Comparison of Diatrizoate and Iohexol for Patient Acceptance and Fecal-Tagging Performance in Noncathartic CT Colonography.

OBJECTIVE: The aim of this study was to compare diatrizoate and iohexol regarding patient acceptance and fecal-tagging performance in noncathartic computed tomography colonography. METHODS: This study enrolled 284 volunteers with fecal tagging by either diatrizoate or iohexol at an iodine concentration of 13.33 mg/mL and an iodine load of 24 g. Patient acceptance was rated on a 4-point scale of gastrointestinal discomfort. Two gastrointestinal radiologists jointly analyzed image quality, fecal-tagging density and homogeneity, and residual contrast agent in the small intestine. The results were compared by the generalized estimating equation method. RESULTS: Patient acceptance was comparable between the 2 groups (3.95 ± 0.22 vs 3.96 ± 0.20, P = 0.777). The diatrizoate group had less residual fluid and stool than the iohexol group ( P = 0.019, P = 0.004, respectively). There was no significant difference in colorectal distention, residual fluid, and stool tagging quality between the 2 groups (all P 's > 0.05). The mean 2-dimensional image quality score was 4.59 ± 0.68 with diatrizoate and 3.60 ± 1.14 with iohexol ( P < 0.001). The attenuation of tagged feces was 581 ± 66 HU with diatrizoate and 1038 ± 117 HU with iohexol ( P < 0.001). Residual contrast agent in the small intestine was assessed at 55.3% and 62.3% for the diatrizoate group and iohexol group, respectively ( P = 0.003). CONCLUSIONS: Compared with iohexol, diatrizoate had better image quality, proper fecal-tagging density, and more homogeneous tagging along with comparable excellent patient acceptance, and might be more suitable for fecal tagging in noncathartic computed tomography colonography.

The effectiveness and biosafety of diatrizoate contrast media in complicated cholelithiasis.

Adverse reactions after intravascular administration of iodine-based contrast media are well-known. Nevertheless the same type of contrast media is also used for endoscopic retrograde cholangiopancreatography and systemic absorption of contrast media after mentioned procedure routinely occurs, not much is known about effects of widely used diatrizoates (Triombrast) on the hepato-pancreato-biliary system in case of cholelithiasis treatment. AIM: The aim of the present study was to determine the effectiveness and biosafety of diatrizoate contrast media in terms of complicated cholelithiasis healing using conventional and improved surgery treatment protocols based on set of biochemical markers. MATERIALS AND METHODS: The paper presents materials of clinical observation and biochemical analysis of 122 patients have been diagnosed with gallstone disease complicated by choledocholithiasis and cholangitis and biliary pancreatitis. Biochemical liver tests before and after surgery treatment using conventional and improved protocols were determined. RESULTS: Biochemical manifestations of hepatocellular injury included exceeded activity of γ-glutamyltranspeptidase and aminotrasferases as well as level of liver fatty acid-binding protein and bilirubin which were different between groups of patients with cholelithiasis who suffered from concomitant cholangitis and pancreatitis. Proposed management algorithm for patients with gallstone disease with concomitant cholangitis and pancreatitis links to get rid of endoscopic retrograde cholangiography with contrast agent from the conventional surgery treatment protocols because its most obvious downside. CONCLUSIONS: Patients with gallstone diseases revealed significant biochemical changes that should be successfully resolved after surgery treatment without endoscopic retrograde cholangio- pancreatography with contrast media because its hepatotoxic effect.

Diatrizoate (Gastrograffin®) Small Bowel Follow Through for Small Bowel Obstructions: Timing and Outcomes.

