Automated software supported versus manual aorto-iliac diameter measurements in CT angiography of patients with abdominal aortic aneurysms: assessment of inter- and intraobserver variation.

BACKGROUND: Open surgical or endovascular abdominal aortic aneurysm (AAA) relies on precise preprocedual imaging. Purpose of this study was to assess inter- and intraobserver variation of software-supported automated and manual multi row detector CT angiography (MDCTA) in aortoiliac diameter measurements before AAA repair. PATIENTS AND METHODS: Thirty original MDCTA data sets (4 x 2mm collimation) of patients scheduled for endovascular AAA repair were studied on a dedicated software capable of creating two-dimensional reformatted planes orthogonal to the aortoiliac center-line. Measurements were performed twice with afour-week interval between readings. Data were analysed by two blinded readers at random order Two different measurement methods were performed: reader-assisted freehand wall-to-wall measurement and semi-automatic measurement. RESULTS: Aortoiliac diameters were significantly underestimated by the semi-automatic method as compared to reader-assisted measurements (p < 0.0031). Intraobserver variability of AAA diameter calculation was not significant (p > 0. 15) for reader-assisted measurements except for the diameter of the left common iliac artery in reader 2 (p = 0.0045) and it was not significant (p > 0. 14) using the semi-automatic method. Interobserver variability was not significant for AAA diameter measurements using the reader-assisted method and for proximal neck analysis with the semiautomatic method (p > 0.27). Relevant interobserver variation was observed for semi-automatic measurement of maximum AAA (p = 0.0007) and iliac artery diameters (p = 0.024). CONCLUSIONS: Dedicated MDCTA software provides a useful tool to minimize aortoiliac diameter measurement variation and to improve imaging precision before AAA repair. For reliable AAA diameter analysis the reader-assisted freehand measurement method is recommended to be applied to a set of reformatted CT data as provided by the software used in this study.

[Individualized dose requirement for spiral-CT analysis of the abdomen]. / Individueller Dosisbedarf bei Spiral-CT-Untersuchungen des Abdomens.

PURPOSE: To search for individualized scan protocols that provide adequate diagnostic information with minimal radiation exposure for abdominal CT in adults. MATERIAL AND METHODS: Beginning with standard settings (120 kVp, 200 mA, 0.75 s, CTDI (w = 11.7 mGy)), which are in the lowest quartile of the actual German radiation dose survey, 119 adults were examined using a single-row detector helical CT with 8 mm collimation and a pitch of 1.5. The individualized scan protocol was defined by repeating the reference scan up to 3 times with different radiation doses following a predefined iteration scheme. The image qualities with standard dose and with individualized dose were assessed independently by 3 radiologists blinded to the exposure parameters. The individualized dose was correlated with the diameter of the patients. RESULTS: The patient diameters varied from 16 to 35 cm and correlated with individualized radiation doses CTDI (w) from 6.4 to 17.6 mGy. We found an exponential correlation (y = 52.3 x e (0.05 x); r(2) = 0.48; p < 0.001) between required tube current (mA) and a. p. diameter (cm) in the epigastric region in adults. CONCLUSION: Maintaining constant exposure parameters results in unnecessary radiation exposure in patients with a diameter of less than 27 cm measured in anterior-posterior direction in the epigastric area. The radiation exposure in adult abdominal CT can be reduced up to 45 % by individualized selection of the tube current without adversely affecting diagnostic performance.

[Embolization therapy of an arteriovenous fistula after percutaneous lithotripsy in combination with angioplasty of an ipsilateral kidney arterial stenosis]. / Embolisationstherapie einer arteriovenösen Fistel nach perkutaner Nephrolitholapaxie in Kombination mit der Angioplastie einer ipsilateralen Nierenarterienstenose.

We describe successful selective coil embolization therapy in a patient with renal hemorrhage caused by iatrogenic pseudoaneurysm after percutaneous nephrostomy and lithotripsy. In the same session, an incidentally detected severe renal artery stenosis that had caused moderate hypertension was treated by balloon angioplasty. No complications occurred. Coaxial micro-catheter technique and platinum microcoils were used for embolization and allowed targeted occlusion of the bleeding renal artery and preserved the surrounding renal parenchyma. Bleeding was controlled immediately and hematuria disappeared after embolization therapy.

