Diffusion-weighted magnetic resonance imaging of breast lesions: the influence of different fat-suppression techniques on quantitative measurements and their reproducibility.

OBJECTIVE: The aim of this study was to evaluate the influence of different fat-suppression techniques on quantitative measurements and their reproducibility when applied to diffusion-weighted imaging (DWI) of breast lesions. METHODS: Twenty-five patients with different types of breast lesions were examined on a clinical 1.5-T magnetic resonance imaging (MRI) system. Two diffusion-weighted sequences with different fat-suppression methods were applied: one with spectral presaturation by inversion recovery (SPIR), and one with short-TI inversion recovery (STIR). The acquisition of both sequence variants was repeated with modified shim volume. Lesion-to-background contrast (LBC), apparent diffusion coefficients (ADC) ADC(0,1000) and ADC(50,1000), and their coefficients of variation (CV) were determined. RESULTS: In four patients, the image quality of DWI with SPIR was insufficient. In the other 21 patients, 46 regions of interest (ROI), including 11 malignant and 35 benign lesions, were analysed. The LBC, ADC(0,1000) and ADC(50,1000) values, which did not differ between initial and repeated measurements, were significantly higher for STIR than for SPIR. The mean CV improved from 10.8 % to 4.0 % (P = 0.0047) for LBC, from 6.3 % to 2.9 % (P = 0.0041) for ADC(0,1000), and from 6.3 % to 2.6 % (P = 0.0049) for ADC(50,1000). CONCLUSION: For STIR compared to SPIR fat suppression, improved lesion conspicuity, higher ADC values, and better measurement reproducibility were found in breast DWI. KEY POINTS: • Quality of fat suppression influences quantitative DWI breast lesion measurements. • In breast DWI, STIR fat suppression worked more reliably than SPIR. • Lesion-to-background contrast and its reproducibility were significantly higher with STIR fat suppression. • Lesional ADCs and their reproducibility were significantly higher with STIR fat suppression.

[The "EVA" Trial: Evaluation of the Efficacy of Diagnostic Methods (Mammography, Ultrasound, MRI) in the secondary and tertiary prevention of familial breast cancer. Preliminary results after the first half of the study period]. / Die "EVA"-Studie: Evaluierung der Leistungsfähigkeit diagnostischer Verfahren (Mammographie, Sonographie, MRT) zur sekundären und tertiären Prävention des familiären Mammakarzinoms -- Zwischenergebnisse nach der ersten Hälfte der Förderungsperiode.

PURPOSE: To investigate the respective diagnostic accuracies of the different breast imaging modalities, i. e., mammography (Mx), high-frequency breast ultrasound (US), and dynamic contrast-enhanced breast (MRI) regarding the early diagnosis of familial (hereditary) breast cancer. MATERIALS AND METHODS: A prospective, non-randomized controlled clinical multi-center trial is performed at 4 academic tertiary care centers in Germany (Ulm, Munchen/Grosshadern, Munster and Bonn) for a total period of 4 years, sponsored by the German Cancer Aid. The protocol consists of semiannual clinical visits and breast ultrasound, and annual bilateral two-view Mx, US and MRI. Imaging studies were first analyzed independently, then Mx was read in conjunction with US, followed by Mx combined with MRI, and finally, all three imaging modalities were read in synopsis. We present the concept and first results of this trial. RESULTS: So far, 748 screening rounds are available for analysis in 613 women. A total of 12 breast cancers have been identified, with 11/12 cases in the pTis or pT1/N0 stage. The mean size of detected invasive cancers was 7 mm. A total of 19 benign lesions were biopsied due to false-positive imaging diagnoses. The breast cancer detection rates were: Mx: 5/12 (42 %), US 3/12 (25 %), MRI 10/12 (83 %), and the positive predictive values: Mx 5/17 (29 %), US 3/15 (30 %), and MRI 10/23 (43 %). CONCLUSION: The preliminary data suggest that early diagnosis of familial breast cancer is feasible by intensified surveillance, in particular with the addition of MRI.

Diagnostic usefulness of segmental and linear enhancement in dynamic breast MRI.