INTRODUCTION: The advent of the Gastrograffin® small bowel follow through (G-SBFT) has resulted in a decreased rate of operative intervention of small bowel obstructions (SBO); however, there is no data to suggest when G-SBFT should be performed. METHODS: We retrospectively reviewed 548 patients, admitted to 1 of 9 hospitals with a diagnosis of SBO. Patients were divided into two categories with regards to timing of G-SBFT: before (early) or after (late) 48 hours from admission. Primary outcomes were length of stay (LOS) and total cost. Secondary outcomes were operative interventions and mortality. RESULTS: Of the reviewed patients, 71% had the G-SBFT ordered early. Comparing early versus late, there were no differences in patient characteristics with regards to age, sex, or BMI. There was a significant difference between LOS (4 vs 8 days, P < 0.05) and total cost ($17,056.19 vs $33,292.00, P < 0.05). There was no difference in mortality (1.3% vs 2.6%, P = 0.239) or 30-day readmission rates (15.6% vs 15.9%, P = 0.509). Patients in the early group underwent fewer operations (20.7% vs 31.9%, P = 0.05). DISCUSSION: Patients that had a G-SBFT ordered early had a decreased LOS, total cost, and operative intervention. This suggests there is a benefit to ordering G-SBFT earlier in the hospital stay to reduce the overall disease burden, and that it is safe to do so with regards to mortality and readmissions. We therefore recommend ordering a G-SBFT within 48 hours to reduce LOS, cost, and need for an operation.

T cell mediated hypersensitivity to previously tolerated iodinated contrast media precipitated by introduction of atezolizumab.

Many adverse reactions associated with immune checkpoint inhibitor (ICI) treatments are immunologically driven and may necessitate discontinuation of the ICI. Herein, we present a patient who had been administered the radio contrast media amidotrizoate multiple times without issue but who then developed a Stevens-Johnson syndrome reaction after coadministration of atezolizumab. Causality was confirmed by a positive re-challenge with amidotrizoate and laboratory investigations that implicated T cells. Importantly, the introduction of atezolizumab appears to have altered the immunologic response to amidotrizoate in terms of the tolerance-elicitation continuum. Proof of concept studies demonstrated enhancement of recall responses to a surrogate antigen panel following in-vitro (healthy donors) and in-vivo (ICI patients) administrations of ICIs. Our findings highlight the importance of considering all concomitant medications in patients on ICIs who develop immune-mediated adverse reactions. In the event of some immune-related adverse reactions, it may be critical to identify the culprit antigen-forming entity that the ICIs have altered the perception of rather than simply attribute causality to the ICI itself in order to optimize both patient safety and treatment of malignancies.

Positive Oral Contrast Solution at MDCT for Suspected Acute Appendicitis in Adults: Rate of Appendiceal Luminal Filling of Normal and Inflamed Appendixes.

OBJECTIVE. The purpose of this study was to assess the rate of appendiceal filling with a positive oral contrast solution at MDCT performed for suspected acute appendicitis in adults. MATERIALS AND METHODS. We performed a retrospective review of MDCT in 684 consecutive adult patients with suspected acute appendicitis in a 19-month period. Patients were excluded if no positive oral contrast solution (500 mL each of water and polyethylene glycol and 30 mL diatrizoate) was given or if the appendix was not visible or absent. After exclusion, images of 519 patients (mean age ± SD, 37.4 ± 16.0 years; 335 women, 184 men) were reviewed for cecal contrast opacification and appendiceal filling. Imaging findings were recorded as positive or negative for acute appendicitis using all available clinical and pathologic data as a reference standard. A control series of CT colonography (CTC) screening examinations (overnight preparation with universal cecal opacification) in 2552 adults without symptoms of appendicitis was also reviewed. RESULTS. Cecal opacification was confirmed in 313/519 (60.3%) patients, with no difference between those considered to be positive (68/107, 63.6%) or negative (245/412, 59.5%) for appendicitis (p = 0.506). When positive oral contrast solution reached the cecum, appendiceal filling was seen in none of the 68 (0%) with appendicitis and in 205 of the 245 (83.7%) without appendicitis (p < 0.0001). Among CTC control subjects, appendiceal filling was similar to the cohort considered to be without appendicitis (2240/2552 [87.8%], p = 0.070). CONCLUSION. In MDCT for suspected acute appendicitis, luminal filling of the noninflamed appendix exceeds 80% when positive oral contrast solution reaches the cecum, indicating results similar to screening CTC. The appendix did not fill in proven acute appendicitis, indicating appendiceal filling may allow exclusion of appendicitis with high certainty. These results suggest positive oral contrast solution may augment diagnostic accuracy and confidence in cases of suspected acute appendicitis.

