Success Rate of Intra-articular Sacroiliac Joint Injection: Fluoroscopy vs Ultrasound Guidance-A Cadaveric Study.

BACKGROUND: Given the unacceptably high miss rates of non-image-guided injections into the sacroiliac joint, either fluoroscopy or ultrasound is recommended for guidance. The real success rate of both techniques was assessed by cadaver dissection. METHODS: Twenty bodies donated to science (40 joints: 15 female and 5 male) were investigated bilaterally. Fluoroscopy and a lower ultrasound-guided approach were performed in 10 bodies each. Conditions during puncture, the subjective feeling of the needle being intra-articular, and, for fluoroscopic guidance, the intra-articular spread of the contrast were assessed. First, 0.5 cc of Iopamidol was injected, followed by 2 mL of red-colored latex. The spread was investigated by dissection via anterior opening of the sacroiliac joint and the dorsal ligaments. RESULTS: Ultrasound guidance was used in 1/20 (5%, 95% CI = 0.9-23.6%) intra-articular injections. In 19/20 (95%, 95% CI = 0.9-23.6%) cases, latex spread in the interosseous sacroiliac ligament was used. Conditions of structural visibility were classified as good in 11/20 (55%, 95% CI = 34.2-74.2%) cases, puncture condition as good in 16/20 (80%, 95% CI = 58.4-91.9%) cases, and subjective feeling of the needle being intra-articular was present in 10/20 (50%, 95% CI = 34.2-74.2%) cases. Fluoroscopy showed an intra-articular injection in 10/20 (50%, 95% CI = 34.2-74.2%) cases. The structure visibility in fluoroscopy was good in 9/20 (45%, 95% CI = 25.8-65.8%), puncture conditions good in 8/20 (40%, 95% CI = 21.9-61.3%), intra-articular contrast spread visible in 10/20 (50%, 95% CI = 34.2-74.2%), and subjective feeling of being intra-articular was present in 17/20 (85%, 95% CI = 64.0-94.8%) cases. CONCLUSIONS: Fluoroscopy clearly showed a higher success rate of intra-articular sacroiliac joint injection.

Prospective comparison of gadoxetic acid-enhanced liver MRI and contrast-enhanced CT with histopathological correlation for preoperative detection of colorectal liver metastases following chemotherapy and potential impact on surgical plan.

OBJECTIVE: To prospectively compare the diagnostic performance of gadoxetic acid-enhanced MRI (EOB-MRI) and contrast-enhanced CT (CECT) for preoperative detection of colorectal liver metastases (CRLM) following chemotherapy and to evaluate the potential change in the hepatic resection plan. METHODS: 51 patients with CRLM treated with preoperative chemotherapy underwent liver imaging by EOB-MRI and CECT prospectively. Two independent blinded readers characterized hepatic lesions on each imaging modality using a 5-point scoring system. 41 patients underwent hepatic resection and histopathological evaluation. RESULTS: 151 CRLM were confirmed by histology. EOB-MRI, compared to CECT, had significantly higher sensitivity in detection of CRLM ≤1.0 cm (86% vs. 45.5%; p < 0.001), significantly lower indeterminate lesions diagnosis (7% vs. 33%; p < 0.001) and significantly higher interobserver concordance rate in characterizing the lesions ≤1.0 cm (72% vs. 51%; p = 0.041). The higher yield of EOB-MRI could have changed the surgical plan in 45% of patients. CONCLUSION: Following preoperative chemotherapy, EOB-MRI is superior to CECT in detection of small CRLM (≤1 cm) with significantly higher sensitivity and diagnostic confidence and interobserver concordance in lesion characterization. This improved diagnostic performance can alter the surgical plan in almost half of patients scheduled for liver resection.

DEVELOPING A TECHNIQUE FOR ULTRASOUND-GUIDED INJECTION OF THE ADULT CANINE HIP.

