Radiation dose is reduced with a single-pass whole-body multi-detector row CT trauma protocol compared with a conventional segmented method: initial experience

Radiation dose data were collected from a calibrated multi-detector row computed tomographic (CT) scanner during trauma CT. One protocol (used with 10 case subjects) involved a single-pass continuous whole-body acquisition from cranial vertex to symphysis pubis, while the other, conventional protocol (used with 10 control subjects) involved scouting and scanning body segments (head, cervical spine, chest, abdomen, and pelvis) individually. Technical factors were kept constant within each body segment for the single-pass and the segmented protocols. Statistics included univariate analysis, two-tailed t testing to evaluate statistical significance of the summary statistic, and power and subject population contingency tables. The mean dose length product (DLP) with the single-pass protocol was 17% lower than the sum of the DLPs of each of the individual body segment scans (P <.001). Analysis of power and subject population by using a difference in mean of 500 mGy. cm and an alpha of.05 revealed a (1-beta) of higher than 0.90 for a sample of 10 patients. Thus, a whole-body single-pass trauma protocol, compared with a typical segmented acquisition protocol matched for imaging technique, resulted in reduced total radiation dose. The reduction in radiation dose is thought to represent a reduction in redundant imaging at overlap zones between body segments scanned in the segmental protocol but not in the continuous acquisition.     

Cerebral fractional anisotropy score in trauma patients: a new indicator of white matter injury after trauma

OBJECTIVE: Previous studies evaluating quantitative cerebral white matter diffusion anisotropy indexes have shown alteration in patients after trauma. To date, no clinically applicable scale exists by which to gauge and test the relevance of these findings. We propose the cerebral fractional anisotropy score in trauma (C-FAST) as an index of white matter injury, and we correlate C-FAST with several predictor and outcome variables. MATERIALS AND METHODS: Fifteen patients were randomly selected from the trauma surgery service. Thirty control patients were randomly selected from the emergency department. All patients were subjected to MRI evaluation, including a diffusion-weighted sequence. Data extracted from the record of each subject included Glasgow Coma Scale, revised trauma score, Abbreviated Injury Scale, initial head CT results, patient disposition, length of hospital stay, and length of stay in intensive care unit. Region of interest measurements were made in fractional anisotropy maps in each of 12 white matter regions. Univariate statistics and a two-tailed t test were performed on the raw fractional anisotropy data. Data were then dichotomized using thresholds from univariate statistics. A C-FAST score was devised from the dichotomized data. Logistic regression analyses were performed among the C-FAST, outcome, and predictor data. RESULTS: Good correlation was noted between the C-FAST and death, hospital stay greater than 10 days, and intensive care unit stay greater than 5 days. Correlation with discharge to rehabilitation facility was good when adjusted for age and sex. Glasgow Coma Scale, revised trauma score, and Abbreviated Injury Scale show good correlation as predictors of a critical C-FAST. CONCLUSION: The C-FAST is a promising index derived from MRI diffusion fractional anisotropy measurements that shows successful correlation with outcome and predictor variables. A larger investigation is needed to verify the validity and stability of the correlations.     

Metabolism of homoharringtonine,a cytotoxic component of the evergreen plant Cephalotaxus harringtonia

Homoharringtonine (HHT), first isolated from the Chinese evergreen Cephalotaxus harringtonia, has been demonstrated to have a broad antitumor activity in rodents and antileukemic effects in humans. We found that HHT was metabolized to an acid product [HHT-acid; 2'-hydroxy-2'-(alpha-acetic acid)-6'-hydroxy-6'-methylheptanoyl cephalotaxine] when incubated with either human plasma or mouse plasma in vitro. The conversion was faster, however, in mouse plasma, and was both time- and temperature-dependent. Boiled plasma prevented the conversion of HHT to HHT-acid, suggesting that the conversion was enzymatically mediated. When mice were given an intravenous (i.v.) injection of HHT (4 mg/kg), the HHT-acid metabolite was found in both plasma and urine. In mice, HHT-acid was detected in the plasma within 5 min of the i.v. injection of HHT and declined rapidly thereafter. The initial half-lives (t 1/2 alpha) of HHT and HHT-acid were 9 and 17 min, respectively. Twenty-four hours after HHT dosing in mice, approximately 29% of the dose was excreted in the urine as HHT and 20% as HHT-acid. High-pressure liquid chromatography and mass spectrometry were used to confirm the identity and quantify HHT and its metabolite, HHT-acid. The HHT concentration inhibiting 50% of the growth of human leukemic HL-60 cells was 20 ng/ml, while for HHT-acid it was 14,500 ng/ml, indicating that the acid form was more than 700 times less cytotoxic than HHT. The lethal dose of HHT affecting 50% (LD50) of mice was 6.7 mg/kg, but HHT-acid produced no apparent toxic effects at doses up to 280 mg/kg.     

