The prevalence and clinical predictors of incidental atherosclerotic renal artery stenosis

Objective

To evaluate the prevalence of incidental renal artery stenosis due to atherosclerosis and associated risk factors in patients with peripheral arterial disease (PAD).

Materials and methods

To determine renal artery stenosis, aortofemoropopliteal digital substraction angiographies (DSA) of 629 consecutive patients with PAD were prospectively reviewed. Angiographies were performed as catheter angiography with automated pump injection. Of the patients, 540 were male (86%) and 89 female (14%) (mean age ± S.D.: 61.5 ± 11.1 years). Statistical analysis was performed to determine the association of significant renal artery stenosis (≥60% diameter stenosis) with patient demographics (age, sex, reason for angiography and smoking status), medical history (diabetes mellitus, hypertension and coronary artery disease), laboratory values (blood creatinine, fasting glucose, triglycerides, LDL, HDL and total cholesterol) and distribution of PAD (aortoiliac, femoropopliteal and crural diseases and multisegment involvement).

Results

Renal artery disease was found in 33% (207 of 629) of all patients with peripheral arterial disease, and 9.6% of patients (n = 60) had significant (≥60%) renal artery stenosis. Only age and hypertension (blood pressure systolic >140 mmHg or diastolic >90 mmHg) were independent risk factors for significant renal artery stenosis on multivariate analysis. Mean age of patients with RAS was 66.5 ± 8.9 years compared with 61 ± 11.2 years for patients without RAS (p < 0.001). Hypertension was found in 41% of the patients in control group and in 63% of the patients in RAS group (p = 0.01).

Conclusion

Incidental renal artery stenosis which can be mild or significant is a relatively common finding among patients with peripheral arterial disease. Advance age and hypertension are closely associated with significant renal artery stenosis.     

Comparison of the aortic valve calcium content in the bicuspid and tricuspid stenotic aortic valve using non-enhanced 64-detector-row-computed tomography with prospective ECG-triggering

Purpose

The aim of our study was to compare the calcium content measured by non-enhanced multidetector-row-computed tomography (MDCT) between patients with significant stenosis of bicuspid (BAV) and tricuspid aortic valve (TAV). Another aim of our study was to assess the accuracy of the non-enhanced MDCT to distinguish BAV and TAV based on the calcified plaque morphology, and to compare the results with the transesophageal echocardiography.

Subjects and methods

A retrospective analysis of prospectively collected data was performed. Consecutive patients with symptomatic aortic stenosis (AS) admitted to hospital for evaluation before valve surgery underwent clinical evaluation, transthoracic and transesophageal echocardiography, and non-enhanced examination with the 64-detector-row CT using prospective ECG triggering with data acquisition in diastolic phase. The data acquisition started at 55% of the R–R interval. The patients were examined in the supine position in mild inspiration. Data were evaluated using dedicated software for calcium scoring, the volume of calcifications and calcium content were obtained.

Results

Thirty-seven patients (20 males, age 48–83 years) were enrolled. BAV was present in 13 patients, TAV in 24 patients. The calcium score in patients with severe AS (mean gradient >50 mmHg) was higher than in those with moderate AS (1123 ± 616 mg versus 634 ± 475, P = 0.011). Significant correlation between the calcium scores and transaortic gradients was found (r = 0.53, P = 0.002). The patients with BAV did not differ significantly from those with TAV in the AS severity (58 ± 13 versus 53 ± 20 mmHg), nor in the valve calcium score (1168 ± 717 versus 795 ± 530 mg, P = 0.093). The overall sensitivity to detect BAV in patients with calcified severe AS was 0.923 (12/13) and specificity 0.958 (23/24). The overall accuracy was 0.945 (35/37).

Conclusion

We observed higher calcium score in patients with severe AS than with moderate AS. However, no difference in aortic valve calcium score between BAV and TAV was found. Thus, in our sample, the aortic valve calcium score correlated with AS severity, not with aortic valve morphology. Based on the calcified plaque space relationship, the aortic BAV and TAV could be distinguished in most cases.     