An accurate method for guiding injections into the canine hip would facilitate diagnostic localization of lameness and targeted treatments. Ultrasound-guided hip injections are commonly used in humans and large animals. Aims of this prospective study were to describe ultrasound (US) anatomy of the adult canine hip and determine the feasibility and accuracy of intra-articular placement of injectate using US-guidance. Seven adult dogs were used to describe US anatomy, five dog cadavers were used to assess the feasibility of the injection technique and 11 dog cadavers were used to assess accuracy of injections. For the accuracy test, 22 joints were injected with iodinated contrast medium by three operators with different experience. With dogs in lateral recumbency, the hyperechoic femoral head surface was identified by following the femoral neck from the greater trochanter or the acetabular rim was localized by following caudally the ilium from the iliac wing. An anechoic gap between the femoral head and acetabular surface represented the joint. The capsule was visible as a triangular echoic structure and the femoral head articular cartilage appeared as an anechoic band. The needle was inserted axial to the greater trochanter and directed in a dorsolateral-ventromedial direction toward the joint space and then pushed through the capsule. Based on postinjection radiography, accuracy was 81.8% at first attempt and 100% at second attempt. This study indicated that US-guided injection is a feasible and accurate technique for injecting the adult canine hip. Future studies in live dogs are needed to assess safety and efficacy.

Low-contrast agent dose dual-energy CT monochromatic imaging in pulmonary angiography versus routine CT.

OBJECTIVE: This study aimed to retrospectively evaluate the feasibility and reliability of low-contrast agent dose dual-energy computed tomography (DECT) monochromatic imaging in pulmonary angiography. METHODS: Computed tomography pulmonary angiography was performed in 86 patients, 41 in 120-kVp computed tomography (CT) and 45 in DECT with low-contrast agent dose. The images in DECT were reconstructed at optimal kiloelectron-voltage (keV), demonstrating the best contrast-to-noise ratio between pulmonary artery and soft tissue, and at 70 keV. Image quality was compared by quantitative and subjective indexes. The radiation doses were recorded. RESULTS: Compared with 120-kVp CT, optimal keV showed superior quantitative indexes with inferior subjective image quality, whereas 70 keV demonstrated no statistical difference in quantitative indexes with superior subjective image quality. All suspicious pulmonary embolisms in DECT were diagnosed confidently by combination of 2 kinds of monochromatic imaging. The radiation dose in DECT is almost twice as 120-kVp CT. CONCLUSIONS: Low-contrast agent dose DECT monochromatic imaging in pulmonary angiography accommodates superior intravascular enhancement and contrast in pulmonary arteries, and improves diagnostic confidence with compatible radiation dose.

Accuracy of intra-articular injection of the glenohumeral joint: a modified anterior approach.

PURPOSE: This study examined the accuracy of our modified anterior approach to the glenohumeral joint using arthrography. METHODS: Two hundred fifty-six consecutive patients with adhesive capsulitis received the glenohumeral joint injection: a mixture of 1 mL of 40 mg of triamcinolone hexacetonide, 2 mL of 2% lidocaine, 3 mL of contrast medium (Ioxitalamate), and 4 mL of normal saline solution, for a total of 10 mL, through a modified anterior approach. Anteroposterior, lateral, and axial arthrography after each injection was performed to determine the accuracy and patterns of the injection. The injection was judged to be successful if some of the contrast medium was placed within the joint. RESULTS: There were 78 male and 178 female patients, and the mean age was 54 years (range, 28 to 87 years). In 232 of the 256 patients (90.6%), the injection was deemed to have reached the glenohumeral joint, and these cases were considered successful. Among these patients, the contrast medium was shown only in the joint in 189 (73.8%), whereas in 43 (16.8%) it was shown both in and out of the joint. Of the 24 misguided injections, 15 (5.9%) had anterior placement, 6 (2.3%) had posterior placement, and 2 (0.8%) had superior placement, whereas the material was located in all portions outside the joint in 1 (0.4%). CONCLUSIONS: This study showed that our modified anterior approach had an accuracy greater than 90% for the intra-articular injection of the glenohumeral joint without radiographic guidance.

Gastric emptying time of oral contrast material in children and adolescents undergoing abdominal computed tomography.

