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.

Inoperable recurrent rectal cancer: results of a prospective trial with radiation therapy and razoxane.

PURPOSE: The effect of the sensitizer razoxane was prospectively evaluated in recurrent rectal cancer. Endpoints of the study were mainly local response rates and survival. METHODS AND MATERIALS: From 1984 to 1990 razoxane was given together with radiation therapy to 40 patients with recurrent inoperable rectal cancer. Loco-regional relapses in the pelvis were isolated in 24 and associated with distant metastases in 16 patients. Special attention was given to the subset of 24 patients with isolated local recurrences. This group was compared with historical controls treated with radiotherapy alone. The dosage of razoxane was 150 mg/m2 daily orally starting 5 days before the first irradiation. The drug was then given each radiation day until the end of treatment. The median radiation dose was 60 (40-62) Gy in the evaluable patients. The minimum follow-up was 32 months and the median 72 months. RESULTS: The rates of complete plus partial responses were 57% and 54%, respectively, for recurrent patients without and with distant metastasis. The 23 evaluable patients with isolated local relapses had a median survival of 24 months (12-94+); all patients surviving at least 1 year. CONCLUSION: The combination of radiotherapy and razoxane may lead to better local control and improved median survival compared to our historical controls and literature reports where radiotherapy alone was used. The treatment is easy to administer and is associated with a moderate toxicity.

MR-myelography: a comparison with conventional myelography.

After creating a MR pulse sequence, called MR-myelography, the purpose of the study was to evaluate the value of this sequence in comparison to conventional myelography. Twenty consecutive patients were examined with conventional and MR-myelography concerning the clinical questions of chronic lumbago, spinal canal stenosis, herniated disc, spondylolisthesis and instability. Six observers assessed both examinations independently for subjective criteria such as pictorial quality, depiction of the dural sac, the nerve roots and their sheaths, artifacts, and the usefulness of single MR-myelography slices. Furthermore the number and extent of stenoses had to be judged as an objective criteria. The employed MR-myelography technique is not able to concur with the quality of conventional myelography. A high-grade stenosis is usually overestimated and low grade stenosis underestimated by MR-myelography. But it is easier to depict further relevant stenoses in a preexisting high grade stenotic spinal canal with MR-myelography. Artifacts of the introduced MR-technique do not disturb pictorial and diagnostic quality very much. In conclusion MR-myelography cannot replace conventional myelography. But together with conventional MR-sequences, MR-myelography can be helpful in the assessment of spinal canal stenosis.

Effects of iodinated contrast agents in MR imaging.

PURPOSE: To investigate the effects of iodinated contrast agents in MRI. MATERIAL AND METHODS: Twenty patients were examined with MRI immediately, 8 and 24 h after lumbar myelography. Signal intensities and calculated T1- and T2-relaxation times of different iodinated contrast agents, a dilution row of iopamidol, and a mixture of CSF and iotrolan were compared with physiological saline solution using different T1- and T2-weighted sequences. 1H-spectroscopy was performed with several solutions containing iodine or other substances. RESULTS: A fluid-fluid level of the CSF existed in the lumbar dural sac in all patients immediately after lumbar myelography with a non-ionic iodinated contrast agent. Increased signal intensity on T1-weighted and decreased signal intensity on T2-weighted sequences was found for all contrast agents, as well as for the dilution row, compared with physiological saline solution. The structure of the side chains of the contrast agents is responsible for the T1- and T2-shortening effect. CONCLUSION: It is important to be aware of the effect of iodinated contrast agents in MRI. To avoid misinterpretation of atypical findings, MRI of the spine should not be performed earlier than 24 h after myelography.

[Implementation of the quality management system ISO/CD2 9001-2000 in a radiology institute]. / Uber die Implementierung des Qualitätsmanagementsystems ISO/CD2 9001-2000 in einem radiologischen Institut.

Quality assurance in health care, a relatively new discipline, has developed rapidly over the last years and is now required by law. The Quality Management System (QMS) ISO 9001 aims at the definition of requirements necessary in order to achieve perfect products and continuous quality improvement. Implementation of this QMS necessitates the analysis and written documentation of all working processes and modes of operation. Furthermore, potential improvement possibilities are defined to guarantee highly qualified, generally applicable and standardised procedures. Time-consuming data assessment is an instrument to enable disclosure and analysis of existing errors as well as to show possibilities of optimization, thus forming the basis for continuous improvement. The new ISO NORM 9001-2000 is process-orientated with an organisational structure strongly recommendable for service institutions and therefore also for a department of radiology.

