Injection Of Contrast Medium Research Articles

CT lymphography for sentinel lymph node mapping of clinically N0 early oral cancer

BackgroundThe objectives of this retrospective study were to evaluate the usefulness of computed tomography lymphography (CTL) and to clarify the optimal timing of CTL in sentinel lymph node (SLN) mapping of clinically N0 early oral cancer.MethodsTwenty patients with clinically N0 early oral cancer underwent CTL with a 128 multi-detector row CT scanner to detect SLN the day before resection of primary tumor and SLN biopsy with indocyanine green (ICG) fluorescence guidance. CT scanning was performed in the first 10 patients at 2, 5, and 10 min after submucosal injection of iopamidol and in the remaining 10 patients at 2, 3.5, 5, and 10 min after the injection of contrast medium. We evaluated the SLN detection rate at each scan timing and the number and location of SLNs. We evaluated whether CTL-enhanced SLNs could be identified intraoperatively as ICG fluorescent lymph nodes.ResultsSLNs were detected by CTL in 19 of the 20 patients (95.0%), and the mean number of SLNs was 2 (range, 1–4). All SLNs were located on the ipsilateral side; 35 of 37 SLNs were located at level I and II, and 2 SLNs were lingual lymph nodes. All SLNs could be detected 2 min and 3.5–5 min after contrast medium injection, and CTL-enhanced SLNs could be identified intraoperatively as fluorescent lymph nodes.ConclusionsCTL could facilitate the detection of SLNs in early oral cancer, and the optimal timing of CT scanning was at 2 and 5 min after injection of contrast medium.

CT-Coronary Angiography

A large body of literature has demonstrated the ability of coronary computed tomographic (CT) angiography to rule out significant stenosis. This test is a non-invasive alternative to conventional cardiac angiography in the work-up of patients suspected of having coronary artery disease (CAD) and increasingly as an option for the people. A multi-slices Computed Tomography (CT) is able to perform coronary angiography with very fast scanning time within a few seconds. It is an imaging test tool to detect cardiovascular disease in the arteries that supply blood to the heart. It can be used to diagnose the cause of chest pain or other symptoms. Chest pain can be caused by myocardial infarction that may need immediate investigation and accurate diagnosis before any treatment. The procedure can be done as out-patient, convenient, and with very minimal contrast media (Dye) injection. A CT coronary angiography relies on a powerful X-ray machine with multi-detectors and special computer software to produce 2D and 3D images of the heart and its blood vessels. A conventional coronary angiography is an invasive procedure that requires a flexible tube (catheter) to be threaded through the groin or arm to the heart or coronary arteries. CT coronary angiography is an advantage, non-invasive, and the option for the patient who have contraindicated for conventional angiography. But clinically conventional angiography is still the gold standard for detecting coronary arterial disease.

A proposed technique for one-step preputial reconstruction in the dog.

To describe a reverse axial pattern flap based on the superficial branch of the dorsal penile artery and describe its use in preputial reconstruction. Ten penises were harvested from canine cadavers; five were used to describe the dermatome supplied by the superficial branch of the dorsal artery of the penis and five to show perfusion of the skin flap. The superficial branch of the dorsal artery of the penis was identified fluoroscopically by injecting contrast material into the dorsal artery of the penis. This artery was then catheterised and injected with methylene blue to identify the perfused area. A skin flap was created by making a full thickness skin incision at the level of the fornix, along the circumference of the penis. The flap was developed by pulling the cut end toward the tip of the penis while undermining the skin. The flap was considered long enough when the cut end of the flap reached the level of the urethral opening. We also describe a case of preputial resection and reconstruction using this flap. Injection of methylene blue demonstrated the arterial supply to the skin flap. This flap was successful in treating the clinical case following resection of a mast cell tumour on the prepuce, although a small area of full thickness flap necrosis, which healed by second intention, developed postoperatively. This technique may be useful for single step preputial reconstruction.

