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.     

Virtual bronchoscopy versus thin section computed tomography in evaluation of moderate and low grade stenoses: receiver operating characteristic curve analysis

Purpose: To evaluate the impact of virtual bronchoscopy, under proper threshold settings, on observer level of confidence in the assessment of bronchial abnormalities producing stenoses ≤75% compared to interpretation of thin section computed tomography (CT) images.

Material and Methods: Sixty-five patients with fiberoptic bronchoscopy positive for tracheobronchial abnormalities were evaluated in a blinded observer study using a commercially available virtual endoscopy software package. The findings of virtual endoscopy were compared with those of fiberoptic bronchoscopy using receiver operating characteristic curves (ROCs) and other statistical tools.

Results: A total of 102 lesions were identified by fiberoptic bronchoscopy, with 44 of these producing bronchial stenoses ≤75%. Concerning the latter lesions, for virtual bronchoscopy the areas under the ROCs were 0.93 and 0.96 for the two observers, respectively, while for thin section CT the corresponding values were 0.86 and 0.88; the differences observed were statistically significant. Contrary to thin section CT, virtual bronchoscopy did not show statistically significant differences from fiberoptic bronchoscopy regarding estimation of degree of stenosis.

Conclusion: Virtual bronchoscopy under proper threshold settings has a statistically significant impact on observer performance where moderate and low-grade bronchial stenoses are concerned and gives an estimate of the degree of stenosis more precisely than thin section CT.     

Multi-detector computed tomography angiography of the hepatic artery in liver transplant recipients

Purpose: To evaluate the ability of multi-detector row computed tomography angiography (CTA) in detecting hepatic artery complications in the follow-up of liver transplant patients, performing volume-rendering as reconstruction technique.

Material and Methods: The anatomy of hepatic artery was studied in 27 liver transplant recipients with a four-row CT scanner using the following parameters: collimation, 1 mm; slice width, 1 mm; table feed, 6-8 mm/s; spiral reconstruction time, 0.5 s; reconstruction interval, 0.5 mm; mAs, 160; kVp, 120. Before the study, the patients received 1000 ml of water as oral contrast agent to produce negative contrast in the stomach and the small bowel. A non-ionic contrast medium was infused intravenously at a rate of 5 ml/s with a bolus tracking system. Volume-rendering of hepatic artery was performed with the 3D Virtuoso software.

Results: The celiac trunk, the hepatic artery, and the right and left hepatic arteries were successfully displayed in high detail in all patients. Side branches, including small collaterals, and hepatic artery anastomosis could also be readily visualized. Volume-rendered CTA detected six hepatic artery stenoses, two hepatic artery thromboses, and two intrahepatic pseudoaneurysms. In two cases, CT detected hepatic artery stenosis with a diameter reduction of less than 50%, while digital subtraction angiography showed a normal artery.

Conclusion: Volume-rendered multi-detector CTA is a promising non-invasive technique, since it allows images of high quality to be generated with excellent anatomical visualization of the hepatic artery and its complications in liver transplant recipients.     

Endovascular treatment of obstructive iliac artery dissections

Purpose: To report our results from a study of the endovascular treatment of flow restricting chronic atherosclerotic or catheter-induced segmental iliac artery dissections with bare stents.

Material and Methods: Thirty symptomatic patients with 32 lesions, including chronic atherosclerotic (n = 21) and catheter-induced (n = 11) segmental arterial dissections, were treated with primary stenting. The common iliac artery was involved in 19 lesions and the external iliac artery in the remaining 13. Two patients had two lesions in the same vessel. Technical success was defined as restoration of the smooth contoured luminal patency with no more than 20% residual stenosis in diameter in atherosclerotic dissections associated with plaque formation or total obliteration of the false lumen in catheter-induced dissections. Complete relief of, or marked improvements in, presenting symptoms, or at least single category improvement, was assessed for clinical success.