Discrepant findings of computed tomography quantification of minimal lumen area of coronary artery stenosis: Correlation with intravascular ultrasound

Objectives

To study the diagnostic performance of computed tomography (CT) quantification of minimal lumen area (MLA) based on multiple factors (image quality, calcification and lesion locations), with reference to intravascular ultrasound (IVUS).

Methods

Consecutive clinically ordered patients were prospectively enrolled in our study. CT quantification of MLA was manually measured on cross-sectional view and further compared with IVUS findings. A significant lesion was defined as ≤6 mm² MLA for the left main (LM) coronary artery and a ≤4 mm² MLA for other epicardial vessels.

Results

Non-calcified lesions had good correlation between CT and IVUS (r = 0.96) and the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 85% (51/60), 93.94% (31/33), 96.23% (51/53) and 77.5% (31/40) respectively. Decreased correlation (r = 0.814) lower specificity (23.81% (5/21)) and positive predictive value (60.98% (25/41)) were observed in calcified subgroup. Artifact-absent lesions demonstrated excellent correlation (r = 0.967) and the sensitivity, specificity, PPV and NPV were 96% (48/50), 93.94% (31/33), 96% (48/50) and 93.94% (31/33) respectively. Impaired correlation (r = 0.584) was noted in artifact-present lesions and the sensitivity, specificity, PPV and NPV were 80% (28/35), 23.81% (5/21), 63.64% (28/44) and 41.67% (5/12) respectively. Excellent correlation between CT and IVUS was noted in proximal epicardial vessels (r = 0.908) and the sensitivity, specificity, PPV and NPV were 92.31% (36/39), 78.13% (25/32), 83.72% (36/43) and 89.29% (25/28) respectively. Middle right coronary artery lesions showed non-significant correlation (r = 0.54, p = 0.055).

Conclusions

CT quantification of MLA can only be accurately achieved in non-calcified lesions with absence of artifact. Diagnostic performance is impaired in calcified lesions.     

The role of second-look ultrasound of BIRADS-3 mammary lesions detected by breast MR imaging

Objective

To asses the value of second-look ultrasound (US) for identifying BIRADS 3 (Breast Imaging Reporting Data System) mammary lesions detected by breast Magnetic Resonance imaging (MRI).

Materials and methods

From April 2008 to May 2009 330 breast MRI were performed of which 60 patients are classified as BIRADS 3. 84 lesions underwent second-look US and percutaneous vacuum biopsy Vacora system US-guided. Statistical analysis: lesions were stratified into two groups: visible on US (Group 1) and not visible on US (Group 2).The clinical impact of second-look US was studied in terms of negative predictive value (NPV).

Results

The positive predictive value (PPV) of category 3 BIRADS MRI was found to be 89%. Second look-US results detected lesions in 51% of the MRI enhancing lesions. The second look-US showed a NPV of 97%. The NPV of second look-US was significantly greater than the NPV of MRI BIRADS 3 (97% vs 89%, p < 0.05). The logistic regression analysis showed a higher number of malignant lesions in group 1 than in group 2 (7vs 2, OR 3.7, p < 0.05).

Conclusions

The second-look US permitted the correct management of subcentimetric MRI BIRADS 3 lesions not visible with conventional imaging tecniques.     

Carotid artery stenting and follow-up: value of 64-MSCT angiography as complementary imaging method to color-coded duplex sonography

Purpose

To compare 64-multi-slice-CT angiography (64-MSCTA) to color-coded duplex sonography (CCDS) in the follow-up after carotid artery stenting (CAS).

Methods

Thirty patients who had an MSCTA and CCDS examination prior and after CAS were included. Twelve closed-cell and 24 open-cell stents were implanted. Neointimal surface, in-stent-restenosis (ISR), stent expansion, and fracture were evaluated. In addition, the occurrence of atherosclerotic lesions leading to a > 50% stenosis in supraaortic vessels was assessed.