Agrobacterium spp. nosocomial outbreak assessment using rapid MALDI-TOF MS based typing, confirmed by whole genome sequencing

BackgroundA number of episodes of nosocomial Agrobacterium spp. bacteremia (two cases per year) were observed at Bern University Hospital, Switzerland, from 2015 to 2017. This triggered an outbreak investigation.MethodsCases of Agrobacterium spp. bacteremias that occurred between August 2011 and February 2017 were investigated employing line lists, environmental sampling, rapid protein- (MALDI-TOF MS), and genome-based typing (pulsed field gel electrophoresis and whole genome sequencing) of the clinical isolates.ResultsWe describe a total of eight bacteremia episodes due to A. radiobacter (n = 2), Agrobacterium genomovar G3 (n = 5) and A. pusense (n = 1). Two tight clusters were observed by WGS typing, representing the two A. radiobacter isolates (cluster I, isolated in 2015) and four of the Agrobacterium genomovar G3 isolates (cluster II, isolated in 2016 and 2017), suggesting two different point sources. The epidemiological investigations revealed two computer tomography (CT) rooms as common patient locations, which correlated with the two outbreak clusters. MALDI-TOF MS permitted faster evaluation of strain relatedness than DNA-based methods. High resolution WGS-based typing confirmed the MALDI-TOF MS clustering.ConclusionsWe report clinical and epidemiological characteristics of two outbreak clusters with Agrobacterium. spp. bacteremia likely acquired during CT contrast medium injection and highlight the use of MALDI-TOF MS as a rapid tool to assess relatedness of rare gram-negative pathogens in an outbreak investigation.

Generation of an induced pluripotent stem cell line (SYSUi002-A) from a patient with coronary slow flow phenomenon.

The coronary slow flow phenomenon (CSFP) is characterized by delayed progression of the injected contrast medium through the coronary tree during coronary angiography due to unknown mechanisms. Here, a human induced pluripotent stem cell (iPSC) line (SYSUi002-A) was established using the Sendai-virus delivery system from dermal fibroblasts of a CSFP patient. This cell line may represent a valuable tool for investigating the pathogenesis and therapeutic strategies of CSFP.

Association of the incidence of venous air embolism on coronary computed tomography angiography with the intravenous access route preparation process.

Venous air embolism (VAE) can be observed in the right heart system on contrast-enhanced computed tomography (CT), following injection of contrast media with a power injector system. Although most VAEs are mostly asymptomatic, they may result in paradoxical air embolism (PAE).To evaluate whether the incidence of VAE on coronary CT angiography is associated with the process of preparation of the intravenous access route.We retrospectively evaluated 692 coronary CT examinations at 3 institutions. Trained CT nurses placed an intravenous cannula in the forearm. Tubes connected to the cannula were prepared in the following ways: A, using an interposed three-way cock and a 20-mL syringe filled with normal saline to collect air contamination in the tube; B, through direct connection to the power injector system without the interposed 3-way cock; and C, using an interposed three-way cock and a 100-mL normal saline drip infusion bottle system to keep the tube patent. The incidence and location of VAE and preparation of intravenous injection were assessed.The overall incidence of VAE was 55.3% (383/692), most frequently observed in the right atrium (81.5%, 312/383). Its incidence varied significantly across the 3 techniques (A: 21.6% (35/162), B: 63.2% (237/375) and C: 71.6% (111/155); P < .001). No patient demonstrated any symptom associated with VAE.Using a 3-way cock with syringe demonstrated the lowest incidence of VAE on coronary CT angiography. It is thus recommended to reduce potential complication risks related to intravenous contrast media injection.

Injection And Infusion Technology Disruption For Use In MRI.