Results: Technical success rate was 100%. No procedure-related complications such as distal emboli or early occlusions were observed. Complete symptom relief was achieved in all patients with catheter-induced dissection and in all but three cases with chronic spontaneous atherosclerotic dissection. In two cases, occlusion of the stents occurred during the follow-up period. Clinical and radiological mean follow-up for 24 months (range 3-55) revealed patency of all other stented segments. Cumulative primary patency rate was 97% over 12 months and 90% over 24 months.

Conclusion: Endovascular treatment of chronic atherosclerotic and catheter-induced short obstructive iliac arterial dissections with bare stents is safe and effective. Patency of the diseased arterial segment with a smooth lumen can be sustained for an extensive period.     

Pulmonary artery diameters measured by multidetector-row computed tomography in healthy adults

Background: The range of the diameters of pulmonary arteries (PA) is not fully shown in the current literature. Contrast-enhanced computed tomography (CT) of the thorax might be used for measuring diameters of the PA.

Purpose: To determine the diameters of PAs in subjects with normal PA pressure by using thoracic CT.

Material and Methods: 126 subjects aged between 19 and 46 years, having normal thoracic CTs (5-mm slice thickness) and normal PA pressures (≤25 mmHg, determined by echocardiography), were included in the study. The diameters of the main, right, and left PAs were measured by using multidetector CT.

Results: The main PA diameters of all the subjects showed a normal distribution, and the mean was 24.0±2.8 mm. The main PA diameters in male and female subjects also showed a normal distribution. The difference between the sexes for the main PA diameters was not significant (P = 0.08). There were correlations between main PA diameter and body-mass index (BMI) (R = 0.41, P = 0.001) and weight (R = 0.34, P = 0.001). However, there was no significant correlation between main PA diameter and height (R = 0.05, P = 0.6).

Conclusion: This study suggests that diameters of the main PA and its main branches show a normal distribution in subjects having normal PA pressures. Based on our findings, the upper limits of the main, right, and left PA diameters are 29.5 mm, 19.8 mm, and 22.1 mm, respectively, in healthy adults.     

Renal artery aneurysm: diagnosis and surveillance with multidetector-row computed tomography

Purpose: To investigate the prevalence of renal artery aneurysms, and to assess the value of multidetector-row computed tomography (MDCT) in diagnosing renal artery aneurysms.

Material and Methods: Altogether, 862 patients underwent arterial-phase contrast-enhanced CT scan of the abdomen in the period November 2003 to October 2005. A search for renal artery aneurysms was performed in our reporting system and revealed six patients with renal artery aneurysm (RAA).

Results: The incidence of RAA was 0.7%. All renal artery aneurysms were solitary, located in the main trunk or the first branch of the renal artery, with sizes from 1.5 cm to 3.4 cm. Five aneurysms were saccular, one fusiform. No underlying thrombosis was seen. Extensive calcification was found in one aneurysm. Three aneurysms were diagnosed using axial images, while three aneurysms were only displayed by volume rendering and maximum-intensity projection images.

Conclusion: This study demonstrates a 0.7% incidence of renal artery aneurysms in a total of 862 patients. MDCT has an important role in detecting and assessing renal artery aneurysms. Some aneurysms can only be displayed by post-processing techniques such as volume rendering and maximum-intensity projection.     

64-slice computed tomography assessment of coronary artery stents: a phantom study

Purpose: To compare the use of a new 64-slice computed tomography (CT) scanner with 16-slice CT in the visualization of coronary artery stent lumen.

Material and Methods: Eight different coronary artery stents, each with a diameter of 3 mm, were placed in a static chest phantom. The phantom was positioned in the CT gantry at an angle of 0° and 45° towards the z-axis and examined with both a 64-slice and a 16-slice CT scanner. Effective slice thickness was 0.6 mm with 64-slice CT and 1 mm with 16-slice CT. A reconstruction increment of 0.3 mm was applied in both scanners. Image quality was assessed visually using a 5-point grading scale. Stent diameters were measured and compared using paired Wilcoxon tests.

Results: Artificial lumen reduction was significantly less with 64-slice than with 16-slice CT. Average visible stent lumen was 53.4% using 64-slice CT and 47.5% with 16-slice MSCT. Most severe artifacts were seen in stents with radiopaque markers. Using 64-slice CT, image noise increased by approximately 30% due to thinner slice thickness.