Results

With MSCTA, >50% ISR was found in 5.6% of cases during a mean follow-up of 41.7 months. Comparing MSCTA and CCDS, grading of ISR and absolute diameters of neointimal surface correlated moderately (Spearman = 0.402, p = 0.015; Pearson = 0.404, p = 0.03). Assessment of the neointimal surface was significantly better with MSCTA (100% vs. 80.6%; p = 0.011). Stent expansion was significant, compared to the basic value, with both modalities and stent types (p < 0.001). Of 237 additionally assessed vessel segments, a > 50% stenosis was detected in 38 (16.0%) vessel segments. Findings were stable in 25 (10.5%) and progressed in 11 (4.6%) vessel segments. Five small intracranial aneurysms were detected in four (13.3%) patients. Of 21 incidental findings in 16 (51.6%) patients there was one with malignancy (4.8%).

Conclusion

With regard to ISR and stent expansion, no significant difference was found, when MSCTA and CCDS were compared. CTA is quite applicable as a complementary imaging method for the follow-up of patients with carotid artery stents. Additional advantages are the detection of supraaortic vessel pathologies and incidental findings.     

Radiologic identification of disaster victims: a simple and reliable method using CT of the paranasal sinuses

Objective

To assess the reliability of radiologic identification using visual comparison of ante and post mortem paranasal sinus computed tomography (CT).

Subjects and methods

The study was approved by the responsible justice department and university ethics committee. Four blinded readers with varying radiological experience separately compared 100 post mortem to 25 ante mortem head CTs with the goal to identify as many matching pairs as possible (out of 23 possible matches). Sensitivity, specificity, positive and negative predictive values were calculated for all readers. The chi-square test was applied to establish if there was significant difference in sensitivity between radiologists and non-radiologists.

Results

For all readers, sensitivity was 83.7%, specificity was 100.0%, negative predictive value (NPV) was 95.4%, positive predictive value (PPV) was 100.0%, and accuracy was 96.3%. For radiologists, sensitivity was 97.8%, NPV was 99.4%, and accuracy was 99.5%. For non-radiologists, average sensitivity was 69.6%, negative predictive value (NPV) was 91.7%, and accuracy was 93.0%. Radiologists achieved a significantly higher sensitivity (p < 0.01) than non-radiologists.

Conclusions

Visual comparison of ante mortem and post mortem CT of the head is a robust and reliable method for identifying unknown decedents, particularly in regard to positive matches. The sensitivity and NPV of the method depend on the reader's experience.     

Central venous stenosis of left versus right arm: its prevalence and effects on image quality in CT of the neck

Objective

The purpose of this study was (1) to evaluate the prevalence of the left and right central venous stenosis by measuring the narrowest area and (2) to assess the effects of the central venous stenosis on perivenous artifacts and reflux of contrast material, in CT of the neck.

Materials and methods

Images of a total of 443 CT of the neck with an injection of contrast material into the left (n = 249) or right (n = 194) arm were retrospectively reviewed. The maximum stenosis area in the central vein ipsilateral to the injection side was measured in each patient. We also graded the perivenous artifacts and reflux of contrast material with 4-point scale. These results were compared between patients with right arm injection and those with left arm injection.

Results

The maximum stenosis area in the left arm was significantly smaller than that in the right arm. The stenosis was most frequently identified at the medial clavicular region. The mean scores of the perivenous artifacts and the reflux of contrast material were significantly higher in patients with left arm injection than in those with right arm injection. The perivenous artifacts and reflux of contrast material were more prominent in patients with central venous stenosis (maximum stenosis area <50 mm²) than those without stenosis.

Conclusions

The image degradation in CT of the neck, due to perivenous artifacts and venous reflux, can be reduced with the right arm injection of contrast material when compared with the left arm injection.     

Quantification of coronary stenosis by dual source computed tomography in patients: a comparative study with intravascular ultrasound and invasive angiography

Objective

To determine the accuracy of dual-source CT (DSCT) to quantify coronary stenosis compared to intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA).

