Ml Of Contrast Medium Research Articles

Preliminary study on contrast flow analysis of thoracic transforaminal epidural block.

BackgroundThe thoracic transforaminal epidural block (TTFEB) is usually performed to treat herpes zoster or postherpetic neuralgia (PHN). Especially, multiple segmental involvements and approximate contrast medium spread range, according to volume, help to choose the proper drug volume in the transforaminal epidural block. This study investigated the contrast medium spread patterns of 1-ml to 3-ml TTFEBs.MethodsA total of 26 patients with herpes zoster or PHN were enrolled in this study. All participants received 1 ml, 2 ml, or 3 ml of contrast medium. Results were divided into Groups A, B and C based on the volume (1, 2, or 3 ml), with n = 26 for each group. After the injection of contrast medium, the spread levels were estimated in both the lateral and anteroposterior (AP) images using fluoroscopy.ResultsThe cephalad spread of contrast medium in the lateral image as expressed by the median (interquartile range) was 2.00 levels (1.00–2.00) for Group A, 2.50 (2.00–3.00) for Group B, and 3.00 (2.00-4.00) for Group C. The caudal spread level of contrast medium was 1.00 (1.00-2.00) for Group A, 2.00 (2.00–3.00) for Group B, and 2.00 (2.00–3.00) for Group C. There was ventral and dorsal spread of the 3-ml contrast medium injection in 88% (23/26) of cases in the lateral image.ConclusionsInjection of 3 ml of contrast medium through the foramina spread 6 levels in a cephalocaudal direction. Spread patterns revealed a cephalad preference. TTFEB resulted in dorsal and ventral spread in a high percentage of cases. This procedure may be useful for transferring drugs to the dorsal and ventral roots.

Detection of Intravascular Injection During Cervical Transforaminal Epidural Injection: A Comparison of Digital Subtraction Angiography and Real Time Fluoroscopy

Background: Transforaminal epidural injection (TFEI) with local anesthetics and steroids are effective in treating spinal radicular pain. However, inadvertent intravascular injection can lead to severe neurologic complications. To reduce complications of intravascular injection, use of imaging modality, such as real-time fluoroscopy (RTF) or digital subtraction angiography (DSA), has been recommended. DSA is an imaging technique that can clearly visualize the blood vessels from surrounding bones or dense soft tissues by subtracting the pre-contrast image from the image after injecting contrast medium. Objective: In this study, we investigated whether there is a difference between RTF and DSA in the detection of intravascular injection during cervical TFEI. Study Design: Clinical study. Setting: Pain clinic in South Korea. Methods: We prospectively examined 137 cervical TFEIs on 128 patients who have a radiating pain from spinal stenosis and herniated nucleus pulposus. The needle position was confirmed using biplanar fluoroscopy and 2 mL of nonionic contrast medium was injected at the rate of 0.5 mL/sec under RTF. Thirty seconds later, 2 mL of nonionic contrast medium was injected at the rate of 0.5 mL/sec under DSA. Intravascular injection was defined as contrast medium spreading throughout the vascular channel during injection of contrast medium under RTF and DSA. This study is registered in the ClinicalTrials.gov (NCT03040648). Results: The detection rate of intravascular injection in RTF was not statistically different compared to that in DSA (30.7 % vs. 34.3%, P > 0.05). Limitations: We injected 2 mL of contrast medium at the rate of 0.5 mL/sec. Further studies about the ideal injection speed and volume of contrast medium for improvement of detection of intravascular injection during TFEI are needed. This study was a single center study. Therefore, multi-center studies are needed to obtain the high level of evidence. Additionally, the procedural pain physician was not blinded to the type of imaging modality, such as RTF and DSA, to detect intravascular injection. To minimize this confirmation bias and provide homogenous procedural conditions for TFEI, the same procedural physician performed all 137 injections. Conclusions: In this study, there is no significant difference in detection rate of intravascular injection between RTF and DSA during cervical TFEI. Key words: Analgesia, bleeding, clinical trials, complications, diagnostic equipment, epidural, radiculopathy, spine

Dynamic CTA in Native Kidneys Using a Multiphase CT Protocol—Potential of Significant Reduction of Contrast Medium