Ultrasensitive Fluorescence Detection of Alzheimer's Disease Based on Polyvalent Directed Peptide Polymer Coupled to a Nanoporous ZnO Nanoplatform.

Amyloid-beta 42 (Aß42), the key biomarker of Alzheimer's disease (AD), aggregates to form neurotoxic amyloid plaques. In this work, we modified two fluorescein isothiocyanate-labeled Aß42-targeting peptides and designed an Aß42-specific ultrasensitive polyvalent-directed peptide polymer (PDPP) to enhance AD diagnosis sensitivity. The dissociation constant of Aß42 by PDPP was 103-fold higher than the single-site-directed peptide. The improved binding was due to the ability of PDPP to detect multiple receptors on the target. The power of the PDPP diagnostic probe was verified in its application to detect Aß42 in cerebrospinal fluid (CSF), which showed a lower limit of detection (LOD) in the fg mL-1 range that is more sensitive than detection by antibodies or single peptides. In addition, we present a novel ultrasensitive diagnostic system using an array of nanoporous ZnO nanoparticles, which play a role in fluorescence signal amplification, to further improve AD diagnosis sensitivity. We enhanced the signal on the basis of the properties of nanoporous ZnO nanoparticles and measured and quantified an ultralow concentration (ag mL-1 range) of Aß42. This PDPP coupled to the nanoporous ZnO-based system is a novel approach to AD diagnosis that might also be useful for the detection of other target biomarkers and clinical applications.

Abiotic reductive deiodination of iodinated organic compounds and X-ray contrast media catalyzed by free corrinoids.

Iodinated X-ray contrast media are known for their stability concerning deiodination in the aquatic environment under aerobic conditions. In this study, we demonstrate the abiotic reductive deiodination of the iodinated contrast media iopromide, iopamidol and diatrizoate in the presence of corrinoids. In addition, triiodinated benzoic acid derivatives with iodine atoms bound at different positions were investigated. Corrinoids like cyanocobalamin (vitamin B12) and dicyanocobinamide served as electron shuttles and as catalysts between the reducing agent (e.g., titanium (III) citrate) and the electron accepting iodinated compound. The concentration decrease of the iodinated compounds followed first-order kinetics with rate constant kobs depending on the iodinated compound. A linear correlation between the rate of iodide release and the corrinoid concentration was observed, with deiodination rates for dicyanocobinamide twice as high as for vitamin B12. Reducing agents with a less negative standard redox potential like dithiothreitol or cysteine caused slower deiodination as the cobalt center was only reduced to its CoII oxidation state. With a temperature increase from 11 to 23 °C, the concentrations of released iodide doubled. A complete deiodination was only observed for the iodinated contrast media but not for structurally similar iodinated benzoic acid derivatives.

Catalytic Degradation of Diatrizoate by Persulfate Activation with Peanut Shell Biochar-Supported Nano Zero-Valent Iron in Aqueous Solution.

An emerging pollutant, diatrizoate (DTZ) has been frequently detected in aqueous solution. Unique reticular peanut shell biochar (BC)-supported nano zero-valent iron (nZVI) composite (nZVI/BC) was successfully synthesized and used as a catalyst for activating persulfate (PS) to promote the removal of DTZ. The structure and morphology of the nanocomposite materials were characterized by scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller measurements, and Fourier transform infrared spectroscopy. The degradation of DTZ (20 mg L-1) was achieved by activating PS with the nanocomposite material. The removal of DTZ reached nearly 100% using 25 mM PS and 0.45 g L-1 nZVI/2BC (mass ratio of nZVI and BC at 1:2) nanocomposite material at pH 3.0 and 25 °C. Influencing factors, such as dosages of nZVI/2BC and PS, temperature, and pH were also investigated. The mechanisms of PS activation with nZVI/2BC were discussed, including BC property, electron transfer, and the identification of free radicals in the reaction. The findings demonstrated that nZVI/BC-PS (peanut shell BC-supported nZVI activating PS) is a promising material for the treatment of refractory organic pollutants.

