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.

Curative treatment of pelvic arteriovenous malformation--an alternative strategy: transvenous intra-operative embolisation.

OBJECTIVES: Pelvic arteriovenous malformations (AVMs) are difficult to treat. Arterial embolisation is the most common strategy but often has poor results. We report an alternative surgical approach of controlled intra-operative transvenous embolisation with long-term results in seven cases. MATERIALS AND METHODS: Between 1980 and 2008, we treated seven patients (four men, three women, mean age 50 years). Indications were rectal bleeding (one case), urinary tract problems (four cases), oedema of lower limb (one case) and high-output cardiac failure (one case). Four of them had previous operations and three had previous attempts for embolisation. Embolisation of the malformation was performed through the internal iliac vein. This was done after clamping of all the feeding and draining vessels. The agent used was cyanocrylate (one case), Ethibloc (one case) and bone wax (five cases). RESULTS: Mortality was 0%. Complications occurred in two patients (28,5%), one pulmonary embolism and one regressive femoral paresis. Three patients were re-operated for various reasons. The mean follow-up period was 6 years (1-12 years). Symptoms resolved in all patients, while control by computed tomography (CT) angioscan revealed one residual shunt. CONCLUSION: Complete surgical excision of pelvic AVMs is not always possible. Embolisation does not offer a permanent cure. Intra-operative transvenous embolisation of persisting complex AVMs appears to be an alternative approach with good immediate and long-term results. Ethylene glycol appears to be the most suitable agent.

Fluid tagging for CT colonography: effectiveness of a 2-hour iodinated oral preparation after incomplete optical colonoscopy.

OBJECTIVE: To evaluate the distal extent and attenuation of bowel opacification achieved after administration of a single low volume dose of oral contrast 2 hours before computed tomographic colonography (CTC) after incomplete optical colonoscopy. METHODS: This retrospective study included 144 patients undergoing CTC after incomplete colonoscopy from April 2006 to July 2008 at 2 separate medical centers. Each patient received 20 to 30 mL of diatrizoate meglumine and diatrizoate sodium solution 2 hours before being scanned. RESULTS: The distalmost extent of opacification was: stomach/small bowel, n = 13; cecum, n = 2; ascending colon, n = 7; transverse colon, n = 19; descending colon, n = 14; sigmoid colon, n = 24; rectum, n = 65. The mean attenuation of each opacified segment was: cecum, 449 Hounsfield units (HU); ascending colon, 474 HU; transverse colon, 468 HU; descending colon, 421 HU; sigmoid colon, 391 HU; and rectum, 382 HU. In 103 (71.5%) patients, oral contrast reached the distal colon (descending colon, sigmoid colon, or rectum). The oral contrast did not reach the colon in only 13 (9.0%) patients. CONCLUSIONS: Oral administration of a small volume hyperosmolar oral contrast agent 2 hours before CTC results in satisfactory colonic opacification in the majority of patients. Adding same-day fluid tagging in incomplete colonoscopy patients presenting for completion CTC should result in adequate fluid opacification for most of the colon, especially proximal segments not visualized at the time of incomplete colonoscopy.

Low-volume hybrid bowel preparation combining saline laxatives with oral contrast agents versus standard polyethylene glycol lavage for colonoscopy.

