Biomedical subjects

E Grabbe

Publications and source records attributed to E Grabbe.

At least 19 recordsLinked to original sources

PubMed2006

[Value of MR-guided localization and biopsy in breast lesions].

Contrast-enhanced dynamic MR mammography can provide important additional diagnostic information when performed for certain indications. When suspicious lesions are identified on MR mammography and cannot be reproduced using other imaging modalities, a decision must be made as to its management, i. e. further diagnostic work-up. One possibility is the short-term follow-up of such findings, resulting in higher costs and a possible delay in the start of treatment of a malignant lesion. An alternative to a follow-up is an MR-guided intervention. MR-compatible equipment has been developed for this purpose. This includes equipment specialized for percutaneous biopsy and preoperative localization. The following is an overview of the diagnostic value of MR-guided biopsy and preoperative localization including the relevant literature.

Biopsy↗

PubMed2005

Applications and literature review of the BI-RADS classification.

The Breast Imaging Reporting and Data System (BI-RADS) of the American College of Radiology (ACR) is a tool created to reduce variability in the terminology used in mammographic reports. An illustration of mammographic examples from our institution interpreted according to the BI-RADS lexicon of the American College of Radiology (ACR) is presented. A literature review concerning the usefulness and limitations of the BI-RADS lexicon is given.

Breast Diseases↗

PubMed2005

[Retrospective analysis of a computer-aided detection (CAD) system in full-field digital mammography in correlation to tumor histology].

PURPOSE: To evaluate the usefulness of a computer-aided detection (CAD) system in full-field digital mammography in correlation to tumor histology. MATERIAL AND METHODS: A total of 476 patients (226 patients with histologically proven malignant tumors, 250 healthy women) took part in this study. The mammograms were studied retrospectively, using the CAD system Image Checker. For 226 patients digital mammograms in MLO-projection were available. For 186 of these patients the CC-projection was also available. CAD markers that correlated with histologically proven carcinomas were considered to be true-positive markers. All other CAD markers were considered to be false-positive. Histologically proven carcinomas without markers were false-negative results. The dependence of the CAD markers placement upon the different carcinoma histologies was studied using the Chi-square test. RESULTS: No significant difference could be proven for the detectability of malignant breast lesions of different histologic types. For the detectability of ductal carcinoma in situ (DCIS), invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC), lobular carcinoma in situ (LCIS), tubular carcinoma and ductulo-lobular carcinoma, the true positives were 71.1 %, 75 %, 70.7 %, 70 %, 60 % and 80 %, respectively, in the MLO projection and 83.9 %, 75.9 %, 81.8 %, 77.8 %, 87.5 % and 33.3 %, respectively, in the CC projection. There was an average of 0.5 false-positive markers per mammographic image. CONCLUSION: The histologic type of carcinoma seems to have no influence on detectability when using the CAD system. The high rate of false-positive markers shows, however, the limited specificity of the CAD system and that improvements are necessary.

Adult↗

PubMed2005

[Non-destructive, preclinical evaluation of root canal anatomy of human teeth with flat-panel detector volume CT (FD-VCT)].

PURPOSE: Successful endodontic diagnostics and therapy call for adequate depiction of the root canal anatomy with multimodal diagnostic imaging. The aim of the present study is to evaluate visualization of the endodont with flat-panel detector volume CT (FD-VCT). MATERIALS AND METHODS: 13 human teeth were examined with the prototype of a FD-VCT. After data acquisition and generation of volume data sets in volume rendering technology (VRT), the findings obtained were compared to conventional X-rays and cross-section preparations of the teeth. RESULTS: The anatomical structures of the endodont such as root canals, side canals and communications between different root canals as well as denticles could be detected precisely with FD-VCT. The length of curved root canals was also determined accurately. The spatial resolution of the system is around 140 microm. Only around 73 % of the main root canals detected with FD-VCT and 87 % of the roots could be visualized with conventional dental X-rays. None of the side canals, shown with FD-VCT, was detectable on conventional X-rays. In all cases the enamel and dentin of the teeth could be well delineated. No differences in image quality could be discerned between stored and freshly extracted teeth, or between primary and adult teeth. CONCLUSION: FD-VCT is an innovative diagnostic modality in preclinical and experimental use for non-destructive three-dimensional analysis of teeth. Thanks to the high isotropic spatial resolution compared with conventional X-rays, even the minutest structures, such as side canals, can be detected and evaluated. Potential applications in endodontics include diagnostics and evaluation of all steps of root canal treatment, ranging from trepanation through determination of the length of the root canal to obturation.