The objective of this study was to assess an optimized renal multiphase computed tomography angiography (MP-CTA) protocol regarding reduction of contrast volume. Thirty patients underwent MP-CTA (12 phases, every 3.5 seconds, 80 kV/120 mAs) using 30 mL of contrast medium. The quality of MP-CTA was assessed quantitatively measuring vessel attenuation, image noise, and contrast-to-noise ratio. MP-CTA was evaluated qualitatively regarding depiction of vessels, cortex differentiation, and motion artifacts (grades 1-4, 1 = best). Mean effective radiation dose was registered. Results were compared to standard renal computed tomography angiography (CTA) (80 mL). Student t test was applied, if variables followed normal distribution. For other variables, nonparametric Mann-Whitney U test was used. All acquisitions were successfully performed, and no patient had to be excluded from the study. MP-CTA enabled high attenuation (aorta: 503 ± 91 HU, renal arteries: 450 ± 73 HU/456 ± 72 HU) at adequate image noise (13.7 ± 1.5) and good contrast-to-noise ratio (34.2 ± 10.2). Good attenuation of renal veins was observed (286 ± 43 HU/282 ± 42 HU). Arterial enhancement was significantly higher compared to renal CTA (aorta: 396 ± 90 HU, renal arteries: 331 ± 74 HU/333 ± 80 HU; P < .001). MP-CTA protocol enabled good image quality of renal arteries (1.5 ± 0.6) and veins (1.7 ± 0.6). Cortex differentiation and motion artifacts were ranked 1.8 ± 0.8 and 1.6 ± 0.8. The mean effective radiation dose was 9 mSv (MP-CTA). Compared to standard renal CTA, the renal MP-CTA enabled the significant reduction of contrast volume and simultaneously provided a significantly higher arterial attenuation.

Influence of Trendelenburg position and pneumoperitoneum treatment on gastroesophageal reflux in dogs.

Gastroesophageal reflux is a latent factor that may cause esophagitis, esophageal stenosis, and aspiration pneumonia through the regurgitation of the gastric fluid contents. For laparoscopic surgery, posture-changing and pneumoperitoneum operations are conducted to develop the visual field. However, few studies have examined the influence of these operations on gastroesophageal reflux. In this experiment using 10 Beagles, 10 mL of contrast medium was administered into the stomach, and the dogs were placed in the Trendelenburg position with 10-degree tilting. Pneumoperitoneum treatment with carbon dioxide was performed, with an intraperitoneal pressure of 10 mmHg. The presence or absence of gastroesophageal reflux was evaluated using computed tomography (CT). In horizontal and Trendelenburg positions, there was no reflux of Contrast medium. However, reflux was observed in the Trendelenburg position under pneumoperitoneum (p<0.05). These results suggest that the risk of gastroesophageal reflux increases during laparoscopic surgery in the Trendelenburg position with 10-degree tilting under an intraperitoneal pressure of 10 mmHg.

Development of an ultrasound-guided technique for retrobulbar nerve block in dromedary camels: a cadaveric study

ObjectiveDescription of an ultrasound (US)-guided technique for retrobulbar nerve blockade in dromedary (Camelus dromedarius) cadavers. Study designProspective experimental cadaveric study that was carried out in three phases: phase I: anatomical dissection and development of US-guided technique; phase II: methylene blue (MB) injection; phase III: contrast medium (CM), US-guided injections with computed tomography (CT) control. AnimalsA total of 36 orbits from 18 heads were obtained from 18 dromedary cadavers. MethodsPhase I: anatomical dissections were carried out bilaterally, using two heads to determine needle site placement. Phase II: a US-guided, lateral, in-plane approach using one of three volumes of MB (3, 6, or 9 mL) was evaluated in six heads (four orbits per volume tested) to establish the ideal injection volume. Injections of MB that strongly stained all retrobulbar nerves were considered successful, whereas insufficient MB volumes resulted in weak or no nerve staining. Phase III: US-guided retrobulbar injection with CM was carried out using 20 orbits. Computed tomography was performed after each injection trial to determine the accuracy of needle placement and CM dispersal. An injection was judged to be successful when the CT images revealed that the needle was located within the retractor bulbi muscle cone and the CM reached the target nerves at the orbitorotundum and the optic foramina. ResultsOnly injection of 9 mL of MB stained the target nerves sufficiently, whereas there was no or only weak staining with 3 and 6 mL, respectively. Therefore, 9 mL of CM was used for the US-guided injections in phase III. Subsequent CT scans revealed satisfying CM distribution within the ocular muscle cone in 18 of 20 cases (90% success rate). Conclusions and clinical relevanceUS-guided retrobulbar injection in dromedary cadavers is feasible. Further research is required to assess its practicality and usefulness in vivo.