PURPOSE: The aim of this study was to compare the quality of low-volume hybrid computed tomography colonography bowel preparation, using both laxatives and oral contrast, with standard polyethylene glycol lavage. METHODS: The study group consisted of 300 consecutive adults (mean age, 58.3 years) who underwent colonoscopy immediately after positive computed tomography colonography. Hybrid bowel preparation for study group was <1 L in total volume, consisting of osmotic cathartic (sodium phosphate or magnesium citrate) in conjunction with oral contrast (2% barium and diatrizoate). A control group of 300 adults (mean age, 58.3 years) underwent primary colonoscopy after standard 4-liter polyethylene glycol lavage without oral contrast. The prospective preparation quality rating by the endoscopist served as the reference standard. A rating of poor/marginal was considered inadequate and adequate/good/excellent was considered diagnostic. RESULTS: The frequency of inadequate bowel preparation was 4.3% (13/300) in the study group vs 12.3% (37/300) for the control group (P < .001). Specifically, preparation was poor or marginal in 10 and 3 cases in the hybrid cohort, respectively, and in 29 and 8 cases in the polyethylene glycol cohort, respectively. Preparation quality was scored as excellent in 32% (96/300) in the hybrid cohort and 23.3% (70/300) in the polyethylene glycol cohort (P < .05). CONCLUSIONS: At colonoscopy, low-volume laxative-oral contrast hybrid preparations are effective for bowel cleansing, perhaps even more so than polyethylene glycol lavage. Beyond improvements in quality, the low-volume preparation may improve patient compliance and would allow for immediate computed tomography colonography if colonoscopy is incomplete, without the need for additional oral contrast tagging.

The pharmacokinetics of the weakly protein-bound anionic compound diatrizoate in serum and synovial fluid of the horse.

PURPOSE: To establish a pharmacokinetic model for the model drug, sodium diatrizoate (DTZ), allowing joint disappearance kinetics to be estimated from serum appearance kinetics following intra-articular administration, and to calculate the relative joint exposure after intravenous and intra-articular DTZ administration (F(iv/IA)). METHODS: Each of five horses received an aqueous solution of 3.9 mg/kg sodium diatrizoate both intravenously and intra-articularly separated by a one-week wash out period. Serum and synovial samples were collected over 7 h and analyzed for content of model compound using inductively coupled plasma mass spectrometry. RESULTS: Differential equations were used for describing the transport of DTZ between the joint and the central compartment. The three-compartment lag-time model obtained demonstrates that the rate of drug appearance in the systemic circulation equals the rate of disappearance from the joint compartment. Following intravenous and intra-articular administration, an average F(iv/IA) of 0.04% (n = 4) was calculated based on the synovial fluid profiles of DTZ. CONCLUSIONS: This study implies that aspects of the intra-articular fate of DTZ can be obtained from serum data in case synovial fluid samplings are limited, for various possible reasons. The low F(iv/IA) may stimulate future research in the field of intra-articular administration of anti-osteoarthritic drugs.

Oral contrast media for body CT: Comparison of diatrizoate sodium and iohexol for patient acceptance and bowel opacification.

OBJECTIVE: The purpose of the study was to determine whether a difference in patient preference exists between iohexol (Omnipaque) and diatrizoate sodium (Gastroview) as oral contrast medium for abdominal-pelvic CT. A secondary objective was to evaluate whether there are significant differences in bowel opacification and adverse effect profile for the two agents. SUBJECTS AND METHODS: From August 2007 through March 2009, 300 patients were enrolled in this prospective study after informed consent was obtained. Eligible patients were identified from those scheduled for outpatient abdominal-pelvic CT. Subjects were randomly assigned to receive one of two oral contrast agents in a double-blinded fashion. Subjects graded the taste using a 5-point scale, and data regarding demographics, total volume, and adverse effects were collected. A direct comparison of 30 mL of each of the two diluted agents in randomized order was then performed. CT images were graded for bowel opacification by two blinded abdominal radiologists. RESULTS: Of 287 subjects who expressed a preference, 233 patients (81%) preferred dilute iohexol compared with 54 patients (19%) who preferred dilute diatrizoate sodium (p < 0.001). Ten patients had no preference, and three patients did not complete the taste comparison study. No difference in bowel opacification was identified between the oral contrast agents (p = 0.27), nor was there a significant difference in adverse effects (p = 0.352). CONCLUSION: Patents preferred dilute iohexol over dilute diatrizoate sodium for oral contrast for abdominal-pelvic CT. There was no significant difference in bowel opacification or adverse effect profile.