Conclusion: Improved spatial resolution of 64-slice CT resulted in superior assessment of coronary artery stent lumen compared to 16-slice CT. However, a relevant part of the stent lumen is still not assessable with multi-slice CT.     

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.     

Magnetic resonance imaging in determination of myocardial ischemia and viability: comparison with positron emission tomography and single-photon emission computed tomography in a porcine model

Background: In patients with chronic left ventricular dysfunction, the size of the viable cardiac muscle is correlated with the prognosis and the outcome of myocardial revascularization.

Purpose: To evaluate the diagnostic value of various imaging techniques in determination of myocardial ischemia and viability.

Material and Methods: A chronic myocardial ischemia animal model was established, in which 10 pigs underwent magnetic resonance imaging (MRI), positron emission tomography (PET), and single-photon emission computed tomography (²⁰¹Tl SPECT) before and 1-2 months after modeling. The size of myocardial ischemia and necrosis was judged, and the imaging manifestations were compared with pathologic findings.

Results: Seven of the 10 animals completed all examinations uneventfully. On dobutamine-stressed cine MRI, 10 (8.93%) segments were found to be akinetic. Perfusion was abnormal in 34 (30.35%) segments. Delayed hyperenhancement was observed in 12 (10.71%) segments. PET detected myocardial necrosis in 17 (15.18%) segments, and SPECT detected myocardial necrosis in nine (8.04%) segments. Histological examination with triphenyltetrazolium chloride (TTC) showed pale necrosis in 14 (12.50%) segments. The number of necrotic segments detected by PET was significantly greater than that by contrast-enhanced MRI (χ² = 5, P = 0.0253, kappa = 0.8028) and cine MRI (χ² = 7, P = 0.0082, kappa = 0.7079). It was also greater than that by TTC (χ² = 3, P = 0.0833, kappa = 0.8879), although the difference was statistically insignificant. The number of necrotic segments detected by SPECT was significantly smaller than that by TTC (χ² = 5, P = 0.0253, kappa = 0.7590), as was the number of necrotic segments detected by cine MRI (χ² = 4, P = 0.0455, kappa = 0.8100). There was no statistically significant difference in the detection of necrotic segments between contrast-enhanced MRI and TTC (χ² = 2, P = 0.1573, kappa = 0.9130).

Conclusion: Cardiac MRI can determine viable myocardium and clearly delineate the location and degree of myocardial necrosis. PET slightly overestimates the extent of the necrotic myocardium and is unable to distinguish transmural necrosis from subendocardial necrosis.     

Split renal function in patients with suspected renal artery stenosis: a comparison between gamma camera renography and two methods of measurement with computed tomography

Purpose: To validate a method for calculating split renal function from computed tomography (CT) compared with gamma camera renography, and to test a new method for the measurement based on a volume-rendering technique.

Material and Methods: Thirty-eight patients, aged 65.7±11.6 (range 37.8-82.1) years, who had undergone both CT angiography and gamma camera renography for a suspected renal artery stenosis were included in this study. Split renal function was calculated from the CT examinations by measuring area and mean attenuation in the image slices of the kidneys, and also by measuring volume and mean attenuation from a 3D reconstruction of the kidneys. Gamma camera renography with ^99mTc-MAG3 with or without captopril enhancement was used as a reference.

Results: The 2D CT method had good correlation with renography (r = 0.93). Mean difference was 4.7±3.6 (0-12) percentage points per kidney. There was also excellent correlation between the two CT methods (r = 1.00).

Conclusion: CT is equivalent to renography in determining split renal function, and the measurement from the CT examination can be made more quickly and equally accurately with a 3D technique.     

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.     

Attempts to improve absolute quantification of cerebral blood flow in dynamic susceptibility contrast magnetic resonance imaging: a simplified T1-weighted steady-state cerebral blood volume approach

Background: Attempts to retrieve absolute values of cerebral blood flow (CBF) by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) have typically resulted in overestimations.

