Vascular 3D Printing with a Novel Biological Tissue Mimicking Resin for Patient-Specific Procedure Simulations in Interventional Radiology: a Feasibility Study.

Three-dimensional (3D) printing of vascular structures is of special interest for procedure simulations in Interventional Radiology, but remains due to the complexity of the vascular system and the lack of biological tissue mimicking 3D printing materials a technical challenge. In this study, the technical feasibility, accuracy, and usability of a recently introduced silicone-like resin were evaluated for endovascular procedure simulations and technically compared to a commonly used standard clear resin. Fifty-four vascular models based on twenty-seven consecutive embolization cases were fabricated from preinterventional CT scans and each model was checked for printing success and accuracy by CT-scanning and digital comparison to its original CT data. Median deltas (Δ) of luminal diameters were 0.35 mm for clear and 0.32 mm for flexible resin (216 measurements in total) with no significant differences (p > 0.05). Printing success was 85.2% for standard clear and 81.5% for the novel flexible resin. In conclusion, vascular 3D printing with silicone-like flexible resin was technically feasible and highly accurate. This is the first and largest consecutive case series of 3D-printed embolizations with a novel biological tissue mimicking material and is a promising next step in patient-specific procedure simulations in Interventional Radiology.

The impact of 18F-FDOPA-PET/MRI image fusion in detecting liver metastasis in patients with neuroendocrine tumors of the gastrointestinal tract.

BACKGROUND: This study assesses the value of image fusion using 18F-fluoro-L-DOPA (18F-DOPA) positron emission tomography (PET) and magnetic resonance imaging (MRI) for examining patients with neuroendocrine tumors (NETs) and a suspicion of metastasis of the liver. METHODS: Eleven patients (five women and six men aged between 20 and 81, with a mean age of 54.6 years) were included in the study. All patients underwent whole-body 18F-DOPA PET examinations and contrast-enhanced MRI with diffusion-weighted sequences (DWS). Image fusion was performed using a semiautomatic voxel-based algorithm. Images obtained using PET and MRI were assessed separately. Side-by-side evaluations of fused PET/MRI images were also performed. RESULTS: In total, 55 liver lesions (52 liver metastases and 3 benign lesions) were detected in the 11 patients. Sensitivity detection for liver lesions was higher when using PET/CT than when using contrast-enhanced MRI without DWSs and lower than using MRI with DWSs. The sensitivity of PET/MRI image fusion in the detection of liver metastasis was significantly higher than that of MRI with DWSs (P < 0.05). CONCLUSION: Images of the liver obtained using PET and MRI in patients with NETs exhibited characteristic features. These findings suggest that an appropriate combination of available imaging modalities can optimize patient evaluations.

Added value of semi-quantitative breast-specific gamma imaging in the work-up of suspicious breast lesions compared to mammography, ultrasound and 3-T MRI.

OBJECTIVE: To prospectively analyse the diagnostic value of semi-quantitative breast-specific gamma imaging (BSGI) in the work-up of suspicious breast lesions compared with that of mammography (MG), breast ultrasound and MRI of the breast. METHODS: Within a 15-month period, 67 patients with 92 breast lesions rated as Category IV or V according to the breast imaging reporting and data system detected with MG and/or ultrasound were included into the study. After the injection of 740-1110 MBq of Technetium-99m ((99m)Tc) SestaMIBI intravenously, scintigrams were obtained in two projections comparable to MG. The BSGI was analysed visually and semi-quantitatively by calculating a relative uptake factor (X). With the exception of two patients with cardiac pacemakers, all patients underwent 3-T breast MRI. Biopsy results were obtained as the reference standard in all patients. Sensitivity, specificity, positive- and negative-predictive values, accuracy and area under the curve were calculated for each modality. RESULTS: Among the 92 lesions, 67 (72.8%) were malignant. 60 of the 67 cancers of any size were detected by BSGI with an overall sensitivity of 90%, only exceeded by ultrasound with a sensitivity of 99%. The sensitivity of BSGI for lesions <1 cm declined significantly to 60%. Overall specificity of ultrasound was only 20%. Specificity, accuracy and positive-predictive value were the highest for BSGI (56%, 80% and 85%, respectively). X was significantly higher for malignant lesions (mean, 4.27) and differed significantly between ductal types (mean, 4.53) and the other histopathological entities (mean, 3.12). CONCLUSION: Semi-quantitative BSGI with calculation of the relative uptake factor (X) can help to characterize breast lesions. BSGI negativity may obviate the need for biopsy of breast lesions >1 cm with low or intermediate prevalence for malignancy. ADVANCES IN KNOWLEDGE: Compared with morphological imaging modalities, specificity, positive-predictive value for malignancy and accuracy were the highest for BSGI in our study. BSGI negativity may support the decision not to biopsy in selected lesions with a low or low-to-moderate pre-test probability for malignancy.

