Virtual reality in preoperative imaging in maxillofacial surgery: implementation of "the next level"?

Not only are current imaging techniques - cone-beam computed tomography (CT), CT, and magnetic resonance imaging (MRI) - becoming more precise in capturing data, but the illustration and interpretation of the acquired images is no longer limited to conventional display screens or projectors. The so-called "virtual reality" (VR) glasses have the potential to engage the viewer in a 3-dimensional space, and ultimately to enable evaluation of the reconstructed anatomical structures from a new perspective. For the first time in the field of oral and maxillofacial surgery (OMFS), a 3-dimensional imaging dataset (cone-beam CT, CT, and MRI) can be evaluated by using VR glasses. A medical student, an OMFS resident, and an OMFS consultant rated the preoperative usability of VR glasses to improve the operative understanding of three cases: a deeply impacted wisdom tooth, a fracture of the lower jaw, and an oncological resection. VR glasses seem to help to simplify operations and give the surgeon a good preoperative overview of the intraoperative findings, particularly in the evaluation of impacted teeth and hard tissue structures. In addition, VR glasses seem to be a promising innovation to help in the training of surgical residents and to teach students. However, the more experienced the surgeon, the smaller is the additional value of VR glasses. Preoperative examination using VR glasses can aid better understanding and planning of the surgical site in the future, and is an innovative piece of advanced technology for displaying CT, cone-beam CT, and MRI anatomical data.

Coronary and carotid atherosclerosis in asymptomatic male marathon runners.

The aim of the study was to evaluate the diagnostic accuracy of carotid ultrasound (CU) to predict coronary atherosclerosis in asymptomatic male marathon runners. A total of 49 male marathon runners older than 45 years (mean age 53.3 ± 7.2 years, range 45-74 years) received CU and cardiac CT angiography (CTA) including calcium scoring (CS). Results of CU and CTA were classified binary: 1. Absence of atherosclerosis and 2. Presence of atherosclerosis. The extent of atherosclerosis was not primary end point of the study. Mean PROCAM score was 2.3% (SD 2.2, range 0.44%-12.34%). One person had to be excluded from analysis (one missing CT-scan). From the remaining 48 marathon runners, 17 (35.4%) had carotid atherosclerosis and 22 (45.8%) coronary atherosclerosis. Atherosclerosis in either exam was diagnosed in 27/48 (56.3%) marathon runners. Diagnostic accuracy of CU to predict coronary atherosclerosis was: sensitivity 54.55% (95% CI 32.2-75.6), specificity 80.8% (CI 60.6-93.4), positive predictive value 70.6 (CI 44.1-89.9), negative predictive value 67.7 (CI 48.6-83.3) with a positive likelihood ratio of 2.84 (CI 1.18-6.82) and a negative likelihood ratio of 0.56 (CI 0.34-0.92). Coronary and/or carotid atherosclerosis can be detected in more than 50% of male marathon runners aged older than 45 years. The diagnostic value of carotid ultrasound to predict coronary atherosclerosis is low but higher than the accuracy of rest- or stress-ECG. As outcome studies in sportsmen are still missing, the routine evaluation of the carotid arteries by ultrasound or even cardiac CT cannot be recommended at present. Furthermore, the incidence of atherosclerosis by our method in normal population is not known.

Bronchial Artery Embolization in Hemoptysis: 10-Year Survival and Recurrence-Free Survival in Benign and Malignant Etiologies - A Retrospective Study.

