Characterisation of Lesions after Stereotactic Radiosurgery for Brain Metastases: Impact of Delayed Contrast Magnetic Resonance Imaging.

AIMS: To investigate if brain metastases and radiation injuries after stereotactic radiosurgery (SRS) have different signal intensity (SI) time courses up to 55 min after contrast agent application and if delayed contrast magnetic resonance imaging (MRI) contributes to improve diagnostic accuracy. MATERIALS AND METHODS: Thirty-four consecutive patients treated with SRS for cerebral metastases were prospectively enrolled in the study. T1-weighted images were acquired on a 3-Tesla MR unit at three time points, at 2 (TP1), 15 (TP2) and 55 (TP3) min after administering contrast agent. A simultaneous, matched-pairs approach was used for region of interest analysis of the entire contrast-enhancing lesion (SI-e), the centre (SI-c), the border of the lesion (SI-b) and the adjacent non-contrast-enhancing tissue (SI-p). SIs of brain metastases and radiation injuries after SRS were compared using a two-level, linear, mixed-effects regression model. RESULTS: In total, 41 lesions were analysed: 16 metastases and 25 radiation injuries. The SI time course of SI-e, SI-c and SI-b proved to be significantly different for both entities (P < 0.001) from TP2 to TP3. The SI of 39/41 lesions increased from TP1 to TP2 for the three parameters. Radiation injuries showed a further signal increase at least for SI-c from TP2 to TP3, whereas for all the three parameters SI decreased in all metastases. CONCLUSION: Brain metastases and radiation injuries after SRS have a characteristic and statistically significantly different SI time course on sequential gadolinium enhancement MRI when late MR studies are included.

Overview of herd and CAEV status in dwarf goats in South Tyrol, Italy.

The analysis of the electronic data processing proved that 323 dwarf goats older than 6 months from 165 farms were kept in 63 of the 116 communes of South Tyrol. The number of dwarf goats maintained ranged from 1 to 19 animals, the average farm size revealed to be of 2 dwarf goats/farm. 47 animals were aged between 6 months and 1 year (AG1), 97 were between 1 - 2 years of age (AG2) and 179 were aged older than 2 years (AG3). The mean age amounted to 3.8 years, the age limit being 10 years. 235 animals were female and 88 animals were male (sex ratio 2.7:1). 187 animals (57.9%) were born between November and April and 136 animals (42.1%) were born between May and October. 13 animals (4.0%) proved to possess antibodies against CAEV in a serological examination performed with ELISA. The herd seroprevalence was 6.1% (10 positive farms). The seropositivity did not vary significantly in the different age groups (AG1: 4.3%; AG2: 4.1%; AG3: 3.9%). The seroprevalence of animals born outdoors between November and April (5.9%) did not differ significantly from those born indoors between May and October (1.5%). The seroprevalence of the female animals (3.4%) did not vary significantly from that of the male goats (5.7%). The low seroprevalence ascertained in the dwarf goats in South Tyrol is due to the non-existing milk production, the marginal contact among each other as well as the sparse animal trade. This study should prompt adequate means of control to be established, so that the introduction of positive animals can be prevented. An eradication programme would be advisable, due to the low disease prevalence and its chances to be successfully implemented.

Ultrasound demonstration of mammographically detected microcalcifications.

PURPOSE: To evaluate the capabilities of breast ultrasound (US) for identifying microcalcifications in benign breast changes, in situ carcinomas, and small nonpalpable invasive carcinomas. MATERIAL AND METHODS: Forty-six consecutive patients with 49 clustered microcalcifications detected by mammography were included in this prospective study. Patients with palpable breast lesions were excluded. Breast US was performed with knowledge of mammographic findings for presence and visibility of microcalcifications, and for parenchymal structure abnormalities. Mammographic and US findings were compared with histology. RESULTS: Nine ductal in situ carcinomas, 2 lobular in situ carcinomas, 11 invasive carcinomas and 27 benign lesions were confirmed by histology. For all lesions, US achieved a sensitivity of 75% in the detection of microcalcifications. The detection rate for microcalcification in invasive and in situ carcinomas was 100%. In 11 cases, no microcalcifications were visible on US; they all proved to be benign on histology. CONCLUSION: Microcalcifications in malignant lesions are reliably recognized by US. They are, however, difficult to detect in fibrocystic breast changes.