The aim of this study was the evaluation of the diagnostic usefulness of ductal or segmental enhancement in dynamic breast MRI. Segmental and ductal enhancement have been established as the breast MRI hallmarks of intraductal breast cancer (DCIS); however, the positive predictive value of this imaging finding is still unknown. In our study, we analysed the overall prevalence of a segmental or a linear enhancement pattern on breast MRI for an unselected cohort of patients. The aim was to evaluate the diagnostic usefulness of segmental or linear enhancement. Second, we asked whether biopsy was necessary also in the absence of mammographic findings suggestive of DCIS. Prospective, consecutive evaluation of 1,003 patients undergoing bilateral dynamic breast MRI. Studies were interpreted by two experienced breast radiologists. A diagnostic or screening two-view mammogram was available for all patients. Biopsy or short-term breast MRI follow-up was recommended for patients showing a segmental or a linear enhancement pattern on breast MRI. The patients' final diagnoses were established by imaging guided excisional or core biopsy or by clinical plus conventional imaging follow-up for a period of 2 years. The prevalence of segmental or linear enhancement was determined for patients with a final diagnosis of benign breast disease compared with those with a diagnosis of breast cancer. One hundred twenty patients had invasive breast cancer, 24 patients had DCIS and 859 patients had unsuspicious breast MRI or benign breast disease. A segmental or a linear enhancement pattern was found for 50/1,003 (5%) patients (17 DCIS, 33 benign breast diseases). Accordingly, the positive predictive value of segmental and linear enhancement is 34% (17/50); the specificity of this criterion is 96% (826/859). For 4/24 (17%) patients, DCIS was visible as segmental or linear enhancement on dynamic breast MRI, whereas no abnormalities were visible on the corresponding mammogram. The overall prevalence of a ductal or a segmental enhancement pattern on breast MRI is low. But this finding has a high specificity and a moderate positive predictive value for intraductal neoplastic changes. We conclude that if segmental or linear enhancement is identified on breast MRI further work-up is necessary. We recommend either direct MR-guided vacuum-assisted core biopsy or short-term follow-up breast MRI within 3 months. If ductal enhancement then persists, MR-guided biopsy should be recommended even in the absence of mammographically visible signs of DCIS.

[Prevalence and type of incidental extramammary findings in MRI of the breast]. / Häufigkeit und Spektrum von Zusatzbefunden ausserhalb des Brustdrüsenparenchyms bei MR-mammographischen Untersuchungen.

PURPOSE: To analyze prevalence and type of relevant incidental findings in patients undergoing breast MRI. MATERIALS AND METHODS: This prospective investigation consists of 1013 patients who underwent breast MRI as follow-up after breast cancer therapy, for pre-operative staging, and for screening of high-risk patients as well as for clarification of unclear clinical examinations and inconclusive conventional mammography. Prevalence and type of relevant incidental extramammary findings were recorded together with the indication of the examination. RESULTS: Incidental extramammary findings were encountered in 92 (9%) of the 1013 patients. MRI had markedly more incidental extramammary findings with the staging examinations (39.5%) and follow-up examinations (11.6%). The prevalence of incidental malignant findings was 81% in patients examined for pre-operative staging. Incidental benign and malignant findings were equally frequent in patients followed after breast cancer therapy. The incidental findings were exclusively benign in patients without a history of breast cancer. CONCLUSION: The interpretation of breast MRI should incorporate a careful analysis of the adjacent extramammary structures. Especially patients followed after breast cancer therapy can be expected to have incidental malignant findings outside the breast.

Severe abdominal infections in neutropenic patients.

Abdominal infections are an important cause of morbidity and mortality in neutropenic patients. We present a retrospective series of 16 patients, mostly with acute leukemia, who developed severe abdominal infections during chemotherapy-induced neutropenia between 1991 and 1997. The frequency among patients with acute leukemia was 2.35% (13 of 553). Thirteen patients presented with enterocolitis and 3 patients presented with cholecystitis. Eight patients died. Bacteremia was present in 6 patients, 4 patients suffered from proven or strongly suspected fungal infections, and 1 patient suffered from cytomegalovirus infection. Early surgical management was required in a patient with intestinal obstruction, whereas other patients could be managed conservatively. Two patients with acute cholecystitis were treated with antibiotics until the end of neutropenia and then were resected. Severe abdominal injections in neutropenic patients, which are often fatal, were caused by nonbacterial microorganisms in one-fourth of the cases and could be managed conservatively in most instances.