Endovascular treatment of a traumatic thoracic aortic aneurysm initially presenting as acute critical limb ischemia.

We describe the successful endovascular treatment of a traumatic thoracic aortic aneurysm in a 32-year old male presenting with acute critical limb ischemia. The patient's condition arose from embolism growth in an aneurysmal lesion incurred seven years previously in a motorcycle accident.

Delay of dialysis in end-stage renal failure: prospective study on percutaneous renal artery interventions.

BACKGROUND: Renal artery stenosis (RAS) is a cause of end-stage renal failure. We studied the effect of percutaneous renal artery intervention (PRI) in patients with advanced, progressive disease at risk for renal failure, hypothesizing a beneficial effect. METHODS: Thirty-nine primary and 14 secondary PRIs were performed on 28 patients with atherosclerotic RAS, serum creatinine >300 micromol/L, and progressive loss of renal function >/=1 year before PRI. Renal function and RA patency were prospectively followed for 12 months after primary and secondary PRI. The intervention's effect on the progressive loss of renal function was calculated by comparing reciprocal slopes of serum creatinine against time before and after PRI. RESULTS: Progression of renal failure slowed significantly following PRI. Mean (+/-SE) slopes of reciprocal serum creatinine values were: 6.69 +/- 0.97 L micromol(-1) day(-1) (x10(-6)) before and 6.76 +/- 3.03 L micromol(-1) day(-1) (x10(-6)) after PRI (P= 0.0007). Fifteen patients (53.5%) showed improvement or stabilization of progressive renal dysfunction. Out of 11 patients expected to become dialysis dependent within one year, 8 (72.7%) experienced an improvement in renal function sufficient to remain dialysis-free. Favorable outcome correlated with a lower creatinine level (P= 0.0137) and a more negative slope of progression (r= 0.49, P= 0.020) at entry. Mortality was 10.7%, and rate of local complications was 7.1%. Deterioration of renal function following PRI was suspected in 17.9% of patients. CONCLUSION: PRI may improve renal function and ultimately delay dialysis in patients with advanced renal failure. Possible advantages must be weighed against the risk of renal failure advancement and high procedure-related complication rate.

[Multi-row detector CT angiography of the abdominal aorta: bolus tracking versus fixed start delay]. / Mehrzeilen-CT-Angiographie der Aorta abdominalis: Bolustracking versus festes Startdelay.

PURPOSE: Prospective comparison between bolus tracking and fixed start delay in multi-row detector CT (MDCT) angiography of the abdominal aorta, to determine which method yields the highest mean contrast. MATERIALS AND METHODS: In a randomized trial, 71 patients underwent multi-row detector MDCT angiography of the abdominal aorta using either a fixed delay of 25 s (n = 36, group F) or an automatic bolus tracking with a 125-HU threshold in the descending aorta (n = 35, group B). All patients received 150 ml of Iopamidol with 300 mg/ml iodine content, power-injected at 4 ml/s. Attenuation values after contrast administration were assessed in aorta, iliac and femoral arteries. Continuous data were compared using two-tailed t-tests and categorical data using Fisher's test. RESULTS: The trigger threshold was reached in all cases. Group B and F did not differ significantly in terms of age (mean 71 +/- 10 years, p = 0.59), weight (mean 81 +/- 16 kg, p = 0.28) and size (mean 173 +/- 8 cm, p = 0.65). An abdominal aneurysm was found in 33 patients of each group. Effective triggered start delay varied between 20 and 44 s in group B (mean 30.3 +/- 5.2 s). Mean global arterial-phase vessel attenuation was 372 HU in group B and 349 HU in group F (no significant difference, p = 0.143). Values tended to be lower in the aorta than in the pelvic arteries (group B: 353 HU aorta, 387 HU iliac arteries; group F: 328 HU aorta, 361 HU iliac arteries). Thus, attenuation tended to be higher further downstream, suggesting the preferred use of a start delay longer than 25 s. CONCLUSION: Bolus tracking in MDCT angiography did not significantly improve the mean contrast in the aorta and pelvic vessel as compared to using a fixed delay. It appears to be useful to extend the start delay to approximately 30 - 35 s in MDCT angiography.

