Friedemann Baum

Classification of hypervascularized lesions in CE MR imaging of the breast

Abstract. The purpose of this paper is to define and evaluate a classification category for contrast-enhanced (CE) MR imaging of the breast based on the BI-RADS mammographic categories of the American College of Radiology. Using five evaluation criteria for MR findings (initial signal increase, postinitial signal behavior, shape, border, and contrast material distribution within enhancing tumors) 522 patients (1031 breasts) were analyzed. Scores were given from 0 to 8 points and classified into five categories (group I: 0 points, negative; group II: 1–2 points, benign; group III: 3 points, probably benign; group IV: 4–5 points, suspicious abnormality; group V: 6–8 points, highly suspicious for malignancy) to 265 focal hypervascularized breast lesions in 244 breasts (patient group A). These findings were correlated with histology or follow-up. Additionally, this classification was correlated to the contrast medium uptake within the parenchyma of the remaining 787 breasts without any focal lesion (patient group B). Two hundred sixty-five hypervascularized lesions in 238 patients (244 breasts, patient group A) were classified into group I: 0%; group II: 27.3%; group III: 22.3%; group IV: 18.6%; and group V: 31.8%. Histology revealed 115 benign and 134 malignant tumors in these groups. Sixteen benign lesions were controlled by follow-up. Sensitivity for the detection of malignancy using the presented multifactorial MRM classification was 92%, and specificity was 92%. Excluding cases of ductal carcinoma in situ specificity increased to 95%. Seven hundred eighty-seven breasts without any focal hypervascularized lesion (patient group B) were classified into groups I or II. Follow-up (n=771) or histology (n=14) confirmed the diagnosis in 785 of these breasts. Histopathology revealed, however, malignant tumors in the remaining two cases. The classification of lesions based on a multifactorial analysis is very helpful in the interpretation of CE MRI of the breast. The evaluation of all diagnostic imaging modalities, however, is essential in determining the correct diagnosis and/or in deciding on the appropriate therapeutic procedure.

Comparative study in patients with microcalcifications: full-field digital mammography vs screen-film mammography

Abstract. The goal of this prospective study was to compare a full-field digital mammography system (FFDM) to a conventional screen-film mammography system (SFM) for the detection and characterization of microcalcifications. Fifty-five patients with 57 isolated microcalcification clusters were examined using a FFDM system (Senographe 2000D, GE Medical Systems, Milwaukee, Wis.) and a SFM system (Senographe DMR, GE Medical Systems, Milwaukee, Wis.). A conventional screen-film mammogram and a digital contact mammogram were obtained of each cluster. The image quality and the number of calcification particles were evaluated, and a characterization (BI-RADS 1–5) of microcalcifications was given by four experienced readers. Histopathology revealed 16 benign lesions (sclerosing adenosis, dysplasia, hamartoma, radial scar) in 15 patients and 21 malignant tumors (in situ carcinoma, invasive carcinoma) in 20 patients. Twenty patients had benign changes verified by long-term follow-up. Image quality of FFDM was assessed as superior to SFM in more than 50% of the cases. The FFDM showed more calcifications in 41% of all cases. Sensitivity and specificity for FFDM vs SFM were 95.2 vs 91.9% and 41.4 vs 39.3%, respectively. Moreover, FFDM demonstrated a higher diagnostic accuracy (deviation: 0.86 BI-RADS steps) compared with FSM (deviation 0.93 BI-RADS steps). The FFDM system with a 100-µm pixel size provides better image quality than SFM in patients with mammographic microcalcifications. The FFDM has a higher sensitivity and a higher reliability in characterizing microcalcifications.

MRI in the evaluation of müllerian duct anomalies.

OBJECTIVE Müllerian duct anomalies (MDAs) result from nondevelopment or nonfusion of the müllerian ducts and occur in 1-5% of women. Accurate diagnosis of the various subtypes is of great importance as MDAs are frequently associated with a broad variety of clinical symptoms. Recently, evidence arose that MRI might play a major role in diagnosis of MDAs. We present four cases of diverse subtypes of MDAs and the corresponding MRI findings. MATERIALS AND METHODS Patients (n = 4) with clinical suspicion of MDAs were examined with MRI. Coronal and transaxial T1- and T2-weighted images were acquired. Diagnosis was made and patients were grouped according to the American Fertility Societys classification. Patients underwent laparoscopy or laparotomy in order to confirm the diagnosis. RESULTS MRI revealed MDAs in all patients. In detail, one patient was diagnosed with hypoplastic uterus, one with unicornuate uterus with a noncommunicating rudimentary horn, one with bicornuate uterus bicollis with a double vagina and one with septate uterus. MRI diagnosis was correct in all cases, as confirmed by subsequent surgical intervention. CONCLUSION MRI is a valuable tool in diagnosis of MDA subtypes. Its use will help to spare patients mutilating surgery and to prevent pregnancy-associated complications.

