Value of color Doppler ultrasonography in the evaluation of orbital vascular flow in end-stage renal disease patients undergoing hemodialysis

Purpose: To evaluate choroidal and retinal vascular flow dynamics by means of color Doppler ultrasonography in patients with end-stage renal disease undergoing hemodialysis and to compare these findings with healthy controls. Material and Methods: Color Doppler ultrasonography and spectral analysis of nasal and temporal posterior ciliary and central retinal artery flow of both eyes were performed in 20 patients (40 eyes) and 22 controls (44 eyes) to assess peak systolic flow velocity, end-diastolic flow velocity, and resistive indices (RI). Patients with hypertension, diabetes mellitus, and any cardiac pathology were not included in the study. A general ophthalmologic examination was performed in all patients and controls. Results: The average peak-systolic and end-diastolic blood flow velocities of nasal (12.88±4.91/6.88±3.26) and temporal (15.22±9.59/6.41±3.97) posterior ciliary artery and central retinal artery (14.94±8.38/6.7±4.13) in patients were significantly higher than the corresponding values of the controls. The RI values of nasal (0.52±0.10) and temporal (0.58±0.12) posterior ciliary artery and central retinal artery (0.55±0.11) in patients with end-stage renal disease undergoing hemodialysis were significantly lower than in the controls. Conclusion: Choroidal and retinal blood flow velocities are higher and RI values for all three vessels lower in patients with end-stage renal disease undergoing hemodialysis compared to healthy controls. These alterations may be related to either increased choroidal blood flow or vasoconstriction of the proximal vessels.     

Tunneled internal jugular catheters in adult patients: comparison of outcomes in hemodialysis versus infusion catheters

Background: Tunneled central venous catheters placed by interventional radiologists are now widely used for hemodialysis and infusion therapies throughout the world. However, complications such as infections and malfunctions still remain a major concern in oncology and hemodialysis patients.

Purpose: To evaluate the long-term follow-up results of tunneled central venous catheters in an adult population in terms of infectious complications and malfunction rates in dialysis and oncology patients.

Material and Methods: We retrospectively reviewed the hospital charts and our electronic database for 434 tunneled internal jugular catheters in 335 consecutive patients between December 2002 and March 2006. Mean patient age was 57 years (range 23-86 years) in the hemodialysis group and 45 years (range 18-83 years) in the infusion group. A total of 224 hemodialysis catheters were placed in 168 patients (68 females, 100 males) and 210 infusion catheters in 167 patients (48 females, 119 males).

Results: Technical success rate was 100%. Mean duration of catheter use was 86 days (1-652 days) and 60 days (2-686 days) for hemodialysis and infusion catheters, respectively. A total of 107 hemodialysis (47%) and 95 infusion catheters (45%) were electively removed due to completion of therapy and resolution of need for dialysis. Revisions were performed 0.22 and 0.11 per 100 catheters days in the hemodialysis and infusion groups, respectively. Our total infection rate was 0.10 episodes per 100 catheter days, and the rate of infections necessitating catheter removal was 0.05 episodes per 100 catheter days in the hemodialysis group, which is lower than that reported in other big series. However, in the infusion group, the rate of infections necessitating catheter removal was 0.28 episodes per 100 catheter days.

Conclusion: Long-term central venous accesses using tunneled internal jugular catheters appeared to be safe and effective for both hemodialysis and long-term infusion therapies, with relatively higher infection rates in oncologic patients.     

A simplified method for continuous hepatic arterial port-catheter system placement not requiring catheter end-hole occlusion

Purpose: To evaluate the efficacy of hepatic port-catheter system placement without distal catheter tip occlusion or gastroduodenal artery embolization distal to the catheter tip.

Material and Methods: A port-catheter system was percutaneously implanted in 29 patients (16 men, 13 women; mean age 65.6 years) with unresectable liver cancer. Persistent blood flow through the end hole of the catheter was verified immediately and 1-10 days after catheter placement.

Results: In all cases, percutaneous port-catheter placement was successfully performed. In seven of 29 (24.1%) patients, flow through the end hole of the catheter was verified immediately after the procedure. However, no flow was seen 1-10 days after the procedure.