Methods

21 patients (23 vessels) were examined with DSCT, IVUS and invasive coronary angiography. Coronary minimal luminal diameter (MLD) and area (MLA) were measured in cross-sectional multi-planar reformatted images perpendicular to the vessel long-axis. The vessel cross-sectional area stenosis (MLA/CSA ratio) was calculated. DSCT results were compared with IVUS and QCA.

Results

A good correlation between DSCT and IVUS was noted for diameter and area stenosis (r = 0.69 and r = 0.73), with an overestimation of MLD stenosis by DSCT (+9.1%) and an underestimation of MLA stenosis (−5.8%). For MLD and MLA, high correlation coefficients (r = 0.78 and r = 0.90, respectively) were found between DSCT and IVUS; and the bias was almost zero (−0.41 mm and +0.1 mm², respectively).The correlation between DSCT and QCA was moderate (r = 0.60) for MLD stenosis with minor overestimation by DSCT (+4.0%) and moderate (r = 0.59) for MLD (bias, +0.01 mm).The cross-sectional area stenosis showed a moderate correlation (r = 0.59) between DSCT and IVUS (+0.00).

Conclusions

DSCT allows accurate quantification of coronary stenosis as compared to IVUS. An excellent correlation was found for the MLA between DSCT and IVUS.     

Magnetic resonance imaging of the lumbar spine with axial loading: a review of 120 cases

Purpose

To evaluate the imaging findings of patients with clinical symptoms of lower back pain who underwent magnetic resonance imaging (MRI) of the lumbar spine with axial loading.

Materials and methods

We examined 120 patients by MRI, before and after axial loading, using a compression device that applied 50% of their body weight for a load time of 5 min. The dural sac cross area (DSCA) was examined by two experienced radiologists before and after axial load, and their findings were compared. Degenerative abnormalities within and adjacent to the spinal canal were also analyzed.

Results

A reduction in DSCA greater than 15 mm² after axial load was defined as significant, and was found in 81 patients (67.5%) and 138 disc spaces (38.3%). Reduction was most frequent at L4-L5 (n = 55). For other disorders, a 9% increase in cases of bulging disc was seen during axial loading, and seven disc spaces showed protrusion/extrusion only after load. Facet joint synovial cysts, foraminal stenosis, and hypertrophy of the flavum ligaments showed almost no differences, pre- and post-load.

Conclusion

For adequate evaluation of lumbar symptoms, examination should be performed with axial loading, especially in cases of suspected spinal stenosis.     

Dynamic MDCT of the pancreas: Is time–density curve morphology useful for the differential diagnosis of solid lesions? A preliminary report

Purpose

CT perfusion has been proposed for pancreatic lesion characterization. However, scan and analysis protocols influence numerical data. To overcome this, the purpose of our study is to evaluate the use of time–density curves obtained from MDCT perfusion of the pancreas for the characterization of normal parenchyma, adenocarcinoma, chronic pancreatitis and endocrine tumors.

Methods

31 patients with solid pancreatic lesions and 21 patients with renal cell carcinoma underwent 64-row MDCT perfusion of the pancreas after injection of 50 cc of a 370 mg I/ml solution at 5 cc/s. 63 time–density curves were obtained from normal parenchyma (21 patients), adenocarcinoma (25), endocrine tumors (4) and atrophic parenchyma (13). Two readers independently categorized the 63 time–density curves into 4 different morphologies: normal wash-in and wash-out (A), low wash-in followed by plateau (B), low wash-in followed by faint wash-out (C) and high wash-in and wash-out (D). Interobserver agreement was calculated with kappa statistics. Fisher test was used to calculate sensitivity, specificity, positive (PPV) and negative (NPV) predictive values for each type of curve.

Results

Interobserver agreement was very good (Kappa = 0.849). Curve A had 94.4% sensitivity, 91.1% specificity, 80.95% PPV, 97.6% NPV for ‘normal parenchyma’. Curve B had 74.19% sensitivity, 93.75% specificity, 92% PPV, 78.95% NPV in diagnosing ‘adenocarcinoma’. Curve C had 45.45% sensitivity, 84.62% specificity, 38.46% PPV, 88% NPV for ‘chronic pancreatitis’. Curve D had 100% sensitivity, 98.33% specificity, 75% PPV, 100% NPV for ‘endocrine tumor’.