Quercetin protects against radiocontrast medium toxicity in human renal proximal tubular cells.

Radiocontrast media (RCM)-induced acute kidney injury (CI-AKI) is a major clinical problem whose pathophysiology is not well understood. Direct toxic effects on renal cells, possibly mediated by reactive oxygen species, have been postulated as contributing to CI-AKI. We investigated the effect of quercetin on human renal proximal tubular (HK-2) cells treated with the radiocontrast medium (RCM) sodium diatrizoate. Quercetin is the most widely studied flavonoid, and the most abundant flavonol present in foods. It has been suggested to have many health benefits, including angioprotective properties and anti-cancer effects. These beneficial effects have been attributed to its antioxidant properties and its ability to modulate cell signaling pathways. Incubation of HK-2 cells with 100 µM quercetin caused a decrease in cell viability and pre-treatment of HK-2 cells with 100 µM quercetin followed by incubation with 75 mgI/ml sodium diatrizoate for 2 hr caused a decrease in cell viability which was worse than in cells treated with diatrizoate alone. However, further incubation of the cells (for 22 hr) after removal of the diatrizoate and quercetin caused a recovery in cell viability in those cells previously treated with quercetin + diatrizoate and quercetin alone. Analysis of signaling molecules by Western blotting showed that in RCM-treated cells receiving initial pre-treatment with quercetin, followed by its removal, an increase in phosphorylation of Akt (Ser473), pSTAT3 (Tyr705), and FoxO3a (Thr32) as well as an induction of Pim-1 and decrease in PARP1 cleavage were observed. Quercetin may alleviate the longer-term toxic effects of RCM toxicity and its possible beneficial effects should be further investigated.

Remote loading of liposomes with a 124I-radioiodinated compound and their in vivo evaluation by PET/CT in a murine tumor model.

Long circulating liposomes entrapping iodinated and radioiodinated compounds offer a highly versatile theranostic platform. Here we report a new methodology for efficient and high-yield loading of such compounds into liposomes, enabling CT/SPECT/PET imaging and 131I-radiotherapy. Methods: The CT contrast agent diatrizoate was synthetically functionalized with a primary amine, which enabled its remote loading into PEGylated liposomes by either an ammonium sulfate- or a citrate-based pH transmembrane gradient. Further, the amino-diatrizoate was radiolabeled with either 124I (t1/2 = 4.18 days) for PET or 125I (t1/2 = 59.5 days) for SPECT, through an aromatic Finkelstein reaction. Results: Quantitative loading efficiencies (>99%) were achieved at optimized conditions. The 124I-labeled compound was remote-loaded into liposomes, with an overall radiolabeling efficiency of 77 ± 1%, and imaged in vivo in a CT26 murine colon cancer tumor model by PET/CT. A prolonged blood circulation half-life of 19.5 h was observed for the radiolabeled liposomes, whereas injections of the free compound were rapidly cleared. Lower accumulation was observed in the spleen, liver, kidney and tumor than what is usually seen for long-circulating liposomes. Conclusion: The lower accumulation was interpreted as release of the tracer from the liposomes within these organs after accumulation. These results may guide the design of systems for controlled release of remote loadable drugs from liposomes.

Ficoll-hypaque separation vs whole blood lysis: Comparison of efficiency and impact on minimal residual disease analysis.