Diagnosis of atrophic rhinitis in a Simmental heifer by computed tomography.

Atrophic rhinitis was diagnosed in a 10-month-old heifer with the assistance of computed tomography. The aetiology of the condition in cattle is uncertain and the clinical disease may be overlooked owing to the lack of signs such as the shortening or deformity of the snout observed in pigs.

Comparison of cystourethrography and dynamic MRI in bladder neck descent.

PURPOSE: The purpose of this work was to test whether there are statistically significant differences between dynamic MR and lateral cystourethrogram measurement results in patients with bladder neck descent. METHOD: Twenty-seven women (39-83 years old, mean 60.6 years old) with urinary incontinence and bladder neck descent were examined by dynamic MRI using a single shot fast spin echo sequence with half-Fourier data acquisition. Bladder neck position, angle of inclination of the urethral axis, posterior vesicourethral angle, and depth of cystoceles were measured at perineal contraction and at maximal pelvic strain. The nonparametric Wilcoxon test for paired values was used to analyze whether there were statistically significant differences between lateral cystourethrogram and dynamic MR measurement results. The Spearman correlation coefficient (rs) was calculated for all parameter pairs. RESULTS: Measurements at maximal pelvic strain showed the greatest levels of agreement between MRI and cystourethrography. The best results were attained for the cystocele measurements (p > 0.5, rs = 0.95). Bladder neck position showed the second best agreement; if MR measurements were corrected by 0.46 cm, no statistically significant difference (p > 0.2, rs = 0.92) was calculated. Measurements at perineal contraction tallied least, probably due to the different positions adopted during the two examinations. CONCLUSION: Measurement data on dynamic MRI for the bladder neck position and the extension of cystocele at maximal pelvic strain are comparable with lateral cystourethrogram data.

[Calcinosis in goats]. / Kalzinose bei Ziegen.

Death, abortion, decreased milk yield and emaciation in dairy goats occurred due to calcinosis in a goat operation on 1100 meter sea level in Tyrol. This could be diagnosed by the clinical, sonographical and pathomorphological investigation. In the basic fodder yellow oat grass proportion was present with 40%. Clinically the apathic goats showed reduced appetite, emaciation, dyspnea, anaemic mucous membranes, heart noises and less activity to move. The blood-chemical examination of one goat revealed an increased activity of AP (199 U/l), calcium and phosphor-concentrations were in normal range. Sonographically liquidothorax and -perikard, calcified pulmonary and aortic valves and a thickened aortic orifice as well as calcification of kidneys, enlargment of liver and ascites could be diagnosed in this goat. The sonographical findings were confirmed by pathomorphological examination.

Pelvic floor descent: dynamic MR imaging using a half-Fourier RARE sequence.

Dynamic magnetic resonance imaging (MRI) using a single shot fast spin-echo technique was evaluated as a noninvasive alternative to cystourethography or colpocystorectography in patients with pelvic organ prolapse and/or urinary incontinence. Thirty-two patients were included in this prospective study. Colpocystorectography was performed in 10 patients who previously had undergone hysterectomy and in 2 patients without history of hysterectomy with clinical suspicion of rectoceles. Bead-chain cystourethrography was performed in 20 patients without hysterectomy. For dynamic MRI, a single-slice half-Fourier RARE sequence (imaging time 2 seconds) was used to depict the pelvic organs at different levels of pelvic strain. The results obtained with dynamic MRI were correlated with the x-ray findings. All 17 cystoceles, 10 rectoceles, 2 enteroceles, and 7 vaginal prolapses could be demonstrated on MRI. Diagnostic information gained from these images was equivalent to that obtained with colpocystorectography and superior to that obtained with cystourethrography; with the latter, important findings were missed (four rectoceles). We conclude that dynamic MRI of the pelvic floor with a half-Fourier RARE sequence can reliably detect descents of all three pelvic compartments, that it requires no contrast agent, and that no radiation exposure is involved.