Imprint cytology versus frozen section: intraoperative analysis of sentinel lymph nodes in breast cancer

Background: Intraoperative analysis of the sentinel node status in breast cancer adds the benefit of proceeding to axillary dissection at the same time as the primary breast operation, without the need for a second trip to theatre. However, the method of intra­operative analysis must be both rapid and accurate for use in this setting. Methods: A prospective series of 20 consecutive patients in one hospital who underwent sentinel node biopsy was performed. Intraoperative evaluation by imprint cytology and frozen section was compared with the final histopathological results. The time taken for both procedures was recorded. Results: A total of 21 sentinel node procedures was performed. The sentinel node was found in 20 procedures (95%). The average time to perform intraoperative pathological analysis was 17 min (range: 5?35 min). Of the eight positive sentinel nodes, five were positive on imprint cytology alone and five were positive on frozen section alone (62.5% accuracy). The statistical false negative rate was 18.8% and the ‘false reassurance rate’ (patients with an initially negative node that was subsequently positive on formal histology who required a second trip to theatre for axillary dissection) was 37.5%. All patients with a negative sentinel node had a negative axilla. Conclusions: Intraoperative analysis of sentinel lymph nodes in breast cancer can be performed quickly. Imprint cytology and frozen section show comparable accuracy in predicting sentinel node status.     

Acyloxymethyl acidic drug derivatives: in vitro hydrolytic reactivity

A series of acyloxymethyl drug derivatives of the NH-acidic drugs, phenytoin and theophylline and of the carboxylic acid drugs, thioctic acid and indomethacin, were prepared in order to determine the effect of varying the nature of the drug on the in vitro rate of hydrolysis catalyzed by porcine liver esterase and human plasma. The acyl portion was comprised of either valeric acid (val) or γ-linolenic acid (GLA). With the exception of some GLA prodrugs, the derivatives displayed first-order kinetics in both enzyme systems. The NH-acidic drug derivatives were hydrolyzed faster than the carboxylic drug derivatives by porcine liver esterase and human plasma. It was found that the short chain valeric acid derivatives were hydrolyzed faster than the GLA derivatives. The rates of hydrolysis for the relatively smaller prodrugs of theophylline and thioctic acid were greater than the rates of hydrolysis for the bulkier phenytoin and indomethacin prodrugs indicating steric hindrance was important. The lipophilicity index, log K, of the valeric acid drug derivatives was plotted against the logarithm of the hydrolysis rate constant, k, and it was observed that log k decreased with an increase in log K. A comparison of these results with those of previous studies where the alkyl and acyl moieties were varied of acyloxyalkyl theophylline derivatives has provided a rationale, based on lipophilicity, for the structure of a prodrug to be designed based on an in vitro desired rate of hydrolysis.     

CT evaluation of appendicitis and diverticulitis. Part II: Diverticulitis

CT has become the primary imaging modality for evaluation of possible diverticulitis. In studies of patients taken to surgery for suspected diverticulitis without first undergoing CT, 25–33 % of resected specimens show no inflammation. The overall accuracy of CT in establishing or excluding the diagnosis is between 84 and 99 %. In patients without diverticulitis, an alternative diagnosis is seen in 50–58 % of cases. The appearance of carcinoma with perforation and diverticulitis may be the same, and, as a result, the degree of certainty in the diagnosis should be stated. Techniques include use of either oral and intravenous contrast or rectally administered contrast. No case of colonic perforation due to rectally administered water-soluble contrast for CT has been reported, although there have been cases of perforation using barium and fluoroscopy. All techniques scan the entire abdomen and pelvis since there are frequent alternative diagnoses seen beyond the area of initial pain.     

