Outcome Analysis and Rational Management of Enhancing Lesions Incidentally Detected on Contrast-Enhanced MRI of the BreastAndrea Teifke1, Hans Anton Lehr2, Toni Werner Vomweg1, Alexander Hlawatsch1 and Manfred Thelen1Audio Available | Share
To compare the value of hydro-MRI with follow-through examinations in the follow-up of Crohn's disease.22 patients known to be suffering from Crohn's disease were examined via 1.5 T-MR system; an oral contrast examination using 1000 ml of a 2.5% mannitol solution was performed in all patients. T2-weighted TSE sequences and T1-weighted SE sequences were performed before and after the intravenous injection of Gd-DTPA. To reduce movement artifacts caused by peristalsis of the gut, intravenous injection of 40 mg Buscopan was given. The findings of hydro-MRI were compared with the follow-through examinations.In the upper gastrointestinal tract, the follow-through examination showed clear advantages compared with hydro-MRI for the demonstration of inflammatory changes in the gut; Hydro-MRI was, however, somewhat more reliable in the ileum and colon. It was also more sensitive than the follow-through for the demonstration of enteric fistulae (four as compared with two cases), and in demonstration extraluminal changes (free fluid in six against zero, and inflammatory adherent loops (four against zero)). Amongst the 22 patients, hydro-MRI was equal (in 10) or better (in 8) than the follow-through examination for demonstrating the intestinal manifestations of Crohn's disease, and follow-through was better in only four.For follow-up of Crohn's disease, hydro-MRI is at least as good as follow-through examination, and is even preferable, because of the absence of radiation exposure of the usually young patients.
Quantification of left and right ventricular function using MRI in young cancer patients treated with cardiotoxic anthracyclines.Twenty-eight patients (mean age 16.4 years) underwent cardiac MRI at 1.5 T. The study protocol consisted of morphologic T2-weighted images with fat suppression and cine steady-state free precession sequences (SSFP) for functional analysis. Seven patients were examined at the end of chemotherapy, two of them also repeatedly during therapy, and 21 patients following an average period of three years after finishing chemotherapy (range one month--20 years)The end-systolic volume index increased and the ejection fraction of the left and right ventricle decreased during anthracycline therapy. Two of seven patients showed a myocardial edema at the end of the therapy. In 15 of all 28 patients, the left ventricular ejection fraction was reduced to less than 55 % (minimum 44 %). No clinical signs of cardiac insufficiency or cardiomyopathy were observed.MRI is able to detect acute as well as chronic subclinical cardiotoxic effects of anthracyclines. Impairment of the right ventricular function should be considered in the diagnosis of anthracycline-induced cardiomyopathy.
Pre-operative localization of abnormal findings during mammography makes it easier to find the lesions if they are not palpable. Our study is based on 373 procedures, using a "harpoon" needle. Radiographs of the operative specimen showed that 66% of the lesions had been completely removed, 15% had been partially removed and 19% could not be identified unequivocally. 172 patients had subsequent mammograms. Amongst these, the lesion had been completely removed in 70%, partially removed in 14% and in 10% it was still present. In 62% dense scar formation made it impossible to be certain whether excision had been complete.
In tracheo- and bronchomalacia, localization and determination of collapse is necessary for planning a surgical procedure. We compared inspiratory and spiral CT, cine CT, and bronchoscopy and evaluated the relevance of each method.Seventeen patients with suspected or verified tracheal stenosis or collapse underwent paired inspiratory and expiratory spiral CT and cine CT during continuous respiration (temporal increment 100 ms). The tracheal cross-sectional area was calculated and compared.In addition to bronchoscopy, further information concerning localization, extent, collapse, stability of the tracheal wall, distal portions of the stenosis, and extraluminal compressions was obtained. A significantly higher degree of tracheal collapse was seen using cine CT compared to paired spiral CT (p < 0.002). The findings changed the further surgical procedure in 3/17 patients. Further distal stenoses were excluded and bronchoscopy was verified in another 10/17.Paired inspiratory and expiratory spiral CT localizes tracheal stenoses and demonstrates clinically relevant extraluminal compression. Improved evaluation of expiratory collapse and further information of localized tracheal instability is provided by cine CT.