[RARE urography in pelvic tumors: diagnostic ranking and comparison with intravenous pyelography]. / RARE-Urographie bei Beckentumoren: Diagnostische Wertigkeit und Vergleich mit der Ausscheidungsurographie.

PURPOSE: To examine if RARE urography may replace conventional intravenous urography in patients with suspected urinary obstruction in pelvic tumours. MATERIALS AND METHODS: In a prospective trial on 120 patients with pelvic tumours scheduled for operation, biplanar RARE urography was performed and compared to conventional intravenous urography and ultrasound findings. RESULTS: In 30 out of 120 patients an ureteric obstruction was diagnosed by ultrasound. Sensitivity of RARE urography for obstruction was 98% as compared to 60% in conventional intravenous urography. In 12 patients additional retrograde cystoureterography showed a sensitivity of 83%. Specificity of RARE urography and intravenous urography was 100%. In combination with axial MR tomography RARE urography yielded a more precise localisation of the site of obstruction and the underlying cause (98%) as compared to conventional urography (60%) and ultrasound (56%). CONCLUSION: By use of RARE urography urinary obstruction can be reliably demonstrated or ruled out. Combining RARE urography with tomographic MR imaging allows the precise depiction of the site of the obstruction and may demonstrate the underlying pathology.

Mycotic aneurysm rupture of the descending aorta.

A 69-year-old diabetic male with salmonella bacteremia developed hypovolemic shock and swelling of the neck. A CT examination revealed massive mediastinal hemorrhage extending into the neck soft tissues caused by false aneurysm rupture of the descending thoracic aorta. Aortography showed continuous extravasation from a large leak at the medial side of the descending thoracic aorta. Although surgical intervention was immediately performed, the patient died 3 weeks later from multiple-organ failure. In this report, CT and angiographic findings of mycotic aneurysm rupture are presented and a review is given.

[Recent developments and applications of MRI sequence technique. I: turbo spin echo, HASTE, turbo inversion recovery, turbo gradient echo, turbo gradient spin sequences]. / Neuere Entwicklungen und Anwendungen in der MR-Sequenztechnik. Teil I: Turbo-Spin-Echo, HASTE, Turbo-Inversion-Recovery, Turbo-Gradienten-Echo, Turbo-Gradienten-Spin-Echo-Sequenzen.

Goal of this two-part report is to provide clinical MRI radiologists with a guide to the world of new and clinically available MRI pulse sequences. Discussed are the principles of rapid scan techniques like multiple spin-echo imaging, multiple gradient echo imaging, echo planar imaging, diffusion and perfusion imaging, and future perspectives (review article).

Cine-MR imaging of the shoulder.

PURPOSE: Shoulder lesions are usually examined with the joint in only one or two positions. We examined the shoulder with the joint in a variety of positions. We also assessed the application of cine-MR to the detection of instability and impingement. MATERIAL AND METHODS: The cine-MR examinations were performed in 30 patients and 15 healthy volunteers. We used an open 0.2 T system and a closed 1.0 T system. Spoiled gradient echo 2D T1-weighted images and turbo spin-echo T1- and T2-weighted images were obtained with a field of view of 180 mm. The examinations were videotaped and evaluated later. RESULTS: Normal variations of the glenohumeral joint were easy to recognize. Sub-luxations and luxations of the humeral head as well as rupture of the labrum were identified. It was also possible to identify the labrum with a signal change after arthroscopic refixation. And we were able to objectively assess distances between the osseous structures during dynamic movement. CONCLUSION: Unlike static MR, cine-MR would appear to be useful in visualizing the capsular ligament complex of the gleno-humeral joint in impingement and instability. It also provides information on dynamic changes and may thus prove to be an important tool for shoulder diagnostics. The method may provide an early diagnosis in the sub-acromial impingement syndrome.

MRI of lymphomas of the orbits and the paranasal sinuses.

