a prostate seed implant. Commercial software makes the process time-efficient and available to any clinical practice with a high-quality treatment planning system. While we use MR to image soft tissue structures, the process could be used with any imaging modality that is able to visualize the prostatic urethra (e.g., ultrasound).

Radiation-associated morbidity in patients undergoing small-field external beam irradiation for prostate cancer

PURPOSE

To quantify complication rates after small-field external beam irradiation for adenocarcinoma of the prostate in a uniformly treated patient population with long follow-up using a simple tool designed to identify subtle treatment-related side effects; and to identify clinical and technical variables associated with increased morbidity after irradiation.

METHODS AND MATERIALS

A total of 441 patients with nonmetastatic adenocarcinoma of the prostate treated at the Joint Center for Radiation Therapy between 1985 and 1989 were eligible for analysis. Gastrointestinal, genitourinary, and sexual function were assessed retrospectively using a patient self-scoring, five-grade toxicity scale. Seven clinical and 15 technical variables were recorded for each patient. The association between the clinical and technical variables and rectal, bladder, and sexual side effects was examined. The 375 patients who received small-field (<12.5 x 12.5-cm) external beam irradiation via a four-field box on a 6-MV (n = 74, or 20% of patients), 8-MV (n = 140, or 37%), or 15-MV (n = 161, or 43%) linear accelerator form the basis for the study. Ninety-one percent of patients received treatment with 1.8-2.0 Gy fractions to a delivered dose of at least 66 Gy. Follow-up was complete through 62 months in living patients, with five (1%) of the entire group lost to follow-up.

RESULTS

A total of 137 of 354 evaluable patients (39%) reported rectal complications after treatment; however, 20 patients(6%) had heme-positive stools as their only symptom and 66 (19%) had mild symptoms not requiring treatment. Only 14% of the entire group required intervention. Of 356 patients, 117 (33%) evaluable for bladder complications developed genitourinary changes: In 14 patients (4%) asymptomatic hematuria occurred, 71 (20%) had mild symptoms not requiring treatment, and 32 (9%) required treatment. Of the 171 patients who were potent prior to radiation, 106 (62%) reported impotence after treatment. No statistically significant association was identified between any clinical or technical variables (including machine energy) assessed and complications.

CONCLUSIONS

In this retrospective review, treatment-related bowel and bladder side effects were not identified in the majority of patients despite the use of a grading system designed to identify subtle changes. Impotence, however, was common. Although pretreatment clinical characteristics varied among patients, they could not be used to predict the subsequent development of complications. The only treatment-related characteristic that varied in this study was machine energy, which did not correlate with complications.

Corneo-scleral rim cultures: donor contamination a case of fungal endophthalmitis transmitted by K-Sol stored cornea

This retrospective study of 549 corneo-scleral rim cultures shows that gentamicin, used in MK and K-Sol medium storage at 4 degrees C, has decreased donor contamination from 43% in whole-globe storage to 13%, but failed to eliminate coagulase negative staphylococci (37%), streptococci (28%) and fungi (28%). Donor-to-host transmitted staphylococcal and streptococcal endophthalmitis have been reported previously. We present the first documented case of donor-to-recipient transmitted fungal endophthalmitis following corneal transplantation using corneas stored in MK or K-Sol solution at 4 degrees C; Candida albicans was isolated. Recommendations are made to assess critically the true incidence of donor fungal contamination and the necessity of adding anti-mycotic agents to preservation medium for 4 degrees C storage. In the absence of ideal antimicrobial cover for corneal preservation solutions, stringent prophylactic measures to reduce contamination and continued monitoring of corneo-scleral rim cultures are warranted, if the poor visual consequences of donor-to-host transmitted endophthalmitis are to be avoided.

The perception of teratogenic risk of cocaine

While there has been a substantial increase in recreational use of cocaine by young adults, conclusive evidence for cocaine teratogenicity in humans is lacking, and even those believing the drug is teratogenic agree that the rates are quite small. While counseling pregnant women on their teratogenic risk, it was our impression that there is an unrealistically high perception of reproductive risk of cocaine. We wished to quantify the perception of teratogenic risk of cocaine by the public, physicians, and by pregnant women who were counseled following gestational exposure to the drug. Women taking cocaine during the first trimester of pregnancy (n = 54), controls with post secondary education (n = 30), and physicians (n = 30) were asked, using a visual analogue scale, to quantify the teratogenic risk of cocaine and the tendency to terminate/continue the pregnancy after first trimester exposure; in the case of the "public" and physicians this was a hypothetical question. Both physicians and the controls perceived cocaine to be teratogenic (13.4 +/- 11% risk of major malformations by physicians, and 56.5 +/- 22.8% by the "public"). The controls believed cocaine to be as hazardous as thalidomide (57.2 +/- 25.6% risk for thalidomide). Asked whether they would wish to terminate such pregnancy in their family, most physicians (56%) and the controls (70%) had a greater than 50% tendency to terminate.(ABSTRACT TRUNCATED AT 250 WORDS)

The clinical significance of elevated CSF and plasma histamine in cerebral aneurysm surgery utilizing cardiopulmonary bypass with total circulatory arrest

Recently there has been a renewed interest in the neurosurgical treatment of large cerebral aneurysms and AV malformations utilising cardiopulmonary bypass (CPB) and total circulatory arrest (TCA). However, the differing tolerance limits of coagulation and bleeding, pH control and fluid constraint are difficult to reconcile. Although clinical assessment, electro encephalogram (EEG) and intracranial pressure-monitoring assist in identification of cerebral damage, CPB and TCA inflict their own penalties with resultant uncertainty in post-operative neurological evaluation, and producing difficulties in interpretation and management. Additionally, an unanswered question is, to what extent the known cardiac and cerebral effects of circulating histamine might influence the post-circulatory arrest recovery in these patients, and whether this would further compromise the neurological result. We report our experience of 9 such cases who underwent this procedure, and were able to achieve a satisfactory neurological result in 7 patients with differing lesions. During the operation both CSF (from the open cranium) and blood (from the right internal jugular vein) were sampled at intervals for subsequent plasma histamine estimation. Despite markedly elevated histamine levels during CPB and TCA, this was not associated with an unfavourable neurological outcome. These early findings have given us encouragement to the useful role of CPB and TCA in these complex neurosurgical presentations, and raise interesting questions about the clinical importance of histamine-evoked cerebral ischaemia that has been demonstrated in experimental models.

Acute dissection of the right ventricular outflow tract after balloon dilatation in a patient with previously corrected tetralogy of Fallot

Percutaneous balloon dilatation has been used successfully to dilate various stenoses occurring after repair of congenital heart disease. Acute dissection of a stenotic right ventricular outflow tract occurred after attempted balloon dilatation in a patient with previously corrected tetralogy of Fallot.