Quantitative CT Predictors of Portal Venous Intervention in Uncontrolled Variceal Bleeding.

OBJECTIVE. The purpose of this study was to quantify abdominal CT predictors of endoscopically refractory, uncontrolled variceal hemorrhage requiring portal venous intervention. MATERIALS AND METHODS. From 2009 to 2018, 64 patients with endoscopically refractory variceal hemorrhage requiring portal venous intervention (variceal hemorrhage group) and 67 patients without hemorrhage but with symptomatic, pressure gradient-proven portal hypertension (control group) underwent CT. CT scans were retrospectively reviewed for the following: varix size, variceal intraluminal protrusion, liver and spleen volumes, and portal vein diameter. RESULTS. Gastric variceal protrusion was found to be a strong CT parameter associated with refractory hemorrhage (mean depth, 0.75 mm in variceal hemorrhage group vs -2.91 mm in control group; p = 0.001). Gastric varix size was also associated with variceal hemorrhage (mean diameter, 8.03 vs 6.51 mm; p = 0.001). However, this trend was not observed in the sizes of the esophageal varices (mean diameter, 6.28 vs 6.43 mm; p = 0.370). Larger spleen volume (mean, 1312 vs 1152 cm3; p = 0.029) and liver volume (mean, 1514 vs 1143 cm3; p = 0.004) were also found to be predictors of variceal hemorrhage. Significant CT threshold findings included gastric variceal protrusion depth more than 0 mm (odds ratio [OR], 6.44), gastric varix size more than 6 mm (OR, 3.89), spleen volume more than 1000 cm3 (OR, 2.63), and liver volume more than 1000 cm3 (OR, 2.82). CONCLUSION. Quantitative imaging parameters on abdominal CT, such as intraluminal protrusion of gastric varices, gastric varix size, and larger spleen and liver volumes, were predictive of portal venous intervention, whereas esophageal varix size was not.

The effects of vitamin D3 during pregnancy and lactation on offspring physiology and behavior in sprague-dawley rats.

Recent findings show that developmental vitamin D deficiency leads to altered brain morphology and behavioral development in the rat offspring. We examined the effects of different dietary vitamin D levels in rat dams on behavior and biochemistry of the offspring. Females were divided into five conditions and received diets containing 0, 1,5, 3.3, 6.0, or 10.0 IU/g of vitamin D3 from mating to weaning. Offspring were tested as juveniles and as adults for anxiety, social learning and behavior, and locomotion. Results show that both deficient and excessive levels of vitamin D3 in juveniles lead to altered physiology and behavior. In juveniles but not adults, variations in vitamin D were related to variations in measures of anxiety and marginally, activity levels. For social behaviors, both juveniles and adults were affected by mothers' diets. In general, offspring of animals receiving abnormal concentrations of vitamin D showed the most deficits.

Robot-assisted radical prostatectomy in patients with previous renal transplantation.

PURPOSE: To evaluate the outcomes of robot-assisted radical prostatectomy (RARP) in patients with previous renal transplantation. PATIENTS AND METHODS: We retrospectively identified all patients who had undergone RARP for localized prostate cancer between 2005 and 2008 at a single institution (N=228). Of these, three patients were renal transplant recipients. A four-arm robotic configuration was used in all patients. Port placement was modified in two of the three renal transplant recipients to avoid trauma to the renal allograft. Preoperative demographics, perioperative parameters, and postoperative outcomes were reviewed. RESULTS: RARP was completed successfully in all three renal transplant recipients. As expected, the American Society of Anesthesiologists score (3.3 vs 2.4) and Charlson weighted index of comorbidity (4.7 vs 2.4) were greater in previous transplant patients. There were no major differences in mean age, Gleason score, body mass index, estimated blood loss, operative time, complications, or oncologic outcomes between the two groups. Each of the patients with renal allografts had an undetectable prostate-specific antigen level and was continent (needing no pads) at 13 months of follow-up. CONCLUSIONS: RARP is feasible in patients with a previous renal transplant. Although technically more challenging, RARP can be performed in previous transplant patients with acceptable morbidity and oncologic outcomes similar to those of other prostate cancer patients.