[Contrast-enhanced subtraction MRT in the spin-echo technic]. / Kontrastverstärkte Subtraktions-MRT in Spin-Echo-Technik.

PURPOSE: The aim of the retrospective study was to determine whether subtraction of spin-echo images is useful for estimating intensity and extension of contrast enhancement when practised in daily routine diagnostic work. METHODS: 348 patients with different diseases of the musculoskeletal and neuro system were examined with MRI using a T1-weighted spin-echo sequence before and after application of 0.1 mmol/kg Gd-DTPA with subsequent subtraction of both measurements. Usefulness of the source images, pictorial quality of subtracted images and intensity of contrast enhancement were assessed subjectively. RESULTS: Subtracted images were of sufficient quality in 85% of the cases, whereas source images were always usable except in 9 patients. It was easier to visualise the extent of contrast enhancement in subtracted than in non-subtracted images in examinations of the musculoskeletal system, whereas there was no difference in the neuro system. Contrast enhancement could definitely be excluded in 15% of the patients and was stated to be of low, medium and high intensity in 21%, 45% and 19%, respectively. In comparison with subtracted images lesions were stated to appear larger in 62% and 87%, smaller in 25% and 13%, and of the same size in 13% and 0% for T2-weighted and fat-suppressed images, respectively. CONCLUSION: Subtraction of spin-echo images before and after application of contrast media is useful for estimating intensity and extension of contrast enhancement without essentially increasing time and costs of the examination. Extension of contrast enhancement in musculoskeletal lesions rarely correlates with the extension of signal changes in T2-weighted and fat-suppressed images.

[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.

[Experiences with a new breast localization needle]. / Erfahrungen mit einer neuen Mammalokalisationsnadel.

In view of the increasing number of biopsies of non-palpable lesions of the female breast we found an ideal localisation system in the Hawkins breast localisation needle. Localisation was successful without technical problems in 31 out of 34 patients. The special advantages of the needle are its stability in position and excellent maneuverability due to the construction of the needle. The very simple handling of the needle is an advantage not only for the radiologist but also for the surgeon.

[The normal CT and ultrasonic findings after a laparoscopic inguinal hernia operation]. / CT- und Ultraschallnormalbefunde nach laparoskopischer Leistenhernienoperation.

Common surgery has been revolutionised by minimal invasive surgery in a very short period of time. Laparoscopic operations of inguinal hernias are routinely done by many surgeons. For interpreting correctly postoperative complications with radiological techniques it is necessary to know the sonographical and CT changes of the normal postoperative situs. For evaluating these changes 23 patients without symptoms were examined between the first and third postoperative day. Typical sonographic findings are high echogenicity of the hernial orifice (17x) and echo-lucent thickening of the spermatic cord. The surgical clips and fleece and CO2 bubbles could not be detected by ultrasound. Using CT we found free peritoneal fluid collection (2x), streaky thickenings in the area of operation (20x), oedema at the hernial orifice (19x), residual CO2 bubbles (22x), thickening of the spermatic cord (22x) and visualisation of the surgical clips. The surgical fleece was invisible in all patients.

[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.

[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.

[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.

Sonography of the injured ulnar collateral ligament of the thumb.

We used high-resolution ultrasonography to image the ulnar collateral ligament in 39 patients who had sustained recent injuries of the metacarpophalangeal joint of the thumb. All the patients were subsequently operated on and the lesions of the ligament were recorded. In 36 patients the preoperative ultrasonographic diagnosis was correct. Five of these showed no rupture of the ligament. In the other 31, ultrasonography correctly distinguished between rupture in situ (15) and rupture with dislocation of the ligament (16). Misdiagnosis by ultrasonography in three cases was due to delay of the investigation (three weeks after injury) in one, to technical error in one and to misinterpretation of the image in one.

[In vitro T1- and T2-relaxation times of coagulating blood and thromboses]. / In vitro T1- und T2-Relaxationszeiten von gerinnendem Blut und Thromben.

A comparison between blood and thromboses is made on behalf of T1 and T2 relaxation data. Thereby, the time interval between the withdrawal and the measurement of blood forms a parameter of investigation. Among the thromboses the surgically removed ones are compared with those aggregated in blood during course of time. As the most outstanding result one can see that the formation of thromboses changes significantly the T1 and T2 relaxation times of 1H und 23Na. The values of the relaxation times obtained for those thromboses which have aggregated within the blood are thereby comparable with those relaxation times found for the surgically removed ones.

[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.

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.

[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.