OBJECTIVES: : Considering the hazards of pulmonary aspiration of oral contrast material (OCM) during general anesthesia, we investigated the gastric emptying time (GET) of OCM in children and adolescents undergoing abdominal computed tomography (CT). PATIENTS AND METHODS: : Included in the study were 101 consecutive patients ages 3.1 to 17.9 years (mean age 12.2 +/- 3.3 years), who underwent contrast-enhanced abdominal CT for suspected acute appendicitis (n = 90), abdominal trauma (n = 10), or suspected ileus (n = 1). Oral iodinated ioxithalamate was given for bowel opacification. Background data (age, sex, weight, chronic diseases, and medication intake), time of initiation and completion of OCM, and time of CT scanning were recorded. To estimate the GET of OCM, CT images were reviewed to examine whether the stomach was empty or full of OCM at the time of imaging. RESULTS: : The Kaplan-Meier curve showed that 75% of the patients had OCM in the stomach 48 +/- 5.2 minutes after its completion, 50% after 74 +/- 7.9 minutes, and 25% after 135 +/- 32.5 minutes; 1 patient still had OCM after 162 minutes. Except for the length of time taken to drink the contrast material (< or =90 minutes was associated with slower empting of the stomach; log rank, P = 0.03), GET of OCM was not correlated with sex (P = 0.16), age (P = 0.15), weight (P = 0.13), or type of diagnosis (P = 0.41). CONCLUSIONS: : Given the variability of GET of OCM and if clinically feasible, we advocate waiting at least 3 hours between completion of OCM ingestion and general anesthesia induction.

Performance of Creatinine Clearance and Estimated GFR in Assessing Kidney Function in Living Donor Candidates.

BACKGROUND: Glomerular filtration rate (GFR) assessment is a key aspect in the evaluation of living kidney donor candidates; however, data on performance of commonly used methods are limited. METHODS: We examined 769 living kidney donor candidates with 24-hour urine collections assessed as accurate by comparing measured creatinine excretion rate (CER) to CER estimated using a 4-variable equation previously developed and validated using robust methodology. RESULTS: Of all collections, 42.6% would have been deemed inaccurate, mostly under-collections, using the conventional weight- and gender-based CER estimation. Creatinine clearance (CrCl) overestimated I-iothalamate GFR (iGFR), estimated GFR (eGFR), underestimated iGFR, and their average [Avg (CrCl and eGFR)] essentially eliminated the GFR bias (median bias = +2.2, -5.4, and -1.0 mL/min/1.73 m, respectively; P < 0.001). This held true for all subgroups except blacks, where all 3 measures overestimated iGFR. Avg (CrCl and eGFR) also offered modestly improved accuracy compared with CrCl alone, as measured by the proportion of values falling within 10% (50.7% versus 45.3%; P = 0.009) and 30% of iGFR (94.5% versus 89.3%; P < 0.001). CONCLUSIONS: When measured GFR is unavailable, the Avg (CrCl and eGFR) provides a better estimate of kidney function in kidney donor candidates than either measure alone, although in blacks the estimates are neither better nor worse.

MDCT for suspected acute appendicitis in adults: impact of oral and IV contrast media at standard-dose and simulated low-dose techniques.

OBJECTIVE: The objective of this study was to prospectively investigate the influence of oral, IV, and oral and IV contrast media on the information provided by MDCT at standard and simulated low radiation doses in adults suspected of having acute appendicitis. SUBJECTS AND METHODS: One hundred thirty-one consecutive patients (80 women, 51 men; age range, 18-87 years; mean age, 37 years) suspected of having appendicitis were randomly assigned to either ingest or not ingest iodinated contrast material. Thereafter, all patients underwent IV unenhanced and enhanced abdominopelvic MDCT with a 4 x 2.5 mm collimation at 120 kVp and 100 mAs(eff). Dose reduction corresponding to 30 mAs(eff) was simulated. Two radiologists independently read scans during separate sessions, assessed appendix visualization, and proposed a diagnosis (i.e., appendicitis or an alternative diagnosis). The final diagnosis was based on either surgical findings or clinical follow-up. Data were analyzed by factorial analysis of multiple correspondences followed by an ascending hierarchic classification method. RESULTS: Factorial analysis and ascending hierarchic classification revealed that, in terms of diagnostic correctness, reader influence predominated over the influence of IV and oral contrast media use and radiation dose but that correctness was also influenced by the patient's sex (p = 0.048) and was lower in cases of alternative diseases (p < 0.001). Visualization of the appendix depended predominantly on the reader rather than on the use of IV, oral, or oral and IV contrast agents or on radiation dose. CONCLUSION: Diagnostic correctness is much more influenced by the reader than by the use of contrast medium (oral, IV, or both) or of simulated low-radiation-dose technique.