IntroductionContrast media injections, infusions, or experiments that require a constant volume flow close to or within a very high magnetic field like in magnetic resonance imaging (MRI) require a liquid reservoir and a power unit to deliver the fluid. However, most power units are driven by motors that are either not MRI-compatible or require external connections that restrict mobility and usage. In this paper, the development of a highly portable, lightweight, and MRI-compatible pump system is explained.MethodsThe energy required to deliver the flow is generated using a pressurized bottle concept. The valve inside the bottle is opened to create a flow which should be maintained constant. In order to find the optimal flow resistance for a constant flow rate, we created multiple setups with different flow resistance.ResultsWe measured the flow rates for different flow resistances by attaching a restring valve to the bottle. The results clearly show that high flow resistance results in lower and more constant flow rate.DiscussionThe optimal flow rate achieved using our current setup was significantly constant but not ideal. Consequently, such a pump system can be used in many medical applications like MRI-compatible contrast agent injectors.

Genetical component of the QT interval is associated with increased mortality in the general population

A 64-year-old man was resuscitated from out-of-hospital VF, and coronary spasm was provoked by ergonovine at catheterization. An ECG was analyzed before and after each intracoronary injection of drugs or contrast medium. The baseline ECG showed nondiagnostic J waves in leads II, III, and aVF, but administration of acetylcholine, contrast medium and nitroglycerin into the right coronary artery induced a distinct augmentation of J-wave amplitudes with changes in the QRS morphology. Transient ischemia induced by the intracoronary administration of these agents seemed to be the mechanism underlying the increase in J-wave amplitudes.

A Case Report of Treatment of Numbness Associated with Contrast Medium Injection using Modified Samul-tang

A Case Report of Treatment of Numbness Associated with Contrast Medium Injection using Modified Samul-tang

Multiphase Iodine Contrast-Enhanced SPECT/CT Outperforms Nonenhanced SPECT/CT for Preoperative Localization of Small Parathyroid Adenomas.

The aim of this study was to assess the value of intravenously contrast-enhanced CT in conjunction with Tc-MIBI SPECT for preoperative localization of parathyroid adenoma. One hundred ninety-two patients with primary hyperparathyroidism were enrolled in the study between May 2015 and May 2017. The patients underwent a preoperative "one-stop shop" examination with Tc-MIBI SPECT/CT by using dual time-point (10 and 90 minutes) protocol and both nonenhanced CT and contrast-enhanced CT acquisition in the arterial and venous phase, 35 and 75 seconds, respectively, after contrast medium injection start. For 149 patients, the imaging results could be correlated to those at surgery and histopathology. The median adenoma weight was 330 mg. The addition of contrast-enhanced CT increased the sensitivity from 81.1% to 89.9% (P = 0.003). The specificity of nonenhanced SPECT/CT was similar to contrast-enhanced CT (96.1% vs 97.9%; P = 0.077). For patients with uniglandular disease (n = 140, 94.0%), the sensitivity increased from 86.4% to 93.6% (P = 0.021) and the specificity from 96.2% to 97.9% (P = 0.118) by adding contrast-enhanced CT. In patients with multiglandular disease (n = 9, 6.0%), adding contrast-enhanced CT improved detection sensitivity from 42.1% to 63.2%. However, these patients were few and significance was not reached (P = 0.125). In this cohort, with generally small parathyroid adenomas, the sensitivity in preoperative localization was greatly improved by adding contrast-enhanced CT to Tc-MIBI SPECT/CT.

Typical alterations of frozen shoulder in MRI examinations

Magnetic resonance imaging (MRI) is routinely used for the diagnostic assessment of diseases of the shoulder joint. Depending on the clinical presentation native imaging, intravenous (IV) or intra-articular injection of contrast medium can be performed (MR arthrography). Advances in imaging technology nowadays enable early detection of characteristic changes in the clinical picture of frozen shoulder. These changes typically include thickening of the coracohumeral ligament, the axillary pouch and the capsule at the rotator interval. Furthermore, obliteration of the subcoracoidal fat pad can also be observed. The MRI examinations also show ahyperintensity in the T2-weighted imaging and a contrast enhancement of the joint capsule. The alterations can show a temporal correlation with the clinical symptoms of the patient.