Purpose: The aim of the study was to evaluate safety, effectiveness, recurrence rate and 10-year survival after bronchial artery embolization (BAE) in benign and malignant etiologies. Methods: The retrospective study includes 100 BAE procedures in 88 patients. Underlying disease was classified as benign (n = 67) and malignant (n = 21) etiologies. Immediate bleeding control and procedure safety were evaluated in all patients. In 51 (58 %) patients, follow-up data with a median follow-up time of 1015 days (range, 494 to 3727 days) were acquired to assess overall survival, time-to-recurrence of bleeding and recurrence-free survival, using Kaplan-Maier estimates to compare differences between both subgroups. Results: Immediate bleeding control was achieved after 96/100 procedures (96 %), with a minor complication rate of 5.0 %. No major complications occurred. The overall survival was 74 % after 1 year and 59 % after 5 years and 10 years. There was a significant difference in survival between the malignant and benign groups (p < 0.0001). Survival was 90 %, 80 % and 76 % at 1 year, 3 years and 10 years, respectively, in the benign group and 18 % and 0 % at 1 year and 3 years, respectively in the malignant group. The median time to recurrence of bleeding and recurrence-free survival were 239 days and 94 % after 1 year and 87 % after 10 years in the benign group, compared to 66 days and 34 % after 1 year and 0 % after 3 years in the malignant group (p = 0.0107). Conclusion: BAE is a safe and highly effective treatment option in hemoptysis. However, the recurrence rate and survival are highly dependent on the underlying disease. Key Points: • BAE is a safe and highly effective treatment option in hemoptysis.• Recurrence rate and survival are strongly dependent on the underlying disease with significantly impaired results in patients with malignant diseases. • Coil embolization is an effective BAE treatment method. Nevertheless, it should be mentioned, that reinterventions can be impeded, if embolization is performed in the proximal part of bronchial arteries. Citation Format: • Syha R, Benz T, Hetzel J et al. Bronchial Artery Embolization in Hemoptysis: 10-Year Survival and Recurrence-Free Survival in Benign and Malignant Etiologies - A Retrospective Study. Fortschr Röntgenstr 2016; 188: 1061 - 1066.

Assessment of the parenchymal blood volume by C-arm computed tomography for radioembolization dosimetry.

PURPOSE: Aim of the study was to evaluate the impact of parenchymal blood volume (PBV) C-arm CT in transarterial radioembolization (TARE) planning procedure regarding the appropriateness of segmental blood supply from selective catheter positions defined by angiographic images compared to PBV mapsto determine the influence of changed target volumes on dose calculation. MATERIAL AND METHODS: A total of 22 consecutive patients (median age, 62 years) underwent a TARE planning procedure were included in this retrospective study. Selective angiograms and selective PBV C-arm CT (right and left liver lobe) were evaluated in a blinded fashion, regarding segmental hepatic artery variants. Volumetry of target volume and dosimetry of glass and resin microspheres were performed. RESULTS: Classification of segment IV and segment I to the corresponding target vascular bed supply was correct in 91.0% (20/22) and 86.4% (19/22) for angiography and C-arm CT, respectively. Except one case, all other liver segments were classified properly to the left and right hepatic arterial supply. Based on the mismatch of the angiographic and the C-arm CT approach, changes of target volume were evident in 27.3% of patients, resulting in a mean mismatch volume of 90±54ml (range, 51-198ml) and a percentage of dose differences of 14.2±11.8% and 12.6±10.6% for the right and 12.5±8.5% and 11.1±7.8% for the left liver lobe in glass and resin microspheres, respectively. CONCLUSION: The C-arm CT approach is superior to the angiographic determination of vascular supply of specific liver segments for dosimetry before radioembolization. Especially for unexperienced interventional radiologists or for a complex anatomy, C-arm CT improves individualized dosimetry concepts.

Volume perfusion computed tomography (VPCT)-based evaluation of response to TACE using two different sized drug eluting beads in patients with nonresectable hepatocellular carcinoma: Impact on tumor and liver parenchymal vascularisation.