The aim of this study was to determine the accuracy of CT angiography (CTA) with a single spiral acquisition for the diagnosis of arterial stenoses and occlusion in patients with peripheral vascular occlusive disease.In a prospective study, intraarterial digital subtraction angiography and i.v. CTA from the groin to the lower calves were performed on 50 patients with vascular occlusive disease. Maximum-intensity-projection images in multiple views were produced. The accuracy of CTA with and without analysis of the axial scans was determined with digital subtraction angiography as the standard.The sensitivities of CTA were 100% for the diagnosis of femoral artery occlusion, 100% for the detection of popliteal artery (including tibial-peroneal arterial trunk) occlusion, and 94% for the detection of tibial artery occlusion. The specificities were 100%, 99%, and 98%, respectively. When maximum-intensity-projection images were interpreted without axial scans, sensitivities were 98%, 85%, and 92% and specificities were 100%, 99%, and 97%, respectively. For the accurate grading of high-grade (75-99%) stenoses of the superficial femoral artery and the popliteal artery (including tibial-peroneal arterial trunk), the sensitivities of CTA were 88% and 73% and the specificities were 94% and 100%, respectively. When maximum-intensity-projection images alone were used, the sensitivities for the correct grading of high-grade stenoses were 58% and 36% and the specificities were 99% and 100%, respectively.CTA from the groin to the lower calves is feasible, and the short examination time is a significantly advantage over the time required for other noninvasive techniques. CTA is particularly accurate in the depiction of femoral artery occlusions. Maximum-intensity-projection images are useful, but analysis of axial scans is more accurate for the grading of arterial stenoses. The results of CTA are encouraging enough to warrant further studies. A CTA protocol covering the pelvic and pedal vessels remains to be established and evaluated.
Assessment of the temporal and spatial dynamics of hyperpolarized Helium-3 (3He) distribution in the lung with ultrafast gradient-echo magnetic-resonance imaging.Coronal images of the lung were acquired using ultrafast gradient-echo pulse sequences with TR/TE = 3.3 ms/1.3 ms (slice thickness, 40 mm) and TR/TE = 2.0 ms/0.7 ms (without slice selection). A series of 80 or 160 projection images was obtained with 210 ms or 130 ms temporal resolution, respectively. Imaging was performed during several respiratory cycles after application of a single bolus of 300 mL hyperpolarized 3He. Measurements were performed in six healthy volunteers (spontaneous breathing).Different phases of in- and expiration could be visualized. During the course of consecutive respiratory cycles the 3He signal decreased due to dilution of 3He in residual alveolar gas and by inspired air, relaxation due to oxygen and the RF pulses, and due to Helium-3 washout. The signal of a single bolus of 3He was detected in the lung for up to four respiratory cycles. Anatomical structures were better visualized on slice selective images than on images without slice selection.Distribution of inspired 3He within the tracheobronchial tree and alveolar space and its washout can be visualized by ultrafast imaging of a single bolus of hyperpolarized 3He gas. This method may allow for regional analysis of lung function with temporal and spatial resolution superior to conventional methods.
To evaluate the diagnostic accuracy of CT and MRI in the diagnosis of malignant peripheral neuroectodermal tumors (MPNT), the imaging data of nine patients with immunehistochemically proven MPNT were retrospectively analyzed. The average age was 24 years (ranging from 5 to 63 years). MRI and CT of all patients showed large tumors with direct infiltration of the surrounding structures. Intratumoral calcifications were not identified. All tumors showed equal to less high signal intensity in T1- and high signal intensity in T2-weighted images. Because of its high soft-tissue contrast, MRI is the most capable imaging modality in the diagnosis and therapy-monitoring in these tumors.