Digital mammography: current state and future aspects

The introduction of digital technique in mammography has been the last step in completing the process of digitalization in diagnostic imaging. Meanwhile, some different digital techniques as well as a couple of different digital mammography systems were developed and have already been available for some years. In this review article, the relevant data of key studies are reported, the current status is defined, and perspectives of digital mammography are described.

Computer-aided detection in direct digital full-field mammography: initial results.

Abstract. For the first time, full-field digital mammography (FFDM) allows computer-aided detection (CAD) analysis of directly acquired digital image data. The purpose of this study was to evaluate a CAD system in patients with histologically correlated breast cancer depicted with FFDM. Sixty-three cases of histologically proven breast cancer detected with FFDM (Senographe 2000D, GE Medical Systems, Buc, France) were analyzed using a CAD system (Image Checker V2.3, R2 Technology, Los Altos, Calif.). Fourteen of these malignancies were characterized as microcalcifications, 37 as masses, and 12 as both. The mammographic findings were categorized as BI-RADS 3 (n=5), BI-RADS 4 (n=17) and BI-RADS 5 (n=40). The sensitivity for malignant lesions and the rate of false-positive marks per image were calculated. The sensitivity and its 95% confidence interval (CI) were estimated. The sensitivity of the CAD R2 system in breast cancer seen on FFDM was 89% for microcalcifications [CI95%=(70%; 98%)] and 81% for masses [CI95%=(67%; 91%)]. As expected, the detection rate was higher in lesions categorized as BI-RADS 5 (37 of 40) compared with lesions categorized as BI-RADS 4 (11 of 17). In the group categorized as BI-RADS 3 the detection rate was 4 of 5 lesions; however, this group was very small. The rate of false-positive marks was 0.35 microcalcification marks/image and 0.26 mass marks/image. The overall rate of false-positive marks was 0.61 per image. CAD based on FFDM provides an optimized work flow. Results are equivalent to the results reported for CAD analysis of secondarily digitized image data. Sensitivity for microcalcifications is acceptable and for masses is low. The number of false-positive marks per image should be reduced.

ECG-gated Multislice Spiral CT for Diagnosis of Acute Pulmonary Embolism

AIM The purpose of this study was to determine the feasibility of echocardiogram (ECG)-gated multi-slice CT angiography (MCTA) in patients with clinical suspicion of acute venous thromboembolism (VTE), to investigate the effect of ECG-gating on cardiac motion artefacts, and to determine the diagnostic reader agreement of ECG-gated MCTA in comparison with conventional MCTA. MATERIALS AND METHODS Forty-eight consecutive patients were prospectively enrolled and randomly underwent ECG-gated (n=25, group 1) or non-ECG-gated (n=23, group 2) eight-slice pulmonary MCTA. Image data were evaluated by three independent chest radiologists with respect to the presence or absence of emboli at different arterial levels (main, lobar, segmental, and subsegmental arteries), and with regard to cardiac motion artefacts. Statistical tests used to calculate inter-observer agreement were weighted kappa statistics, extended kappa statistics and confidence indices indicating three-reader agreement accuracy. RESULTS Twenty-seven patients (56.3%) were diagnosed to have pulmonary embolism (13 from group 1, 14 from group 2). Cardiac motion artefacts were significantly more frequent in group 2 (70% in group 2 versus 13% in group 1, p=0.0001). The overall diagnostic agreement was excellent with both MCTA techniques (three-reader confidence index for all vascular territories: 0.76 and 0.84 for groups 1 and 2, respectively (extended kappa=0.69 and 0.78, respectively); three-reader confidence index for diagnosis of VTE: 0.94 and 0.85 for groups 1 and 2, respectively (extended kappa=0.91 and 0.73, respectively), weighted kappa=0.81-0.83 and 0.92-0.95 for groups 1 and 2, respectively, and did not differ significantly between the two groups. In addition there was no significant difference of inter-observer agreement in either group at any assessed pulmonary arterial level. CONCLUSION ECG-gated pulmonary MCTA is feasible in patients with clinical suspicion of VTE. However, ECG-gated image acquisition did not influence the diagnostic reader agreement accuracy and inter-observer agreement of MCTA. Hence, it does not appear to be advantageous for the MCTA diagnosis of pulmonary embolism.