INTRODUCTION: The high-throughput era remarkably changed molecular laboratory practice. Actually, the increasing number of processed samples requires to reduce the risk of operator biases, by automating or simplifying as much as possible both the analytical and the pre-analytical phases. Minimal residual disease (MRD) studies in hematology often require a simultaneous processing of many bone marrow and peripheral blood samples from patients enrolled in prospective, multicenter, clinical trials, monitored at several planned time points. METHODS: In this study, we demonstrate that red blood cell lysis (RBL) pre-analytical procedure can replace the time-consuming Ficoll stratification as cell recovering step. Here, we show a MRD comparison study using both total white blood cells and mononuclear cells recovered by the 2 procedures from 46 follicular lymphoma (FL), 15 multiple myeloma (MM), and 11 mantle cell lymphoma (MCL) patients enrolled in prospective clinical trials. RESULTS: The experiments were performed in the 4 laboratories of the Fondazione Italiana Linfomi (FIL) MRD Network and showed superimposable results, in terms of good correlation (R = 0.87) of the MRD data obtained by recovering blood cells by the 2 approaches. CONCLUSION: Based on these results, the FIL MRD Network suggests to optimize the pre-analytical phases introducing RBL approach for cell recovery in the clinical trials including MRD analysis.

The effect of aspirated barium sulfate, iodixanol, and diatrizoic acid on survival and lung injury in a lagomorph model.

OBJECTIVES/HYPOTHESIS: Contrast agents are an integral component of the video fluoroscopic swallow study. Agents commonly used include barium sulfate (E-Z Paque), iodixanol (Visipaque), and diatrizoic acid (Gastrografin). Barium is water insoluble, whereas iodixanol and diatrizoic acid are water-soluble iodine-based agents. The detrimental effect of these agents on the lungs has not been systematically evaluated. Our aim was to evaluate and compare the effects of aspirated barium, iodixanol, and diatrizoic acid on pulmonary injury in a lagomorph model. STUDY DESIGN: Animal model. METHODS: Twenty adult male New Zealand White rabbits were divided into four groups (n = 5). Group 1 received 3 mL of barium sulfate injected into the trachea for 3 consecutive days. Group 2 received 3 mL of iodixanol injected into the trachea for 3 consecutive days. Group 3 received 3 mL of diatrizoic acid injected into the trachea for 3 consecutive days. A control group received 3 mL of air injected into the trachea under an identical protocol. All animals were euthanized on day 4, and the lung and trachea were harvested for blinded histopathologic analysis. The primary outcome measure was survival. The secondary endpoint was a blinded, histologic grading system of lung injury. RESULTS: Two animals in the barium group, one in the diatrizoic acid group, and 0 animals in the iodixanol and control groups died. The overall lung injury score for the barium (60.60 ± 6.34) and iodixanol groups (52.30 ± 3.11) were significantly higher (worse) than the diatrizoic acid (49.60 ± 7.64) and control groups (37.80 ± 3.56) (P < .05). Diatrizoic acid produced the least amount of lung injury. CONCLUSIONS: The data suggest that 3 mL of aspirated barium sulfate (E-Z Paque) over 3 consecutive days causes more severe lung injury in a lagomorph model than 3 mL of aspirated iodixanol (Visipaque) and diatrizoic acid (Gastrografin). Diatrizoic acid caused the least histologic evidence of lung injury. LEVEL OF EVIDENCE: NA Laryngoscope, 127:E148-E152, 2017.

Multicenter, randomized study to optimize bowel preparation for colon capsule endoscopy.