Optimizing Contrast Media Injection Protocols in Computed Tomography Angiography at Different Tube Voltages: Evaluation in a Circulation Phantom.

The aim of this study was to investigate the minimum iodine delivery rate (IDR) and contrast media (CM) volume required for diagnostic contrast enhancement of 350 HU (Hounsfield units) in the ascending aorta at different kV settings. Dynamic computed tomography acquisitions from 70 to 150 kV were performed in a circulation phantom. First, injections with IDR ranging from 0.1 to 2.0 g I/s were tested for each kV. In the second part, the IDR was held constant, whereas the CM volume was reduced from 50 to 10 mL. Diagnostic aortic peak enhancement for each kV was compared using the Kruskal-Wallis test. P < 0.05 was considered statistically significant. The mean aortic peak enhancement for all diagnostic IDRs was 368.7 ± 11.1 HU. Diagnostic IDRs returned similar aortic peak enhancement values for all protocols (all P ≥ 0.18). For the second part of the study, a diagnostic enhancement was yielded by using a minimum of 30 mL of CM for 110 kV, 25 mL for 100 and 90 kV, and 15 mL for 80 and 70 kV. Our study suggests that a differentiated approach reducing the CM volume for tube voltages of less than 120 kV and increasing the IDR for higher kV settings seems to be the most effective approach.

Investigation into intraoral approach for nerve block injection at the mental foramen in the horse

SummaryInvasive dental procedures performed in the standing, sedated horse are facilitated by local and regional anaesthesia. The traditional transcutaneous approach to the mental foramen is used to desensitise the incisive region including the mandibular incisors, but is not well tolerated by many sedated patients. In this study, a new, intraoral needle insertion technique for nerve block at the mental foramen was investigated. In 15 equine cadaver heads and two live horses, computed tomography (CT) was used to verify Tuohy needle placement into each mental foramen using an intraoral technique. Varying volumes of contrast medium (3, 6, 10 mL) were injected into the mandibular canal with and without digital occlusion of the mental foramen. The distance of retrograde flow was measured. Additionally, measurements were taken to determine the position of the mental foramen within the interdental space. Correct placement of Tuohy needles and injection of contrast medium into the mandibular canal using an intraoral approach at the mental foramen was achieved in all injections. Retrograde flow of contrast medium was accomplished with all volumes, regardless of occlusion. Although not statistically significant, the 10 mL group appeared to have a greater distance of flow. The needle insertion technique described here appears to be a potential alternative to traditional transcutaneous approaches to mental nerve block for procedures involving the incisive region. In addition, it was found that 79% of the mandibular canals injected with 10 mL of contrast medium had retrograde flow to the position of PM4, suggesting this method may be a useful alternative technique for nerve block for the more rostrally located cheek teeth. The location of the mental foramen was consistently found in the distal third of the interdental space (approximately 60–80% of the distance between the distal aspect of the lateral corner incisor and the mesial aspect of the second premolar).

Post-mortem computed tomography angiography using left ventricle cardiac puncture: A whole-body, angiographic approach.

Post-mortem computed tomography (PMCT) and PMCT angiography (PMCTA) are rapidly becoming effective and practical methods in forensic medicine. In this article, the authors introduce a whole-body PMCTA approach involving left ventricle cardiac puncture. This procedure was performed in 9 males and 3 females. PMCT was performed first. Then a biopsy core needle was used for a percutaneous puncture into the left ventricle through the intercostal area under CT guidance. 1000 mL of contrast media (diatrizoate meglumine and normal saline [0.9%] at 1:2 ratio) was injected at a rate of 50 mL/8 s, followed by CT scan. Visualization of systemic arteries was achieved in 11 cases, while only partial visualization was achieved in 1 case, which may have been related to incomplete thawing of the cadaver. PMCTA results revealed no vascular diseases and abnormalities in 10 victims. Among the 10 victims, 4 post-scan autopsies were performed and found no vascular abnormalities, consistent with the PMCTA results. Autopsy of the other 6 victims were refused by the relatives. PMCTA revealed signs of internal carotid artery aneurysm inside the sphenoid sinus in one victim, which was confirmed by autopsy. PMCTA results of another victim showed signs of stenosis and blockage of the distal part of the right vertebral artery and basilar artery. Thromboembolism of those arteries was found during autopsy. Compared with other existing PMCTA methods for examination of vascular injuries and diseases, this technique involves simple procedures, is less time consuming, has lower associated costs, does not require specialized equipment, provides adequate imaging quality, and is suitable for centres not equipped with cardiopulmonary bypass machines or other specialized equipment.