Ultra-low-dose protocol for CT-guided lung biopsies.

PURPOSE: Computed tomography (CT) scans are a significant source of radiation to patients. It was hypothesized that technical success and complication rates would not be significantly changed by radically lowering the CT dose during lung biopsies with an ultra-low-dose (ULD) protocol. MATERIALS AND METHODS: A total of 100 consecutive patients aged 11-89 years who underwent biopsies of lung lesions were evaluated. Technical parameters were altered halfway through the study from the standard dose (140 kV localizing/100 kV subsequent guiding scans with auto-mA) to a ULD protocol (100 kV, 7.5 mAs) as part of a quality initiative. ULD studies were evaluated subjectively for image quality on a five-point scale. Patients' body mass indexes, total estimated radiation doses (dose-length product), technical success rates, and complications were compared between the standard-dose and the ULD groups. RESULTS: Average radiation dose was reduced from 677.5 mGy·cm for the standard-dose group to 18.3 mGy·cm for the ULD group (P < .0001). In the ULD group, image quality was rated as adequate or better in 96% of cases. Pneumothoraces necessitating chest tube placements occurred in 10% and 6% of cases in the ULD and standard dose groups, respectively (P = .715). Technical success rates of 92% and 98% were obtained in the ULD and standard dose groups, respectively (P = .362). CONCLUSIONS: Radiation dose to the chest during CT-guided percutaneous lung biopsies is reduced greater than 95% versus a standard protocol through the use of a ULD CT protocol without decreasing technical success or patient safety.

Effect of reduced radiation CT protocols on the detection of renal calculi.

PURPOSE: To determine the effect of reduced radiation (tube charge, measured as milliamperes per second) protocols on the sensitivity and specificity of multidetector computed tomography (CT) in the detection of renal calculi. MATERIALS AND METHODS: This Health Insurance Portability and Accountability Act-compliant human cadaveric study was approved by the Department of Anatomic Pathology with strict adherence to the university policy for handling donor specimens. Three to five renal stones (range, 2.0-4.0 mm) were randomly placed in 14 human cadaveric kidneys and scanned with a 16-detector CT scanner at 100, 60, and 30 mAs while maintaining other imaging parameters as constant. Following acquisition, images were reviewed independently by two radiologists who were blinded to the location and presence of renal calculi. Interobserver agreement was measured with kappa statistics. The McNemar test was used to compare the sensitivity and specificity between different radiation settings for each reader. RESULTS: Specificity for both readers ranged from 105 (0.95; 95% confidence interval [CI]: 0.90, 0.99) to 109 (0.99; 95% CI: 0.95, 1.0) of 110 without significant differences between 30 and 60 mAs to the standard 100 mAs (P = .500 to >.999). Sensitivity ranged from 42 (0.74; 95% CI: 0.60, 0.84) to 48 (0.84; 95% CI: 0.72, 0.93) of 57, also without significant differences (P = .070 to >.999). When renal calculi detection rates were analyzed by size, 3.0-4.0-mm stones were detected well at all tube charge settings, ranging from 86%-90% (n = 21 for 3.0-mm stones) to 95%-100% (n = 19 for 4.0-mm stones). However, 2.0-mm stones were poorly detected at all tube charge settings (29%-59%; 5-10 of 17). Overall interobserver agreement for stone detection was excellent, with kappa = 0.862. CONCLUSION: Decreasing the tube charge from 100 to 30 mAs resulted in similar detection of renal stones while reducing patient radiation exposure by as much as 70%. Multidetector CT scanning parameters should be tailored to minimize radiation exposure to the patients while helping detect clinically significant renal stones.

Effect of low dose radiation computerized tomography protocols on distal ureteral calculus detection.