Prevention of contrast-associated acute kidney injury in cancer patients undergoing radiologic investigation using contrast media; a short-review to current knowledge

Contrast agents are non-biologically active substances required for various diagnostic imaging procedures. Exposure to contrast materials, predispose some patients to renal disturbances entitled as contrast-associated acute kidney injury. Nephropathy of contrast medium is a deterioration of renal function which happens within 24 to 72 hours after iodinated contrast medium injection. Cancer individuals have several risk factors for contrast-associated acute renal failure, consisting of administration of chemotherapy regimen, which are mainly nephrotoxic, presence of diabetes or chronic renal failure, hypertension, taking of non-steroidal anti-inflammatory drugs, simultaneous use of nephrotoxic drugs, aminoglycosides, cisplatin, cyclosporine A or amphotericin B, increases the risk of contrast-associated acute renal failure. Similarly, age more than65 years old and anemia is an independent risk factor for contrast-associated acute kidney injury and also timing of CT within 45 days after last chemotherapy and low fluid intake, as the common risk factors in cancer individuals.

3104 Esophageal Hematoma: A Colossal Obstacle

INTRODUCTION: Esophageal hematomas are rare but well described phenomena that can present as retrosternal chest pain, hematemesis, and dysphagia. They are seen in association with anticoagulation therapy, mechanical trauma, and increased intraesophageal pressure as caused by excessive retching and vomiting. We describe a case of esophageal hematoma following catheter ablation for treatment of atrial fibrillation. CASE DESCRIPTION/METHODS: A 73 year old female with chronic obstructive pulmonary disease, nephrectomy, rheumatic heart disease status post mechanical mitral valve on warfarin, refractory atrial fibrillation was admitted for hematemesis after elective atrial fibrillation ablation. The patient underwent TEE during which an esophageal probe was required for repositioning of the esophagus. No blood was seen when the probe was removed, but at the end of the procedure the patient had hematemesis. INR at presentation was 3.7. The patient was emergently intubated and an EGD revealed a large clot occluding the mid-esophagus, denuded mucosa with oozing from multiple sites, and a large clot in the fundus (Figure 1). A chest CTA showed circumferential esophageal thickening and distention with non-enhancing blood products extending from above the thoracic inlet to the GE junction, with clot also outlined by oral contrast within the gastric lumen. No definite communication between the esophagus and atrial pulmonary veins was identified. A repeat endoscopy the next day again showed the large esophageal hematoma (Figure 2) and was aborted to avoid additional esophageal trauma. A week later, CTA chest showed persistent esophageal intramural hematoma with no evidence of aortoenteric fistula. Cardiothoracic surgery was consulted and placed a percutaneous gastrostomy tube. The patient was recovering well, but shortly upon extubation, the patient died of cardiorespiratory arrest. DISCUSSION: Esophageal hematomas typically develop in middle-aged women and present as a triad of retrosternal chest pain, dysphagia and hematemesis. The mechanism producing the hematoma may determine the site. For example, a hematoma from vomiting would be at the esophagogastric junction, whereas from a caustic substance might be at points of narrowing. It can be visualised on endoscopy or as a filling defect on barium esophagogram. Computed tomographic images reveal a mass confined to the esophageal lumen that does not enhance with injection of contrast medium. Conservative and supportive care remains the main therapeutic modality.

Low-Dose Computed Tomography With Two- and Three-Dimensional Postprocessing as an Alternative to Plain Radiography for Intrathecal Catheter Visualization: A Phantom Pilot Study