Ex vivo assessment of irrigant penetration and renewal during the cleaning and shaping of root canals: a digital subtraction radiographic study.

AIM: To assess radiographically irrigant penetration in the root canal system of curved roots during root canal shaping procedures ex vivo. METHODOLOGY: Thirty extracted mandibular molar teeth with moderate to severe curvature were used. A special aiming device was used to guarantee that each successive radiograph was taken with the same positioning. The mesiolingual canal of each tooth was instrumented using the ProTaper system. For each step of the shaping procedure, two irrigation modalities were repeated in the same order. Active irrigation consisted of a 0.5-mL flush of sodium diatrizoate solution (Hypaque 50%) immediately followed by agitation with a size 08 K-file. Passive irrigation consisted of a 0.5-mL flush of sodium hypochlorite solution delivered with a syringe through a 27-gauge notched tip needle. A digital radiograph was taken after each modality and stored on computer for subsequent digital subtraction and measures of the depths of irrigant penetration. Comparisons were performed within an analysis-of-variance framework in a repeated-measures approach. RESULTS: The penetration of irrigants was significantly greater for each successive step of the shaping procedure when the two modalities were analysed separately (P < 0.001). The difference between the two modalities was statistically significant for each step of the shaping procedure (P < 0.0001). CONCLUSIONS: Shaping root canals improved both penetration and exchange of irrigant inside the root canal system. Complete renewal of the solution was impossible to achieve with a conventional syringe delivery system and a limited volume of solution. Recapitulation with a K-file after flushing improved irrigant penetration.

Ex vivo assessment of irrigant penetration and renewal during the final irrigation regimen.

AIM: To assess irrigant penetration in curved canals after shaping procedures ex vivo. METHODOLOGY: Thirty extracted mandibular molars with moderate to severe root canal curvature were included. A special aiming device was used to guarantee that each successive radiograph was taken with the same positioning. The mesiolingual canal of each tooth was instrumented with ProTaper rotary files. Apical third preparation was completed with an F1 instrument before additional step-back enlargement using F2 then F3 instruments. For each apical taper, the teeth were submitted successively to active irrigation (AI) then to passive irrigation (PI). AI consisted of a 0.5 mL flush of sodium diatrizoate (Hypaque 50%) immediately followed by manual mechanical activation with a gutta-percha point. PI consisted in flushing the canals with sodium hypochlorite passively delivered with a syringe. A digital radiograph was taken after each modality. The influence of needle tip design, needle tip insertion level, irrigant volume, root canal taper and solution activation was assessed by using digital subtraction radiography and measures of the depths of irrigant penetration. Comparisons were performed within an analysis of variance framework in a repeated-measures approach. RESULTS: For PI, all the four explanatory variables 'apical taper', 'volume of irrigant used', 'corono-apical level of needle tip placement', 'needle tip design' had a significant (P < 0.005) influence on outcome of irrigation penetration. CONCLUSIONS: Only active irrigation allowed complete penetration and exchange of irrigating solution. For syringe irrigation alone, the level of needle tip placement in the canal was the most dominating factor.

Radiologic assessment of gastric emptying of water-soluble contrast media: New data security from a longitudinal study. / Evaluación radiológica del vaciamiento gástrico de medio de contraste hidrosoluble: nuevos datos de seguridad de un estudio longitudinal.

