CT fluoroscopy-guided lung biopsy with novel steerable biopsy canula: ex-vivo evaluation in ventilated porcine lung explants.

The purpose was to evaluate ex-vivo a prototype of a novel biopsy canula under CT fluoroscopy-guidance in ventilated porcine lung explants in respiratory motion simulations. Using an established chest phantom for porcine lung explants, n = 24 artificial lesions consisting of a fat-wax-Lipiodol mixture (approx. 70HU) were placed adjacent to sensible structures such as aorta, pericardium, diaphragm, bronchus and pulmonary artery. A piston pump connected to a reservoir beneath a flexible silicone reconstruction of a diaphragm simulated respiratory motion by rhythmic inflation and deflation of 1.5 L water. As biopsy device an 18-gauge prototype biopsy canula with a lancet-like, helically bended cutting edge was used. The artificial lesions were punctured under CT fluoroscopy-guidance (SOMATOM Sensation 64, Siemens, Erlangen, Germany; 30mAs/120 kV/5 mm slice thickness) implementing a dedicated protocol for CT fluoroscopy-guided lung biopsy. The mean-diameter of the artificial lesions was 8.3 +/- 2.6 mm, and the mean-distance of the phantom wall to the lesions was 54.1 +/- 13.5 mm. The mean-displacement of the lesions by respiratory motion was 14.1 +/- 4.0 mm. The mean-duration of CT fluoroscopy was 9.6 +/- 5.1 s. On a 4-point scale (1 = central; 2 = peripheral; 3 = marginal; 4 = off target), the mean-targeted precision was 1.9 +/- 0.9. No misplacement of the biopsy canula affecting adjacent structures could be detected. The novel steerable biopsy canula proved to be efficient in the ex-vivo set-up. The chest phantom enabling respiratory motion and the steerable biopsy canula offer a feasible ex-vivo system for evaluating and training CT fluoroscopy-guided lung biopsy adapted to respiratory motion.

Leash your guiding catheter: or how to obtain a stable catheter position for crossover iliac embolization procedures.

We present a safe and quick technique for crossover embolization procedures of the internal iliac artery with high-profile guiding catheter systems, after a pull-through maneuver with establishment of a crossover catheter-snare system. The attached snare is used to stabilize and direct the guiding catheter.

Influence of additional breast ultrasound on cancer detection in a cohort study for quality assurance in breast diagnosis--analysis of 102,577 diagnostic procedures.

PURPOSE: To determine the value of a breast ultrasound (US) examination in addition to mammography in cases of American College of Radiology (ACR) tissue pattern III and IV in symptomatic women and women at risk. MATERIALS AND METHODS: A prospective cohort was initiated between 2001 and 2005 with a total of 59,514 patients and 102,744 mammograms. Documentation was available for 102,557 diagnostic procedures. Breast US was indicated in all women with ACR III and IV in addition to a suspicious clinical examination and in cases of masses and focal asymmetries in mammography. RESULTS: In total, 62,006 additional USs were performed, in which 116 mammographically and clinically occult breast cancers were diagnosed (detection rate: 1.9/1,000 examinations), while mammography alone (40,551 examinations) revealed 903 cancers (22.3/1,000). Of all 1,019 breast cancer findings, 12.8% were detected because of the combination of mammography and US. In the group with ACR III/IV, 15.9% of cancers were found by supplemental US compared with mammography alone. CONCLUSION: The addition of US to mammography vs. mammography alone resulted in a significant (P < 0.01) increase in breast cancer detection rate.

Renal artery stenosis evaluation: diagnostic performance of gadobenate dimeglumine-enhanced MR angiography--comparison with DSA.

PURPOSE: To prospectively determine diagnostic performance and safety of contrast material-enhanced (CE) magnetic resonance (MR) angiography with 0.1 mmol per kilogram of body weight gadobenate dimeglumine for depiction of significant steno-occlusive disease (> or =51% stenosis) of renal arteries, with digital subtraction angiography (DSA) as reference standard. MATERIALS AND METHODS: This multicenter study was approved by local institutional review boards; all patients provided written informed consent. Patient enrollment and examination at centers in the United States complied with HIPAA. Two hundred ninety-three patients (154 men, 139 women; mean age, 61.0 years) with severe hypertension (82.2%), progressive renal failure (11.3%), and suspected renal artery stenosis (6.5%) underwent CE MR angiography with three-dimensional spoiled gradient-echo sequences after administration of 0.1 mmol/kg gadobenate dimeglumine at 2 mL/sec. Anteroposterior and oblique DSA was performed in 268 (91.5%) patients. Three independent blinded reviewers evaluated CE MR angiographic images. Sensitivity, specificity, and accuracy of CE MR angiography for detection of significant steno-occlusive disease (> or =51% vessel lumen narrowing) were determined at segment (main renal artery) and patient levels. Positive and negative predictive values and positive and negative likelihood ratios were determined. Interobserver agreement was analyzed with generalized kappa statistics. A safety evaluation (clinical examination, electrocardiogram, blood and urine analysis, monitoring for adverse events) was performed. RESULTS: Of 268 patients, 178 who were evaluated with MR angiography and DSA had significant steno-occlusive disease of renal arteries at DSA. Sensitivity, specificity, and accuracy of CE MR angiography for detection of 51% or greater stenosis or occlusion were 60.1%-84.1%, 89.4%-94.7%, and 80.4%-86.9%, respectively, at segment level. Similar values were obtained for predictive values and for patient-level analyses. Few CE MR angiographic examinations (1.9%-2.8%) were technically inadequate. Interobserver agreement for detection of significant steno-occlusive disease was good (79.9% agreement; kappa = 0.69). No safety concerns were noted. CONCLUSION: CE MR angiography performed with 0.1 mmol/kg gadobenate dimeglumine, compared with DSA, is safe and provides good sensitivity, specificity, and accuracy for detection of significant renal artery steno-occlusive disease.