OBJECTIVE: Response monitoring of transarterial chemoembolization (TACE) with the help of volume perfusion computed tomography (VPCT) at day one post-TACE and analysis of TACE-impact on tumor and uninvolved liver parenchymal perfusion by using different particles sizes and epirubicin dose. MATERIALS AND METHODS: Institutional review board approved this prospective study. VPCT was performed in the baseline, post-interventional (FU1; 24 h post-TACE) and at follow-up (FU2; median, 81 days) in 45 consecutive patients. 100-300 µm (n=17) and 300-500 µm (n=28) drug eluting beads (DEB) using an epirubicin dose of (<=25 vs. >25) were administered. VPCT was performed for 40-s using 80 kV, 100/120 mAs, 64×0.6 mm collimation, 26 consecutive measurements, IV injection (50 ml iodinated contrast), flow rate (5 ml/s). Blood flow (BF), blood volume (BV) and k-trans were registered as average and max values in the tumor. Arterial liver perfusion (ALP), portal-venous perfusion (PVP) and the hepatic perfusion index (HPI) were registered both in tumor and non-involved liver parenchyma. Response to TACE was classified by VPCT as complete (CR), partial (PR) or no response (NR). RESULTS: A significant reduction of viable tumor tissue was found in all patients between baseline and FU1 (p<0.001) being independent on particle size and epirubicin dose (p>0.05). PPV/NPV/sensitivity/specificity of post-interventional VPCT (FU1) results for prediction of the mid-term tumor course (FU2) were 100%/70%/76%/100%. There was generally a significant increase of the ALP between baseline and FU1 in the liver parenchyma coupled by a significant subsequent decrease (normalization) of ALP and HPI between FU1 and FU2. CONCLUSION: VPCT accurately measures impact of TACE on liver tumor and hepatic parenchymal perfusion. The former proved not to be significantly dependent on particle size and epirubicin dose. There was no persistent perfusion deficit in the liver after TACE.

Prevalence of Subclinical Coronary Artery Disease in Middle-Aged, Male Marathon Runners Detected by Cardiac CT.

PURPOSE: To evaluate the prevalence of coronary artery disease (CAD) in middle-aged, male marathon runners using coronary dual source CT angiography (DSCTA). MATERIALS AND METHODS: 50 male marathon runners older than 45 years (mean age: 52.7, standard deviation: 5.9 years, range: 45 to 67 years) received DSCTA including calcium scoring (CS) in addition to standard pre-participation screening. Based on standard risk factors, the risk for coronary events was calculated using the PROCAM score. Coronary status was defined using the following system: 1. absence of CAD (CS zero, no coronary plaques) 2. mild coronary atherosclerosis (CS > 0, coronary plaques with luminal narrowing < 50 %), 3. moderate coronary atherosclerosis (CS > 0, luminal narrowing > 50 %), 4. significant CAD (CS > 0, luminal narrowing > 75 %). RESULTS: The mean PROCAM score was 1.85 % (standard deviation = 1.56, range 0.39 to 8.47 %). 26/50 marathon runners had no atherosclerosis. 1 of the remaining 24 participants had significant CAD, 3 had moderate coronary atherosclerosis and 20 had mild coronary atherosclerosis. Treadmill exercise testing was unremarkable in terms of myocardial ischemia in all participants. Age, systolic blood pressure, personal minimum time, family history of cardiovascular disease and PROCAM score were factors associated with an increased risk for coronary atherosclerosis. CONCLUSION: Coronary atherosclerosis can be detected in almost 50 % of male marathon runners aged older than 45 years. In 24 % of the participants plaques were located in the proximal coronary system. However, only a minority of these persons have obstructive CAD. As expected, treadmill exercise testing failed to detect these persons that possibly have a higher risk for coronary events. KEY POINTS: • Coronary atherosclerosis can be detected in ~50 % of male marathon runners > 45 years. • Only a minority of these persons have obstructive CAD. • Treadmill exercise testing failed to detect these persons. • Cardiac CT might help to identify athletes with elevated risk for coronary events, especially in persons with a family history of coronary artery.

[Diagnostic accuracy of dual energy CT angiography in patients with diabetes mellitus]. / Diagnostische Genauigkeit der Dual-energy-CT-Angiographie bei Patienten mit Diabetes mellitus.