CT Angiography in the Emergency Department: Maximizing Contrast Enhancement and Image Quality While Minimizing Radiation Dose and Contrast Material Volume: Vascular/Interventional Radiology.

CT angiographic image quality and radiation dose can be optimized for each patient by applying knowledge of the principles of intravenous contrast material flow and the factors that influence contrast enhancement.

Contrast Spread in the Superoposterior Approach of Transforaminal Epidural Steroid Injections for Lumbosacral Radiculopathy.

ObjectiveTo observe the contrast spread in superoposterior transforaminal epidural steroid injection (SP TFESI) and investigate the correlation between spread patterns and efficacy.MethodsThirty-one patients with lumbosacral radiculopathy underwent single-level TFESI under fluoroscopy. The final needle tip position was targeted toward the SP quadrant of the intervertebral foramen. To observe the spread, 1 mL of contrast material was injected, followed by a steroid injection. The contrast spread was graded anteroposteriorly and vertically in the epidural space. The effect of SP TFESI was evaluated by proportional pain score reduction.ResultsLevels injected were L4-5 (n=20) and L5-S1 (n=11). Seventeen cases were lateral, and 14 were central herniated disc (HD). Baseline mean visual analog scale score was 6.23. Contrast dispersed dorsally in all the cases, and 45.2% cases showed a concurrent ventral spread. The proportion of the pain reduction after 2 weeks showed no difference between the two groups. In vertical spreading analysis, mean cephalic/caudal grades were 1.40/1.55 at L4-5 level and 1.73/1.64 at L5-S1 level. The HD location had no effect on contrast dispersion.ConclusionIn SP TFESI, ventral contrast spread did not guarantee a better effect; however, the extent of cephalic flow in ventral expansion group correlated with the proportion of pain reduction.

High-Pitch Coronary CT Angiography at 70 kVp Adopting a Protocol of Low Injection Speed and Low Volume of Contrast Medium.

ObjectiveTo evaluate the feasibility and image quality (IQ) of prospectively high-pitch coronary CT angiography (CCTA) with low contrast medium injection rate at 70 kVp.Materials and MethodsOne hundred and four patients with suspected coronary artery disease (body mass index < 26 kg/m2, sinus rhythm and heart rate < 70 beats/min) were prospectively enrolled and randomly divided into two groups. In group A and group B, 28 mL and 40 mL of 370 mgI/mL iodinated contrast media was administrated at a flow rate of 3.5 and 5 mL/s, respectively. CT values, noise, signal-to-noise ratio, contrast-to-noise ratio (CNR) of the proximal segments of coronary arteries and subjective IQ were evaluated.ResultsThe CT values and noise in group A were significantly lower than those in group B (434–485 Hounsfield units [HU] vs. 772–851 HU, all p < 0.001; 17.8–22.3 vs. 23.3–26.4, all p < 0.005). The CNRs of the right coronary artery and left main artery showed no statistical difference between the two groups (42.1 ± 13.8 vs. 36.8 ± 16.0, p = 0.074; 38.7 ± 10.6 vs. 38.1 ± 17.0, p = 0.819). No statistical difference was observed between the two groups in IQ scores (3.04 ± 0.75 vs. 3.0 ± 0.79, p = 0.526) and diagnostic ratio (96.1% [50/52] vs. 94.2% [49/52], p = 0.647).ConclusionProspective high-pitch CCTA at 70 kVp with 28 mL of contrast media and injection rate of 3.5 mL/s could provide diagnostic IQ for normal-weight patients with heart rate of < 70 beats/min.