Conclusion: It is not necessary to occlude the end hole of the catheter tip and embolize the gastroduodenal artery beyond the catheter tip when placing a port-catheter system for repeated hepatic arterial infusion chemotherapy.     

Percutaneous placement of central venous catheters: comparing the anatomical landmark method with the radiologically guided technique for central venous catheterization through the internal jugular vein in emergent hemodialysis patients

Purpose: To compare the success and immediate complication rates of the anatomical landmark method (group 1) and the radiologically (combined real-time ultrasound and fluoroscopy) guided technique (group 2) in the placement of central venous catheters in emergent hemodialysis patients.

Material and Methods: The study was performed prospectively in a randomized manner. The success and immediate complication rates of radiologically guided placement of central venous access catheters through the internal jugular vein (n = 40) were compared with those of the anatomical landmark method (n = 40). The success of placement, the complications, the number of passes required, and whether a single or double-wall puncture occurred were also noted and compared.

Results: The groups were comparable in age and sex. The indication for catheter placement was hemodialysis access in all patients. Catheter placement was successful in all patients in group 2 and unsuccessful in 1 (2.5%) patient in group 1. All catheters functioned adequately and immediately after the placement (0% initial failure rate) in group 2, but 3 catheters (7.5% initial failure rate) were non-functional just after placement in group 1. The total number of needle passes, double venous wall puncture, and complication rate were significantly lower in group 2.

Conclusion: Percutaneous central venous catheterization via the internal jugular vein can be performed by interventional radiologists with better technical success rates and lower immediate complications. In conclusion, central venous catheterization for emergent dialysis should be performed under both real-time ultrasound and fluoroscopic guidance.     

Ectopic pregnancy--the leash sign. A new sign on transvaginal Doppler ultrasound

Purpose: To evaluate the efficacy of transvaginal Doppler ultrasound in the diagnosis of ectopic pregnancy.

Material and Methods: Over a period of 3 years, 100 women with signs suggestive of a possible ectopic pregnancy were evaluated with endovaginal sonography and Doppler. The fallopian tubes were examined for the presence of low-resistance arterial flow.

Results: Of the 100 cases, 19 women had ectopic pregnancies. It was observed that all cases of ectopic pregnancies had a typical eccentric leash of vessels on color Doppler that showed a low resistance placental type of flow on spectral Doppler.

Conclusion: We propose a new reliable sign of ectopic pregnancy called the leash sign. This sign has a sensitivity of 100% and specificity of 99%, a positive predictive value of 95% and negative predictive value of 100%, thus helping in the diagnosis of early ectopic pregnancy, and resulting in earlier treatment with reduced morbidity and mortality.     

Inadvertent intra-arterial drug injections: the role of angiographic and clinical findings

Purpose: To evaluate the angiographic findings of patients who have inadvertently injected oral formulations of drugs into an upper extremity artery.

Material and Methods: The radiology files for the previous 4 years were analyzed retrospectively. Seven patients were referred from the Emergency Department for angiography and possible thrombolysis during that time period.

Results: The worst clinical results were found among the patients whose angiographic examinations showed absent flow. Two patients who were treated with local thrombolysis had no better results compared to the other five patients.

Conclusion: Findings of delayed flow and absent flow in angiography should lead to intensified conservative treatment, especially among patients who have clinical findings of delayed capillary refilling or/and impaired muscular strength.     

Percutaneous transluminal cutting-balloon angioplasty for hemodialysis access stenoses resistant to conventional balloon angioplasty

Purpose: To examine the value of cutting-balloon percutaneous transluminal angioplasty (PTA) for hemodialysis access with residual stenosis after conventional balloon PTA.

Material and Methods: Angioplasty with conventional balloons was performed on 48 hemodialysis access stenoses in 28 patients. If the balloon waist still remained at the rated burst pressure, the balloon was reinflated up to three times. Fifteen of 48 stenoses had residual stenoses of more than 30% after conventional balloon PTA. In these 15 stenoses, additional cutting-balloon PTA was performed.