[Transjugular liver core biopsy: indications, results, and complications]. / Transjuguläre Leberstanzbiopsie: Indikationen, Ergebnisse, Komplikationen.

PURPOSE: To evaluate benefit, feasibility, and frequency of complications with transjugular liver biopsy using a semi-automatic Tru-cut system. MATERIALS AND METHODS: Eighty-five consecutive patients (57 males, 28 females) with various liver disorders (cirrhosis [30], hepatitis [12], acute hepatopathy [34], orthotopic liver transplantation [8], hepatocellular carcinoma [1]), coagulopathies (n=71) and/or ascites (n = 46) were referred to our department for a transjugular liver biopsy. Mean age was 48 +/- 16 years (range 17 to 75 years). Success and complications were retrospectively evaluated from the radiology reports, pathology reports, and patient files. Success was defined as procuring a tissue specimen that enabled a definite histological diagnosis. The complications included thrombosis at the puncture site, hematoma, cardiac arrhythmia, capsular perforation, hemorrhage, and cardiac damage. Mortality included all deaths within 30 days after the procedure. Procedure-related mortality included all deaths related to the procedure. RESULTS: The procedure was technically successful in 80 patients (94 %) and unsuccessful in 5 patients (6 %) due to a failed hepatic vein cannulation (1 patient with Budd Chiari syndrome and total liver vein occlusion, 4 patients with unsuitable anatomy). One biopsy pass was made in 22 patients, and two passes were made in 45 and three or more passes in 14 patients, all in a single session. The sample quality was judged by the pathologist as good in 71 of 80 patients (89 %) and poor in 8 patients (10 %). A diagnosis was not possible in 1 patient. Eight procedure-related complications occurred, which were classified according to the criteria of the Society of Interventional Radiology (SIR) as minor in 5 (3 type A, 2 type B) and major in 3 (1 pneumothorax, type C, 1 nonfatal bleeding, type D, and 1 fatal bleeding, type F). Procedure-related mortality was 1 %, overall mortality 15 % (mostly due to progressive liver failure). CONCLUSION: In patients with coagulopathies, transjugular liver biopsy is a viable alternative for hepatic tissue evaluation with a good sample quality. In a small number of patients severe complications may occur.

[Penile angiography and superselective embolization therapy in arterial priapism]. / Penisangiographie und superselektive Embolisationstherapie bei high-flow Priapismus.

PURPOSE: To report feasibility, benefit and complications of penile angiography and superselective penile embolization in arterial priapism. MATERIALS AND METHODS: Four consecutive patients (aged 28, 29, 40 and 49 years), who underwent penile angiography for arterial priapism (high-flow priapism) within a four-year period, were identified by a keyword search of our radiology information system. One patient had sustained a direct penile trauma (severe blow to the erected penis) and three patients suffered from recurrent spontaneous priapism. All patients had previously undergone corporeal aspiration and noradrenaline injection to achieve detumescence. Two patients had one or several unsuccessful spongiocavernous shunt procedures. RESULTS: In three of the four patients, superselective pudendal and penile angiography demonstrated pathologic arteriocavernous shunting. In two of the three patients, superselective embolization using a coaxial micro-catheter was attempted. In one of the two patients, the cavernous artery became spastic before embolization material was actually injected, inducing immediate and lasting detumescence. In the other patient, unilateral Gelfoam embolization led to immediate detumescence but the priapism recurred 12 hours after the procedure. A subsequent contralateral Gelfoam embolization was successful. Erectile function was preserved in all cases. No procedure-related complications occurred. CONCLUSION: Our experience supports the prevailing opinion found in the current literature that superselective coaxial embolization constitutes the treatment of choice in patients with high-flow priapism. Prognosis is good with high probability of preserving the erectile function.

[Comparison between biventricular cine MRI and MR flow quantification in ascending aorta and pulmonary outflow tract for the assessment of intracardial shunt volumes]. / Vergleich von biventrikulärer MR-Volumetrie und MR-Flussmessungen in Aorta ascendens und Truncus pulmonalis zur intrakardialen Shuntbestimmung.