AIM: To assess the cleansing efficacy and safety of a new Colon capsule endoscopy (CCE) bowel preparation regimen. METHODS: This was a multicenter, prospective, randomized, controlled study comparing two CCE regimens. Subjects were asymptomatic and average risk for colorectal cancer. The second generation CCE system (PillCam® COLON 2; Medtronic, Yoqneam, Israel) was utilized. Preparation regimens differed in the 1st and 2nd boosts with the Study regimen using oral sulfate solution (89 mL) with diatrizoate meglumine and diatrizoate sodium solution ("diatrizoate solution") (boost 1 = 60 mL, boost 2 = 30 mL) and the Control regimen oral sulfate solution (89 mL) alone. The primary outcome was overall and segmental colon cleansing. Secondary outcomes included safety, polyp detection, colonic transit, CCE completion and capsule excretion ≤ 12 h. RESULTS: Both regimens had similar cleansing efficacy for the whole colon (Adequate: Study = 75.9%, Control = 77.3%; P = 0.88) and individual segments. In the Study group, CCE completion was superior (Study = 90.9%, Control = 76.9%; P = 0.048) and colonic transit was more often < 40 min (Study = 21.8%, Control = 4%; P = 0.0073). More Study regimen subjects experienced adverse events (Study = 19.4%, Control = 3.4%; P = 0.0061), and this difference did not appear related to diatrizoate solution. Adverse events were primarily gastrointestinal in nature and no serious adverse events related either to the bowel preparation regimen or the capsule were observed. There was a trend toward higher polyp detection with the Study regimen, but this did not achieve statistical significance for any size category. Mean transit time through the entire gastrointestinal tract, from ingestion to excretion, was shorter with the Study regimen while mean colonic transit times were similar for both study groups. CONCLUSION: A CCE bowel preparation regimen using oral sulfate solution and diatrizoate solution as a boost agent is effective, safe, and achieved superior CCE completion.

Objective and Subjective Intrapatient Comparison of Iohexol Versus Diatrizoate for Bowel Preparation Quality at CT Colonography.

OBJECTIVE: The purpose of this study is to objectively and subjectively compare nonionic iohexol and ionic diatrizoate iodinated oral contrast agents as part of a cathartic bowel regimen within the same CT colonography (CTC) cohort, with otherwise identical preparations. MATERIALS AND METHODS: In this retrospective study, 46 adults with no symptoms (mean age, 59.4 years; 26 men and 20 women) returning for follow-up CTC over a 9-month interval underwent the same bowel preparation with the exception of 75 mL of iohexol 350 in place of 60 mL of diatrizoate. All other preparation components (bisacodyl, magnesium citrate, and 2% barium) remained constant. Objective volumetric analysis of residual colonic fluid volume and fluid attenuation was performed. Additionally, two radiologists experienced with CTC who were blinded to the specific bowel preparation scored each of six colonic segments for adherent residual solid stool using a previously validated 4-point scale (0 for no stool; 1-3 for increasing residual stool). A paired t test was used for comparison of the cohorts. RESULTS: No clear clinically meaningful difference was found between the two preparations on overall objective or subjective evaluation. The mean (± SD) residual fluid volume was 173 ± 126 mL with the iohexol preparation and 130 ± 79 mL with the diatrizoate preparation (p = 0.02). The mean total colonic stool score was 2.5 (0.42/segment) with iohexol and 2.3 (0.38/segment) with diatrizoate (p = 0.69). The mean fluid attenuation was higher with iohexol (849 ± 270 HU) compared with diatrizoate (732 ± 168 HU) (p = 0.03). CONCLUSION: On the basis of this direct intrapatient comparison, we found that oral iohexol is a suitable alternative to diatrizoate for fluid tagging as part of a cathartic bowel preparation at CTC. Because this nonionic tagging agent is more palatable, less expensive, and likely safer than ionic diatrizoate, our CTC program now uses iohexol as the standard recommended regimen.

Aneurysmal bone cyst: A 19-case series managed by percutaneous sclerotherapy.