Adult↗

PubMed2004

[Flat-panel detector-based computed tomography: accuracy of experimental growth rate assessment in pulmonary nodules].

PURPOSE: To determine the performance of an a-Si/CsJ flat-panel detector-based volumetric computed tomography (VCT) prototype in volumetry of synthetic nodules in a pulmonary phantom, and to assess VCT accuracy in the assessment of hypothetic tumor growth rates based on predefined tumor doubling times. METHODS: The true volumes of 50 synthetic nodules (diameter range = 1.36 - 5.34 mm) were determined and VCT volumetry was performed before and after isovolumetric deformation of the nodules. The percent measurement error (PMF) was calculated as the percent difference of the measured from the true volume. Based on the PMF, the minimum interval between two scans was determined that would be needed to depict tumor growth corresponding to the minimum number of required follow-up days (FUDs). Based on predefined tumor doubling times (VDT) FUDs were determined before and after nodule deformation. RESULTS: Measured volumes of undeformed and deformed nodules of 0.99 - 20.05 mm (3) differed significantly from corresponding true volumes (p = 0.002 - 0.004). The PMFs of these nodules significantly exceeded the values measured in larger nodules (p = 0.0001 - 0.0029). In addition, PMFs were significantly lower before than after deformation (1.33 - 7.14 % and 0.61 - 11.09 %, respectively; p = 0.002). For theoretical VDTs of 177 and 396 days, the calculated FUDs for detection of tumor growth were 19.1 and 42.7 days before deformation, and 30.2 and 67.6 days after deformation for nodules < 2 mm, respectively. CONCLUSION: VCT allows for accurate volumetry of smallest pulmonary nodules and may become a valuable clinical tool for depiction of tumor growth of even small lesions within very short scan intervals.

Data Interpretation, Statistical↗

PubMed2004

[Diagnosis and classification of calcaneal fractures in computed tomography].

PURPOSE: To compare image quality of single-slice spiral CT (SSCT) and multislice spiral CT (MSCT) in the diagnosis and classification of calcaneal fractures and to present a rapid and precise algorithm for the classification system of Stuermer. MATERIALS AND METHODS: In 102 patients with 124 calcaneal fractures, spiral CT was performed, in 82 cases as SSCT with a slice thickness (SD) of 3 mm, a table speed (TS) of 3 - 4 mm/rot and an increment of 1.5 mm. In 42 cases, patients were scanned using MSCT (SD of 1.25 mm, increment 0.8 mm). For these examinations, 2 different scan protocols were used, with a TS of 3.75 mm/rot in one group (n = 21) and a TS of 7.5 mm/rot in the other group (n = 21). The image quality of axial sections and reconstructed images was assessed on a scale from 1 to 5 (1 = very good; 5 = insufficient). The fractures were evaluated using a classification system according to Stuermer, which assigns three main groups (A/B/C) and three subtypes (1/2/3). RESULTS: MSCT had substantial advantages over SSCT with respect to scan time and image quality, especially for multiplanar reformatting (median 1.5 versus 4.0). TS showed no significant influence on the image quality. The standardized evaluation of the images enabled a classification of fractures within 5 minutes. All fractures could be assigned to the different types and subtypes. This classification system takes into account the severity of the fracture and the therapeutic approach. The most common type (90 of 124 fractures) were "joint depression" fractures (type C), which were treated by surgery in 92 %. Type A fractures were treated conservatively in 72 %. CONCLUSION: Spiral CT, especially MSCT, allows rapid diagnosis and precise classification of calcaneal fractures, achieved with high quality multiplanar reformatting. The presented classification in different fracture types and subtypes allows an adequate planning of therapy.

Adolescent↗

PubMed2003

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.

Acute Disease↗

PubMed2003

Ultrasound-guided laser interstitial thermo therapy for treatment of non-resectable primary and secondary liver tumours--a feasibility study.