Identification of Contrast Induced Nephropathy (CIN) with intravenous iso-Osmolar contrast media in renal failure patients with and without additional comorbidities undergoing Computed Tomography

Aim: To identify contrast induced nephropathy with intravenous iso-osmolar contrast media in renal failure patients with additional comorbidities undergoing computed tomography. Study design: Hospital based observational study. Methods: A retrospective study was conducted on 207 patients with pre-existing renal failure and comorbidities. In this study we collected pre-contrast creatinine values available within 3 weeks and post-contrast creatinine value was collected on 2nd and 5th day following CM injection in order to check early and late contrast induced nephropathy (CIN). Rate of CIN with and without comorbid conditions in CKD patients were calculated. Then we assessed the incidence of CIN with different amount of CM administered. We also calculated the relation of CIN with pre-contrast creatinine and eGFR range, which was categorized as 1.4- 2.0 mg/dL, 2.0-3.0 mg/dL and >3 mg/dL and >60ml and 80ml of contrast media. CIN risk was better determined by eGFR than Creatinine value. Conclusion: CIN rate was clinically significant in CKD patients with comorbidities who received an iso-osmolar contrast media.

Analysis of thoracic epidurography and correlating factors affecting the extent of contrast medium spread.

BackgroundThoracic epidural anesthesia is frequently used to maintain intraoperative and postoperative analgesia. Frequently, 3 ml of local anesthetic is used as a test dose, or for intermittent epidural injection. We assessed the extent of the spread of 3 ml of contrast medium in the thoracic epidural space and attempted to identify any correlating factors affecting the epidurography.MethodsA total of 70 patients were enrolled in the study, and thoracic epidural catheterizations were performed under fluoroscopic guidance. Using 3 ml of contrast medium, epidurography was evaluated to confirm the number of spinal segments covered by the contrast medium. Correlation analysis was performed between patient characteristics (sex, age, body mass index, weight, height, and location of catheter tip) and the extent of the contrast spread.ResultsThe mean number of vertebral segments evaluated by contrast medium was 7.9 ± 2.2 using 3 ml of contrast medium. The contrast spread in the cranial direction showed more extensive distribution than that in the caudal direction, with statistical significance (P < 0.01). Patient height demonstrated a negative correlation with the extent of distribution of contrast medium (r = −0.311, P < 0.05).ConclusionsThoracic epidurography using 3 ml of contrast medium results in coverage of a mean of 7.9 ± 2.2 spinal segments, with more extensive cranial spread, and patient height showed a weak negative correlation with the distribution of contrast medium.

Retrograde maxillary nerve perineural injection: A tomographic and anatomical evaluation of the infraorbital canal and evaluation of needle type and size in equine cadavers

The aim of this study was to investigate a new approach for equine maxillary nerve blocks, which can facilitate several orofacial surgeries. Current techniques aim at the maxillary foramen and approach via the zygomatic arch, conferring the risk of injury to several delicate structures in the target area. To investigate the feasibility of a retrograde approach from the infraorbital foramen, an anatomic study of the infraorbital canal and its surrounding structures was performed on 13 cadaveric skulls using computed tomography and anatomical dissection. Measurements included canal length and volume, its conformation and relationship with the enclosed structures, and infraorbital foramen diameters. The technical approach to simulate the distribution of local anaesthetic within the infraorbital canal was further defined, including needle selection among seven different needles, evaluating ease of insertion, trauma to surrounding tissues and spread of contrast medium toward the target area. To validate the technique, two Tuohy needles were randomly inserted at 12 infraorbital foramina and 10 mL of contrast medium was injected. CT verified the spread of the solution and possible complications.Each canal had a serpentine-curved pathway. Anatomical dissections evidenced gaps between the infraorbital nerve, vessels and the infraorbital canal. The integrity of these structures had been preserved from the passage of the selected Tuohy needles. This study suggests a feasible approach to the maxillary nerve block within the infraorbital canal providing an appropriate needle selection and technique to limit complications.

SU‐F‐I‐29: Investigating the Impact of the Amount of Contrast Material Used in Abdominal CT Examinations Regarding the Diagnosis of Appendicolith