Aufwand, Zuverlässigkeit und histologische Ergebnisse der MR-gesteuerten Vakuumbiopsie suspekter Mammabefunde – retrospektive Auswertung von 389 Interventionen

The aim of this study was to evaluate the effort, accuracy, histological diagnoses and value of MR-guided vacuum biopsy (10-gauge, 9-gauge) as the diagnostic procedure for suspicious breast lesions visible on MRI alone. 389 MR-guided vacuum biopsies of suspicious MRM findings were performed in 365 patients either with a Vacora system (10G, Bard Company) or an ATEC system (9G, Suros Company). The retrospective study included the number of specimens, the table time, the complication rate, and the histopathological results for open biopsy and the findings after follow-up. The study included 341 unilateral unilocular, 12 unilateral bilocular and 12 bilateral unilocular MR-guided vacuum biopsies. In 27 patients (3.9%) the planned intervention was canceled because the lesion could not be reproduced. The average number of specimens was 15.1 (range 4 - 75) with the 10G technique and 14.6 (range 4 - 38) with the 9G technique. The table time was 43.2 min (range 17 - 95 min). Histology revealed concordant benign lesions in 231 cases (59.4%), borderline lesions in 50 cases (12.8%), malignant tumors in 106 cases (DCIS 30 [7.7%], invasive carcinoma 76 [19.5%]), and discordant findings in 2 cases (0.5%). The complication rate was less than 1%. MR-guided vacuum biopsy of the breast is an effective method for the minimally invasive percutaneous evaluation of suspicious breast lesions seen on MRI alone. As a consequence, primary open biopsy can be avoided and the rate of unnecessary surgical interventions reduced. There were no major differences between 10G and 9G vacuum biopsy systems.

Digitale Vollfeldmammographie: Vergleich zwischen radio-graphischer Direktvergrößerung und digitalem Monitorzooming

ZusammenfassungFragestellung. Es soll geklärt werden, ob und inwieweit das Zooming einer primär digital gewonnenen Röntgenmammographie die zusätzliche Anfertigung einer direkten Vergrößerungsmammographie entbehrlich macht. Methodik. Im Rahmen einer intraindividuellen Vergleichsstudie wurde bei 55 Patientinnen mit 57 Mikroverkalkungen die Aussagekraft der direkten Vergrößerungsmammographie (Faktor 1,8 [MAG1,8]) mit der nachträglich vom Monitorbild gezoomten Aufnahme (Faktor 1,8 [ZOOM1,8]) verglichen. Vier Auswerter stuften die Bildqualität ein und führten eine Charakterisierung der Verkalkungen nach der BI-RADS-Kategorisierung des American College of Radiology (ACR) durch. Ergebnisse. Histopathologisch fanden sich 16 benigne (sklerosierende Adenose, Hyperplasie, Hamartom, radiäre Narbe) und 21 maligne Veränderungen (DCIS, invasive Karzinome). Bei den restlichen 20 Patienten lagen gutartige Veränderungen vor, die im Verlauf über mehr als 2 Jahre befundkonstant waren. Die Bildqualität der direkten Vergrößerungsmammographie wurde besser eingeschätzt als die der gezoomten Aufnahme. Auch die Sensitivität der MAG1,8 war mit 97,5% der gezoomten Aufnahme (ZOOM1,8: 96,3%) geringfügig überlegen. Im Gegensatz hierzu zeigten die nachbearbeiteten Monitorbilder eine höhere Spezifität (MAG1,8: 34,3%, ZOOM1,8: 40%), einen besseren PPV (MAG1,8: 47,5%, ZOOM1,8: 49,8%) und eine günstigere Treffsicherheit (MAG1,8: 58,1%, ZOOM1,8: 61,2%). Die durchschnittliche Abweichung der BI-RADS-Kategorien lag bei 0,45 für MAG1,8 und bei 0,44 für ZOOM1,8. Schlussfolgerungen. Die digitale Aufnahmetechnik erlaubt aufgrund der Option des Monitorzoomings in aller Regel den Verzicht auf eine zusätzliche direkte Vergrößerungsmammographie. Hieraus resultieren eine weitere Verbesserung des Work-flows und ein Potenzial zur Dosisreduktion.AbstractPurpose. Our goal was to compare digital magnification mammograms with images zoomed from the digital contact mammogram in patients with microcalcifications. Patients and methods. Fifty-five patients with 57 microcalcification clusters were evaluated with a FFDM system (Senographe 2000D, GE). In addition to a digital contact mammogram, a digital direct magnification mammogram (factor 1,8 [MAG1,8]) and an image zoomed from the contact mammogram with a magnification factor of 1,8 [ZOOM1,8] were obtained in each patient. The image quality (perfect = 5 points to inadequate = 1 point) and the characterization of microcalcifications (BI-RADS 2–5) were evaluated by 4 readers. The results were compared to histopathologic findings in 35 patients (37 lesions) and follow-up in 20 patients. Results. Histopathology revealed 16 benign and 21 malignant lesions. 20 patients had benign changes verified by long-term follow-up. Image quality of direct magnification FFDM was assessed superior (4,44 points) to zoomed images (4,14 points). Sensitivity was superior for direct magnification (97,5%) in comparison to the zoomed images (96,3%). However, specificity (MAG1,8: 34,3%, ZOOM1,8: 40%), PPV (MAG1,8: 47,5%, ZOOM1,8: 49,8%) and accuracy (MAG1,8: 58,1%, ZOOM1,8: 61,2%) were better with zooming technique. Deviation steps from best BI-RADS assessment were 0,45 for MAG1,8 and 0,44 for ZOOM1,8. Conclusions. In patients with mammographic microcalcifications, monitor zooming of the digital contact mammogram is equivalent to direct magnification FFDM. Therefore, monitor zooming allows a reduction of the radiation exposure and an optimization of the work-flow.