OBJECTIVES: Peripheral arterial disease (PAD) represents a major and highly prevalent complication in patients with diabetes mellitus. The diagnostic, non-invasive work-up by computed tomography angiography (CTA) is limited in the presence of extensive calcification. The aim of the study was to determine the diagnostic accuracy of dual energy CTA (DE-CTA) for the detection and characterization of PAD in patients with diabetes mellitus. MATERIAL AND METHODS: In this study 30 diabetic patients with suspected or known PAD were retrospectively included in the analysis. All subjects underwent DE-CTA (Somatom Definition Flash, Siemens Healthcare, Erlangen, Germany) prior to invasive angiography, which served as the reference standard. Blinded analysis included assessment of the presence and degree of peripheral stenosis on curved multiplanar reformatting (MPR) and maximum intensity projections (MIP). Conventional measures of diagnostic accuracy were derived. RESULTS: Among the 30 subjects included in the analysis (83% male, mean age 70.0 ± 10.5 years, 83% diabetes type 2), the prevalence of critical stenosis in 331 evaluated vessel segments was high (30%). Dual energy CT identified critical stenoses with a high sensitivity and good specificity using curved MPR (100% and 93.1%, respectively) and MIP images (99% and 91.8%, respectively). In stratified analysis, the diagnostic accuracy was higher for stenosis pertaining to the pelvic and thigh vessels as compared with the lower extremities (curved MPR accuracy 97.1% vs. 99.2 vs. 90.9%; respectively, p < 0.001). CONCLUSION: The use of DE-CTA allows reliable detection and characterization of peripheral arterial stenosis in patients with diabetes mellitus with higher accuracy in vessels in the pelvic and thigh regions compared with the vessels in the lower legs.

Computer-based quantification of the Achilles tendon thickness in sequential B-mode ultrasound images: a study of feasibility and reliability.

INTRODUCTION: Assessment of the Achilles tendon thickness (ATT) using B-mode ultrasound is a common technique for clinical evaluation of chronic mid-part tendinosis. Currently used image-based assessment is limited by relatively high inter- and intra-observer variability. In this study, it was tested whether a new sequence-based automated assessment of ATT provides more reliable and reproducible results than the standard image-based procedure. MATERIALS AND METHODS: A total of 118 non-operated tendons of 59 healthy subjects (44, range 28-50 years) were analysed using an automated image based as well as a newly developed automated sequence-based method. Correlation and agreement of both methods were evaluated. The root mean square deviation (RMSD) and a Bland-Altman analysis were performed to highlight observer (n = 18 tendons) as well as reader (n = 40 tendons) dependent variabilities of both methods. RESULTS: A strong correlation was found between image and sequence-based ATT assessment (p = 0.92). The Bland-Altman analysis showed a good agreement between both methods (mean difference 0.0018, 95 % CI: -0.046; 0.05). In repetitive examinations, sequence-based analysis showed a significant reduction concerning reader- and observer-dependent variability compared to image-based assessment. The RMSD for repetitive sequence-based measurements was approximately 0.3 mm (compared to 0.6 mm for image-based measurement), respectively. CONCLUSIONS: The study shows sequence-based automated assessment of ATT being clearly superior to the standard image-based procedure. The new method provides a clear reduction of reader as well as observer-dependent variability. Due to the decreased scattering of measurement data sequence-based measurement seems especially valuable for quantification of small tendon thickness changes such as exercise-induced hypertrophy.

Endovascular aneurysm repair of abdominal aortic aneurysms: standards, technical options and advanced indications.

UNLABELLED: Since the introduction of endovascular aneurysm repair (EVAR) in 1991, the endovascular therapy with newest stent grafts has assumed a prominent role in the clinical management of abdominal aortic aneurysms (AAA) with a superior perioperative mortality of EVAR and an equivalent mid-term outcome, compared to open surgery. Newest techniques using chimney or periscope grafts and customized fenestrated and branched stent grafts allow the endovascular treatment of complex pararenal AAA. This article reviews EVAR in the treatment of AAA, evidence based results and advanced indication by newest interventional techniques and technical developments. KEY POINTS: • EVAR has become standard treatment of abdominal aortic aneurysm with equivalent results to open surgery.• Technical advancements and the introduction of newest stent grafts continually expand the indication of EVAR.• Chimney- and periscope grafts as well as custom-made prothesis systems allow endovascular treatment of complex para- and suprarenal aneurysms.