BACKGROUND AND OBJECTIVES: Practice guidelines for preoperative fasting have not clearly established the fasting time needed after oral administration of water-soluble contrast media. The aim of this study was to determine the time required for the gastric emptying during the water-soluble contrast media in patients with acute abdominal pain. METHODS: This prospective longitudinal study included sixty-eight patients older than 18 years of age with acute abdominal pain, who required a water-soluble contrast media enhanced abdominal computed tomography study. Plain radiographs were obtained hourly until complete the gastric emptying. Patients with probable bowel obstruction were not included in the study. RESULTS: A total of 31 (45,6%), 54 (79,4%), and 64 (94,1%) patients achieved a complete gastric clearance of barium in 1, 2 and 3 hours, respectively. All patients achieved complete emptying of water-soluble contrast media within 6 hours. Gastric emptying time was not associated with gender (P=0,44), body mass index (P=.35), fasting time prior to water-soluble contrast media intake (P=0,12), administration of opioids in the emergency room (P=0,7), and the presence of comorbidities (P=0,36). CONCLUSION: Ninety-four percent of the patients with acute abdominal pain achieved complete gastric emptying within 3hours after the administration of water-soluble contrast media. All of them achieved complete gastric emptying within 6hours. The results suggested 6hours after oral intake of the contrast media is enough to complete transit of water-soluble contrast media through the stomach and avoid unnecessary risks.

Efficacy and safety of percutaneous transhepatic portal embolization before right liver resection using an ethibloc/lipiodol mixture: a single-center experience.

AIM: The purpose of this study was to evaluate the safety and efficacy of percutaneous transhepatic portal vein embolization of the right portal vein with an Ethibloc/Lipiodol mixture to induce hypertrophy of the left liver lobe in patients with primarily unresectable liver tumor. METHODS: 15 patients (8 primary liver tumors, 7 liver metastases) underwent portal vein embolization. Liver volumetry, duration of hospitalization, complication rates, relevant laboratory values were documented. RESULTS: In 13/15 patients (84.6%) embolization could be performed with a median of 8.8 ml (range 1.5-28 ml) Ethibloc/Lipiodol. One minor procedure-related complication (subcapsular hematoma) occurred, which did not affect the two-step liver resection. No patient developed acute liver failure after embolization or liver resection. The volume of the left liver lobe increased significantly (p = 0.0015) by 25% from a median of 750 ml (587-1,114 ml) to 967 ml (597-1,249 ml). 11/13 (81.8%) of the embolized patients underwent liver resection at a median of 49 days after embolization. Median hospitalization time was 4 days after embolization and 7 days after liver resection. Median overall survival of the 11 operated patients was 376 days. CONCLUSION: Percutaneous transhepatic portal vein embolization using an Ethibloc/Lipiodol mixture is a safe, feasible, and efficient interventional procedure.

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.

Iopamidol as an oral contrast media for computed tomography: a taste comparison to iohexol, diatrizoate sodium, and barium sulfate.

OBJECTIVES: The objective of this study is to compare the palatability of iopamidol and iohexol. METHODS: This was a blinded and randomized trial in which fifty healthy subjects taste tested iopamidol (Isovue, Bracco Diagnostics), iohexol (Omnipaque, GE Healthcare), diatrizoate meglumine and diatrizoate sodium solution (Gastrografin, Bracco Diagnostics), and barium sulfate suspension 2.1% w/v, 2.0% w/w (READI-CAT2, E-Z-EM). Participants scored palatability on a continuous scale from 0 to 40 (0 = intolerable, 10 = unpleasant but tolerable, 20 = neutral, 30 = kind of like, 40 = strongly like). RESULTS: Mean scores (SD/SEM) for the contrast agents (n = 50) were iopamidol = 21.0 (8.4/1.2); iohexol = 21.8 (7.1/1.0); Gastrografin = 16.8 (9.6/1.4); and barium = 23.7 (9.1/1.3). One-way ANOVA equality of means test shows rejection of the hypothesis that the means are equal (F* = 6.550, p = .000). Post hoc testing demonstrates Gastrografin to be significantly less preferred to barium (p = .000) and iohexol (p = .012). No difference was found between iopamidol and iohexol (p = .959). One-way ANOVA equality of means test of just iopamidol, iohexol, and barium does not reject the hypothesis that means are equal (F* = 1.778 and p = .174). CONCLUSION: There is no significant difference in palatability between iopamidol and iohexol, supporting the use of iopamidol as a viable alternative to iohexol as an oral contrast agent.

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.