PURPOSE: The purpose of this study was to point out MR characteristics of non-Hodgkin lymphomas of the orbits and the paranasal sinuses and the benefit of fat-suppressed contrast-enhanced sequences. METHOD: The MR images of 16 patients with lymphoma of the orbits and the paranasal sinuses were retrospectively analyzed for signal intensity, contrast enhancement, bone destruction, and mass effect. The findings were confirmed by means of biopsy (Stage IE disease) or follow-up imaging after chemotherapy (Stage IV disease). RESULTS: MRI clearly delineated the extension of the lymphomas. On the T1-weighted images, the signal intensity of the lymphoma was hypointense compared with the gray matter of the brain in 12 cases and intermediate in 4 cases. The T2-weighted fast SE images showed a hyperintense signal in 12 cases, intermediate in 3 cases, and even hypointensity in 1 case. All lesions enhanced after intravenous Gd-DTPA administration, reliably visible in the T1-weighted fat-suppressed sequences but not visible in three cases in the T1-weighted SE sequences. Bony wall destruction was evident in cases with paranasal but never in isolated orbital lymphoma. CONCLUSION: While extension of lymphoma can be accurately described by MRI, a specific diagnosis is not achievable on the basis of signal intensities and enhancement patterns alone. Therefore, at least in cases of suspected Stages IE and IIE, biopsy proof is needed. Fat-suppressed contrast-enhanced sequences possess the highest detection rate and should therefore always be applied.

MR imaging of the carpal tunnel.

OBJECTIVE: Investigations were conducted regarding changes of carpal tunnel shape during wrist motion and the variations of space for the median nerve as well as the preoperative signs of carpal tunnel syndrome (CTS) and the postoperative restitution. METHODS: Axial MR images (1.0 T) were performed at the level of the distal radioulnar joint, pisiforme bone and hook of hamate level of 20 wrists of patients with clinical symptoms of CTS and further 20 wrists of volunteers. This was conducted with the wrist in neutral position, 45 degrees extension and 45 degrees flexion. T2-weighted signal intensity of the median nerve were measured in 18 patients pre- and postoperatively. RESULTS: The increase of the cross-sectional area of the median nerve at the pisiform level and the flattening of the median nerve at the hook of hamate level as well as the volar bowing of the flexor retinaculum at the pisiform and hook of hamate level were significantly greater in patients with CTS than in those with normal wrists (P < 0.05-0.001). In postoperative follow-up studies the distal flattening of the median nerve recovered in 94%. The signal intensity of the median nerve on T2-weighted images decreased in 67%. CONCLUSIONS: Flexion at the pisiform and hamate level as well as extension at the pisiform level narrows the space available for the median nerve potential leading to compression of the median nerve. MR imaging is accurate and reliable for diagnosis and postoperative follow-up of CTS.

Proton magnetic resonance spectroscopy of the brain in symptomatic and asymptomatic patients with liver cirrhosis.

BACKGROUND & AIMS: Hepatic encephalopathy (HE) is associated with typical changes of cerebral metabolite pattern observed by proton magnetic resonance (MR) spectroscopy consisting of a depletion of myo-inositol and an increase of glutamine. The aim of this study was to determine whether abnormalities in brain metabolism in neurologically asymptomatic patients with liver cirrhosis can be detected by spectroscopy. METHODS: In a prospective study, 39 patients with liver cirrhosis were examined clinically according to standardized neuropsychological tests to define whether overt, subclinical, or no hepatic encephalopathy was present. All patients underwent proton MR spectroscopy at short echo times. RESULTS: Spectroscopy allowed for the diagnosis of subclinical HE in 4 of 4 cases and of overt HE in 10 of 11 cases. In 24 cases of mere liver cirrhosis and normal neuropsychological testing, a typical metabolic pattern with a depletion of myo-inositol and an increased glutamine peak were found. A good correlation between the glutamine signal and the clinical grading was found. CONCLUSIONS: Proton MR spectroscopy allows for the diagnosis of HE and subclinical HE, also shows the typical pathological metabolite pattern in patients with cirrhotic livers without subclinical HE, and might be more sensitive than neuropsychological testing. Glutamine could serve as a spectroscopic marker for the clinical state of the patients.