High-pitch computed tomography of the lung in pediatric patients: an intraindividual comparison of image quality and radiation dose to conventional 64-MDCT.

PURPOSE: The aim of this study was to investigate frequencies of typical artifacts in low-dose pediatric lung examinations using high-pitch computed tomography (HPCT) compared to MDCT, and to estimate the effective radiation dose (Eeff). MATERIALS AND METHODS: Institutional review board approval for this retrospective study was obtained. 35 patients (17 boys, 18 girls; mean age 112 ±â€Š69 months) were included and underwent MDCT and follow-up scan by HPCT or vice versa (mean follow-up time 87 days), using the same tube voltage and current. The total artifact score (0 - 8) was defined as the sum of artifacts arising from movement, breathing or pulsation of the heart or pulmonary vessels (0 - no; 1 - moderate; 2 - severe artifacts). Eeff was estimated according to the European Guidelines on Quality Criteria for Multislice Computed Tomography. The Mann-Whitney U test was used to analyze differences between the patient groups. The Spearman's rank correlation coefficient was used for correlation of ordinal variables. RESULTS: The scan time was significantly lower for HPCT compared to MDCT (0.72 ±â€Š0.13 s vs. 3.65 ±â€Š0.81s; p < 0.0001). In 28 of 35 (80 %) HPCT examinations no artifacts were visible, whereas in MDCT artifacts occurred in all examinations. The frequency of pulsation artifacts and breathing artifacts was higher in MDCT compared to HPCT (100 % vs. 17 % and 31 % vs. 6 %). The total artifact score significantly correlated with the patient's age in MDCT (r = - 0.42; p = 0.01), but not in HPCT (r = - 0.32; p = 0.07). The estimated Eeff was significantly lower in HPCT than in MDCT (1.29 ±â€Š0.31 vs. 1.47 ±â€Š0.37 mSv; p < 0.0001). CONCLUSION: Our study indicates that the use of HPCT has advantages for pediatric lung imaging with a reduction of breathing and pulsation artifacts. Moreover, the estimated Eeff was lower. In addition, examinations can be performed without sedation or breath-hold without losing image quality. KEY POINTS: • Fewer artifacts in pediatric lung imaging with HPCT• Reduced Eeff in HPCT• HPCT without sedation or breath-hold without loss of image quality.

Assessment of the nature of residual masses at end of treatment in lymphoma patients using volume perfusion computed tomography.

OBJECTIVES: To determine the diagnostic benefit of volume perfusion computed tomography (VPCT) at end of treatment for response assessment in lymphoma patients. METHODS: Seventy-five patients with different lymphoma subtypes were included: 50/75 patients had residual masses at end of treatment, 26/50 patients underwent VPCT at baseline and at end of treatment, and 24/50 patients only had end-of-treatment VPCTs. We evaluated the size of the main lymphoma mass, its blood flow (BF), blood volume (BV) and k-trans, calculated ratios (baseline and end of treatment) as well as sensitivity/specificity/negative (NPV)/positive predictive values (PPV). For VPCT at end of treatment, a cutoff threshold between responders and non-responders was calculated. RESULTS: For patients undergoing VPCT at baseline and end of treatment, reduction in size, BF, BV and k-trans was significant (P < 0.001). Identification of non-response was reached at: <53% reduction in size (sensitivity/specificity/accuracy/PPV/NPV of 88.89%/62.5%/80.77%/84.21%/71.43%), <15% reduction of BF (sensitivity/specificity/accuracy/PPV/NPV of 100%/37.5%/80.77%/0.26%/100%), or <45% reduction of k-trans (sensitivity/specificity/accuracy/PPV/NPV of 88.89%/75%/84.62%/88.89%/75%). In the subgroup undergoing VPCT at end of treatment, BF >18.51 ml/100 ml indicated non-responsiveness (sensitivity 92.86%, specificity 72.73%, accuracy 84%, PPV 81.25%, NPV 88.89%). CONCLUSIONS: VPCT seems adequate for assessment of lymphoma response at end of treatment. The degree of residual lymphoma perfusion at end of treatment helps to identify patients likely to remain in remission 1 year after completion of therapy. KEY POINTS: • Volume perfusion computed tomography (VPCT) offers measurements for assessing tumour response. • Perfusion parameter changes measured by VPCT correlate with antitumour therapy response. • In lymphoma, baseline and end-of-treatment perfusion parameter ratios can predict response. • Perfusion measurements after treatment identify patients likely to remain in remission.