[Cervico-facial lymphangiomas. What's the appropriate management?]. / Les lymphangiomes kystiques cervicofaciaux. Quelle prise en charge thérapeutique?

BACKGROUND: Cystic hygroma is a benign and uncommon vascular tumor. Therapeutic difficulties are variables and are discussed with regard to different clinical forms. The curative treatment is surgical. AIM: The purpose of this study is to discuss the management of the vascular malformation. PATIENTS AND METHODS: We present a retrospective study over a period of 11 years (1995- 2005); about 12 patients treated and followed in ENT department of Habib Thameur Hospital of Tunis. RESULTS: The average age of the patients was 29 years and the average size of the tumor was 7 cm in diameter. A voluminous cervical mass was noted in 3 cases. Local inflammation with respiratory restriction were observed in one patient. Surgical treatment was performed in 8 cases without recurrences. Injection of sclerosing agent (Ethibloc) was indicated in 4 cases because of the volume of the tumor. The following was marked by reduction of the tumor volume. Surgical excision was completed in one case. CONCLUSION: The management of lymphangioma is challenging. Surgical excision is the best treatment in limited forms. The prognosis of voluminous lymphangiomas is transformed by sclerosing injections.

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.

The preparation and characterization of liposomes containing X-ray contrast agents.

Unilamellar phospholipid vesicles loaded with the water-soluble, ionic X-ray contrast agent diatrizoate (Hypaque, Renografin) were manufactured by reverse-phase evaporation for use as organ-enhancing agents in X-ray computed tomography. Encapsulation efficiency was determined as a function of various diatrizoate concentrations in vesicles of varying lipid composition. Loss of encapsulated diatrizoate over 24 h was examined in vesicles composed of several egg phosphatidylcholine/cholesterol ratios. Size estimates for loaded vesicles were obtained by negative-stain electron microscopy, Millipore filtration and light microscopy. Intravenous in vivo injection of loaded vesicles in the rat resulted in significant enhancement of both spleen and liver on subsequent scans. Vesicles were similarly prepared with the water-soluble, nonionic agent metrizamide (Amipaque). Encapsulation efficiency was determined, and in vivo behavior was observed.

Two-dimensional contrast echocardiography. II. Transpulmonary studies.

A method using contrast two-dimensional echocardiography for left ventricular chamber and myocardial opacification from a right-sided pulmonary capillary wedge position is described. A total of 152 studies were carried out in nine mongrel dogs. Four different catheters with different catheter tip cross-sectional areas (varying from 0.75 to 2.3 mm2) were used. In addition, catheter position (six different positions in the pulmonary circulation), pressure of injection and type of echo contrast agent (hand-agitated and sonicated) were studied. In all 152 studies, two independent observers agreed that echo contrast was seen in the left ventricular chamber after a pulmonary capillary wedge injection of 8 cc of echo contrast agent followed by a flush injection of 8 cc saline solution. In 71% of the studies, the two independent observers agreed about the degree of opacification on a qualitative scale of 0 to 3+. Time from injection from the catheter tip to the appearance of echo contrast in the left atrium was 6.2 +/- 4.8 seconds for sonicated Renografin-76 and 2.8 +/- 0.6 seconds for sonicated sorbitol 70% (p less than 0.05). Correlation for the disappearance rate of echo contrast as determined for the region in the mid left ventricular chamber and thermodilution cardiac output was fair (r = -0.78; n = 14). In 24 studies, it was not possible to demonstrate the appearance of echo contrast in the myocardium. Peak videointensity of 10 duplicate injections showed a mean percent error of 10.4 +/- 2.1% for sonicated Renografin-76 and 1.4 +/- 0.8% for sonicated sorbitol 70%.(ABSTRACT TRUNCATED AT 250 WORDS)

Dosing of contrast material to prevent contrast nephropathy in patients with renal disease.