ObjectivesIn intrathecal drug delivery, visualization of the device has been performed with plain radiography. However, the visibility of the related structures can be problematic. In troubleshooting, after the contrast material injection via the catheter access port, a computed tomography (CT) scan has been used. In troubleshooting, we also used a non‐contrast CT scan with 2D and 3D reconstructions. With the current phantom study, we aimed to obtain high‐resolution imaging of a poor opaque catheter with the use of a low‐dose single‐energy 2D and 3D CT scan with limited radiation exposure as a substitute for plain radiography.Materials and MethodsThe catheter was placed into a fatty substance and mounted on an anthropomorphic abdomen phantom followed by CT with varying kVp settings and with added tin beam filtering. Dose levels corrected based on the spinal catheter tip on T8 would result in a calculated effective dose in the range of the mSv's calculated for the plain x‐ray examination.ResultsUltimately, Sn100 kVp has the best trade‐off between visibility, artifacts, and noise for a fixed dose. Although 3D VRT imaging was challenging at this low dose level, we could make a full evaluation possible with complementary 2D projections.ConclusionsWe could correctly identify the catheter and related structures, which supports the investigation of this in vivo and side‐by‐side evaluation with plain radiography. If found superior, then this technique may be able to replace plain radiography, while providing better visualization and acceptable radiation exposure.Conflict of InterestDr. Delhaas reports personal fees from Medtronic Inc., as a previous consultant, outside the submitted work; Prof. van der Lugt reports grants from GE Healthcare, Siemens, Stryker, Medtronic, and Penumbra outside the submitted work.

P1916A novel echo-guided approach of cryoballoon ablation without using contrast medium

Abstract Background Pulmonary vein isolation (PVI) using cryoballoon requires contrast medium injection for the confirmation of appropriate venous occlusion. However, some patients have contra-indications against contrast use such as allergy for contrast medium, bronchial asthma or renal dysfunction. We hypothesized that intra-cardiac echocardiographic observation of microbubble leakage after saline injection from the cryoballoon lumen can be used as a maker of incomplete venous occlusion. Purpose The aim of this study was to assess the effect of echo-guided approach using saline injection on the acute clinical outcomes as well as the amount of contrast medium. Methods Twenty consecutive patients with paroxysmal atrial fibrillation (AF) were studied. They had any reason to avoid using contrast medium. Plain CT scan was performed in all cases to understand the anatomical features. Intra-cardiac echocardiography was used in all cases to guide transseptal puncture and to confirm pulmonary-vein occlusion. Procedural results and clinical outcomes were compared with patients who were performed by the conventional method (n=279). Results In all study patients, we could perform PVI without using contrast medium. A total of 2 patients required touch-up ablation using radiofrequency ablation catheter. The procedure time (85±23 vs 86±27 min, P=0.84), the dose of radiation exposure (108±78 vs. 140±133 mmGy/m2, P=0.29), and ratio of requiring touch-up ablation (5% vs 4%, P=0.81) were similar between the study group and the reference group. There was no significant difference in the AF-free survival rate (73% vs. 76%, P=0.79) during a follow-up period of 14±6 months. Images of ICE Conclusion Echo-guided approach using saline infusion was effective and less invasive in terms of reduction of contrast use.

Incidence and risk of dialysis therapy within 30 days after contrast enhanced computed tomography in patients coded with chronic kidney disease: a nation-wide, population-based study.