Seminal vesicle invasion: accuracy and analysis of infiltration patterns with high-spatial resolution T2-weighted sequences on endorectal magnetic resonance imaging.

OBJECTIVE: To evaluate the accuracy of high-spatial resolution T2-weighted endorectal magnetic resonance imaging (eMRI) for detection and pattern depiction of seminal vesicle invasion (SVI) in patients with prostate cancer (PCa). METHODS: 376 patients were included who underwent eMRI for staging before radical open prostatectomy at 1.5 T with an endorectal coil. Statistical accuracy for detection of SVI was calculated. MR images of patients with SVI were further evaluated by two radiologists according to the classification by Wheeler and Ohori. RESULTS: In the cohort, 35 patients had SVI after histopathological evaluation of the prostatectomy specimen (stage pT3b). Sensitivity and specificity for detection of SVI were 48.6 and 97.7%, respectively. Negative and positive predictive values and overall accuracy were 94.9, 68.0, and 93.1%, respectively. Infiltration pattern analysis showed that type I invasion was most common with 48.6 followed by type IIa (31.4%) and IIb (20%). Type III was not present. There was no statistical significant difference between the three groups regarding Gleason score, age, and prostate-specific antigen level. CONCLUSIONS: eMRI with high-spatial resolution T2-weighted imaging is accurate for assessment of SVI. Depiction of different infiltration types of SVI is feasible. By adding information about the extent of SVI, diagnostic reporting and risk stratification could be improved.

Achillodynia - radiological imaging of acute and chronic overuse injuries of the achilles tendon.

In the past decades the incidence of acute and chronic disorders of the Achilles tendon associated with sport-induced overuse has steadily increased. Besides acute complete or partial ruptures, achillodynia (Achilles tendon pain syndrome), which is often associated with tendon degeneration, represents the most challenging entity regarding clinical diagnostics and therapy. Therefore, the use of imaging techniques to differentiate tendon disorders and even characterize structure alterations is of growing interest. This review article discusses the potential of different imaging techniques with respect to the diagnosis of acute and chronic tendon disorders. In this context, the most commonly used imaging techniques are magnetic resonance imaging (MRI), B-mode ultrasound, and color-coded Doppler ultrasound (US). These modalities allow the detection of acute tendon ruptures and advanced chronic tendon disorders. However, the main disadvantages are still the low capabilities in the detection of early-stage degeneration and difficulties in the assessment of treatment responses during follow-up examinations. Furthermore, differentiation between chronic partial ruptures and degeneration remains challenging. The automatic contour detection and texture analysis may allow a more objective and quantitative interpretation, which might be helpful in the monitoring of tendon diseases during follow-up examinations. Other techniques to quantify tendon-specific MR properties, e. g. based on ultrashort echo time (UTE) sequences, also seem to have great potential with respect to the precise detection of degenerative tendon disorders and their differentiation at a very early stage.

In vitro stent lumen visualisation of various common and newly developed femoral artery stents using MR angiography at 1.5 and 3 tesla.