AIM: Therapeutic options for primary and secondary liver tumours not suitable for resection or transplantation are limited. In this palliative situation, the scope of ablative therapeutic procedures has improved. Laser interstitial thermotherapy is a minimal invasive procedure for local tumour destruction within solid organs. This pilot study reports initial clinical experience using ultrasound-guided percutaneous laser interstitial thermotherapy. METHODS: Sixty patients between the ages of 34 and 78 years with non-resectable primary and secondary liver tumours were treated palliatively with Nd:YAG laser interstitial thermotherapy. High resolution abdominal ultrasound with power duplex was used to control the placement and coagulation procedure. RESULTS: In all cases, sonographic imaging allowed exact placement of the laser probe and verification of thermocoagulation by a resulting hyperechogenic signal enhancement. The maximum diameter of laser-induced destruction measured 5 cm. Ultrasound with power duplex and echo enhancer, CT or MRI scans indicated necrosis of treated tumour lesions. No serious adverse event occurred and 30-day-mortality was zero. CONCLUSIONS: Ultrasound-guided laser interstitial thermotherapy is safe and reliably ablates primary and secondary liver tumours. The combination of high resolution ultrasound and laser therapy facilitates a minimally invasive but elaborate treatment. Besides chemotherapy, this procedure could be a useful palliative treatment to control the mass of liver tumours unsuitable for resection or transplantation.

Adult↗

PubMed2003

[The contribution of different postprocessing methods for multislice spiral CT in acute pulmonary embolism].

PURPOSE: To investigate the value of different postprocessing algorithms for multislice spiral CT (MSCT) in diagnosing acute pulmonary embolism. MATERIALS AND METHODS: Forty-eight patients with suspected pulmonary embolism prospectively underwent MSCT using an 8-slice spiral CT. Using a confidence level on a three-point scale, three radiologists reviewed 2-mm and 5-mm axial slices, 5-mm and 10-mm axial maximum intensity projections (MIP) and 2-mm coronal slices as well as interactively generated multiplanar reformatted images. A subsequent consensus reading of the primary 1.25-mm axial slices served as gold standard. ROC analysis was applied to the various vascular sections. RESULTS: The ROC analysis revealed a higher diagnostic accuracy of the 2-mm axial sections as compared to the 5-mm axial slices (Az = [0.988;0.976] vs. Az = [0.988;0.802]). Coronal and multiplanar reformations also showed excellent diagnostic accuracy (Az = [0.972;0.949] and Az = [0.997;0.951], respectively) and were significantly superior to the 5-mm axial slices through the segmental and subsegmental arteries (p=0.05). MIP showed the weakest diagnostic accuracy (Az = [0.967;0.802] for 5-mm MIP; Az = [0.879;0.781] for 10-mm MIP). CONCLUSION: Thin axial slices as well as coronal and multiplanar reformations are superior to thick axial slices in the diagnosis of acute pulmonary embolism. MIP is not suited for accurate diagnosis of pulmonary embolic disease.

Acute Disease↗

PubMed2003

[Contrast-enhanced MR angiography of the arterial and portovenous system of the liver with varying concentrations of contrast medium].

PURPOSE: To evaluate the diagnostic value of a higher concentrated contrast medium (gadobutrol) for contrast-enhanced MRA of the hepatic arteries and portovenous system. MATERIALS AND METHODS: The examinations were performed on a 1.5-Tesla whole body imaging system (Magnetom Symphony Quantum, Siemens) with a 30-mTesla/m gradient field strength using a phased-array body coil. A 3D FLASH sequence (TR/TE/FA 3.88 ms/1.44 ms/25(3)) was used imaging the hepatic arteries and portovenous system after determination of the circulation time. The study included 50 patients, with 25 patients (group 1) injected with 0.2 mmol Gd-GTPA/kg body weight and 25 patients (group 2) injected with 0.1 mmol gadobutrol/kg body weight. The signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) were calculated for both groups. The image quality was graded by three radiologists on a 5-point scale. RESULTS: The highest SNR was measured in group 1, with no statistically significant differences of the SNR in the abdominal aortal, coeliac trunk and common hepatic artery. CNR was also similar in both groups. Likewise, portal, superior mesenteric and splenic veins showed no statistically significant differences. All cases were found to have a good image quality. CONCLUSION: For MRA of the hepatic arteries and the portal veins, the higher concentrated Gd-DTPA contrast medium gadobutrol can be used at half the dosage recommended for the standard Gd-DTPA contrast medium.

Adult↗

PubMed2003

[Diagnostic performance of retrospectively ECG-gated multislice CT of acute pulmonary embolism].