Conclusions

The morphology of MDCT perfusion time–density curves appears to be useful in characterizing pancreatic lesions, and might help overcome the differences in scan and postprocessing techniques.     

Carotid artery stenosis: performance of advanced vessel analysis software in evaluating CTA

Objectives

The aim of this study was to evaluate time efficiency and diagnostic reproducibility of an advanced vessel analysis software for diagnosis of carotid artery stenosis.

Material and methods

40 patients with suspected carotid artery stenosis received head and neck DE-CTA as part of their pre-interventional workup. Acquired data were evaluated by 2 independent radiologists. Stenosis grading was performed by MPR eyeballing with freely adjustable MPRs and with a preliminary prototype of the meanwhile available client-server and advanced visualization software syngo.via CT Vascular (Siemens Healthcare, Erlangen, Germany). Stenoses were graded according to the following 5 categories: I: 0%, II: 1–50%, III: 51–69%, IV: 70–99% and V: total occlusion. Furthermore, time to diagnosis for each carotid artery was recorded.

Results

Both readers achieved very good specificity values and good respectively very good sensitivity values without significant differences between both reading methods. Furthermore, there was a very good correlation between both readers for both reading methods without significant differences (kappa value: standard image interpretation k = 0.809; advanced vessel analysis software k = 0.863). Using advanced vessel analysis software resulted in a significant time saving (p < 0.0001) for both readers. Time to diagnosis could be decreased by approximately 55%.

Conclusions

Advanced vessel analysis application CT Vascular of the new imaging software syngo.via (Siemens Healthcare, Forchheim, Germany) provides a high rate of reproducibility in assessment of carotid artery stenosis. Furthermore a significant time saving in comparison to standard image interpretation is achievable.     

Non-invasive assessment of congenital pulmonary vein stenosis in children using cardiac-non-gated CT with 64-slice technology

Background

Management of congenital pulmonary vein stenosis is a diagnostic challenge. Echocardiography may be insufficient and thus cardiac catheterization remains the reference standard in this setting. The aim of the study was to investigate the accuracy of cardiac-non-gated CT using 64-slice technology in detecting congenital pulmonary vein stenosis in children.

Materials and methods

CT examinations were consecutively performed from May 2005 to December 2006 in 13 children aged 1.5–12 months (median 5 months) for suspected congenital pulmonary vein stenosis. Cardiac-non-gated CT acquisitions were performed after the peripheral injection of contrast agent. Pulmonary veins were evaluated for their pattern of connectivity from the lung to the left atrium and for the presence of stenosis. CT findings of pulmonary vein stenosis were compared with combined findings available from echocardiography, catheterization and surgery.

Results

Pulmonary veins from the right lung (n = 29) and left lung (n = 26) were evaluated as separate structures (N = 55). Of the 55 structures, 32 had surgical and/or catheterization data and 45 had echocardiography for comparison. CT visualized 100% (55/55) of the investigated structures, while echocardiography visualized 82% (45/55). In the 13 subjects CT identified 10 stenotic pulmonary veins. CT confirmed the echocardiography suspicion of pulmonary vein stenosis in 100% (7/7) and established a new diagnosis in 3 other patients. CT agreed with surgery/catheterization in 100% (10/10) of the available comparisons.

Conclusion

Cardiac-non-gated CT assessed the pulmonary veins more completely than echocardiography and should be considered as a viable alternative for invasive pulmonary venography for detecting pulmonary vein stenosis in children.     

Assessment of coronary artery disease by post-mortem cardiac MR

Objectives

Minimally invasive or virtual autopsies are being advocated as alternative to traditional autopsy, but have limited abilities to detect coronary artery disease. It was the objective of this study to assess if the occurrence of chemical shift artifacts (CSA) along the coronary arteries on non-contrast, post-mortem cardiac MR may be used to investigate coronary artery disease.