MR imaging--guided large-core (14-gauge) needle biopsy of small lesions visible at breast MR imaging alone.

PURPOSE: To report our experience with magnetic resonance (MR) imaging-guided large-core breast biopsy of lesions visible at breast MR imaging only. MATERIALS AND METHODS: Stereotactic large-core (14-gauge) needle biopsy of 78 lesions visible at MR imaging only was performed with MR imaging guidance in 59 patients. Results were validated with excisional biopsy or mastectomy in 42 lesions and with radiologic-pathologic correlation and/or follow-up MR imaging for at least 2 years in another 17 lesions. The accuracy of MR imaging--guided core biopsy was determined for those 59 lesions with established validation. The effect on patient treatment was evaluated by comparing the prebiopsy treatment plan with the ultimate treatment. RESULTS: Histologic diagnosis from core biopsy was possible in 77 (99%) of 78 lesions. In the 59 lesions with established validation, the diagnostic accuracy of MR imaging--guided core biopsy was 98% (58 of 59). Successful MR imaging--guided core biopsy findings changed treatment in 70% (54 of 77) of lesions. Difficulties were due to the unsatisfactory performance of earlier types of MR imaging--compatible biopsy guns and decreasing target visibility during intervention. CONCLUSION: MR imaging--guided large-core stereotactic breast biopsy is sufficiently accurate for obtaining histologic proof of lesions visible only at MR imaging. It can change patient treatment by reducing unnecessary surgical biopsy and can enable one-step surgery for breast cancers.

[MRI of the lung parenchyma]. / MRT des Lungenparenchyms.

Up to now the role of lung imaging in routine diagnostic work-up of pulmonary diseases has remained rather limited. However, the well-known technical problems of lung MRI (low spatial resolution, motion artifacts, low signal-to-noise ratio of the lung parenchyma) have been reduced by recent technical advances, thus leading to a significantly improved image quality in MRI of the lungs. Compared to helical CT good results have been demonstrated using a cardiac and respiratory triggered T2 weighted turbo spin echo sequence which should be included in every imaging protocol. Recent studies have proven that MRI is comparable or even better than the gold-standard helical CT regarding the staging of bronchogenic cancer and follow-up examinations of pneumonia and lung metastases. For other indications like the assessment of pulmonary nodules and the early diagnosis of pneumonia MRI has shown promising results; however these results need to be confirmed in larger patient groups. In patients with chronic infiltrative lung disease, CT scanning remains the superior imaging modality due to the inferior spatial resolution of MRI. In conclusion MRI is a reliable alternative imaging method to helical CT for many indications; in some cases it may be a promising additional examination method.

MR imaging of pneumonia in immunocompromised patients: comparison with helical CT.

OBJECTIVE: A T2-weighted turbo spin-echo sequence was compared with CT in immunocompromised patients with opportunistic pneumonia. SUBJECTS AND METHODS: Sixteen patients with pneumonia shown on helical CT were examined using MR imaging within 2 days. MR examinations were performed on a 1.5-T system with a transversal T2-weighted ultrashort turbo spin-echo sequence using expiratory gating and diastolic triggering. Two radiologists reviewed the MR and CT images independently. The number, localization, and morphology of lesions were noted. MR image quality was rated using a 4-point scale. RESULTS: The results of the CT and MR examinations concerning the number and morphology of pulmonary lesions caused by pneumonia were identical in 75% of the patients (n = 12). MR imaging was able to depict all typical features of pneumonia including different stages of parenchymal infiltration (ground-glass versus consolidation). MR imaging depicted early necrotizing pneumonia not shown on contrast-enhanced CT in 25% of the patients (n = 4); 82% of the MR examinations were rated as excellent (1 point) or good (2 points). CONCLUSION: T2-weighted turbo spin-echo imaging is able to depict characteristic features of pneumonia and shows excellent results compared with CT. This MR technique offers advantages in patients with pneumonia because of its higher sensitivity for necrotizing pneumonia.