Results: The mean residual percent diameter stenoses before and after conventional balloon PTA were 77.6±3.4% and 48.6±8.5%, respectively. Additional cutting-balloon PTA decreased the mean residual percent diameter to 27.9±10.0%, and the cutting balloon was completely inflated without complication. In 12 patients, the 6-month primary patency rate (±SE) was 90.0% (9.5), and the 1-year primary patency rate (±SE) was 25.0% (14.8).

Conclusion: Additional cutting-balloon PTA was found useful for reducing residual stenosis.     

Correlation of femoral artery flow velocity waveform with ipsilateral iliac artery stenoses assessed with magnetic resonance imaging

Background: Magnetic resonance (MR) permits quantitative flow velocity measurements that could be used to detect changes in the curve profile downstream of a high-grade stenosis.

Purpose: To assess whether MR flow measurements can be used to detect iliac artery stenoses.

Material and Methods: Contrast-enhanced magnetic resonance angiography (MRA) and quantitative flow measurements in the lower aorta and proximal femoral arteries were performed in 29 patients with suspected iliac artery stenoses. Stenoses were graded into five degrees: 0%, 1-49%, 50-74%, 75-99%, and 100% diameter reduction. The femoral artery waveforms were evaluated qualitatively by two independent reviewers regarding peak systolic velocity (PSV), aortofemoral difference in time-to-peak (ΔTTP), systolic acceleration (SA), curve-shape index (CSI), and the presence of an early diastolic flow reversal. The correlation between these parameters and the degree of stenosis was assessed.

Results: A significant correlation with degree of stenosis was observed for the qualitative flow waveform evaluations, with a high degree of interobserver agreement (κ = 0.84). A significant correlation was also found between degree of stenosis and PSV, ΔTTP, SA, CSI, and presence of diastolic flow reversal. The flow velocity pattern, however, remained unchanged, both qualitatively and quantitatively, up to a stenosis degree of at least 75%.

Conclusion: Iliac artery stenoses cause femoral artery flow waveform changes that can be detected with MRI, but only at high-grade levels.     

Investigation of the effect of exhaust particles on ocular blood flow in highway toll collectors using color Doppler ultrasonography

PURPOSE: To investigate the effect of exhaust particles on orbital blood flow velocity of the ophthalmic artery, central retinal artery, and posterior ciliary artery by color Doppler ultrasonography in highway toll collectors. MATERIAL AND METHODS: Color Doppler imaging was used to measure the peak-systolic and end-diastolic flow velocities and resistivity indices of the ophthalmic artery, central retinal artery, and posterior ciliary artery in 20 toll collectors and 20 controls. RESULTS: Both the peak-systolic and the end-diastolic flow velocities were decreased in the ophthalmic artery, central retinal artery, and posterior ciliary artery, and the resistivity index was increased in the central retinal artery in toll collectors when compared with control groups. Results were considered statistically significant if P<0.05. CONCLUSION: It was determined that the effect of exhaust particles reduced ocular blood flow velocity in toll collectors as measured by color duplex Doppler ultrasonography.     

Hemodynamic effect of iopromide in pancreas-duodenum transplanted rats

Background: Radiological contrast media (CM) have been suggested to be able to impair pancreatic microcirculation, especially in acute pancreatitis.

Purpose: To evaluate the effects of the low-osmolar CM iopromide on total pancreatic and especially islet blood perfusion after whole pancreas transplantation.

Material and Methods: Rats receiving a pancreas-duodenum transplantation 2 days earlier, i.e., with graft pancreatitis, were injected with iopromide. Blood perfusion measurements were then made with a microsphere technique.

Results: The graft blood perfusion was decreased in control rats when compared to the endogenous pancreas. Administration of iopromide increased both total pancreatic and islet blood perfusion in the grafted pancreas, but not in the endogenous gland. No effects on blood perfusion to either the native or transplanted duodenum were seen after iopromide administration.

Conclusion: Iopromide increases the blood perfusion of a whole pancreas transplant 2 days after implantation, i.e., when graft pancreatitis is present. The consequences of this CM-induced hyperperfusion for graft pancreatic function remain to be established.     