CT fluoroscopy guided biopsy of small pulmonary and upper abdominal lesions: efficacy with a modified breathing technique.

PURPOSE: To characterize a new protocol of computed tomographic (CT) fluoroscopy-guided biopsy of the lung and upper abdomen to minimize the intervention time, complication rate, and exposure to ionizing radiation for both the patient and the radiologist. MATERIALS AND METHODS: Fifty patients (23 women, 27 men; mean age, 64.3 years; age range, 36-83 years) with lung (n = 41) or upper abdomen (n = 9) nodules 15 mm or smaller underwent CT fluoroscopy-guided biopsy from November 2005 to October 2006. The mean nodule diameter was 12.6 mm (range, 8-15 mm), the mean depth to skin was 57.3 mm (range, 20-114 mm), and the mean depth of nodules from pleura and/or peritoneum was 18.9 mm (range, 1-77 mm). Histopathologic evaluation of samples was performed on the day of the procedure. A CT fluoroscopy-guided biopsy protocol was established as follows: (a) native CT with breath-holding at an intermediate respiration level, (b) selection of section position with target nodule and insertion of an 18-gauge coaxial biopsy needle extrapleurally and/or extraperitoneally virtually targeting at nodule, (c) start of CT fluoroscopy (130 kVp, 30 mAs, 5-mm-thick sections) at inspiration level with the patient expiring, (d) stop of CT fluoroscopy when the target nodule reaches the section position, short breath-hold, needle advancement to the target nodule, (e) control of needle position with CT fluoroscopy, and (f) biopsy. RESULTS: The mean total table time was 23.8 minutes (range, 15-41 minutes), the mean duration of CT fluoroscopy was 8.2 seconds (range, 4-23 seconds), and the mean duration of breath-holding--including needle insertion to target nodule and control CT fluoroscopy--was 10.3 seconds (range, 5-15 seconds). There were three minor pneumothoraces that required no further intervention, seven minor pulmonary hemorrhages, three moderate pulmonary hemorrhages with hemoptysis, and one moderate liver hematoma. There were no major complications. The diagnostic accuracy of biopsy samples was 96%. CONCLUSIONS: The presented modification of CT fluoroscopy-guided biopsy of mobile pulmonary and upper abdominal lesions is a rapid and safe procedure, requiring only short exposure to ionizing radiation.

Value of single-dose contrast-enhanced magnetic resonance angiography versus intraarterial digital subtraction angiography in therapy indications in abdominal and iliac arteries.

The objective of the study was to prove the value of single-dose contrast-enhanced magnetic resonance angiography [three-dimensional (3D) ceMRA] in abdominal and iliac arteries versus the reference standard intra-arterial digital subtraction angiography (i.a.DSA) when indicating a therapy. Patients suspected of having abdominal or iliac artery stenosis were included in this study. A positive vote of the local Ethics Committe was given. After written informed consent was obtained, 37 patients were enrolled, of which 34 were available for image evaluation. Both 3D ceMRA and i.a. DSA were performed for each patient. The dosage for 3D ceMRA was 0.1 mmol/kg body weight in a 1.5-T scanner with a phased-array coil. The parameters of the 3D-FLASH sequence were as follows: TR/TE 4.6/1.8 ms, effective thickness 3.5 mm, matrix 512 x 200, flip angle 30 degrees , field of view 420 mm, TA 23 s, coronal scan orientation. Totally, 476 vessel segments were evaluated for stenosis degree by two radiologists in a consensus fashion in a blinded read. For each patient, a therapy was proposed, if clinically indicated. Sensitivity, specificity, positive and negative predictive values, and accuracy for stenoses > or = 50% were 68%, 92%, 44%, 97%, and 90%, respectively. In 13/34 patients, a discrepancy was found concerning therapy decisions based on MRA findings versus therapy decisions based on the reference standard DSA. The results showed that the used MRA imaging technique of abdominal and iliac arteries is not competitive to i.a. DSA, with a high rate of misinterpretation of the MRAs resulting in incorrect therapies.

Chronic mesenteric ischemia: stenting of mesenteric arteries.