PURPOSE: Comparison between biventricular volumetric measurements and flow measurements in ascending aorta (Ao) and pulmonary outflow tract (Pu) for quantification of intracardial shunts, and evaluation of the combination of biventricular cine MRI with flow measurements for the assessment of RV and LV heart failure and valvular regurgitation (VR). MATERIAL AND METHODS: In 24 patients, right (RV) and left (LV) ventricular volumetric and flow measurements were performed in the Ao and Pu to assess the ratio of RV stroke volume (SV) or, respectively, pulmonary SV to LV SV or, respectively, systemic aortic SV (Qp/Qs). 34 patients without echocardiographically proven shunt or VR served as control group for measurement accuracy. Left-to-right shunt ratios were calculated from RV and LV SV, Pu and Ao SV, Pu and LV SV, and RV and Ao SV. Left ventricular VR was calculated by the difference of LV SV and Ao SV, and right ventricular VR by the difference of RV SV and Pu SV. Global systolic function was evaluated by biventricular cine MRI. RESULTS: Intracardial shunts with Qp/Qs > 1.16 can be quantified by flow measurements in Ao and Pu. Using biventricular volumetric measurements in cases without VR, requires a Qp/Qs > 1.21. 17 of 18 intracardiac shunts were identified on MRI, and all 8 hemodynamically significant shunts were quantitatively confirmed. The diagnosis of complete shunt closure or absent shunt was correctly made in all 6 cases. RV EF reduction was found in 6 of 24 patients. LV EF reduction was also found in 6 of 24 patients. CONCLUSION: Flow measurements in Ao and Pu are more accurate than biventricular cine MRI for the assessment of Qp/Qs ratios. Flow measurements in Ao and Pu combined with biventricular cine MRI enables the quantification of hemodynamic significant shunts, higher grade VR and biventricular global systolic function with a single examination.

[Development of mycotic aneurysms of the superior mesenteric artery after septic embolism]. / Entwicklung eines mykotischen Aneurysmas der A. mesenterica superior nach septischer Embolie.

Mycotic aneurysms of the aorta and the visceral arteries are life-threatening diseases, due to potential rupture and organ or limb ischemia. They occur in endocarditis, immunodeficiency, bacteremia and fungemia, and have a poor prognosis. We report on a case of a 54-year-old male patient suffering from abdominal angina after mitral valve replacement for septic mycotic endocarditis. In presence of a mycotic-embolic occlusion of the left popliteal artery and multiple septic organ infarctions a mycotic aneurysm of the superior mesenteric artery was found in abdominal spiral-CT. Based on sequential spiral-CT examinations, this case demonstrates the development of a septic aneurysm of the superior mesenteric artery.

[Virtual endoscopy of the upper, central and peripheral airways with multirow detector CT]. / Virtuelle Endoskopie der oberen, zentralen und peripheren Atemwege mit Mehrzeilen-Spiral-CT.

Virtual endoscopy of the upper, central and peripheral airways (virtual laryngoscopy or virtual bronchoscopy) produces endoluminal images similar to those of fiberoptic endoscopy. In particular, virtual endoscopy is useful for the assessment of endoluminal tumor extent and tracheobronchial stenosis. Especially since the introduction of multirow detector CT, high-resolution virtual-endoscopic images of the airways can be reconstructed. Either surface rendering or volume rendering can be used for realistic depiction of the airways. Semitransparent color-coded volume rendering is advantageous, because adjacent structures can be displayed in addition to endoluminal views. A major advantage of virtual endoscopy over fiberoptic endoscopy is its non-invasiveness. With virtual endoscopy, even a high-grade stenosis is passable, enabling evaluation of the distal airways. Disadvantages are its inability to depict mucosal color and to perform therapeutic maneuvers. In comparison to other CT display modes, virtual endoscopy allows a more realistic assessment of tracheobronchial stenosis than axial CT slices and multiplanar reformats. Virtual endoscopy of the airways can be used complementary to fiberoptic endoscopy before tracheotomy, stent implantation or lung resection and for post-operative follow-up. In the future, virtual airway endoscopy will be increasingly applied for interactive virtual reality guidance of airway procedures such as bronchoscopy and surgery.