Balloon occlusion test of the internal carotid artery: correlation with stump pressure and 99mTc-HMPAO SPECT

Purpose: To evaluate the correlation of stump pressure during balloon occlusion test and relative cerebral blood flow (relative CBF) as measured by ^99mTc-hexamethylpropyleneamine oxime (^99mTc-HMPAO) single-photon emission computed tomography (SPECT) after test occlusion.

Material and Methods: Balloon occlusion test of the internal carotid artery (ICA) was performed in 25 patients. The count ratio of occluded hemisphere to non-occluded hemisphere was calculated on ^99mTc-HMPAO SPECT. The ratio of mean stump pressure to mean arterial pressure during carotid occlusion during the balloon occlusion test was compared with the count ratio of ^99mTc-HMPAO SPECT.

Results: Two patients failed to tolerate even brief carotid occlusion. The other 23 patients showed no ischemic deficit during occlusion of the ICA. In 13 of these 23 patients, the ratios of mean stump pressure to mean arterial pressure were more than 50%, and the count ratios on SPECT were more than 85%. In 10 of 23 patients, the ratios of mean stump pressure to mean arterial pressure were less than 50%, and the count ratios on SPECT were variable.

Conclusion: Maintenance of a mean stump pressure of 50% or more of the mean systemic pressure during test occlusion indicates adequate cerebral blood flow during carotid occlusion.     

Influence of iothalamate on renal medullary perfusion and oxygenation in the rat

Purpose: To evaluate controversial results regarding the effect of the contrast medium (CM) iothalamate on renal medullary blood flow by applying two different methods simultaneously.

Material and Methods: The outer medullary blood flow (OMBF) response was estimated using laser-Doppler flowmetry and hydrogen gas wash-out (microelectrodes) simultaneously. Outer medullary oxygen tension (P_O2) was measured using Clark type microelectrodes. Iothalamate was injected i.v. at 1600 mg I/kg body weight for 2 min.

Results: CM induced a transient 28% decrease in OMBF as measured with the laser Doppler. The hydrogen gas wash-out rate was reduced by 50%, indicating a reduced perfusion. CM induced a transient 60% reduction in P_O2, while renal fluid and electrolyte excretion increased several fold.

Conclusion: The CM iothalamate reduces outer medullary perfusion as estimated by two different techniques applied simultaneously. The P_O2 in the same region was also reduced. Previous controversies regarding the effect of iothalamate on OMBF can be explained by extreme dosage and injection rates greatly exceeding clinical relevance.     

Transcatheter arterial embolization in patients with bleeding duodenal ulcer: an alternative to surgery

Purpose: To evaluate the efficacy and safety of transcatheter arterial embolization (TAE) in patients with bleeding/rebleeding duodenal ulcers.

Material and Methods: Over a 6-year-period, 40 consecutive patients with bleeding/rebleeding after endoscopic therapy and/or surgery for duodenal ulcer were included in the study. Superselective angiographic catheterization and coil embolization were performed by the same interventional radiologist.

Results: Lasting hemostasis was achieved in 26 of 40 patients (65%). Transfusion requirement was reduced from median 14 (range 3-35) units of blood before TAE to 2 (range 0-53) units after TAE. Ten patients died, five because of continuous bleeding. No adverse effects as a result of TAE were seen.

Conclusion: TAE is an effective and safe treatment in a significant proportion of patients with bleeding duodenal/rebleeding ulcers after therapeutic endoscopy and/or surgery.     

Accessory renal artery stenosis and hypertension: are these correlated? Evaluation using multidetector-row computed tomographic angiography

Background: Renal artery stenosis may produce hypertension, and this condition is referred to as renovascular hypertension (RVH).

Purpose: To evaluate, by using multidetector-row spiral computed tomographic angiography (MDCTA), whether a relationship between accessory renal artery stenosis and hypertension may be hypothesized.

Material and Methods: 214 patients (142 males, 72 females; mean age 66 years) who had previously undergone an MDCTA to study the abdominal vasculature were retrospectively studied. Patients with renal artery stenosis (RAS) were excluded from this analysis. The patients were studied by means of a four-detector-row CT, and scans were obtained after intravenous bolus administration of 110-140 ml of a nonionic contrast material with a 3-6 ml/s flow rate. As a second step, by means of statistical analysis, hypertension data were compared with findings of accessory artery stenosis. Two radiologists first independently reviewed the MDCTA images and then, in case of disagreement, in consensus. Interobserver agreement was calculated for all measurements.