BackgroundPatients with chronic kidney disease (CKD) are considered at risk of contrast-induced acute kidney injury and possible subsequent need for dialysis therapy. Computed tomography (CT) is the most commonly performed examination requiring intravenous iodinated contrast media (ICM) injection. The actual risk of dialysis in CKD patients undergoing CT with ICM remains controversial. Furthermore, it is also uncertain whether these at-risk patients can be identified by means of administrative data. Our study is conducted in order to determine the incidence and risk of dialysis within 30 days after undergoing contrast enhanced CT in CKD coded patients.MethodsThis longitudinal, nation-wide, populated-based study is carried out by analyzing the Taiwan National Health Insurance Research Database retrospectively. Patients coded under the diagnosis of CKD who underwent CT are identified within randomly selected one million subjects of the database. From January 2012 to December 2013, 487 patients had undergone CT with ICM. A total of 924 patients who underwent CT without ICM are selected as the control group. Patients with advanced CKD or intensive care unit (ICU) admissions are assigned to the subgroups for analysis. The primary outcome is measured by dialysis events within 30 days after undergoing CT scans. The cumulative incidence is assessed by the Kaplan–Meier method and log-rank test. The risk of 30-day dialysis relative to the control group is analyzed by the Cox proportional hazards model after adjusting for age, sex, and baseline comorbidities.ResultsThe numbers and percentages of dialysis events within 30 days after undergoing CT scans are 20 (4.1%) in the CT with ICM group and 66 (7.1%) in the CT without ICM group (p = 0.03). However, the adjusted hazard ratio (aHR) for 30-day dialysis was 0.84 (95% CI [0.46–1.54], p = 0.57), which is statistically non-significant. In both advanced CKD and ICU admission subgroups, there are also no significant differences in 30-day dialysis risks with the aHR of 1.12 (95% CI [0.38–3.33], p = 0.83) and 0.95 (95% CI [0.44–2.05], p = 0.90), respectively.ConclusionsWithin 30 days of receiving contrast-enhanced CT scans, 4.1% of CKD coded patients required dialysis, which appear to be lower compared with subjects who received non-contrast CT scans. However, no statistically significant difference is observed after adjustments are made for other baseline conditions. Thereby, the application of administrative data to identify patients with CKD cannot be viewed as a risk factor for the necessity to undergo dialysis within 30 days of receiving contrast-enhanced CT scans.

Diagnostic value of fusion of metabolic and structural images for stereotactic biopsy of brain tumors without enhancement after contrast medium injection

BackgroundThe heterogeneous nature of glioma makes it difficult to select a target for stereotactic biopsy that will be representative of grade severity on non-contrast-enhanced lesion imaging. The objective of this study was to evaluate the benefit of fusion of metabolic images (PET 18F-DOPA) with magnetic resonance imaging (MRI) morphological images for cerebral biopsy under stereotactic conditions of glioma without contrast enhancement. Patients and methodsThis single-center prospective observational study conducted between January 2016 and April 2018 included 20 consecutive patients (mean age: 45±19.5 years; range, 9–80 years) who underwent cerebral biopsy for a tumor without MRI enhancement but with hypermetabolism on 18F-FDOPA PET (positron emission tomography). Standard 18F-FDOPA uptake value (SUVmax) was determined for diagnosis of high-grade glioma, with comparison to histomolecular results. ResultsHistological diagnosis was made in all patients (100%). Samples from hypermetabolism areas revealed high-grade glial tumor in 16 patients (80%). For a SUVmax threshold of 1.75, sensitivity was 81.2%, specificity 50%, PPV 86.7% and VPN 40% for diagnosis of high-grade glioma. No significant association between SUVmax and histomolecular mutation was found. Conclusion18F-FDOPA metabolic imaging is an aid in choosing the target to be biopsied under stereotactic conditions in tumors without MR enhancement. Nevertheless, despite good sensitivity, 18F-FDOPA PET is insufficient for definitive diagnosis of high-grade tumor.

Intracoronary pressure increase due to contrast injection for optical coherence tomography imaging

BackgroundOptical coherence tomography (OCT) requires intracoronary injection of contrast media to remove blood from the field of view during image acquisition. Contrast injection may cause a temporal increase in intracoronary pressure. The aim of this study was to compare the intracoronary pressure during contrast injection between OCT and coronary angiography. MethodsWe measured intracoronary pressure by using a pressure guidewire during contrast injection for OCT and angiography in 30 coronary arteries (mean fractional flow reserve = 0.90 ± 0.03). Contrast media was injected into coronary artery through the guiding catheter by using a mechanical injector pump. ResultsIntracoronary pressure before contrast injection was similar between OCT and angiography (systolic pressure: 123 ± 18 mmHg vs. 122 ± 19 mmHg, p = 0.863). Intracoronary pressure was increased due to contrast injection in both OCT (systolic pressure: 123 ± 18 mmHg to 132 ± 18 mmHg, p < 0.001) and angiography (systolic pressure: 122 ± 19 mmHg to 128 ± 19 mmHg, p < 0.001). The increase in intracoronary pressure was slightly greater in OCT compared with angiography (absolute increase of systolic pressure: 9 ± 2 mmHg vs. 6 ± 1 mmHg, p < 0.001; and relative increase of systolic pressure: 8 ± 2% vs. 5 ± 1%, p < 0.001). Intracoronary pressure during contrast injection was not significantly different between OCT and angiography (systolic pressure: 132 ± 18 mmHg vs. 128 ± 19 mmHg, p = 0.831). ConclusionsContrast injection for OCT induced significant but small increase in intracoronary pressure compared with that for angiography.