[Virtual laryngoscopy and multiplanar reformats with multirow detector CT for detection and grading of upper airway stenosis]. / Virtuelle Laryngoskopie und multiplanare Reformationen mit Mehrzeilen-Spiral-CT zur Detektion und Graduierung von Stenosen der oberen Luftwege.

PURPOSE: A controlled trial was performed to compare non-invasive multislice CT (virtual laryngoscopy, axial CT slices, coronal and sagittal reformats) in the detection and grading of upper airway stenosis with fiberoptic laryngoscopy. MATERIAL AND METHODS: Multislice CT and fiberoptic laryngoscopy were used to examine 111 upper airway sections (supraglottis, glottis, subglottis, trachea) in 29 patients. CT data were acquired on a multirow detector CT (collimation 4 x 1 mm, reconstruction interval 1 mm, IV contrast) and postprocessing was performed using multiplanar reformatted images (MPR) and virtual laryngoscopy. RESULTS: All CT methods accurately detected upper airway stenosis (accuracy was 96 % for virtual laryngoscopy and MPR and 94 % for axial CT-slices). Correlation of fiberoptic and virtual laryngoscopy (r = 0.94) for grading of stenosis was closer than with sagittal reformats (r = 0.80), coronal reformats (r = 0.72), and axial CT slices (r = 0.57). Even high grade stenosis could be passed with virtual laryngoscopy that was impassable for fiberoptic laryngoscopy. CONCLUSIONS: Virtual laryngoscopy enabled better assessment of stenosis as compared to reading of axial CT slices or MPR. Virtual laryngoscopy is complementary to fiberoptic laryngoscopy and should be combined with axial CT slices and MPR readings for evaluation of the surrounding structures.

Establishing radiological percutaneous gastrostomy with balloon-retained tubes as an alternative to endoscopic and surgical gastrostomy in patients with tumours of the head and neck or oesophagus.

The purpose of this study was to report our experience introducing radiological percutaneous gastrostomy (RPG) catheters at a hospital where hitherto only endoscopic and surgical methods have been used. The feasibility, success, time requirements, and complications of RPG were prospectively evaluated during a 12-month period. 26 consecutive patients (median age 63 years, range 41-91 years) underwent gastropexy with T-fasteners followed by insertion of a 12-18 F balloon tube through a peel-away introducer and were followed-up clinically and radiologically. Success and complications occurring within 30 days were assessed. RPG was technically successful in all cases. Median procedure time was 34 min (range 20-90 min), median fluoroscopy time 6.9 min (range 2.3-30 min). 13 surgical gastrostomies were avoided. One minor complication (peristomal leakage) occurred in a patient with gastric reflux and atony. Another patient destroyed the balloon of his tube by injecting food into the balloon port, which led to tube dislocation and peritonitis. In conclusion, radiological gastrostomy can be quickly learned by radiologists and is readily accepted by clinicians. It is an alternative to surgical gastrostomy when percutaneous endoscopic gastrostomy is not feasible, but can also be used as the primary method instead of the endoscopic method.

[Comparison between fast MR flow quantification in breathhold technique in ascending aorta and pulmonary trunc with right and left ventricular cine-MRI for the assessment of stroke volumes in healthy volunteers]. / Vergleich von schneller MR-Flussmessung in Atemanhaltetechnik in Aorta ascendens und Truncus pulmonalis mit rechts- und linksventrikulärer Cine MR-Bildgebung zur Schlagvoluminabestimmung bei Probanden.