Extracellular acidosis differentiates pancreatitis and pancreatic cancer in mouse models using acidoCEST MRI.

Differentiating pancreatitis from pancreatic cancer would improve diagnostic specificity, and prognosticating pancreatitis that progresses to pancreatic cancer would also improve diagnoses of pancreas pathology. The high glycolytic metabolism of pancreatic cancer can cause tumor acidosis, and different levels of pancreatitis may also have different levels of acidosis, so that extracellular acidosis may be a diagnostic biomarker for these pathologies. AcidoCEST MRI can noninvasively measure extracellular pH (pHe) in the pancreas and pancreatic tissue. We used acidoCEST MRI to measure pHe in a KC model treated with caerulein, which causes pancreatitis followed by development of pancreatic cancer. We also evaluated the KC model treated with PBS, and wild-type mice treated with caerulein or PBS as controls. The caerulein-treated KC cohort had lower pHe of 6.85-6.92 before and during the first 48 h after initiating treatment, relative to a pHe of 6.92 to 7.05 pHe units for the other cohorts. The pHe of the caerulein-treated KC cohort decreased to 6.79 units at 5 weeks when pancreatic tumors were detected with anatomical MRI, and sustained a pHe of 6.75 units at the 8-week time point. Histopathology was used to evaluate and validate the presence of tumors and inflammation in each cohort. These results showed that acidoCEST MRI can differentiate pancreatic cancer from pancreatitis in this mouse model, but does not appear to differentiate pancreatitis that progresses to pancreatic cancer vs. pancreatitis that does not progress to cancer.

Fluid-modulated bipolar radiofrequency ablation: an ex-vivo evaluation study.

BACKGROUND: The effect of radiofrequency ablation (RFA) can be modulated by fluid injection. PURPOSE: To evaluate the potential of different fluids to modulate the effect of bipolar RFA in an ex-vivo liver model. MATERIAL AND METHODS: A bipolar RFA system with an internally cooled needle-shaped applicator (20-mm active tip) was used to induce coagulation lesions in ex-vivo porcine liver. Prior to the ablation procedure, 1-ml samples of seven different fluids were injected (0.9% saline, gadopentetate dimeglumine, ioxithalamate, 10% hydroxyethyl starch, 5% glucose, 95% ethanol, distilled water). Each fluid was used for five RF ablations. During the procedure, applied energy, impedance, and time were recorded. Additionally, temperature was measured at a fixed distance of 0.5 and 1.0 cm from the RF probe. Generator output was set to 20 W, as recommended by the vendor. Five ablation procedures without fluid injection served as the reference standard. The lesion diameters were measured, and volume and an efficiency index (coagulation volume/procedure duration) calculated and compared (ANOVA, Student-Newman-Keuls test). RESULTS: In comparison to the reference standard, fluid injection resulted in an enlargement of mean coagulation volume for all fluids. In comparison to RF ablation alone (1.42+/-0.33 cm(3)), significant increase (P<0.001) of lesion size was found using gadopentetate dimeglumine, hydroxyethyl starch, glucose, and ethanol. The largest lesions were generated using preinjection of hydroxyethyl starch. Most energy could be applied after injection of glucose. Comparing the efficiency index, no statistically significant differences were found. CONCLUSION: Besides the modulation of the electrical conductivity, the increase in thermal conductivity also contributes to the enhancement of RFA by the injection of the tested fluids. Further studies are needed to evaluate this effect for larger injection volumes under in-vivo conditions.

Oil-based or water-based contrast for hysterosalpingography in infertile women: a cost-effectiveness analysis of a randomized controlled trial.