Displacement of malignant cells into the portal triad of the liver results in reduced liver perfusion, mimicking segmental Fatty liver.

Liver steatosis is often observed in different clinical situations. Oncological patients undergoing systemic therapy often develop liver steatosis, which can be diagnosed with normal routine scans such as CT and ultrasound. In this case report, we show that an isolated infiltration of the portal triad with tumor cells could mimic a fatty-like infiltration of the liver. Radiologists and clinicians should be aware of this pitfall and should perform a biopsy in cases of doubt.

Comparison of standardized pre- and postoperative functional pelvic cine-MRI in patients with a bulbourethral composite suspension due to post-prostatectomy incontinence.

OBJECTIVES: To compare functional pelvic cine-MRI in patients with post-prostatectomy incontinence before and after implantation of a bulbourethral composite suspension. PATIENTS AND METHODS: Functional pelvic 1.5 T cine-MRI was performed at rest, under standardized Valsalva pressure and during micturition in six patients with post-prostatectomy incontinence before and 3 months after a bulbourethral composite suspension. Visibility and positioning of the implant as well as membranous urethral length (MUL) and positioning of the bladder neck (BN) in comparison with the pubococcygeal line (PCL) were evaluated. Clinical outcome was measured by patient-reported pad use and standardized questionnaires (ICIQ-UI SF and I-QOL). Paired data were tested with a Wilcoxon signed-ranks test. RESULTS: Surgery was successfully performed in all patients. All patients returned to complete voiding. The ICIQ-UI SF score decreased significantly from median 16.5 to 5 (p = 0.016). I-QOL increased significantly from 70.5 to 93.5 (p = 0.047). Pad use improved from median 2 pads to 0 pads postoperatively (p = 0.031). Four of six patients were completely pad-free, and 2 were failures with persisting urinary incontinence. MRI revealed significant differences of the MUL at rest with median of 8 mm pre- and 13 mm postoperatively (p = 0.016). BN showed a significant elevation with respect to PCL under Valsalva with in median 0.5 to 5 mm postoperatively (p = 0.016). No significant MRI differences were found between patients showing clinical success or failure. CONCLUSIONS: The bulbourethral composite suspension was associated with an increase in urethral length, urethral coaptation zone and bladder neck elevation, implying a non-compressive mode of action.

[Imaging of transmesocolic internal hernias following retrocolic Roux-Y reconstruction: tips and tricks for radiologists]. / Bildgebung transmesokolischer innerer Hernien nach retrokolischer Roux-Y-Rekonstruktion: Tipps und Tricks für Radiologen.

Among all entities causing intestinal obstruction, internal hernias are rare. However, after retrocolic laparoscopic Roux-Y reconstruction, transmesocolic internal hernias may occur. The loss of mesenteric fat favors the formation of transmesocolic internal hernias, which are the most common type of acquired internal hernias. CT findings of segmental intestinal obstruction are similar in all underlying diseases including peritoneal adhesions, which are the most important differential diagnosis to postoperative internal hernias. Since internal hernias typically alter spatial relationships within the peritoneal cavity, precise analysis of intraperitoneal topography is the most important clue to differentiate internal hernias from peritoneal adhesions. Based on readily identifiable anatomic reference points and structures, so-called landmarks, specific features of internal hernias in CT imaging are outlined. Particular attention is paid to mesenteries, because they define compartments within the peritoneal cavity. Focusing on transmesocolic internal hernias, the anatomy of the mesocolon transversum is described in detail. Finally, we present a checklist facilitating the diagnosis of internal hernias in everyday practice.

[Clinical relevance and indications for cardiac magnetic resonance imaging 2013: an interdisciplinary expert statement]. / Klinischer Stellenwert und Indikationen zur Magnetresonanztomografie des Herzens 2013: Ein interdisziplinäres Expertenstatement.

During the last years the indications of Cardiac Magnetic Resonance Imaging (CMRI) have been continuously expanded. However, the acceptance of the method by cardiologists and radiologists does not correlate with respect to the diagnostic potential. Several factors, such as expensive equipment, relatively long examination times, high technical know how and lack of remuneration, limit the application of CMRI in everyday clinical practice. Furthermore, doctors tend to apply more conventional, well established diagnostic procedures, the access to the method is still limited and there exist difficulties in the interdisciplinary collaboration. The interdisciplinary Austrian approach to Cardiac Imaging is aimed to improve the aforementioned problems and to support the implementation of CMRI in the diagnostic tree of cardiac diseases thus enabling a cost efficient management of patients in cardiology.