Purpose:The purpose of this study is to report the case of a young adult in which the incomplete oral administration of contrast material led to diagnosis of an appendicolith, which cause acute appendicitis.Methods:A male 34 years old underwent CT examination due to acute abdominal pain in the upper abdomen. An ultrasound examination of the upper abdomen and kidneys, an x‐ray examination of the abdomen and a CT scan of the entire abdomen and pelvis after both oral and IV administration of contrast material were performed. In the ultrasound examination, both kidneys gallbladder and spleen appeared normal and the x‐ray examination did not show any pathological findings. As part of the CT examination, the patient received oral contrast material less than 500 ml due to lack of cooperation by the patient as a result of his abdominal pain.Results:The CT abdomen revealed a severely inflamed appendix that was significantly dilated at 1.1 cm. Moreover, it demonstrated a 1.4 cm appendicolith. The portion of the oral contrast material that was injected to the patient covered the upper abdomen and as a result an appendicolith could be revealed in the lower abdomen. If the patient had received the 1,000ml of contrast material, the whole abdomen would have been covered with the contrast in danger to lose the appendicolith, which caused the inflammation.Conclusion:Based on the findings of this study, in suspicion of acute appendicitis nephrolithiasis and ureterolithiasis, we propose to start the CT protocol with a CT scan without oral contrast material and then proceed with oral and IV contrast not only to succeed gastric intestinal differentiation but also to avoid covering the lower abdomen and obscure any small stones that may exist.

A new assessment for syndesmosis injury – The ‘Chertsey test’

IntroductionIf a syndesmosis injury is not detected, or not treated appropriately, it can lead to pain and arthritis. Various techniques have been described to look for the presence of a syndemosis injury. If concern is raised regarding malreduction, the most recognised way of checking accuracy of the reduction (of the fibula into the incisura) is bilateral postoperative ankle CT scans. This not only exposes the patient to further radiation, but can normally only be done once the surgery is completed and so if adjustment is needed, this requires a further operation, encompassing further surgical risks.We developed a simple assessment, which both gives accurate intra-operative demonstration of an injury to the syndesmosis and also can check how well the fibula has been reduced (if required), without the need for further radiological investigation or surgical intervention.The objectives were to test how easy it was to perform the test and apply it to a number of different ankle fractures. MethodsPeri-operatively, 2–4ml of contrast medium was injected into the ankle joint in cases where there was concern about injury to the syndesmosis. If there was a ‘positive’ test, and a ‘blush’ of dye leaked into the surrounding soft tissues, then fixation of the syndesmosis was performed (as per the surgeon's preferred technique). After fixation was completed, a further injection of contrast medium was injected to see if the fibular had been anatomically reduced into its incisura. The test was performed on 15 ankles. ResultsThere were no difficulties in performing the test and no complications reported. The test clearly demonstrated where there had been an injury to the syndesmosis and also confirmed the accurate reduction of the fibula when there had been stabilisation of the syndesmosis. ConclusionsIt has proved to be an easy and reliable adjunct to ankle fixation surgery and may have further indications.

Feasibility of 320-row area detector CT coronary angiography using 40mL of contrast material: assessment of image quality and diagnostic accuracy.

To assess the image quality and diagnostic accuracy of 320-row area detector CT (320-ADCT) coronary angiography using 40mL of contrast material in comparison with 60-mL protocol. This retrospective study included 183 patients who underwent 320-ADCT coronary angiography using 40mL of contrast and additional 183 sex- and body mass index-matched patients using 60mL of contrast constituting the control group. Both groups used the same 5-mL/sec injection rate. Quantitative image quality measurements and diagnostic accuracies were calculated and compared. Mean attenuation and contrast-to-noise ratio (CNR) at the aorta and all coronary arteries were lower in the 40-mL group than in the 60-mL group (all, p < 0.05), except for the CNR at proximal coronary arteries at 100 kVp (p = 0.073). However, the proportion of coronary segments with vessel attenuation >250 HU was not different between groups (all, p > 0.05), except for distal coronary arteries at 80 kVp (p = 0.001). Furthermore, there were no differences in per-patient and per-segment diagnostic accuracies between the groups (all, p > 0.05). 320-ADCT coronary angiography using 40mL of contrast showed image quality and diagnostic accuracy comparable to the 60-mL protocol, demonstrating the clinical feasibility of lowering the risk of contrast-induced nephropathy through contrast volume reduction. • 320-ADCT might enable reduction of contrast material volume. • A 40-mL contrast protocol for 320-ADCT provided acceptable image quality. • A 40-mL contrast protocol for 320-ADCT demonstrated sufficient diagnostic accuracy.

Volume and Movement Affecting Flow of Injectate Between the Biceps Tendon Sheath and Glenohumeral Joint: A Cadaveric Study.