[CT angiography hemodynamically relevant to renal artery stenosis. Evaluation of AXIAL, MPR, MIP and SSD reconstruction procedures under standard investigation conditions]. / CT-Angiographie hämodynamisch relevanter Nierenarterienstenosen. Evaluation der Rekonstruktionsverfahren AXIAL, MPR, MIP und SSD unter standardisierten Untersuchungsbedingungen.

PURPOSE: To evaluate the various reconstruction methods of helical-CT angiography for the assessment of hemodynamically relevant renal artery stenoses in comparison to i.a. DSA. METHODS: In 76 renal arteries the reconstruction modalities AXIAL, MRP, MIP and SSD of helical-CT angiography were compared with the results of i.a. DSA for the determination of the grade and location of the stenosis. RESULTS: The highest accuracy of stenosis grading was 76% with AXIAL reconstruction. In 8% of the cases grading of the stenosis was not evaluable by the AXIAL reconstruction. In these cases, a higher sensitivity in the detection of hemodynamically relevant stenoses (> grade II, > 50%) was achieved with the reconstruction mode MPR (96%) than with MIP (92%). In 51% of the cases the reconstruction mode SSD was not suitable for any diagnosis of renal artery stenosis because of overlying calcified plaques. CONCLUSIONS: The evidence of hemodynamically relevant stenosis in helical-CT angiography in comparison to i.a. DSA succeeds most reliable by using the reconstruction modality AXIAL in combination with MPR. The MIP reconstruction provides information about the anatomy of the renal arteries within one image.

Breast MR imaging screening in 192 women proved or suspected to be carriers of a breast cancer susceptibility gene: preliminary results.

PURPOSE: To compare magnetic resonance (MR) imaging with conventional imaging in screening high-risk women. MATERIALS AND METHODS: This prospective trial included 192 asymptomatic and six symptomatic women who, on the basis of personal or family history or genetic analysis, were suspected or proved to carry a breast cancer susceptibility gene. RESULTS: Fifteen breast cancers were identified: nine in the 192 asymptomatic women (six in the first and three in the second screening round) and six in the symptomatic patients. Concerning the asymptomatic women, four of the nine breast cancers were detected and correctly classified with mammography and ultrasonography (US) combined; another two cancers were visible as well-circumscribed masses and were diagnosed as fibroadenomas. MR imaging allowed the correct classification and local staging of all nine cancers. In 105 asymptomatic women with validation of the 1st-year screening results, the sensitivities of mammography, US, and MR imaging were 33%, 33% (mammography and US combined, 44%), and 100%, respectively; the positive predictive values were 30%, 12%, and 64%, respectively. CONCLUSION: The accuracy of MR imaging is significantly higher than that of conventional imaging in screening high-risk women. Difficulties can be caused by an atypical manifestation of hereditary breast cancers at both conventional and MR imaging and by contrast material enhancement associated with hormonal stimulation.

Breakthrough invasive fungal infections in neutropenic patients after prophylaxis with itraconazole.

This study analyses invasive fungal infections in neutropenic patients with haematological malignancies during antifungal prophylaxis with itraconazole. From September 1994 to December 1998 20 patients developed fungal infections. Two patients suffered from disseminated infections by yeasts and 18 patients suffered from pulmonary infections by moulds (eight proven, 10 highly probable in high-resolution CT scans). In these patients the itraconazole trough concentrations exceeded 500 ng ml-1 (measured by high performance liquid chromatography) significantly less often (median 48%, interquartile range 0-100%) than in another group of 150 leukaemia patients without invasive fungal infections who received 287 courses of prophylaxis with itraconazole at our institution (median 100%, interquartile range 38-100%, P = 0.039). Twelve patients died, six of these had refractory disease. Patients with fatal invasive fungal infections had lower median itraconazole concentrations immediately before occurrence of the infection than patients with non-fatal infections: 120 (0-478) ng ml-1 versus 690 (305-1908) ng ml-1 (P = 0.039). In conclusion, this analysis of breakthrough invasive fungal infections during prophylaxis with itraconazole demonstrates that patients with itraconazole trough concentrations below 500 ng ml-1 were significantly more likely to develop fungal infections and that the last itraconazole trough concentration before occurrence of the infection was significantly lower in patients with fatal invasive fungal infections.