Methods

We retrospectively compared autopsy and CT findings of 30 cases with significant (≥75%), insignificant (<75%), or absent coronary artery stenosis to post-mortem cardiac MR findings. The chi-square test was used to investigate if the occurrence of CSA depends on the presence or absence of stenosis. Sensitivity, specificity and predictive values were calculated for each finding.

Results

CSA indicates the absence of (significant) stenosis (p < 0.001). The occurrence of paired dark bands in lieu of CSA on post-mortem cardiac MR suggests (significant) coronary arteries stenosis (p < 0.001). Both findings have a high specificity but low sensitivity.

Conclusions

CSA is a marker of vessel patency. The presence of paired dark bands indicates stenosis. These criteria improve the ability of minimally invasive or virtual autopsy to detect coronary artery disease related deaths.     

Flow and peak velocity measurements in patients with aortic valve stenosis using phase contrast MR accelerated with k-t BLAST

Objective

To investigate the accuracy of velocity measurements in patients with aortic valve stenosis using phase contrast (PC) imaging accelerated with SENSE (Sensitivity Encoding) and k-t BLAST (Broad-use Linear Acquisition Speed-up Technique).

Methods

Accelerated quantitative breath hold PC measurements, using SENSE and k-t BLAST, were performed in twelve patients whose aortic valve stenosis had been initially diagnosed using echocardiography. Stroke volume (SV) and peak velocity measurements were performed on each subject in three adjacent slices using both accelerating methods.

Results

The peak velocities measured with PC MRI using SENSE were −8.0 ± 9.5% lower (p < 0.01) compared to the peak velocities measured with k-t BLAST and the correlation was r = 0.83. The stroke volumes when using SENSE were slightly higher 0.4 ± 17.1 ml compared to the SV obtained using k-t BLAST but the difference was not significant (p > 0.05).

Conclusions

In this study higher peak velocities were measured in patients with aortic stenosis when combining k-t BLAST with PC MRI compared to PC MRI using SENSE. A probable explanation of this difference is the higher temporal resolution achieved in the k-t BLAST measurement. There was, however, no significant difference between calculated SV based on PC MRI using SENSE and k-t BLAST, respectively.     

Evaluation of carotid vessel wall enhancement with image subtraction after gadobenate dimeglumine-enhanced MR angiography

Objectives

This study was aimed at testing the value of image subtraction for evaluating carotid vessel wall enhancement in contrast-enhanced MR angiography (MRA).

Materials and methods

IRB approval was obtained. The scans of 81 consecutive patients who underwent carotid MRA with 0.1 mmol/kg of gadobenate dimeglumine were reviewed. Axial carotid 3D T1-weighted fast low-angle shot sequence before and 3 min after contrast injection were acquired and subtracted (enhanced minus unenhanced). Vessel wall enhancement was assigned a four-point score using native or subtracted images from 0 (no enhancement) to 3 (strong enhancement). Stenosis degree was graded according to NASCET.

Results

With native images, vessel wall enhancement was detected in 20/81 patients (25%) and in 20/161 carotids (12%), and scored 2.0 ± 0.6 (mean ± standard deviation); with subtracted images, in 21/81 (26%) and 22/161 (14%), and scored 2.5 ± 0.6, respectively (P < 0.001, Sign test). The overall stenosis degree distribution was: mild, 41/161 (25%); moderate, 77/161 (48%); severe, 43/161 (27%). Carotids with moderate stenosis showed vessel wall enhancement with a frequency (17/77, 22%) significantly higher than that observed in carotids with mild stenosis (1/41, 2%) (P = 0.005, Fisher exact test) and higher, even though with borderline significance (P = 0.078, Fisher exact test), than that observed in carotids with severe stenosis (4/43, 9%).

Conclusion

Roughly a quarter of patients undergoing carotid MRA showed vessel wall enhancement. Image subtraction improved vessel wall enhancement conspicuity. Vessel wall enhancement seems to be an event relatively independent from the degree of stenosis. Further studies are warranted to define the relation between vessel wall enhancement and histopathology, inflammatory status, and instability.     