Color Doppler and duplex flow analysis for classification of breast lesions.

The purpose of this study was to evaluate the differences of blood supply in benign and malignant breast tumors by color Doppler flow measurements. The study included 471 patients, 133 with carcinomas, 325 with benign breast lesions, and 13 with mastitis. An ATL UM9/HDI was used with an electronic 10-MHz linear array broadband transducer. The following flow data were analyzed: Presence of vascularity; number of tumor arteries; the mean, minimum, maximum RI index, and AB ratio; the mean, minimum, and maximum peak systolic flow velocity and the sum of all peak systolic flow velocities in each tumor. In all cancers and in most benign pathologies vascularity was found. Highly significant differences between benign and malignant were found for all quantitative flow data such as number of tumor arteries and blood flow velocity (P < 0.0001). Flow profiles analyzed by RI index and AB ratio showed a trend for increased flow resistance in malignancies. However, due to the wide overlap between benign and malignant, indices did not allow a sufficient differentiation. The study showed that standardization of the Doppler examination technique and equipment parameters is essential for vascularity assessment of tumors.

[Quantitative CT assessment of the proximal femur. Experimental studies on its correlation with breaking load in femoral neck fractures]. / Quantitative CT des proximalen Femurs. Experimentelle Untersuchungen zur Korrelation mit der Bruchlast bei Schenkelhalsfrakturen.

PURPOSE: In an experimental study, the correlation between the trabecular bone density of the different regions of the proximal femur and the fracture load in the setting of femoral neck fractures was examined. METHODS: The bone mineral density of 41 random proximal human femora was estimated by single-energy quantitative CT (SE-QCT). The trabecular bone density was measured at the greatest possible extracortical volume at midcapital, midneck and intertrochanteric level and in the 1 cm3 volumes of the centres of these regions in a standardised 10 mm thick slice in the middle of the femoral neck axis (in mg/ml Ca-hydroxyl apatite). The proximal femora were then isolated and mounted on a compression/bending device under two-legged stand conditions and loaded up to the point when a femoral neck fracture occurred. RESULTS: Statistical analysis revealed a linear correlation between the trabecular bone density and the fracture load for the greater regions, with the highest value in the maximal area of the head (coefficient factor r = 0.76). CONCLUSION: According to our data, the measurement of the trabecular bone by SE-QCT at the femoral head is a more confident adjunct than the neck or trochanteric area to predict a femoral neck fracture.

Hoffa fracture--a radiologic diagnostic approach.

Hoffa fracture is a rare injury consisting of unicondylar tangential posterior fracture of the distal femur. On plain radiographs the fracture line is clearly seen. However, some fractures and musculotendinous injuries may display subtle features and may be difficult to detect even with optimal images. We explain the mechanism of injury, discuss the diagnostic work-up and the operative and nonoperative management.

[Computerized tomography findings score in the differentiation of adrenal tumors in patients with extra-adrenal malignomas]. / Computertomographischer Befundungscore zur Differenzierung von Nebennierentumoren bei Patienten mit extraadrenalen Malignomen.

PURPOSE: In a retrospective study the diagnostic accuracy of computed tomography for the differentiation of benign from malignant adrenal masses in patients with extra-adrenal malignancies was evaluated. For this differentiation a new score system was tested. PATIENTS AND METHODS: Size, density, structure, and borders of adrenal masses in 60 patients with extra-adrenal tumours were analysed and scored. The single criteria and the total score values were correlated with the final diagnosis achieved either by histology or by follow-up CT examinations. RESULTS: Score values above 4 indicated always metastases and score values below 2 were benign lesions. An overlap occurred at score values between 2 and 3 resulting in an overall accuracy of 83.3%. CONCLUSION: Single CT criteria are not reliable enough to differentiate benign from malignant adrenal lesions: better results are achieved by using our scoring system.