AIM: This study determined the diagnostic performance of ECG-gated MSCT in comparison with conventional MSCT. MATERIALS AND METHODS: Forty-five consecutive patients prospectively underwent ECG-gated (group 1, n = 23) or non-ECG-gated (group 2, n = 22) 8-slice MSCT of the pulmonary arteries. Image data were interactively evaluated by three independent chest radiologists with respect to the presence of emboli at different arterial levels, and with regard to cardiac motion artefacts. Consensus reading by two experienced chest radiologists served as diagnostic gold standard. ROC analysis was carried out for the different vascular sections. RESULTS: Twenty-five patients (56 %) were diagnosed to have pulmonary embolism (13 from group 1, 12 from group 2). Cardiac motion artefacts were significantly more frequent in group 2 (70 % in group 2 versus 13 % in group 1, p < 0.05). There was no significant difference between the two groups in the overall sensitivities (0.92 vs. 0.95) and specificities (0.92 vs. 0.98) or in sensitivities and specificities at any assessed pulmonary arterial level. CONCLUSION: ECG-gated MSCT pulmonary angiography does not significantly influence the diagnostic performance of MSCT in these patients. Therefore no recommendation for routine clinical practice can be given.

Adolescent↗

PubMed2003

Dose reduction in full-field digital mammography: an anthropomorphic breast phantom study.

The aim of this study was to evaluate the potential for radiation dose reduction by using other beam qualities in full-field digital mammography (FFDM) compared with screen-film mammography (SFM). FFDM was performed using an amorphous silicon detector with a caesium iodide scintillator layer (Senographe 2000D, GE, Milwaukee, USA). SFM was performed using a state-of-the-art conventional system (Senographe DMR, GE, Milwaukee, USA) with a dedicated screen-film combination. An anthropomorphic breast phantom with superimposed microcalcifications (50-200 microm) was used to evaluate the detectability of microcalcifications. Contact mammograms and magnification views (m=1.8) performed with both the digital and the screen-film system were compared. Images were exposed automatically. Molybdenum/Molybdenum (Mo/Mo) anode-filter combination, 28 kVp and 63 mAs were selected by the automatic optimization of parameters (AOP) of the conventional system. This exposure protocol (protocol A) was also used as baseline for the digital system. Dose reduction in digital mammography was achieved by using protocol B with Mo/Rh and 31 kVp and protocol C with Rh/Rh and 32 kVp. The detectability of microcalcifications was assessed by 3 experienced readers with a confidence level ranging from 1 to 5. A receiver operating characteristic (ROC) analysis was performed. In protocol A the area under the ROC-curve (A(z)) for contact views performed by the screen-film system was 0.64 and for those performed with the FFDM system 0.68. The A(z) values were 0.74 in protocol B and 0.65 in protocol C for the digital system. For the conventional and digital magnification views A(z) values were 0.71 and 0.79, respectively. For protocol B the A(z) value was 0.81 and for protocol C it was 0.76. There is no statistically significant difference in the A(z) values for the different protocols in digital mammography and no significant difference from the screen-film system. A potential for dose reduction by using other beam qualities seems to be possible with this digital system.

Anthropometry↗

PubMed2002

Value of F-18 FDG hybrid camera PET and MRI in early takayasu aortitis.

Takayasu aortitis (TA) is a chronic inflammatory and fibrotic vasculitis of large- and medium-sized arteries. Early stages of the disease show a panarteritis and inflammatory wall thickening of the aorta and its branches, whereas advanced (fibrotic) stages comprise stenosis, aneurismatic transformation and occlusion. Magnetic resonance imaging visualises early-stage disease with high accuracy and is considered to be the method of choice in the diagnosis of TA. The aim of this article is the detailed comparison of FDG-PET performed with a hybrid camera and MR imaging in five patients with early TA. Five patients (median age 60 years) were enrolled during an ongoing prospective study on [18F]2'-deoxy-2-fluoro-D-glucose (FDG) hybrid camera PET in patients with fever of unknown origin (FUO). These patients underwent MR imaging after establishing the diagnosis of TA. Abnormal FDG uptake in the wall of the aorta was noted in all patients. The bracheocephalic artery and the common carotid arteries were visualized in 3 cases. Increased uptake of the subclavian artery was found in 3 patients and in 4 patients pathological uptake was noted in the ilio-femoral vessels. Of 34 vascular regions studied, 26 (76%) showed elevated FDG uptake. On transversal MR images vessel wall thickening and contrast enhancement of the thoracic aorta was found in 4 patients (ascending aorta/aortic arch: n=2; descending aorta: n=3; abdominal aorta: n=1). Additionally, vessel wall pathologies of the subclavian and the common carotid arteries could be shown in 1 patient and in another patient in the ilio-femoral arteries. No abnormalities were found using contrast-enhanced MR angiography. Of 28 vascular regions studied, 9 (32%) showed vasculitis on MRI. The FDG-PET is a suitable whole-body screening method in the primary diagnosis of early TA, especially in those cases with early disease that present with uncharacteristic symptoms such as FUO. Both MRI and MRA remain indispensable in the exact determination of the pathomorphological changes and in the documentation of complications such as stenosis, aneurismatic transformation and occlusion.