Purpose: To improve DSC-MRI CBF estimates by calibrating the DSC-MRI-based cerebral blood volume (CBV) with a corresponding T1-weighted (T1W) steady-state (ss) CBV estimate.

Material and Methods: 17 volunteers were investigated by DSC-MRI and ¹³³Xe SPECT. Steady-state CBV calculation, assuming no water exchange, was accomplished using signal values from blood and tissue, before and after contrast agent, obtained by T1W spin-echo imaging. Using steady-state and DSC-MRI CBV estimates, a calibration factor K = CBV(ss)/CBV(DSC) was obtained for each individual. Average whole-brain CBF(DSC) was calculated, and the corrected MRI-based CBF estimate was given by CBF(ss) = K×CBF(DSC).

Results: Average whole-brain SPECT CBF was 40.1±6.9 ml/min·100 g, while the corresponding uncorrected DSC-MRI-based value was 69.2±13.8 ml/min·100 g. After correction with the calibration factor, a CBF(ss) of 42.7±14.0 ml/min·100 g was obtained. The linear fit to CBF(ss)-versus-CBF(SPECT) data was close to proportionality (R = 0.52).

Conclusion: Calibration by steady-state CBV reduced the population average CBF to a reasonable level, and a modest linear correlation with the reference ¹³³Xe SPECT technique was observed. Possible explanations for the limited accuracy are, for example, large-vessel partial-volume effects, low post-contrast signal enhancement in T1W images, and water-exchange effects.     

Transcatheter arterial embolization for massive hemoptysis in patients with coal workers' pneumoconiosis: an 11-year experience

Background: Transcatheter arterial embolization (TAE) is a safe and well-established treatment option to control hemoptysis, but there are few studies focused on treating hemoptysis accompanying coal workers' pneumoconiosis (CWP).

Purpose: To evaluate the immediate and long-term efficacy of TAE for control of massive hemoptysis in patients with CWP, and to clarify the factors which influence the frequency of rebleeding.

Material and Methods: This study included 34 CWP patients with massive hemoptysis who were treated with 47 TAE sessions over the last 11 years. Immediate (within 1 month) and long-term outcomes (mean 37 months, range 1 month-11 years) were evaluated retrospectively. The relationships between the frequency of rebleeding and the type of CWP, angiographic findings, and presence of tuberculosis were evaluated.

Results: The immediate success rate was 91.2% (31/34). In 23 patients (68%), hemoptysis did not recur on long-term follow-up. In eight patients who received repeated procedures for recurrent hemoptysis, bleeding was discovered in the non-bronchial systemic artery (n = 13) or bronchial artery (n = 7). The frequency of recurrent hemoptysis was higher in cases with complicated pneumoconiosis (n = 7) than in cases of the simple type (n = 1; P = 0.029). There was no statistical difference between rebleeding and angiographic findings or the presence of tuberculosis.

Conclusion: TAE is an effective treatment modality for controlling massive hemoptysis in patients with CWP. However, many non-bronchial systemic collaterals contribute to recurrent hemoptysis. Furthermore, there is a high probability of rebleeding in patients with the complicated type of CWP, and extra care must be taken in the embolization procedure.     

Standardized volume-rendering of contrast-enhanced renal magnetic resonance angiography

Purpose: To propose a technique for standardizing volume-rendering technique (VRT) protocols and to compare this with maximum intensity projection (MIP) in regard to image quality and diagnostic confidence in stenosis diagnosis with magnetic resonance angiography (MRA).

Material and Methods: Twenty patients were examined with MRA under suspicion of renal artery stenosis. Using the histogram function in the volume-rendering software, the 95th and 99th percentiles of the 3D data set were identified and used to define the VRT transfer function. Two radiologists assessed the stenosis pathology and image quality from rotational sequences of MIP and VRT images.

Results: Good overall agreement (mean κ = 0.72) was found between MIP and VRT diagnoses. The agreement between MIP and VRT was considerably better than that between observers (mean κ = 0.43). One of the observers judged VRT images as having higher image quality than MIP images.