Qualitätsmanagement in einer radiologischen Abteilung

ZusammenfassungZiel. Umsetzung qualitätsverbessernder Maßnahmen in der röntgendiagnostischen Abteilung einer universitären Einrichtung zur Verbesserung der internen Handlungsabläufe sowie der Kontakte im Bereich von Schnittstellen (Patient, Zuweiser, MTRA, Radiologe). Methodik. Nach der Durchführung von Vorgesprächen und Vorstudien erfolgten durch einen Berater moderierte halbtägige Workshops zu den Themen “Verhalten gegenüber Patienten”, “Befunderstellung und Verhältnis zu den Überweisern” sowie “Forschung und Ausbildung”. Es wurden Veränderungsmaßnahmen zum Abbau der wichtigsten Qualitätshemmnisse in verschiedenen Handlungsfeldern definiert und noch im Workshop durch den Abteilungsleiter entschieden. Ergebnisse. In 8 Behandlungsfeldern wurden insgesamt 53 Maßnahmen beschlossen, die jeweils von einem Verantwortlichen innerhalb einer definierten Frist umzusetzen waren. Nach 6 Monaten waren 46 (86%) dieser Maßnahmen komplett realisiert und weitere 4 (8%) innerhalb noch laufender Fristen in Bearbeitung. Anhand einer Patienten- und Zuweiserumfrage konnte die Zufriedenheit z. B. im Hinblick auf den Umgang mit Wartezeit bzw. Befunderstellung partiell gesteigert werden. Schlussfolgerungen. Die Durchführung qualitätsverbessernder Maßnahmen in einer radiologischen Abteilung führt zu einer deutlichen Verbesserung der internen Betriebsabläufe und z. T. auch der externen Kommunikation. Essentielle Bestandteile einer solchen Optimierung sind die Unterstützung durch einen abteilungsexternen Berater sowie eine konsequente Kontrolle der Umsetzungserfolge.AbstractPurpose. To increase the quality of internal and external interactions (patients, clinical colleagues, technicians, radiologists) in a department of radiology. Method. Accompanied by a well-experienced adviser workshops have been performed dealing with different topics like “contact to patients”, “performance of the radiological report and interaction with the referring colleague” or “research and teaching”. A catalogue of different actions was defined to reduce hindrances within the internal and external work-flow. Results. A total number of 53 actions was defined and related to different persons who were responsible for the realisation of the measures within a time interval. Six months after starting the quality management 46 (86%) of the defined actions were realised successfully, and another 4 (8%) measures were still running. There was a moderate increase of satisfaction of the patients and clinical colleagues considering the waiting time. Conclusions. A quality management in a radiological department allows an optimisation of the internal and external interactions. However, the guidance of a well-experienced adviser is as essential as the continuous control of successful finished measures.

Short first-pass MRI of the breast.

To reduce examination time and costs, a new concept for MRI of the breast is presented. This short first-pass MRI takes 4–5 minutes and could be applied to approximately three-quarters of all women.