OBJECTIVE: To determine the cost effectiveness of the use of oil-based versus water-based contrast in infertile women undergoing hysterosalpingography (HSG). DESIGN: Economic evaluation alongside a multicenter randomized trial. SETTING: Hospitals. PATIENT(S): Infertile women with an ovulatory cycle, 18-39 years of age, low risk of tubal pathology. INTERVENTION(S): Use of oil-based versus water-based contrast during HSG. MAIN OUTCOME MEASURE(S): Costs per additional ongoing pregnancy and per live birth within 6 months of randomization, incremental cost-effective ratios (ICERs). RESULT(S): A total of 1,119 women were randomized to HSG (oil-based contrast, n = 557; water-based contrast, n = 562). After HSG, most women had no additional treatment; a minority had IUI or IVF. In the oil group, 39.7% women had an ongoing pregnancy within 6 months of randomization versus 29.1% women in the water group. There was a 10.7% increase in the live birth rate in the oil group. For ongoing pregnancy, the mean costs per couple were US$2,014 in the oil group and US$1,144 in the water group, with a corresponding ICER of US$8,198 per additional ongoing pregnancy. For live birth, the mean costs per couple were US$11,532 in the oil group and US$8,310 in the water group, with a corresponding ICER of US$30,112 per additional live birth. CONCLUSION(S): Hysterosalpingography with oil-based contrast results in higher 6-month ongoing pregnancy and live birth rate. If society is willing to pay US$8,198 for an additional ongoing pregnancy, HSG with oil-based contrast is a cost-effective strategy compared with HSG with water-based contrast for infertile, ovulatory women at low risk for tubal pathology. CLINICAL TRIAL REGISTRATION NUMBER: Dutch Trial Register, NTR 6577 (www.trialregister.nl).

Telebrix Gastro in the management of adhesive small bowel obstruction.

BACKGROUND: This study aimed to determine whether an abdominal radiograph 8 hours after ingesting oral Telebrix Gastro is a reliable marker for non-operative management in patients with adhesive small bowel obstruction. METHODS: During a 5-year period (January 1, 1995, through December 31, 2000), 97 patients were admitted for small bowel occlusion due to adhesion with no indication for immediate surgery. All received 100 mL of Telebrix Gastro via gastric tube for small bowel obstruction due to adhesion. If the contrast reached the colon within 8 hours on plain abdominal radiograph, the test was considered to be negative. RESULTS: 126 cases of small bowel occlusions were analyzed due to recurring episodes for 11 patients. The test was negative in 113 cases (89.7%), and in this group, only two patients underwent surgery, the remaining being managed non-operatively. The 13 cases (10.3%) with a positive test for occlusion underwent surgery. The sensitivity, specificity and accuracy of the finding of contrast media reaching the colon as an indicator for conservative treatment were 98%, 100%, and 98%, respectively. CONCLUSIONS: A water-soluble contrast study can be of significant help in the clinical management of patients suspected of having small bowel obstruction.

[Unilateral periocular angioedema after application of contrast agent]. / Einseitiges periokuläres Angioödem nach Kontrastmittelgabe.

This article presents a case report of unilateral, periocular angioedema after intravenous application of a contrast agent with a temporary increase of intraocular pressure in an eye in which trabeculectomy had been carried out 5 weeks previously.

Radiation dose enhancement therapy with iodine in rabbit VX-2 brain tumors.

Loading tissue with iodine enhances the radiation dose absorbed from low energy X-rays. In order to test whether this is a useful procedure for treating brain tumors, we infused radiographic contrast media into rabbits carrying VX-2 brain tumors and delivered 15 Gy of 120 kVp X-rays in 3 fractions to the tumor. From CT scans we estimated that the dose enhancement was approximately 30%. The median survival times, after tumor detection on CT, of untreated rabbits, treated with radiation alone, and treated with radiation plus contrast media were 3, 25.5, 38.5 days, respectively. The repeated infusion of contrast media, 3.5 g of iodine per kg of body weight, did not affect kidney function as measured by serum creatinine levels. This method of enhancing radiation dose in brain tumors therefore appears promising.

Ambulatory GFR measurement with cold iothalamate in adults with chronic kidney disease.