INTRODUCTION: Sclerotherapy offers an alternative to surgery for the treatment of aneurysmal bone cyst (ABC). The main objective of the present study was to assess the radiological efficacy of sclerotherapy in terms of ossification on MRI. Secondary objectives were to assess clinical efficacy on pain evaluation and to analyze recurrence and complications according to type of sclerosing agent and intraoperative imaging technique. MATERIALS AND METHODS: Between 2006 and 2014, 19 patients (7 females, 12 males, aged 3 to 17 years) with ABC treated by sclerotherapy were included. Six received Ethibloc(®), 9 Aetoxisclerol(®), 2 liquid absolute alcohol, and 2 absolute alcohol gel. Assessment used fluoroscopy in 17 cases and CT in 2. Ossification was assessed on MRI and pain on a visual analog scale and HEDEN score. RESULTS: Ossification was complete in 11 cases (84.6%) and partial in 2 (15.4%). Eighteen patients (94.7%) were pain-free at 3 months. There was no recurrence, at a minimum 2 years' follow-up. One case of skin necrosis was observed, associated with use of liquid absolute alcohol; there was 1 case of arterial reflux of Ethibloc(®) under CT control. DISCUSSION: Sclerotherapy enables minimally invasive treatment of lesions that are deep, difficult of access to surgery and potentially damaging. Use of absolute alcohol gel and fluoroscopic control seems to improve the risk/benefit ratio, limiting complications by vascular extravasation of the sclerosing agent, thanks to real-time visualization of diffusion. Its clinical and radiological efficacy makes sclerotherapy and alternative primary treatment choice in ABC. LEVEL OF EVIDENCE: IV, retrospective study.

CT colonography after incomplete optical colonoscopy: bowel preparation quality at same-day vs. deferred examination.

PURPOSE: To objectively compare the volume, density, and distribution of luminal fluid for same-day oral-contrast-enhanced CTC following incomplete optical colonoscopy (OC) vs. deferred CTC on a separate day utilizing a dedicated CTC bowel preparation. METHODS: HIPAA-compliant, IRB-approved retrospective study compared 103 same-day CTC studies after incomplete OC (utilizing 30 mL oral diatrizoate) against 151 CTC examinations performed on a separate day after failed OC using a dedicated CTC bowel preparation (oral magnesium citrate/dilute barium/diatrizoate the evening before). A subgroup of 15 patients who had both same-day CTC and separate-day routine CTC was also identified and underwent separate analysis. CTC exams were analyzed for opacified fluid distribution within the GI tract, as well as density and volume. Data were analyzed utilizing Kruskal-Wallis and Wilcoxon Signed Rank tests. RESULTS: Opacified luminal fluid extended to the rectum in 56% (58/103) of same-day CTC vs. 100% (151/151) of deferred separate-day CTC (p < 0.0001). For same-day CTC, contrast failed to reach the colon in 11% (11/103) and failed to reach the left colon in 26% (27/103). Volumetric colonic fluid segmentation for fluid analysis (successful in 80 same-day and 147 separate-day cases) showed significantly more fluid in the same-day cohort (mean, 227 vs. 166 mL; p < 0.0001); the actual difference is underestimated due to excluded cases. Mean colonic fluid attenuation was significantly lower in the same-day cohort (545 vs. 735 HU; p < 0.0001). Similar findings were identified in the smaller cohort with direct intra-patient CTC comparison. CONCLUSIONS: Dedicated CTC bowel preparation on a separate day following incomplete OC results in a much higher quality examination compared with same-day CTC.

Reducing the Radiation Dose for CT Colonography: Effect of Low Tube Voltage and Iterative Reconstruction.

RATIONALE AND OBJECTIVES: The purpose of this study was to assess the effect of a low-tube-voltage technique and iterative reconstruction (IR) on the radiation dose and image quality of computed tomography colonography (CTC). MATERIALS AND METHODS: We studied 30 patients (14 women and 16 men; mean age, 64.5 ± 13.1 years; range, 39-90 years) with colorectal cancer referred for surgical treatment. All underwent CTC with fecal tagging under a standard 120-kVp protocol in the supine position and a 100-kVp protocol in the prone position. The 120-kVp images were reconstructed with filtered back projection (FBP). The 100-kVp images were postprocessed using FBP and a hybrid type of IR (adaptive iterative dose reduction 3D). The effective radiation dose (ED), image noise, and contrast-to-noise ratio (CNR) were compared among the three protocols. The visual image quality was scored on a four-point scale. RESULTS: The mean ED was significantly lower under the 100-kVp protocol than the 120-kVp protocol, resulting in a 27% radiation dose decrease (3.5 ± 2.0 vs 2.5 ± 1.5 mSv; P < .01). Image noise decreased by 48%, and the mean attenuation of tagged fluid increased from 452 to 558 HU on images acquired at 100 kVp with IR compared to that in the 120-kVp protocol; these differences were significant. The mean CNR was significantly higher under the 100 kVp with IR than the other two protocols. We found no significant differences in the visual scores for diagnostic utility between the 100 kVp with IR and the 120 kVp with FBP protocol (P = .10). CONCLUSIONS: Low-tube-voltage CTC reduced the radiation dose by approximately 27% while maintaining the image quality.