[MRT versus CT in the diagnosis of pneumonias: an evaluation of a T2-weighted ultrafast turbo-spin-echo sequence (UTSE)]. / MRT versus CT in der Diagnostik von Pneumonien: Evaluation einer T2-gewichteten ultraschnellen Turbo-Spin-Echo-Sequenz (UTSE).

PURPOSE: To evaluate a T2-weighted URSE sequence for the assessment of pulmonary infiltrations in comparison to CT. METHODS: 28 MRT scans of 22 patients with confirmed pneumonia were recorded on a 1.5 Tesla apparatus with an expiratory and diastolic triggered, T2-weighted ultrafast-spin-echo sequence in axial slice mode with the following parameters: TReff/TE/Turbo-factor 2000-4000/90 ms/21-23; slice thickness/separation 6/0.6 mm; FOV 360 mm; 24 slices. 24 spiral CTs (since thickness/table advance: 1-2 mm/10mm) were available for comparison. The separate evaluation of MRTs and CTs was performed by three radiologists in a consensus procedure with regard to pulmonary lesions (e.g., infiltration, round foci, net patterns) and image quality of the MRTs (4-step scale). RESULTS: In 71% of the cases the CTs and MRTs agreed with the diagnosis and representation of the lesions, in 25% MRT was superior. MRT was better for the detection of pulmonary abscesses. In 93% the image quality of the MRT was very good to good. CONCLUSIONS: MRT in the technique presented here is in most cases equal to CT for the detection of pneumonia. Diagnosis of pulmonary abscesses seems to be better with MRT.

Infantile fibromatosis of the neck with intracranial involvement: MR and CT findings.

CT and MR imaging studies were performed in a 3-year-old boy with infantile fibromatosis arising from the infratemporal fossa and extending into the middle cranial fossa. On CT scans, the lesion was hyperattenuating (44-49 Hounsfield units [HU]), enhancing significantly after application of contrast material (63-66 HU). The MR images showed a multilobulated lesion of heterogeneous signal intensity. The tumor was markedly hypointense on T2-weighted images and slightly hypointense on T1-weighted images relative to brain tissue, iso- or slightly hyperintense relative to tongue muscle on both T2- and T1-weighted images, and enhanced strongly after administration of gadopentetate dimeglumine.

Dynamic breast MR imaging: are signal intensity time course data useful for differential diagnosis of enhancing lesions?

PURPOSE: To assess the relevance of the signal intensity time course for the differential diagnosis of enhancing lesions in dynamic magnetic resonance (MR) imaging of the breast. MATERIALS AND METHODS: Two hundred sixty-six breast lesions were examined with a two-dimensional dynamic MR imaging series and subtraction postprocessing. Time-signal intensity curves of the lesions were obtained and classified according to their shapes as type I, which was steady enhancement; type II, plateau of signal intensity; or type III, washout of signal intensity. Enhancement rates and curve types of benign and malignant lesions were compared. RESULTS: There were 101 malignant and 165 benign lesions. The distribution of curve types for breast cancers was type I, 8.9%; type II, 33.6%; and type III, 57.4%. The distribution of curve types for benign lesions was type I, 83.0%; type II, 11.5%; and type III, 5.5%. The distributions proved significantly different (chi 2 = 139.6; P < .001). The diagnostic indices for signal intensity time course were sensitivity, 91%; specificity, 83%; and diagnostic accuracy, 86%. The diagnostic indices for the enhancement rate were sensitivity, 91%; specificity, 37%; and diagnostic accuracy, 58%. CONCLUSION: The shape of the time-signal intensity curve is an important criterion in differentiating benign and malignant enhancing lesions in dynamic breast MR imaging. A type III time course is a strong indicator of malignancy and is independent of other criteria.

[Detection of focal lung lesions with magnetic resonance tomography using T2-weighted ultrashort turbo-spin-echo-sequence in comparison with spiral computerized tomography]. / Detektion fokaler Lungenläsionen mit der Magnetresonanz-Tomographie mittels T2-gewichteter Ultrashort-Turbo-Spin-Echo-Sequenz im Vergleich zur Spiral-Computer-Tomographie.