Results: The overall number of detected accessory renal arteries was 74 in 56 of the 214 patients. Accessory renal artery stenosis was detected in 21 of the 56 patients. There was a difference in the prevalence of hypertension between patients with (n = 21) and without (n = 35) accessory renal artery stenosis (P = 0.0187). Interobserver agreement was good (kappa value 0.733).

Conclusion: Any statistical association between the presence of accessory renal artery stenosis and hypertension could not be disclosed. However, accessory renal artery stenosis, detected by MDCTA, is an important pathological sign that the radiologist has to assess in the light of its possible association with hypertension.     

Embolization of accessory left gastric artery to prevent acute gastric mucosal lesions in patients undergoing repeated hepatic arterial infusion chemotherapy

Purpose: To retrospectively evaluate results of selective embolization of the accessory left gastric artery prior to repeated hepatic arterial infusion chemotherapy using a port-catheter system.

Material and Methods: Of 22 patients with unresectable advanced liver cancer who underwent percutaneous implantation of a port-catheter system, an accessory left gastric artery was revealed by arteriography in 16 patients before and in six patients after port-catheter implantation. The right gastric artery was embolized to prevent gastric mucosal lesions in all 22 patients. In addition, the accessory left gastric artery was selectively embolized for the same purpose using from one to six microcoils, which were from 3 to 5 mm in diameter. Within 10 days after implantation, arteriography was performed while contrast material was infused via the port.

Results: Selective embolization of the accessory left gastric artery was successful in all 22 patients. No complication related to embolization of this artery occurred in any patient. A gastrointestinal mucosal lesion developed in only one case during hepatic arterial infusion chemotherapy, but was unrelated to the accessory left gastric artery.

Conclusion: Prophylactic embolization of the accessory left gastric artery is useful to avoid development of a gastrointestinal mucosal lesion resulting from hepatic arterial infusion chemotherapy.     

Impact of digital imaging on radiation doses to the patient during X-ray examination of the urinary tract

Purpose: To compare radiation doses given to patients undergoing IVU (intravenous urography) before and after digitalization of our X-ray department.

Material and Methods: IVU examinations were monitored with dose area product meters before and after the X-ray department changed to digital techniques. The first step was a change from film-screen to storage phosphor plates, while the second step involved changing to a flat panel detector. Forty-two patients were included for the film-screen situation, 69 when using the storage phosphor plates, and 70 using the flat panel detector.

Results: A dose reduction from 41.8 Gycm² to 31.5 Gycm² was achieved with the first step when the film-screen system was replaced with storage phosphor plates. A further reduction to 12.1 Gycm² was achieved using the flat panel detector.

Conclusion: The introduction of the flat panel detectors made a considerable dose reduction possible.     

Percutaneous vertebroplasty for patients with osteoporosis: a one-year follow-up

Purpose: To evaluate changes in height and wedge angle of treated vertebral bodies and kyphosis angle 1 year after vertebroplasty.

Material and Methods: We reviewed radiographs of 95 vertebral bodies treated with vertebroplasty in 60 patients with osteoporosis. Only vertebral bodies with imaging evidence of a new fracture or avascular necrosis received vertebroplasty. Images were obtained for evaluation before vertebroplasty (B), within 2 weeks after vertebroplasty (T), and after 1 year (T1).

Results: The mean wedge angle decreased by 5.4° from B to T1. Mean of the anterior, central, and posterior heights of the fractured bodies increased by 12.6%, 9.6%, and 3.1%, respectively, from B to T1. The kyphosis angle improved by 3.2° initially from B to T, but the improvement later disappeared. In 48% of these patients, a new fracture developed after vertebroplasty, and 63% of the fractures were adjacent to a vertebroplasty-treated vertebral body.

Conclusion: The increase in height and wedge angle of the vertebral bodies generally lasted at least 1 year. Improvement in kyphosis angles was lost 1 year after vertebroplasty because new fractures occurred in 48% of these patients. Prevention of new fractures after vertebroplasty remains an important task.     