[Current status of 3D/4D volume ultrasound of the breast]. / Aktueller Stand der 3D-/4D-Volumensonografie der Mamma.

3D/4D volume ultrasound is an established method that offers various options for analyzing and presenting ultrasound volume data. The following imaging techniques are based on automatically acquired ultrasound volumes. The multiplanar view is the typical mode of 3D ultrasound data presentation. The niche mode view is a cut open view of the volume data set. The surface mode is a rendering technique that represents the data within a volume of interest (VOI) with different slice thicknesses (typically 1-4 mm) with a contrast-enhanced surface algorithm. Related to the diagnostic target, the transparency mode helps to present echopoor or echorich structures and their spatial relationships within the ultrasound volume. Glass body rendering is a special type of transparency mode that makes the grayscale data transparent and shows the color flow data in a surface render mode. The inversion mode offers a three-dimensional surface presentation of echopoor lesions. Volume Contrast Imaging (VCI) works with static 3D volume data and is able to be used with 4D for dynamic scanning. Volume calculation of a lesion and virtual computer-assisted organ analysis of the same lesion is performed with VoCal software. Tomographic Ultrasound Imaging (TUI) is the perfect tool to document static 3D ultrasound volumes. 3D/4D volume ultrasound of the breast provides diagnostic information of the coronal plane. In this plane benign lesions show the compression pattern sign, while malignant lesions show the retraction pattern or star pattern sign. The indeterminate pattern of a lesion combines signs of compression and retraction or star pattern in the coronal plane. Glass body rendering in combination with Power-Doppler, Color-Doppler or High-Definition Flow Imaging presents the intra- and peritumoral three-dimensional vascular architecture. 3D targeting shows correct or incorrect needle placement in all three planes after 2D or 4D needle guidance. In conclusion, it is safe to say that 3D/4D volume ultrasound of the breast is technically advanced and suitable for daily diagnostic and interventional breast work in addition to routinely used 2D sonography.

Forty-slice spiral computed tomography of the coronary arteries: assessment of image quality and diagnostic accuracy in a non-selected patient population.

PURPOSE: To investigate prospectively the image quality and diagnostic accuracy of 40-slice computed tomography (CT) for the detection of hemodynamically significant coronary artery disease (CAD) in a non-selected, consecutive patient cohort. MATERIAL AND METHODS: Forty consecutive patients (28 men, 12 women) underwent both 40-slice CT and conventional invasive coronary angiography (ICA) within 10+/-7 days. The results of both methods were compared on a per-segment and per-patient basis, using ICA as the standard of reference. RESULTS: According to ICA, significant CAD was present in 30/40 patients (75%). Of a total of 545 segments, 43 segments (7.9%) could not be sufficiently evaluated by CT due to motion artifacts in 15 segments (34.9%), small vessel size and suboptimal contrast enhancement in 14 segments (32.6%), severe calcification in 10 segments (23.3%), and opacified adjacent structures such as cardiac veins in four segments (9.3%). Segment-based analysis for detection of significant stenosis >50% yielded an overall sensitivity, specificity, positive predictive value, and negative predictive value of 87%, 99%, 98%, and 95%, respectively. Restricting the assessment to clinically relevant proximal coronary segments led to an increase in sensitivity to 96%, specificity to 99%, and negative predictive value to 99%. Patient-based analysis demonstrated a high negative predictive value (91%) of CT for excluding significant CAD, even when all segments were included in the analysis. CONCLUSION: In a non-selected patient population with a high prevalence of CAD, 40-slice CT demonstrates high diagnostic accuracy in the assessment of significant CAD per patient and per segment.

[Normal cardiac diameters in cine-MRI of the heart]. / Normalwerte der Herzdurchmesser in der Cine-MRT.