PURPOSE: To compare spiral CT and MRT for the detection of focal pulmonary lesions. PATIENTS AND METHODS: 50 patients with focal pulmonary lesions confirmed by spiral CT were examined using a T2-weighted UTSE sequence (TE: 90 ms, TR: 1500-3000 ms, echo interval 9 ms, 8 mm slice thickness, diastolic triggering, expiratory breath gating). Image quality was compared using a 4-stage scale. Lesions with a minimum size of 2 mm were counted and measured in the CT image. The results were compared with the MRT images. RESULTS: The image quality in CT examinations with an average value of 1.22 better than that in MRT (1.78). In total 163 pulmonary lesions with a size of 2-115 mm were found by CT. MRT found 151/163 lesions (92.6%). Of the 12 lesions not detected, 9 were smaller than 4 mm, 1 corresponded to a 12 mm large, completely calcified granuloma. In 2 cases there was a 4 or 5 mm large unspecific scar. Thus, 160/163 (98.1%) of all lesions larger than 3 mm were detected. CONCLUSIONS: MRT with use of a suitable UTSE sequence is an alternative to CT for the detection of focal pulmonary lesions with a size larger than 3 mm.

Changing role of invasive aspergillosis in AIDS--a case control study.

OBJECTIVE: From December 1993 until January 1996 we observed 10 cases of invasive aspergillosis in a cohort of 140 patients with AIDS (7%). By contrast, no invasive aspergillosis was diagnosed in a cohort of 278 patients with AIDS between 1986 until 1993. METHODS: Case controls were assigned randomly to each patient with invasive aspergillosis from the total pool of HIV-infected patients. Patients with invasive aspergillosis were studied retrospectively by matched-pairs analysis with respect to risk factors, radiological, microbiological and autopsy findings. RESULTS: Patients with aspergillosis had more AIDS-defining events (3.5 [2-5] vs. 2 [2-3], median [range], P < 0.05) and a longer median survival time with full-blown AIDS (31.5 [14-45] months vs. 20.5 [5-32] months, P < 0.005) than their case controls. Patients with invasive aspergillosis tended to have lower white blood cell counts and exhibited significantly decreased median CD4 counts (7 [0-44]/mm3 vs. 27 [8-57]/mm3, P < 0.05). CONCLUSIONS: Due to better management of opportunistic diseases and improved antiretroviral therapy, the lifespan of patients with full blown AIDS is prolonged. Patients who have survived four or more AIDS-defining events are at risk for invasive aspergillosis. This risk is associated with low white blood cell counts and CD4 cell counts.

Antifungal prophylaxis with itraconazole in neutropenic patients with acute leukaemia.

The efficacy of antifungal prophylaxis with itraconazole capsules and its serum concentrations were evaluated in patients intensively treated for acute leukaemia. A consecutive group of patients without systemic antifungal prophylaxis (January 1993 to August 1994, period 1) was compared with another consecutive group of patients (period 2) who received itraconazole capsules (September 1994 to April 1995 400 mg/day, from May 1995 onwards 600 mg/day). All patients admitted with acute leukaemia and standard or high-dose chemotherapy were included into the study. Clinical endpoint was mortality from proven fungal infection. Seventy-six patients and 148 courses of cytotoxic chemotherapy were analysed in the control group as well as 47 patients and 112 treatment courses in the intervention group. Antifungal prophylaxis led to a significant decrease of mortality from invasive fungal infections (8.8%-0.9%, P = 0.005). The median trough concentration of itraconazole of all measurements was 520 ng/ml (range 230-793) in patients who received 400 mg/day and 760 ng/ml (370-1200) in patients receiving a dosage of 600 mg/day (P = 0.002). These findings suggest that itraconazole is an effective drug for antifungal prophylaxis but also that a considerable number of patients do not reach the desired trough levels (>500 ng/ml) with itraconazole capsules.

Geotrichum capitatum septicaemia in neutropenic patients: case report and review of the literature.

We report a case of systemic infection with Geotrichum capitatum in a patient with acute myeloid leukaemia. Three days before death, the patient developed acute renal failure, probably caused by occlusion of glomerula with hyphae of G. capitatum. Up until now, prophylaxis and treatment of infections caused by Geotrichum capitatum have not been established. However, the prophylactic administration of high-dose itraconazole and the therapeutic use of liposomal amphotericin B are subjects of discussion.