PURPOSE: Unenhanced multidetector computerized tomography is the imaging modality of choice for urinary calculi but exposes patients to substantial radiation doses with a subsequent risk of radiation induced secondary malignancy. We compared ultra low dose and conventional computerized tomography protocols for detecting distal ureteral calculi in a cadaveric model. MATERIALS AND METHODS: A total of 85 calcium oxalate stones 3 to 7 mm long were prospectively placed in 14 human cadaveric distal ureters in 56 random configurations. The intact kidneys, ureters and bladders were placed in a human cadaveric vehicle and computerized tomography was performed at 140, 100, 60, 30, 15 and 7.5 mA seconds while keeping other imaging parameters constant. Images were independently reviewed in random order by 2 blinded radiologists to determine the sensitivity and specificity of each mA second setting. RESULTS: Overall sensitivity and specificity were 98% and 83%, respectively. Imaging using 140, 100, 60, 30, 15 and 7.5 mA second settings resulted in 98%, 97%, 97%, 96%, 98% and 97% sensitivity, and 83%, 83%, 83%, 86%, 80% and 84% specificity, respectively. Interobserver agreement was excellent (kappa >0.87). There was no significant difference in sensitivity or specificity at any mA second settings. All false-negative results were noted for 3 mm calculi at a similar frequency at each mA second setting. CONCLUSIONS: Ultra low dose computerized tomography protocols detected distal ureteral calculi in a fashion similar to that of conventional computerized tomography protocols in a cadaveric model. These protocols may decrease the radiation dose up to 95%, reducing the risk of secondary malignancies.

Renal stone detection using unenhanced multidetector row computerized tomography--does section width matter?

PURPOSE: We determined the effect of reconstructed section width on sensitivity and specificity for detecting renal calculi using multidetector row computerized tomography. MATERIALS AND METHODS: Three to 5 renal stones 2 to 4 mm in size were randomly placed into 14 human cadaveric kidneys and scanned by 16-row detector computerized tomography at 1.25 mm collimation and identical scanning parameters. After acquisition images were reconstructed with a section width of 1.25, 2.5, 3.75 and 5.0 mm, and reviewed independently by 2 blinded radiologists. Comparisons of sensitivity and specificity between different section widths were assessed with the McNemar test and Cochran's Q statistics. RESULTS: Specificity was not significantly affected by section width (94.6% to 97.7%). In contrast, sensitivity increased as stone size increased and as section width decreased. Sensitivity to detect all stones was 80.7%, 80.7%, 87.7% and 92.1% for 5.0, 3.75, 2.5 and 1.25 mm section widths, respectively. Interobserver agreement for stone detection was excellent (kappa 0.858). Although the 2.0 mm stone detection rate improved with thinner section widths (79.4% vs 52.9% for 1.25 vs 5.0 mm, p = 0.004), stones greater than 2.0 mm were similarly detected at different slice selections (p = 0.056 to 0.572). CONCLUSIONS: Independent of other scanning parameters reconstruction section width influences the ability to detect small renal calculi. It must be considered when creating computerized tomography protocols.

Prospective comparison of four laparoscopic vessel ligation devices.

PURPOSE: The merits of laparoscopic sealing devices have been poorly characterized. The purpose of this study was to compare two bipolar sealing devices [LigaSure V (LS) and Gyrus PK (GP)], an ultrasonic device [Harmonic Scalpel ACE (HS)] and a novel device using nanotechnology [EnSeal PTC (ES)]. MATERIALS AND METHODS: The ability of all four 5 mm devices to seal 5 mm bovine arteries was tested under controlled temperature and humidity in accordance with manufacturer specifications. Study endpoints included lateral thermal spread, time to seal, burst pressure, smoke production and subjective (blinded review of video clips) and objective (measured using an aerosol monitor) effect upon visibility. RESULTS: The HS demonstrated the least thermal spread. The LS (10.0 secs) and GP (11.1 secs) had the fastest sealing times (p<0.001 for both) when compared to ES (19.2 sec) and HS (14.3 sec). Mean burst pressure values were: LS 385 mm Hg, GP 290 mm Hg, ES 255 mm Hg and HS 204 mm Hg. The HS had the best subjective visibility score and the lowest objective smoke production (2.88 ppm) compared to the GP (74.1 ppm), ES (21.6 ppm) and LS (12.5 ppm), (p<0.01 for all). CONCLUSIONS: The LS has the highest burst pressure and fastest sealing time and was the highest rated overall. The HS produced the lowest thermal spread and smoke but had the lowest mean burst pressure. The GP had the highest smoke production, and variable burst pressures. Despite employing nanotechnology, the ES device was the slowest and had variable burst pressures.