BACKGROUND: The purpose of this study is to develop a method that eliminates the use of radioactive agents, reduces the length of inpatient visits, and does not require urine collection for the measurement of glomerular filtration rate (GFR) in adults with chronic kidney diseases (CKD). METHODS: We measured simultaneous urinary and plasma clearance of iothalamate using high-performance liquid chromatography in 30 patients with CKD after a continuous subcutaneous infusion of iothalamate at a rate of 125 microL/h for a 24-hour period. To ascertain whether a steady state was achieved with a 24-hour infusion, in 20 additional patients, we infused iothalamate continuously for 48 hours and measured GFR after 24 and 48 hours. RESULTS: Plasma iothalamate levels and urinary excretion rates obtained after 24- and 48-hour infusions were similar. GFR estimated by plasma clearance (44.4 mL/min; 95% confidence interval [CI], 37.0 to 53.3) was similar to urinary clearance (41.6 mL/min; 95% CI, 34.7 to 50.0) and without bias (average difference, 7%; 95% CI, +18% to -38%; P = 0.866). There also was acceptable agreement between plasma and urinary clearance of iothalamate (coefficient of variation [CV], 19.6% between techniques). Reproducibility of day-to-day plasma continuous infusion clearance technique was less than 12%. There was good agreement (CV, 19.9%) between inulin and renal iothalamate clearances. CONCLUSION: These data show that ambulatory infusion of iothalamate can be used to measure GFR in adults with CKD without the need for urine collections with acceptable precision and without exposure to radioactivity.

Solute excretion during intravenous urography: a comparison of sodium and methylglucamine iothalamates.

The sodium and methylglucamine salts of iothalamic acid were compared as urographic agents. The two drugs were administered intravenously to dogs at a dose of 600 mgI/kg. The outputs and concentrations of the major urinary solutes and the injected solutes were measured to define the differences in renal excretion of sodium and methylglucamine iothalamates. The action of methylglucamine as a relatively inert osmotic diuretic was reconfirmed. When sodium iothalamte was adminstered the tubular reabsorption of sodium and chloride was greater than when methylglucamine iothalamate was used. It is suggested that this reabsorption explains the advantage of sodium-linked agents over methylglucamine-linked agents in urography.

Fluid compartment distribution of intravenous iothalamate in the dog.

The distribution of 125I iothalamate between the intravascular and extravascular fluid compartments was determined after intravenous injection in dogs. Simultaneous measurements of total blood volume, blood iothalamate concentrations and urinary iothalamate excretion were made and permitted calculation of extravascular iothalamate. The drug diffused very rapidly to the extravascular space: more than half had reached the extravascular space one minute after injection. The ratio of extravascular to intravascular iothalamate rose to a plateau of 6.8. We conclude that the contrast material responsible for tissue opacification during radiography is primarily extravascular and that the levels of contrast in plasma during urography are affected less by renal excretion than by distribution between fluid compartments.

Why does kidney size change during I.V. urography?

Meglumine iothalamate (280 ml I/ml) and sodium iothalamate (400 mg I/ml) in doses of 700 mg I/kg bw, were injected i.v. as a bolus in dogs. Renal size, urine flow rate, arterial pressure, renal blood flow and mean transit time and renal blood volume were measured before and after injection. All changes were qualitatively and quantitatively identical for both drugs. They produced a small transient renal shrinkage followed by a greater and prolonged renal enlargement. During the period of renal enlargement, urine flow increased. The time course of the enlargement paralleled the increase of urine flow rate. Renal blood flow also increased but both the mean transit time and renal vascular volume decreased. Therefore, the kidney size increase after i.v. injection of large doses of urographic contrast media cannot be attributed to an increased volume of the vessels. Most likely it is caused by diuresis-induced increase in the volume of the tubules.

Gated computed tomography of the human heart.

Production of in vivo images of the human heart, with delineation of the individual cardiac chambers and myocardial wall thickness, was accomplished by coupling a relatively simple electrocardiographic gating device to a translate-rotate type of computed body tomographic scanner. Differentiation between the myocardial wall and the intracardiac blood pool was attainable in the patient with a normal hematocrit only when intravenous iodinated contrast media was used.

Iothalamate ethyl ester as hepatolienographic agent.

In search of a hepatolienographic agent, the iothalamate ethyl ester particulate suspension was prepared with the average particle size of 1.5 mu in diameter. When mixed with plasma of different animal species, the physical properties of the particular suspension changed significantly. The nature of this difference is not understood but is probably related to protein-particle interaction in the different species. Doses of 550 mg iodine per kg body weight as a single intravenous infusion of the particulate suspension resulted in satisfactory opacification of liver and spleen in rats, followed by complete loss of radiopacity within three days. Larger doses resulted in the death of the rats within 12-14 hours. In general, the mice tolerated larger doses than rats, but there was very poor opacification of the liver, despite good opacification of spleen. Further work is being carried out to improve the suspension and to better understand the difference in behavior of the particulate suspension in different animal species.