In vivo nephroprotective efficacy of propolis against contrast-induced nephropathy.

PURPOSE: Contrast agents administered in diagnostic imaging or interventional procedures of clinical radiology may cause contrast-induced nephropathy (CIN). Preventive measures against CIN involve pharmaceutical pretreatments, such as N-acetylcystein (NAC) or calpain, but alternative medicines can also be helpful. This study aims to assess the prospects of a natural compound, propolis, as a potential nephroprotector against a specific contrast agent, diatrizoate. METHODS: In vivo experiments were performed on 35 male rats in five groups: control, diatrizoate alone, and pretreatments with propolis, NAC, or calpain one hour before diatrizoate administration. Three days later, blood and renal tissue samples were collected and quantitatively processed for determining induced changes in critical biomarkers malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT), as well as serum creatinine and plasma urea. RESULTS: Diatrizoate increased creatinine (113%), urea (400%), and MDA (162%) levels and decreased GSH (-71%), SOD (-69%), GSH-Px (-77%), and CAT (-73%) levels. Evaluating the response of each pretreatment provided sufficient evidence that propolis was as effective as either NAC or calpain, but consistently more prominent in restoring the MDA, GSH, SOD, and GSH-Px levels close to their normal range. This outcome demonstrated the nephroprotective effect of propolis against CIN. CONCLUSION: Propolis protects renal tissue against toxicity, free radicals, and other adverse effects induced by diatrizoate. This function is most likely exerted through the antioxidant and antitoxic activities of propolis.

Iohexol versus diatrizoate for fecal/fluid tagging during CT colonography performed with cathartic preparation: comparison of examination quality.

OBJECTIVE: We aimed to compare iohexol vs. diatrizoate as fecal/fluid tagging agents for computed tomography colonography (CTC) regarding examination quality. METHODS: Forty prospective patients (M:F = 23:17; 63 ± 11.6 years) received CTC using 50 mL (350 mgI/mL) oral iohexol for tagging. Forty other indication-matched, age-matched, and sex-matched patients who underwent CTC using 100 mL diatrizoate for tagging and otherwise the same technique, were retrospectively identified. Two groups were compared regarding overall examination quality, per-patient and per-segment scores of colonic bubbles (0 [no bubbles] to 5 [the largest amount]), and the volume, attenuation, and homogeneity (untagged, layered, and homogeneous) of the residual colonic fluid. RESULTS: The iohexol group demonstrated a greater amount of colonic bubbles than the diatrizoate group: mean per-patient scores ± SD of 1.2 ± 0.8 vs. 0.7 ± 0.6, respectively (p = 0.003); and rates of segments showing ≥ grade 3 bubbles of 12.9 % (85/659) vs. 1.6 % (11/695), respectively (p = 0.001). Residual colonic fluid amount standardized to the colonic volume did not significantly differ: 7.2 % ± 4.2 vs. 7.8 % ± 3.7, respectively (p = 0.544). Tagged fluid attenuation was mostly comparable between groups and the fluid was homogeneously tagged in 98.7 % (224/227) vs. 99.5 % (218/219) segments, respectively (p = 0.344). Iohexol caused more colonic bubbles when used during cathartic CTC. Otherwise, examination quality was similarly adequate with both iohexol and diatrizoate. KEY POINTS: • When used for tagging, iohexol caused significantly more colonic bubbles than diatrizoate. • The residual colonic fluid amount did not significantly differ between iohexol and diatrizoate. • The quality of fluid tagging was similarly adequate in both iohexol and diatrizoate.