The objective of our study was to determine if flow of injectate between the biceps tendon sheath and the glenohumeral joint is a function of injectate volume or of motion of the upper extremity. Sixteen upper-extremity fresh-frozen cadaveric specimens were used. Initially, three ultrasound-guided biceps tendon sheath injections were performed using 2, 5, and 10 mL of contrast material. Immediately after the injections, the specimens were imaged using CT. If contrast material was not visualized within the glenohumeral joint, the specimen was manipulated for 5 minutes and reimaged using CT to assess for contrast material within the joint. Five separate ultrasound-guided glenohumeral joint injections were also performed using 5 mL (three specimens), 10 mL (one specimen), and 15 mL (one specimen) of contrast material. The specimens underwent CT, and the presence or absence of contrast material in the biceps tendon sheath was documented before and after manipulation. Next, eight additional ultrasound-guided biceps tendon sheath injections were performed using 2 mL (six specimens) and 5 mL (two specimens) of contrast material. The 5- and 10-mL biceps tendon sheath injection specimens and the 5-, 10-, and 15-mL glenohumeral joint specimens showed communicating contrast flow on the initial CT study. Only two of the seven 2-mL biceps tendon sheath injection specimens showed flow of contrast material into the glenohumeral joint from the biceps tendon sheath on the initial CT study; the remaining five specimens showed no communication even after manipulation. Communication between the biceps tendon sheath and the glenohumeral joint may be a function of injectate volume rather than patient movement.

Ultrasound-Guided Lower Cervical Nerve Root Injectate Volumes Associated With Dorsal Root Ganglion and Epidural Spread.

We aimed to estimate the spread of injections for ultrasound-guided cervical nerve root blocks and to determine the optimal injectate volume required in this procedure. A total of 32 ultrasound-guided injections (C5-C8) were made in 4 fresh cadavers. The target on each cervical root was the space between the posterior tubercle and the cervical root at the most proximal location possible on the sonogram. After ultrasound-guided needle insertion, 0.5 mL of a contrast medium was injected 4 times. The dye flow patterns were confirmed with fluoroscopy each time, and we recorded whether the contrast medium reached the dorsal root ganglion level or the epidural space. After the injections, the needle tip location was determined by computed tomography and image reconstruction. All injections produced typical neurograms. The contrast medium reached the dorsal root ganglion in 29 of 32 (90.6%) injections (mean ± SD, 0.84 ± 0.42 mL of contrast medium) and the epidural space in 10 of 32 (31.3%) injections (1.30 ± 0.54 mL of contrast medium). The mean distance between the needle tip and neural foramen was 9.64 ± 3.68 mm, and this distance correlated positively with the volume of contrast medium necessary to reach the dorsal root ganglion or the epidural space. Ultrasound-guided cervical nerve root blocks show potential utility for targeting an anesthetic into the cervical root area. This study may be helpful for deciding the most appropriate volume for the procedure.

Recombinant Brain Natriuretic Peptide for the Prevention of Contrast-Induced Nephropathy in Patients with Chronic Kidney Disease Undergoing Nonemergent Percutaneous Coronary Intervention or Coronary Angiography: A Randomized Controlled Trial.

The role of brain natriuretic peptide (BNP) in the prevention of contrast-induced nephropathy (CIN) is unknown. This study aimed to investigate BNP's effect on CIN in chronic kidney disease (CKD) patients undergoing elective percutaneous coronary intervention (PCI) or coronary angiography (CAG). The patients were randomized to BNP (0.005 μg/kg/min before contrast media (CM) exposure and saline hydration, n = 106) or saline hydration alone (n = 103). Cystatin C, serum creatinine (SCr) levels, and estimated glomerular filtration rates (eGFR) were assessed at several time points. The primary endpoint was CIN incidence; secondary endpoint included changes in cystatin C, SCr, and eGFR. CIN incidence was significantly lower in the BNP group compared to controls (6.6% versus 16.5%, P = 0.025). In addition, a more significant deterioration of eGFR, cystatin C, and SCr from 48 h to 1 week (P < 0.05) was observed in controls compared to the BNP group. Although eGFR gradually deteriorated in both groups, a faster recovery was achieved in the BNP group. Multivariate logistic regression revealed that using >100 mL of CM (odds ratio: 4.36, P = 0.004) and BNP administration (odds ratio: 0.21, P = 0.006) were independently associated with CIN. Combined with hydration, exogenous BNP administration before CM effectively decreases CIN incidence in CKD patients.