PURPOSE: To measure the normal diameters of cardiac cavities in standard cardiac views using cine MRI. MATERIALS AND METHODS: Fifty-six volunteers were examined (27 male, 29 female) on a 1.5 T MR unit with ECG-triggered single shot free precision (SSFP) cine MR sequences and parallel image acquisition. Standardized echocardiographic planes were used to depict the heart of all volunteers (short axis, 4-chamber view, left and right 2-chamber views). The different diameters of the cardiac cavities were measured using a fixed protocol. RESULTS: For the estimation of ventricular dilatation, the important female/male cross diameters of the left ventricle are 45.2 +/- 3.4/51.6 +/- 4.6 mm diastolic and 30.5 +/- 3.5/33.8 +/- 3.6 mm systolic, and of the right ventricle 30.7 +/- 3.8/37.1 +/- 5.9 mm diastolic and 22.3 +/- 3.8/28.1 +/- 4.4 mm systolic. For the determination of a left ventricular hypertrophy, relevant septal wall thickness measured in the short axis of the left ventricle of female/male volunteers are 8.0 +/- 1.0/9.9 +/- 1.2 mm diastolic and 10.9 +/- 1.4/13.6 +/- 1.9 mm systolic. The measured normal values of male volunteers were generally higher than those of female volunteers. The thickness of the ventricular septum correlated well when measured in the short axis and 4-chamber view. When measured in the 4-chamber view, the longitudinal diameter of the ventricles had a higher value in diastole and a lower value in systole, compared to the 2-chamber views of the right and left cardiac cavities. The atrial longitudinal diameters were higher in the 4-chamber view compared to the 2-chamber views, without any difference in systole or diastole. CONCLUSION: Diameters of cardiac cavities are easily and quickly measured. Using the tables with the normal values published here, it is simple to estimate an abnormal size of the heart.

[Implementation of BIRADSTM together with an organization of percutaneous breast biopsies: experiences, reactions]. / Implementierung der BIRADSTM-Klassifikation in Kombination mit einer Organisation der perkutanen Nadelbiopsie von Brustläsionen: Erfahrungen, Reaktionen.

PURPOSE: To record the acceptance and reactions of radiologists and physicians who recommend patients for mammography after simultaneous establishment of BIRADS TM and a registration of the results of percutaneous breast biopsies. MATERIALS AND METHODS: To improve clarity of mammographic reports and to provide guidance concerning any necessary percutaneous breast biopsies the Breast Imaging Data And Reporting System (BIRADS TM) has been introduced regionally together with a registration of percutaneous breast biopsies. Using a questionnaire, 25 radiologists and 230 referring physicians were asked on acceptance and reactions concerning the established system. RESULTS: Of the 15 answering radiologists, 93 % considered BIRADS TM a worthwhile effort and 87 % found the biopsy guidelines to be useful. They regarded the acceptance of the referring physicians and patients as high (80 %). Up to 69 % of the 52 participating physicians stated a better understanding of the mammographic reports, an easier comprehension of the dignity classification of a mammographic lesion and the feeling of an improvement in their work. Preoperative assessment of histology was found to be valuable by 94 % of the referring physicians. They believe that more than half of the patients benefit from the biopsy guidelines and that the majority of patients accept this approach. CONCLUSION: BIRADS TM is useful to standardize and improve mammographic reports. It is advantageous to link BIRADS TM with guidelines for percutaneous breast biopsies.

Diffusion-weighted MRI in diffuse axonal injury of the brain.

The goal of this study was to identify and describe the different types and patterns of tissue injury which are encountered by diffusion-weighted imaging (DWI) in diffuse axonal injury (DAI) of the brain. The DWI data sets of 98 patients who suffered from a closed-head injury were retrospectively evaluated. Medical records were reviewed to rule out pre-existing neurological diseases. Lesions were studied for their DWI signal characteristics and lesion size or extension. Traumatic lesions were classified into three categories depending on their signal characteristica on DWI and apparent diffusion coefficient (ADC) maps: type 1, DWI- and ADC-hyperintense most likely representing lesions with vasogenic edema; type 2, DWI-hyperintense, ADC-hypointense indicating cytotoxic edema; type 3, central hemorrhagic lesion surrounded by an area of increased diffusion. According to the size and extent of lesions, injury was classified into three groups: group A, focal injury; group B, regional/confluent injury; and group C, extensive/diffuse injury. Our study showed that diffusion-weighted imaging differentiates between lesions with decreased and increased diffusion in patients with DAI. Different degrees of tissue injury extent were noticed. Future prospective studies should study if this additional information can be used as a predictor of injury reversibility, final outcome and prognosis.

[Practical usage of a quality management system according to ISO 9001 : 2000 focusing on the double contrast (barium) enema]. / Praktische Anwendung eines Qualitätsmanagementsystems nach ISO 9001:2000 am Beispiel von Qualitätsverbesserungsmassnahmen beim Kolon-Kontrastmitteleinlauf, Germany.