Value of conventional chest radiography for the detection of coronary calcifications: comparison with MSCT

Purpose

To evaluate if computed tomography (CT) coronary calcium scoring is needed after detection of coronary calcifications on conventional chest radiographs.

Materials and methods

One hundred and five patients (67 men; 57.2 ± 12.8 years) with suspected coronary artery disease underwent conventional chest radiography and non-enhanced, retrospectively ECG-gated multislice spiral CT (MSCT) of the heart (4 mm × 2.5 mm, 120 kV, 133 mAs_eff.). Chest radiographs were assessed independently by two radiologists. Detection of coronary calcifications was compared between both methods. Sensitivity, specificity, negative and positive predictive values, median, 25% and 75% percentiles for the detection of coronary calcifications were calculated. Receiver operating characteristics (ROC) analyses were computed.

Results

In 90 patients, MSCT revealed coronary calcifications. The mean coronary calcium score was 526.2 (0–4784.5). On chest radiographs, coronary calcifications were correctly detected in 46 (61) patients by observer 1 (observer 2). The corresponding sensitivity was 51.1% in observer 1 and 67.8% in observer 2. Median of detected coronary calcifications was 361.9 (426.4) for observer 1 (observer 2). Corresponding 25% und 75% percentiles were 109.6 (109.6) and 798.5 (898.5). The area under the ROC curve was 0.636 for observer 1 and 0.715 for observer 2. There was no correlation between image quality and the detection of coronary calcifications on plain film radiographs.

Conclusion

As coronary calcifications of various extents are inconsistently detected on plain chest radiographs, CT calcium scoring may not be omitted even if coronary artery calcifications were detected on conventional chest radiographs.     

Computer-aided diagnosis in breast DCE-MRI--quantification of the heterogeneity of breast lesions

Purpose

In our study we aim at the quantification of the heterogeneity for differential diagnosis of breast lesions in MRI.

Materials and methods

We tested a software tool for quantification of heterogeneity. The software tool provides a three-dimensional analysis of the whole breast lesion. The lesions were divided in regions with similar perfusion characteristics. Voxels were merged to the same region, if the perfusion parameters (wash-in, wash-out, integral, peak enhancement and time to peak) correlated to 99%. We evaluated 68 lesions from 50 patients. 31 lesions proved to be benign (45.6%) and 37 malignant (54.4%). We included small lesions which could only be detected with MRI.

Results

The analysis of heterogeneity showed significant differences (p < 0.005; AUC 0.7). Malignant lesions were more heterogeneous than benign ones. Significant differences were also found for morphologic parameters such as shape (p < 0.001) and margin (p < 0.007). The analysis of the enhancement dynamics did not prove successful in lesion discrimination.

Conclusion

Our study indicates that the region analysis for quantification of heterogeneity may be a helpful additional method to differentiate benign lesions from malignant ones.     

Coronary CT angiography with iterative reconstruction in early triage of patients with acute chest pain

Background

Patients who present to the emergency department (ED) complaining of acute chest pain are of clinical concern because a small percentage will have acute coronary syndrome (ACS). The American College of Cardiology (ACC) and the American Heart Association (AHA) recommend hospitalization for patients with a low-to-intermediate risk of ACS who have initial negative ECG and enzyme test results. A negative coronary CT angiography (CCTA) during the triage has a very high negative predictive value for ruling out ACS decreasing the length of hospital stay. Recent techniques e.g. ASiR in CCTA should be used to decrease the radiation dose as low as possible.

Objective

The aim of this study is to evaluate the role of low radiation dose CCTA with ASiR in triage of low-risk patients with acute chest pain in emergency department. A negative CCTA early in the workup may enable a shorter length of stay.

Subjects and methods

We studied 54 selected patients (55.6% men; mean age 48 ± 6 years) with chest pain who were awaiting hospital admission to rule out ACS despite the absence of diagnostic ECG changes and normal cardiac enzymes on ED presentation. Patients underwent CCTA before hospital admission. Afterward, patients received standard clinical care (SCC). ER physicians involved in the patient’s care were blinded to the results of CCTA. An expert panel established the presence or absence of ACS based on AHA guidelines. The CCTA images were evaluated for the presence of significant coronary artery stenosis (diameter reduction >50%) and were used to make a triage decision.