The coexistence of gestational hypertension and diabetes: influence on pregnancy outcome

Gestational hypertension (GHTN) and gestational diabetes mellitus (GDM) are both insulin resistance states. Perinatal outcome of GHTN or GDM alone are well established, but their combined effect on pregnancy outcome is underinvestigated. Our objective was to determine if pregnancies complicated by GHTN/GDM have higher rates of morbidity. We identified nulliparous women with singleton pregnancies delivering at 37 to 40 weeks of gestation from 1995 to 2004 from a database. Outcomes of pregnancies complicated by GHTN only, GDM only, or combined GHTN/GDM were compared with controls. Data analysis included the Mann-Whitney U test, the Kruskal-Wallis H test, and analysis of variance. Multivariate analysis was used to adjust for confounders. Of 14,880 patients, there were 11,349 controls, 2604 GHTN, 728 GDM, and 199 GHTN/GDM. After controlling for covariates, GHTN significantly increased cesarean section (C/S) rate (odd ratio [OR], 1.62; confidence interval [CI], 1.47 to 1.78), rates of admittance to the neonatal intensive care unit (NICU), and birth of large for gestational age (LGA) infants. GDM significantly increased C/S (OR, 1.42; CI 1.21 to 1.66), rates of NICU admission (OR, 1.32; CI, 1 to 1.75), birth of LGA (OR, 1.51; CI 1.14 to 1.98), and macrosomic infants (OR, 1.53; CI, 1.12 to 2.08). Rates of LGA infants (OR, 1.85; CI, 1.19 to 2.86) and C/S (OR, 2.03; CI, 1.52 to 2.71) were significantly increased with GHTN/GDM. We concluded that GHTN or GDM is associated with increased rates of adverse outcomes. Their coexistence further increases adverse perinatal outcomes.     

CT evaluation of appendicitis and diverticulitis. Part I: Appendicitis

CT has become the primary imaging modality for evaluation of possible appendicitis. About 20 % of patients taken to surgery for appendicitis without CT have had a normal appendix removed. CT has demonstrated overall accuracy of between 93 % and 98 %. Alternative diagnoses are seen in 34–80 % of patients without appendicitis but who were suspected of having appendicitis. For evaluation of appendicitis different techniques have been successful, including the use of no contrast, use of oral and intravenous contrast, and use of rectally administered contrast. Scanning of the entire abdomen and pelvis and scanning of an area limited to the right lower quadrant are also options. Ultrasonography has been shown to have a role in pediatric patients. If ultrasonography is positive, CT is not necessary. If ultrasonography is negative, CT should follow.     

Eating disorder behaviors of ethnically diverse urban female adolescent athletes and non-athletes.

This study compared Caucasian, Hispanic, and African-American urban adolescent athlete and non-athlete females for relative frequency of behavioral and psychological indices of eating disorders, while controlling for physical size. High school female athletes (n=571) and non-athletes (n=463) completed the Eating Disorder Inventory (EDI) composed of eight subscales that measure behavioral and psychological indices common in anorexia nervosa and bulimia nervosa. The MANCOVA for the main effect of ethnicity showed Caucasians and Hispanics scored significantly higher than African-Americans on six of the eight behavioral and psychological subscales of the EDI (p<0. 05). A MANCOVA for the main effect of athletic status showed no significant differences between athletes and non-athletes on the behavioral subscales of the EDI (p>0.05). This study suggests that Hispanic and Caucasian urban adolescent females are comparably more at-risk for eating disorders than African-American urban adolescent females. In addition, athletes were no more at-risk than non-athletes for eating disordered behaviors.