PURPOSE: We describe the implementation of quality improvement measures in a quality management system. METHODS: With questionnaires for radiologists and patients, we investigated the relations between patient preparation and diagnostic quality serving the main purpose, to improve diagnostic quality with the help of more detailed patient information (e.g., changing preparation sheets and handling out "peri-med" information sheets to the patients). Furthermore, a comparative data ascertainment at other institutes was integrated. RESULTS: For the group of outpatients, increasing process quality (patient information) and outcome (diagnostic quality) could be achieved. Taking aspects of quality costs into consideration, a decrease in costs due to failures was achieved. CONCLUSION: More detailed patient information has positive effects on diagnostic quality of the double contrast (barium) enema.

Gliomatosis cerebri: intra vitam stereotactic determination in two cases and review of the literature.

Gliomatosis cerebri (GC) is an infiltrative neoplastic process that is diffusely distributed through neural structures, whose anatomical configuration remains intact. Most of the cases with GC reported in the literature were diagnosed at autopsy (101/110, 92%). We report two cases of GC in a 42-year-old woman and a 65-year-old man. The diagnosis was confirmed neuropathologically after MRI-guided stereoetactic biopsy. External radiation therapy was performed and led to a complete recovery of all clinical signs. Follow-up examinations 17 and 21 months after diagnosis showed permanent reversal of all clinical and radiological signs. MRI should be used as a primary imaging study in the evaluation of GC and for the determination of the target points for stereotactic biopsy. We discuss the aetiology, clinical manifestation, difficulties of intra vitam diagnosis, and management of this rare condition in the light of other 110 (101 postmortem and nine intra vitam) reported cases of GC in the literature.

[Advanced breast biopsy instrumentation (ABBI) experiences and critical comments]. / Advanced Breast Biopsy Instrumentation (ABBI) Erfahrungen und kritische Bemerkungen.

UNLABELLED: Advanced breast biopsy instrumentation (ABBI) experiences and critical comments. PURPOSE: To describe our three-years' experience with advanced breast biopsy instrumentation (ABBI). MATERIALS AND METHODS: Considering lesion size, type and location as well as patient specific criteria 89 patients were selected for an ABBI. The documented data like duration, complication and change of the procedure, size of the lesions and biopsy cannulas, histologic outcome and further treatment were analysed retrospectively. RESULTS: ABBI was successful in 63 of 89 patients. Cancer was found in 18 patients (29 %) with a surgical re-excision to achieve tumour-free margins in 89 %. 45 patients had benign lesions (71 %) with a benign to malignant ratio of 2.5 : 1. ABBI was unsuccessful or had to be replaced by other biopsy techniques in 26 patients (29 %). In four of these patients the localization needle was already placed. Analysing the three-year period ABBI frequency dropped each year with an overall reduction of 63 %. Despite a good benign to malignant ratio the surgical re-excision rate in cancer patients is disappointing. Although using precise selection criteria for ABBI the rate of failed biopsies and changeover to another biopsy procedure was too high. The reduction of ABBI procedures during the three-year period is assumed to be an expression of the negative experiences with the method but also a refusal of the assigning colleagues to use ABBI. CONCLUSION: For the evaluation of suspected breast lesions ABBI is too invasive and too expensive. On the other hand ABBI is too ineffective as a therapeutic tool to remove suspected lesions. Therefore it is not warranted to use ABBI instead of other concurrent biopsy techniques.

The value of intraoperative angiography in surgery of intracranial aneurysms: a prospective study in 126 patients.

The value of intraoperative digital subtraction angiography in surgery for intracranial aneurysms, the benefits and cost-effectiveness are a matter of discussion. We prospectively studied 126 patients with 144 aneurysms, most on the anterior intracranial circulation, who underwent clipping and intraoperative angiography. Follow-up was 28.4 +/- 13.1 months. We tried to work out the indications for intraoperative angiography of the anterior circulation and its cost-effectiveness. In 10.3 % of patients (9 % per aneurysm) unexpected findings were shown by intraoperative angiography: inadequately clipped aneurysms in 10 (7.9 %), a completely unclipped aneurysm in one (0.8 %) and occluded major arteries in two (1.6 %). A broad neck was a variable of statistical significance for inadequate clipping or stenosis or occlusion of an adjacent vessel. There was a strong trend for aneurysms more than 15 mm in diameter to be "risky". Their site was not a predictive factor. We believe that intraoperative angiography is indicated in surgery not only on large and giant aneurysms, but also broad-based aneurysms of the anterior cerebral circulation regardless of their size. It is cost-effective compared to postoperative angiography. The rate of stroke in our hands was 0.8%.