A novel protocol for three-dimensional rotational venography with low-dose contrast media in preoperative angiography of brain tumours.

The most appropriate imaging protocol for three-dimensional rotational venography (3D RV) has not been established. The aim of this study was to optimise the protocol for 3D RV with low-dose contrast media using time-density curve analysis. Twenty-five consecutive patients with brain tumours who received preoperative assessment with 3D RV were retrospectively collected and included in this study. To optimise the imaging delay time of 3D RV with low-dose contrast media, time-density curve analysis was performed on two-dimensional conventional angiography. The image quality for depicting cortical veins and venous sinuses was compared to that of magnetic resonance (MR) venography in five cases. A total of 27 3D RVs were performed in 25 patients. The time-density curves of cortical veins were different from those of cerebral arteries or sinuses. The mean time to peak of cortical veins was significantly longer than the time to peak of cerebral arteries (2.47 ± 0.35 seconds vs. 6.44 ± 1.14 seconds; p < 0.0001) and shorter than the time to peak of venous sinuses (6.44 ± 1.14 seconds vs. 8.18 ± 1.12 seconds; p < 0.0001). The optimal imaging delay time could be determined as the phases in which cortical arterial opacities disappeared and cortical veins started to appear. The mean dose of injected contrast media was 5.3 mL. The image quality of cortical veins in 3D RV was superior to that in MR venography in all cases. Three-dimensional RV with low-dose contrast media was useful for the preoperative assessment of cortical veins in patients with brain tumours.

An augmented patient-specific approach to administration of contrast agent for CT renal angiography.

ABSTRACTPurpose This hybrid retrospective and prospective study performed on 200 consecutive patients undergoing renal CTA, investigates the opacification of renal vasculature, radiation dose, and reader confidence.Materials and Methods 100 patients were assigned retrospectively to protocol A and the other 100 were allocated prospectively to protocol B. Both protocols implemented a contrast material and saline flow rate of 4.5 mL/sec. Protocol A utilized a 100 mL of low-osmolar nonionic IV contrast material (Ioversol 350 mg I/mL) while protocol B employed a patient-tailored contrast media formula using iso-osmolar non-ionic (Iodixanol 320 mg I/mL).Results Arterial opacification in the abdominal aorta and in the bilateral main proximal renal arteries demonstrated no statistical significance (p>0.05). Only the main distal renal artery of the left kidney in protocol B was statistically significant (p<0.046). In the venous circulation, the IVC demonstrated a significant reduction in opacification in protocol B (59.39 HU ± 19.39) compared to A (87.74 HU ± 34.06) (p<0.001). Mean CNR for protocol A (22.68 HU ± 13.72) was significantly higher than that of protocol B (14.75 HU ± 5.76 p< 0.0001). Effective dose was significantly reduced in protocol B (2.46 ± 0.74 mSv) compared to A (3.07 ± 0.68 mSv) (p<0.001). Mean contrast media volume was reduced in protocol B (44.56 ± 14.32 mL) with lower iodine concentration. ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (p< 0.0001), with inter-reader agreement increasing from moderate to excellent in renal arterial visualization.Conclusion Employing a patient-tailored contrast media injection protocol shows a significant refinement in the visualization of renal vasculature and reader confidence during renal CTA.