Results

Four patients (7.4%) with chest pain had at least one significant coronary stenosis on CCTA (sensitivity 100%, specificity 96%, accuracy 96.3%, positive predictive value (PPV) 66.7% and negative predictive value (NPV) 100%). Significant coronary stenosis was excluded in 48 of the 54 patients by CCTA (88.9%), potentially saving about 71.6% of unnecessary hospital admission hours.

Conclusion

CCTA based detection of significant coronary stenosis has potential role to decrease the length of hospital stay , without reducing appropriate patient care, in low risk patients with acute chest pain. CCTA should be done with lowest radiation possible using recent techniques.     

Value of contrast-enhanced sonographic micro flow imaging for prostate cancer detection with t-PSA level of 4-10ng/mL

Objectives

To compare the efficiency of contrast-enhanced ultrasonographic micro flow imaging (MFI) with conventional transrectal ultrasound (TRUS) in detecting prostate cancer with serum total prostate-specific antigen (t-PSA) of 4.0–10.0 ng/mL. To evaluate the value of contrast-enhanced ultrasonographic MFI in detecting prostate cancer with t-PSA in diagnostic gray zone.

Methods

47 patients with t-PSA 4.0–10.0 ng/mL underwent gray scale, power Doppler TRUS and MFI examinations before ultrasound guided biopsies. Biopsies were performed at twelve sites in the base, the mid-gland and the apex of the prostate in each patient, when there was no abnormal ultrasound finding. When an abnormality was present at MFI, the biopsy specimen from the corresponding site was directed toward the abnormal finding. With histological results of prostate biopsy as reference standards, we assessed the cancer detection of these three methods.

Results

564 specimens were collected in this study, in which 101 were prostate cancer confirmed histologically. 152 of 564 specimens were demonstrated abnormal on MFI images, in which 71 were malignant and 81 were benign confirmed histologically. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) for MFI in detecting prostate caner were 70.3%, 82.5%, 80.3%, 46.7% and 92.7%, respectively. The sensitivity and NPV for MFI were significantly better than gray scale (38.6%, 86.9%) and power Doppler (32.7%, 86.0%) (P < 0.001) TRUS.

Conclusions

Contrast-enhanced ultrasonographic MFI could significantly improve the detection rate of prostate cancer with t-PSA in diagnostic gray zone (4–10 ng/mL) than conventional ultrasound.     

Factors influencing technical success and outcome of percutaneous balloon angioplasty in de novo native hemodialysis arteriovenous fistulas

Objective

To determine predictors of technical success, dysfunction recurrence and patency after percutaneous transluminal angioplasty (PTA) of de novo dysfunctional hemodialysis arteriovenous fistulas (AVFs).

Methods

Retrospective analysis of first time PTA of 167 AVF in 162 patients (100 men, 66 ± 13 years). Anatomical (location, length, grade and number of stenoses) and clinical variables (sex, age, prior AVF, diabetes mellitus and AVF age, side and location) were reviewed.

Results

217 stenoses or segmental occlusions were treated. Technical success rate (84.4%) was higher in radiocephalic AVF compared to brachial artery–median vein AVF (p = 0.030) and was negatively correlated with initial stenosis (p = 0.049). Dysfunction recurrence was seen in 52.7% and correlated negatively with technical success (p = 0.013) and AVF age (p = 0.008). Early dysfunction (within 6 months) was negatively correlated with AVF age (p = 0.016) and positively with diabetes (p = 0.003). Higher AVF age resulted in higher primary (p = 0.005) and secondary patency rates (p = 0.037–0.005).

Conclusions

Technical success of PTA in hemodialysis AVF is affected by AVF type and initial stenosis and has significant effect on dysfunction recurrence, but not on AVF longevity. Younger AVF has increased risk for (early) recurrent dysfunction and lower patency rates. Patients with diabetes mellitus have higher risk for early dysfunction.