Aged↗

PubMed2002

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

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 [CI(95%)=(70%; 98%)] and 81% for masses [CI(95%)=(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.

Breast Neoplasms↗

PubMed2002

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

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- micro m 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.

Breast Neoplasms↗

PubMed2002

Imaging skeletal anatomy of injured cervical spine specimens: comparison of single-slice vs multi-slice helical CT.

Our objective was to compare a single-slice CT (SS-CT) scanner with a multi-slice CT (MS-CT) scanner in the depiction of osseous anatomic structures and fractures of the upper cervical spine. Two cervical spine specimens with artificial trauma were scanned with a SS-CT scanner (HighSpeed, CT/i, GE, Milwaukee, Wis.) by using various collimations (1, 3, 5 mm) and pitch factors (1, 1.5, 2, 3) and a four-slice helical CT scanner (LightSpeed, QX/i, GE, Milwaukee, Wis.) by using various table speeds ranging from 3.75 to 15 mm/rotation for a pitch of 0.75 and from 7.5 to 30 mm/rotation for a pitch of 1.5. Images were reconstructed with an interval of 1 mm. Sagittal and coronal multiplanar reconstructions of the primary and reconstructed data set were performed. For MS-CT a tube current resulting in equivalent image noise as with SS-CT was used. All images were judged by two observers using a 4-point scale. The best image quality for SS-CT was achieved with the smallest slice thickness (1 mm) and a pitch smaller than 2 resulting in a table speed of up to 2 mm per gantry rotation (4 points). A reduction of the slice thickness rather than of the table speed proved to be beneficial at MS-CT. Therefore, the optimal scan protocol in MS-CT included a slice thickness of 1.25 mm with a table speed of 7.5 mm/360 degrees using a pitch of 1.5 (4 points), resulting in a faster scan time than when a pitch of 0.75 (4 points) was used. This study indicates that MS-CT could provide equivalent image quality at approximately four times the volume coverage speed of SS-CT.

Cervical Vertebrae↗

PubMed2002

Screen film vs full-field digital mammography: image quality, detectability and characterization of lesions.

The objective of this study was to compare screen-film mammography (SFM) to full-field digital mammography (FFDM) regarding image quality as well as detectability and characterization of lesions using equivalent images of the same patient acquired with both systems. Two mammography units were used, one with a screen-film system (Senographe DMR) and the other with a digital detector (Senographe 2000D, both GEMS). Screen-film and digital mammograms were performed on 55 patients with cytologically or histologically proven tumors on the same day. Together with these, 75 digital mammograms of patients without tumor and the corresponding previous screen-film mammograms not older than 1.5 years were reviewed by three observers in a random order. Contrast, exposure, and the presence of artifacts were evaluated. Different details, such as the skin, the retromamillary region, and the parenchymal structures, were judged according to a three-point ranking scale. Finally, the detectability of microcalcifications and lesions were compared and correlated to histology. Image contrast was judged to be good in 76%, satisfactory in 20%, and unsatisfactory in 4% of screen-film mammograms. Digital mammograms were judged to be good in 99% and unsatisfactory in 1% of cases. Improper exposure of screen-film system occurred in 18% (10% overexposed and 8% underexposed). Digital mammograms were improperly exposed in 4% of all cases but were of acceptable quality after post-processing. Artifacts, most of them of no significance, were found in 78% of screen-film and in none of the digital mammograms. Different anatomical regions, such as the skin, the retromamillary region, and dense parenchymal areas, were better visualized in digital than in screen-film mammography. All malignant tumors were seen by the three radiologists; however, digital mammograms allowed a better characterization of these lesions to the Breast Imaging Reporting and Data System (BI-RADS;) [corrected] categories (FFDM better than SFM in 23 of 165 vs 9 of 165 judged cases in SFM). In conclusion, digital mammography offers a consistent, high image quality in combination with a better contrast and without artifacts. Lesion detection in digital images was equal to that in screen-film images; however, categorization of the lesions to the BI-RADS classification was slightly better.

Adult↗

PubMed2002

Classification of hypervascularized lesions in CE MR imaging of the breast.

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, post-initial 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.

Breast↗