Conclusion: Presenting renal MRA images with VRT gave results in good agreement with MIP. With VRT protocols defined from the histogram of the image, the lack of an absolute gray scale in MRI need not be a major problem.     

Hyperperfusion on perfusion computed tomography following revascularization for acute stroke

Purpose: To describe the findings of hyperperfusion on perfusion computed tomography (CT) in four patients following revascularization for acute stroke.

Material and Methods: In 2002-2003, among a series of 6 patients presenting with an acute stroke and treated with intra-arterial thrombolysis, we observed the presence of hyperperfusion in 3 patients on the follow-up CT perfusion. We included an additional patient who was treated with intravenous thrombolysis and who had hyperperfusion on the follow-up CT perfusion. We retrospectively analyzed their CT perfusion maps. Cerebral blood volume (CBV) and cerebral blood flow (CBF) maps were compared between the affected territory and the normal contralateral hemisphere.

Results: In the four patients, the mean CBV and CBF were 3.6±2.0 ml/100 g and 39±25 ml/100 g/min in the affected territory compared to the normal side (mean CBV = 2.7±2.1 ml/100 g, mean CBF = 27±23 ml/100 g/min). There was no intracranial hemorrhage in the hyperperfused territories. At follow-up CT, some hyperperfused brain areas progressed to infarction, while others retained normal white to gray matter differentiation.

Conclusion: CT perfusion can demonstrate hyperperfusion, which can be seen in an ischemic brain territory following recanalization.     

Do contrast media (iomeprol, gadopentetate dimeglumine) deteriorate ischemia/reperfusion injury of the liver?

Background: Hepatic microcirculation is a main determinant of reperfusion injury and graft quality in liver transplantation. One of the important diagnostic procedures to recognize reperfusion failure is contrast-enhanced computed tomography or magnetic resonance imaging.

Purpose: To examine the additional effect of contrast media (iomeprol and gadopentetate dimeglumine) on hepatic microcirculation and hepatic cellular damage in the phase of early ischemia/reperfusion injury of the rat liver.

Material and Methods: The partial warm ischemia-reperfusion injury model of rat liver was used. Microcirculation and leukocyte-endothelium interaction were measured by intravital microscopy. Hepatic cellular damage was indicated by liver enzyme activity in the sera. The evaluation parameters were measured at baseline and at 30, 60, and 90 min after reperfusion. The contrast media (iomeprol group, n = 6; gadopentetate dimeglumine group, n = 6) or Ringer's solution (control group, n = 8) were applied after 30 min of reperfusion.

Results: No additional injury to the ischemia/reperfusion injury of the liver after intravenous application of radiographic contrast media was found. Some protective effect was even recorded after application of iodinated contrast media.

Conclusion: The use of contrast media during diagnostic procedure of the liver seems to be relatively safe, even in the stage of early reperfusion after liver transplantation.     

Cost-effectiveness of computed tomographic colonography: a prospective comparison with colonoscopy

Purpose: To estimate the cost-effectiveness of detecting colorectal polyps with computed tomographic colonography (CTC) and subsequent polypectomy with primary colonoscopy (CC), using CC as the alternative strategy.

Material and Methods: A marginal analysis was performed regarding 103 patients who had had CTC prior to same-day CC at two hospitals, H-I (n = 53) and H-II (n = 50). The patients were randomly chosen from surveillance and symptomatic study populations (148 at H-I and 231 at H-II). Populations, organizations, and procedures were compared. Cost data on time consumption, medication, and minor equipment were collected prospectively, while data on salaries and major equipment were collected retrospectively. The effect was the (previously published) sensitivities of CTC and CC for detection of colorectal polyps≥6 mm (H-I, n = 148) or ≥5 mm (H-II, n = 231).

Results: Thirteen patients at each center had at least one colorectal polyp≥6 mm or ≥5 mm. CTC was the cost-effective alternative at H-I (€187 vs. €211), while CC was the cost-effective alternative at H-II (€239 vs. €192). The cost-effectiveness (costs per finding) mainly depended on the sensitivity of CTC and CC, but the depreciation of equipment and the staff's use of time were highly influential as well.