OBJECTIVES: To evaluate stent lumen assessment of various commonly used and newly developed stents for the superficial femoral artery (SFA) using MR angiography (MRA) at 1.5 and 3 T. METHODS: Eleven nitinol stents and one cobalt-chromium stent were compared regarding stent lumen visualisation using a common three-dimensional MRA sequence. Maximum visible stent lumen width and contrast ratio were analysed in three representative slices for each stent type. A scoring system for lumen visualisation was applied. RESULTS: Nitinol stents showed significantly better performance than the cobalt chromium stent (P < 0.05) at 1.5 and 3 T. Maximum visible stent lumen ranged between 43.4 and 95.5 %, contrast ratio between 7.2 and 110.6 %. Regarding both field strengths, seven of the nitinol stents were classified as "suitable". Three nitinol stents were "limited", and one nitinol stent and the cobalt chromium stent were "not suitable". CONCLUSIONS: Intraluminal loss of signal and artefacts of most of the SFA stents do not markedly limit assessment of stent lumen by MRA at 1.5 and 3 T. MRA can thus be considered a valid technique for detection of relevant in-stent restenosis. Applied field strength does not strongly influence stent lumen assessment in general, but proper choice of field strength might be helpful.

High-pitch dual-source CT angiography of supra-aortic arteries: assessment of image quality and radiation dose.

INTRODUCTION: High-pitch CT angiography (CTA) is a recent innovation that allows significant shortening of scan time with volume coverage of 43 mm per second. The aim of our study was to assess this technique in CTA of the head and neck. METHODS: CTA of supra-aortic arteries was performed in 50 patients using two acquisition protocols: conventional single-source 64-slice (pitch 1.2) and high-pitch dual-source 128-slice CT (pitch 3.2). Subjective and objective image quality of supra-aortic vessel ostia as well as intra- and extra-cranial segments was retrospectively assessed by blinded readers and radiation dose compared between the two protocols. RESULTS: Conventional and high-pitch CTA achieved comparable signal-to-noise ratios in arterial (54.3 ± 16.5 versus 57.3 ± 14.8; p = 0.50) and venous segments (15.8 ± 6.7 versus 18.9 ± 8.9; p = 0.21). High-pitch scanning was, however, associated with sharper delineation of vessel contours and image quality significantly improved at the level of supra-aortic vessel ostia (p < 0.0001) as well as along the brachiocephalic trunk (p < 0.0001), the subclavian arteries (p < 0.0001), proximal common carotid arteries (p = 0.01), and vertebral V1 segments (p < 0.0001). Using the high-pitch mode, the dose-length product was reduced by about 35% (218.2 ± 30 versus 141.8 ± 20 mGy × cm). CONCLUSIONS: Due to elimination of transmitted cardiac motion, high-pitch CTA of the neck improves image quality in the proximity of the aortic arch while significantly lowering radiation dose. The technique thus qualifies as a promising alternative to conventional spiral CTA and may be particularly useful for identification of ostial stenosis.

A technical approach for transfemoral managing of hostile angulated pelvic vessel access in abdominal endovascular aneurysm repair: a new technique for establishing a buddy wire.

PURPOSE: Endovascular aneurysm repair (EVAR) can be challenging in angulated access vessels. The aim of this study was to evaluate a new wire technique for installing a buddy wire in the event of failure of simple advancing of a super stiff guide. MATERIALS AND METHOD: We investigated 8 patients eligible for EVAR. All patients presented with heavily kinked pelvic access and failure of primary advancing of a stiff guide wire through a placed catheter. A double wire technique with a combination of soft and stiff wires was applied to place a super stiff buddy wire. Cumulative angulation quantified by the sum of angles of the tortuous pelvic access vessels was measured in pre- and post-interventional CT as well as in angiographic studies of the EVAR procedure. Patients were followed up on by CT in the first 6 months. RESULTS: A buddy wire could be installed in all patients (100%) with significant straightening of the access vessel from a median cumulative angulation of 252.4±38.1° before intervention to 159.4±44.6° after placement of the buddy wire (p<0.001). There was no technical failure of device passage and all stent-grafts could be deployed safely. Three cases of stenosis caused by torsion distal to the aortic stent-graft were seen after stent-graft delivery. One case of stenosis was hemodynamically relevant and was successfully stented. No major adverse events occurred within the first 6 months of follow-up.  CONCLUSION: The new step-by-step wire technique is feasible and safe in the case of hostile pelvic vessel access, and facilitates the advancement of aortic stent-grafts in off-label patients.