PURPOSE: Evaluation of accordance and reproducibility of the stroke volume assessment of fast flow measurement in breathhold technique in the ascending aorta and pulmonary trunc with fast right (RV) and left ventricular (LV) cine-MRI. MATERIAL AND METHODS: The correlation an accordance of stroke volumes (SV) were evaluated by flow measurements in the ascending aorta and pulmonary trunc and RV and LV volumetric cine-MRI in 33 cardiac healthy volunteers. Interobserver and intraobserver variability of the different measurement methods and locations were checked in 10 cardiac healthy volunteers. RESULTS: With respect to the early systolic flow and the extrapolation of the endiastolic flow rate the difference in SV was smaller than 1,5 ml/m(2) for all possible combinations. The interobserver and intraobserver variabilities of flow measurements were significantly lower by approximately a factor of 2.5 than those of RV and LV cine-MRI. CONCLUSION: The accordance of fast prospective triggered flow measurements in the ascending aorta and pulmonary trunc with RV and LV cine-MRI can be achieved with reasonable limits of agreement. Flow measurements are more reproducible than cine-MRI.

[Low-osmolar gadodiamide as alternative contrast agent for diagnostic angiography and angiographic interventions in patients with renal insufficiency]. / Einsatz von niederosmolarem Gadolinium zur angiographischen Darstellung und bei interventionell-radiologischen Eingriffen bei niereninsuffizienten Patienten.

PURPOSE: To evaluate the benefit and feasibility of gadolinium contrast agents for intra-arterial use in diagnostic and therapeutic angiography in patients with renal insufficiency. METHODS: In 15 patients with planned peripheral or renal vascular interventions digital subtraction angiography with intra-arterial administration of gadolinium (gadodiamide n = 14, gadolinium-DTPA n = 1) was performed. Gadolinium was used selectively after peripheral catheter placement, mainly as an adjunct to CO2 (n = 12), to assess the distal run-off vessels or to characterize stenotic lesions. RESULTS: In 14 cases gadolinium yielded good or satisfactory results that were superior to those of CO2 angiography in the femoropopliteal region and calf, but also to the aorto-iliac vessels and the renal arteries. A small amount of iodinated contrast media was administered due to insufficient contrast of gadolinium in one patient. Mean serum creatinine level after angiography (295 +/- 167 micromol/l; range 125 - 764 micromol/l) was not significantly different (p >/= 0,37) from the initial level (279 +/- 149 micromol/l; range 143 - 728 micromol/l). CONCLUSION: Gadolinium is a viable alternative contrast agent for digital subtraction angiography and percutaneous transluminal angioplasty in patients with renal insufficiency. It enhances the diagnostic evaluation of stenosis and run-off vessels.

[Primary and long-term success of percutaneous biliary metallic endoprotheses (Wallstents) in malignant obstructive jaundice]. / Primärerfolg und Langzeitergebnisse biliärer Wallstent-Endoprothesen bei malignem Verschlussikterus.

OBJECTIVE: To assess the primary and long-term success of percutaneous metallic endoprotheses (wallstent) in malignant jaundice. METHODS: Retrospective, uncensored analysis of 86 consecutive patients (42 men, 44 women, age 34 to 90 years, mean 62 years), who were percutaneously treated with wallstents for malignant jaundice within a six-year time interval. Indications were pancreatic cancer in 9, gallbladder cancer in 15, Klatskin's tumor in 31, and metastatic disease in 31 cases. The indication for percutaneous stenting was inoperability and lack of endoscopic access. The level of the obstruction was within the liver hilus in 44, extrahepatic in 20, and within a biliodigestive anastomosis in 22 cases. Forty-five patients had undergone abdominal surgery previously. Mean survival was 8.0 months (range, 3 days to 57 months). RESULTS: In 85 of 86 cases (99 %) biliary stenting was feasible. In 82 cases (95 %) laboratory tests indicated regression of the biliary obstruction. Sixty-six patients (77 %) also experienced a clinical benefit from the procedure and in 65 (76 %) patients long-term palliation was achieved and lasted for at least three-quarters of the remaining time of survival. Technical problems with the procedure, usually stent foreshortening, were encountered in 12 cases (14 %). Thirty-days morbidity was 26 % (cholangitis in 15, pancreatitis in 3, liver failure in 2, effusion in 1, hemobilia in 1 case), thirty-day mortality was 15 %, procedure-related in one case. The reintervention rate was 20 %, the patency rate was 91 %, 73 %, and 58 % after 3, 6, and 12 months, respectively. CONCLUSION: Even after exhaustion of both surgical and endoscopic therapy options percutaneously deployed wallstents enable effective long-term palliation of malignant jaundice.