Conclusion: Detection of colorectal polyps≥6 mm or ≥5 mm with CTC, followed by polypectomy by CC, can be performed cost-effectively at some institutions with the appropriate hardware and organization.     

Treatment of acute ischemic brain infarction with the assistance of local intraarterial thrombolysis with recombinant tissue-type plasminogen activator

Background: Cerebral infarction is usually due to arterial occlusion. Prompt treatment with thrombolytic drugs can restore blood flow and improve recovery from an infarct.

Purpose: To evaluate the clinical efficacy and safety of local intraarterial thrombolysis with recombinant tissue-type plasminogen activator (rtPA) in patients with acute middle cerebral artery (MCA) infarctions within 6 hours of the onset of symptoms.

Material and Methods: Sixteen patients (10 females and six males) aged from 42 to 61 years, with acute MCA territory infarcts were selected for treatment with local i.a. rtPA up to 6 hours after the onset of symptoms. Patient selection was based on clinical examination, computed tomography (CT), and digital subtraction angiography (DSA). A clinical evaluation was performed before treatment, at the time of discharge, and 90 days post-procedure on the basis of modified Rankin and NIHSS scores. Controls (n = 16, nine females and seven males) aged from 51 to 70 years were treated only with intravenous anticoagulation using i.v. heparin infusion. The control group was evaluated with multidetector CT (MDCT) angiography performed on entry to the study and at 2-4 hours afterwards.

Results: Eight patients (50%) achieved a modified Rankin score of 2 or less as the primary outcome after 90 days follow-up. The secondary clinical outcome at 90-day follow-up was as follows: NIHSS score ≤1, three (19%) of the patients; NIHSS score ≥50% decrease, nine (56%) of the patients. A recanalization rate of 75% was achieved in 12 of the 16 treated patients, but only 12.5% in two of the 16 patients in the control group. Intracerebral hemorrhage occurred in two (12.5%) of the patients in the treatment group, but in only one patient (6%) in the control group. There were no deaths in the treated group after thrombolysis up to the time of discharge; however, during the 90-day follow-up, two patients died compared to three patients in the control group (19% vs. 12.5% mortality rate).

Conclusion: Patients with cerebral infarction who were treated within 6 hours of onset using intraarterial rtPA thrombolysis had a significantly improved clinical outcome 90 days after the procedure compared to patients treated only with intravenous anticoagulation.     

Is subcutaneous local anesthesia in shoulder magnetic resonance arthrography necessary?

Background: Magnetic resonance arthrography is a well-established diagnostic method in degenerative and traumatic disorders of the shoulder. Some radiologists prefer to apply a local anesthetic to the skin prior to performing the joint puncture. However, no information regarding the efficacy of local anesthetics exists.

Purpose: To assess patient discomfort in arthrography injection.

Material and Methods: A patient survey (n = 74) utilizing a visual analog scale (VAS) measured the intensity of pain in arthrography injection by those receiving local anesthetics (n = 36) versus those who did not (n = 38).

Results: Mean VAS scores were 20.8 (median 10.5, SD 24.3) for those receiving local anesthetics versus 19.3 (median 13.0, SD 20.7) for those who did not (P = 0.83, Mann-Whitney U test).

Conclusion: Routine use of local anesthesia of the skin in arthrography injection is unnecessary.     

In vitro coronary artery imaging with sixteen-slice helical computed tomography

Purpose: To determine the benefits of submillimeter coronary computed tomography (CT) angiography in vitro.

Material and Methods: The coronary arteries of three domestic pigs were filled with contrast agent and depicted with clinically applicable CT angiography protocols with a slice thickness of 0.63 to 2.5 mm.

Results: With 2.5 mm slices, only the third-degree coronary artery branches could be discerned. With 1.25 mm slices, some fourth-degree branches of the right coronary artery could be discerned upon maximum intensity projections. With 0.63 mm slices, fourth-degree coronary artery branches could be discerned in all locations.

Conclusion: The introduction of 16-row detector CT with submillimeter z-axis resolution translates into an order-of-magnitude benefit for the depiction of coronary artery branches.