This article focuses on stent placement in mesenteric arteries in patients with the rare diagnosis of chronic mesenteric ischemia. We present a survey from the initial stage of recognition of this gastrointestinal disorder and its manifestations to treatment by stenting to avoid further ischemic episodes and bowel infarction and necrosis. The advantages of stent placement in splanchnic arteries are discussed in comparison to open surgical revascularization.

A multicenter, site-independent, blinded study to compare the diagnostic accuracy of contrast-enhanced magnetic resonance angiography using 1.0M gadobutrol (Gadovist) to intraarterial digital subtraction angiography in body arteries.

PURPOSE: Prospective evaluation of diagnostic accuracy of single field-of-view contrast-enhanced MR Angiography (ceMRA) with 1.0M gadobutrol compared to intraarterial DSA in body arteries. MATERIALS AND METHODS: In an European multicenter study 179 patients underwent ceMRA and DSA. For each indication five prospectively defined vessel segments were evaluated by local investigators onsite and by three site-independent blinded readers (BR) independently. RESULTS: The agreement between ceMRA and DSA diagnosis was statistically significant in the onsite (96.6%) and blinded reader (86.6-90.2%) evaluation. Sensitivity, specificity, accuracy, positive (PPV) and negative predictive values (NPV) for detection of relevant stenosis (>50%) were calculated for the right and left internal carotid arteries, and common and external iliac arteries: Sensitivity was 95-98% (onsite) and 76-96% (BR), specificity 94-96% (onsite) and 86-94% (BR), accuracy 96% (onsite) and 87-93% (BR), NPV 98-99% (onsite) and 84-98% (BR), and PPV 79-93% (onsite) and 44-91% (BR), respectively. CONCLUSION: CeMRA of body arteries using 1.0M gadobutrol provides diagnostic information comparable to intraarterial DSA.

Stent placement with the monorail technique for treatment of mesenteric artery stenosis.

PURPOSE: To analyze the immediate and midterm success of stenting of mesenteric arteries by a monorail technique in patients with chronic mesenteric ischemia. MATERIALS AND METHODS: In this prospective case series, 19 patients (11 male, 8 female; mean age, 62.9 +/- 10.4 y; range, 36-82 y) with 23 symptomatic stenoses of mesenteric arteries were treated with stent placement by a monorail technique in a radiologic intervention center over a period of 4.5 years. Clinical examinations and duplex sonography were used to evaluate the stents' patency and clinical success. Kaplan-Meier graphs were calculated to analyze the patency and freedom-from-symptom rate. RESULTS: Initial technical success rate was 22/23 (96%). Mean follow-up was 17 months (range, 1-58 mo). Primary patency and primary clinical success rates were 82% and 78%, respectively. According to Kaplan-Meier tables, the patency rates were 96%, 87%, 76%, and 61% at 0, 1, 15, and 24 months, respectively, and the freedom-from-symptom rates were 95%, 90%, 72%, and 54% at 0, 1, 24, and 30 months, respectively. No peri-interventional complications occurred. Two patients died of cardiac failure in the hospital within 30 days after intervention; deaths were not related to the intervention. CONCLUSIONS: Stent placement by a monorail technique in mesenteric arteries is an effective and safe treatment for symptomatic stenoses in patients with chronic mesenteric ischemia after a mean follow-up of 17 months.

Value of fat-suppressed PD-weighted TSE-sequences for detection of anterior and posterior cruciate ligament lesions--comparison to arthroscopy.

OBJECTIVE: To evaluate fat-suppressed (FS) proton-density-weighted (PDw) turbo spin-echo (TSE) magnetic resonance imaging for the detection of anterior and posterior cruciate ligament lesions in comparison to arthroscopy. MATERIALS AND METHODS: In a prospective study 31 knee joints were imaged on a 1.5T MR scanner (Vision, Siemens, Erlangen) prior to arthroscopy using following sequences: (a) sagittal FS-PDw/T2w TSE (TR/TE: 4009/15/105 ms); (b) sagittal PDw/T2w TSE (TR/TE:3800/15/105 ms). Further imaging parameters: slice thickness 3mm, FOV 160 mm, matrix 256 x 256. A total of 62 anterior and posterior cruciate ligaments (ACL/PCL) were evaluated, standard of reference was arthroscopy. Sensitivity, specificity, positive (ppv) and negative predictive value (npv) and accuracy were calculated. RESULTS: Twenty-one cruciate ligament ruptures were detected in arthroscopy, 19 ACL- and 2 PCL-ruptures (on MRI 34/124, 25/62 ACL, 9/62 PCL lesions). For all four sequences in the 31 patients with arthroscopic correlation sensitivity, specificity, ppv, npv and accuracy were 86%, 98%, 95%, 93% and 94% for detection of tears, and 84%, 100%, 100%, 80% and 90% for ACL-ruptures respectively. The two PCL-ruptures were true positive in all sequences, one intact PCL was diagnosed as torn (false positive). CONCLUSIONS: Fat-suppressed PDw/T2w TSE-MR sequences are comparable to PDw TSE sequences for the detection of ACL/PCL-lesions.