Coraco- or costoclavicular paraosteoarthropathies in patients with severe central neurological disorders

Background: Paraosteoarthropathy (POA) is a frequent disabling orthopedic complication after severe central neurological impairment. The hip is the most frequently affected joint (32.1%) followed by the elbow and the shoulder (25%).

Purpose: To evaluate coraco- and costoclavicular paraosteoarthropathy in patients with severe central neurological disorders.

Material and Methods: We report a series of five consecutive patients with severe central neurological disorders who developed a POA of the clavicular region (coracoclavicular or costoclavicular POA). Every patient underwent a clinical, radiological, and computed tomographic (CT) examination of the shoulder region.

Results: Four patients had a history of traumatic brain injury (TBI), and one an acute disseminated encephalomyelitis (ADEM). They developed POA of the clavicular region, although not around the glenohumeral joint. The patients complained of shoulder pain and of moderate limitation of movements. Radiological and CT examinations showed the presence of a bony formation in the coracoclavicular space in four cases and extending from the clavicle to the first rib around the costoclavicular joint in one case.

Conclusion: In patients with severe brain lesions suffering from shoulder pain and moderate limitation of joint movements, POAs of the clavicular region are rare but should be considered.     

Magnetic resonance-assisted imaging of slow flow in the pancreatic and common bile duct in healthy volunteers

Background: Magnetic resonance cholangiopancreaticography (MRCP) is commonly used to evaluate the pancreatic (PD) and common bile duct (CBD), and the addition of secretin is used to obtain functional information (S-MRCP). Neither method gives any information on flow velocities within the ducts.

Purpose: To evaluate a new, MRI diffusion-based, slow-flow-sensitive sequence for the detection of slow flow changes in the PD and CBD.

Material and Methods: Seven healthy volunteers were examined. A modified single-shot turbo spin-echo sequence was used to detect slow flow changes. Three b factors (0, 6, and 12 s/mm²) were used. The flow sensitivity was applied in two directions, vertically and horizontally. Scanning was performed before and after glucagon was given, and again after an intravenous injection of secretin. The sequence gives signal loss from a duct when flow increases, and such changes were recorded.

Results: All images showed the PD with b = 0 (no flow sensitization). After administration of glucagon, artifacts from bowel movements were reduced and visibility of the PD was improved at both b = 6 and b = 12. Significant reduction of the visibility of the PD, indicating increased flow, was recorded both at b = 6 and b = 12 after the administration of secretin. There were no changes in the visibility of the CBD.

Conclusion: This study shows that MRI-based detection of slow flow changes inside the PD is possible. Due to the sequence's high sensitivity to any motion, further studies are required before adopting the method for clinical use.     

Radiological contrast media and pancreatic blood perfusion in anesthetized rats

Background: Radiological contrast media (CM) have been suggested to be able to impair pancreatic microcirculation.

Purpose: To evaluate the effects of an iso-osmolar (iodixanol, 290 mOsm/kg H₂O) and a low-osmolar (iopromide, 660 mOsm/kg H₂O) CM on total pancreatic and islet blood perfusion.

Material and Methods: Thiobutabarbital-anesthetized rats were injected with iodine-equivalent doses (600 mg I/kg body weight) of iodixanol or iopromide. Saline or low-osmolar mannitol (660 mOsm/kg H₂O) solutions served as control substances. Blood perfusion measurements were then carried out with a microsphere technique.

Results: Iso-osmolar iodixanol had no effects on blood perfusion. Low-osmolar iopromide increased total pancreatic blood perfusion, whereas islet blood perfusion was unchanged. No differences were seen when mannitol solutions were given.

Conclusion: Neither an iso-osmolar nor a low-osmolar CM affected pancreatic islet blood perfusion, whereas the low-osmolar CM increased total pancreatic blood perfusion. The absence of hemodynamic effect of low-osmolar mannitol suggests that the hyperosmolality per se of iopromide versus iodixanol does not induce the hemodynamic effect. The consequences of the effect of iopromide for pancreatic function remain to be established.