PURPOSE: Contrast-induced renal dysfunction has been reported to occur in 15% to 42% of patients with underlying azotemia, but there is disagreement as to whether its incidence is reduced by limiting the amount of contrast material. To adjust the amount of contrast material to the severity of azotemia, we have utilized the following formula to calculate a contrast material "limit" in patients with renal disease: Contrast material limit = (formula; see text) PATIENTS AND METHODS: Over a 10-year period, 115 patients (53 men, 62 women, aged 61 +/- 11 [mean +/- SD] years) with renal dysfunction (baseline serum creatinine level greater than or equal to 1.8 mg/dL) underwent cardiac catheterization and angiography, after which the level of serum creatinine was measured daily for five days. The amount of contrast material that was given adhered to the limit in 86 patients (Group I) and exceeded it in 29 (Group II). RESULTS: Contrast-induced renal dysfunction (an increase in serum creatinine greater than or equal to 1.0 mg/dL) occurred in two (2%) patients in Group I and in six (21%) patients in Group II (p less than 0.001). Of the 48 patients with concomitant diabetes mellitus, the contrast limit was surpassed in 16, six (38%) of whom had contrast nephropathy. Only two of the 32 (6%) diabetic patients in whom the contrast limit was not exceeded had contrast nephropathy (p less than 0.001). CONCLUSIONS: Thus, contrast-induced renal dysfunction occurs infrequently if the amount of contrast material is limited in accordance with the degree of azotemia. Diabetic patients have a high incidence of contrast nephropathy, particularly when they receive an excessive amount of contrast. In patients with diabetes and renal impairment, it may be preferable to perform angiography as a staged procedure or to utilize alternative (non-contrast) techniques to obtain the desired information rather than to exceed the prescribed contrast limit.

Effect of intracoronary injections of sonicated microbubbles on left ventricular contractility.

Despite the recent interest in contrast-enhanced echocardiography as a means of defining myocardial perfusion, the effects of echo contrast agents on left ventricular (LV) contractility in humans remains poorly defined. This is particularly relevant because intracoronary injection of contrast agents used for angiographic visualization of coronary arteries produces significant alterations in LV hemodynamics. The relation of LV end-systolic wall stress (sigma es) to rate-corrected velocity of fiber shortening (Vcfc), a load-independent index of contractility, was studied in 7 patients undergoing elective coronary arteriography. Two-dimensional and targeted M-mode echocardiographic and central aortic pressure tracings were recorded during injections of standard volumes of angiographic (7 to 9 ml of nonsonicated Renografin-76) and echocardiographic (1.5 to 2.0 ml of sonicated Renografin-76) contrast agents into the left main coronary artery. The order in which agents were injected was randomly determined. Myocardial contractility was assessed under control conditions and 5 and 15 seconds after injection. Alterations in contractility relative to control were measured as the change in Vcfc after elimination of afterload (sigma es) as a confounding variable. An injection of Renografin-76 adequate for angiographic imaging of coronary artery anatomy resulted in a significant depression of LV contractility (p less than 0.001) in conjunction with a tendency toward increased afterload (p = 0.12); recovery occurred by 15 seconds after injection. The smaller amounts of sonicated Renografin-76 required to give adequate contrast enhancement of the myocardium did not alter LV contractile state or afterload.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between renal lymph flow and changes in kidney size during urography.

Using direct cannulation of renal lymphatic vessels and simultaneous photography of the exposed dog kidney during urography, the time schedule of variations in lymph flow and kidney size was established. The intravenous contrast injection produced heavy increase of renal lymph flow during the first 8 minutes of urography. Peak values were observed 3--4 minutes after injection. From 8 to 11 minutes after injection the lymph flow was depressed below the baseline, followed by a tendency of reestablishment. Generally after 25 minutes the lymph flow returned to its baseline level. The earliest response of kidney size upon intravenous contrast injection was a rapid, short-lived decreased, followed by a distension during the first 3 minutes. Thereafter a tendency to return to the preurographic size was observed. However none of the kidneys returned entirely to the baseline size during one hour of observation. The possible physiologic explanations of the observations are discussed.