Jutta Peters

A microfluorimetric study of translational diffusion in erythrocyte membranes

A method is described which permits quantitative study of translational diffusion in the membranes of single cells. Human erythrocytes were labelled with fluorescein isothiocyanate and then hemolyzed, which yielded ghosts of normal shape and strong fluorescence. By application of sodium dodecylsulfatepolyacrylamide gel electrophoresis it was found that a very large part of fluorescein isothiocyanate was bound to the proteins of the erythrocyte membrane. In a fluorescence microscope, single ghosts were exposed to a sharply bounded intensive beam of light in such a manner that in each case only one half of the ghost was bleached. By microscopic measurements it was studied whether fluorescent material would diffuse from the unbleached part of the membrane into the bleached part and vice versa. However, within the measuring time of 20 min at room temperature a significant degree of such a diffusion could not be detected. In order to evaluate the experimental data quantitatively, the diffusion equation for a spherical surface was solved, and the obtained solution furthermore was integrated over the hemispheres. By these means a value of 3 · 10−12 cm2/s was derived from the experimental data as an upper limit for the diffusion coefficient of fluorescein isothiocyanate-labelled compounds in the erythrocyte membrane at 20°–23°C.

Traumatic injuries of the pelvis and thoracic and lumbar spine: does thin-slice multidetector-row CT increase diagnostic accuracy?

The objective is to evaluate different multidetector-row CT (MDCT) strategies for adequate classification of spinal and pelvic injuries. Seventy intubated patients after multiple trauma underwent conventional radiography (CR) and MDCT. Examinations included the pelvis (P), the lumbar spine (LS) and the thoracic spine (TS). Conventional radiographs, 3-mm (CT5) and 5-mm scans (CT3) and 3-mm and 5-mm scans combined with MPR (CT3R/CT5R) were compared to surgery, autopsy and clinical course. MDCT led to significantly better results than CR (P<0.01). Correlation coefficients were r=1.0 (CT3R), r=0.96 [TS] to r=1.0 [P/LS] (CT5R), r=0.8 [P] to r=1.0 [TS] (CT3), r=0.80 [P] to r=0.86 [TS] (CT5) and r=0.3 [TS] to r=0.69 [P] (CR). Fractures were identified by CT3R in 100% of cases, by CT5R in 95%, by CT3 in 90% [P]−100% [TS], by CT5 in 83.3% [LS]−90% [P] and by CR in 57.1% [TS]−87.2% [P]. Unstable fractures were identified in 100% by CT3R, CT5R and CT3, 85.7% [TS]−100% [P/LS] by CT5 and 57.1% [TS]−80% [P] by CR. Only overlapping thin-slice multiplanar reformation allows for an adequate classification of spinal and pelvic injuries and thus is highly emphasized in patients after severe blunt trauma.

Evaluation of the Stereotactic 8g Vacuum-assisted Breast Biopsy in the Histologic Evaluation of Suspicious Mammography Findings (bi-rads Iv)

Purpose:The purpose of this study was to evaluate the potential of the new 8G stereotactic vacuum-assisted breast biopsy (ST-driver, Mammotome; Ethicon Endosurgery) in the histologic evaluation of BI-RADS IV microcalcifications. Materials and Methods:Fifty-eight patients with 61 mammographic BI-RADS IV microcalcifications underwent stereotactic vacuum-assisted breast biopsy (SVAB). The new 8G system was mounted on the ST driver, which was formerly used only with the handheld version under sonographic guidance. The evaluation criteria for each biopsy were minimally invasive and operative histologies, the time needed for biopsy, the amount of bleeding, number of rotations and specimen, the degree of resection, and the complications. Results:Fifty-eight of 61 biopsies were technically successful because ≥50% were resected (29 × 100%, 8 × 90%, 5 × 80%, 6 × 70%, 3 × 50%, 3 × 0%). In 7 cases with representative biopsies of segmental suspicious microcalcifications, the degree of resection could not be exactly measured. All but 2 biopsies were performed without clinically relevant complications and after gaining enough specimens (Ø 12.6 specimen, 1.85 rotations). Those 2 patients showed evidence of severe bleeding into the breast tissue and operative revision had to be performed (3.5%). The size of intramammary hematoma was measurable in 27 biopsies and showed a range from 0.5 to 5 cm (Ø 2.7 cm). The average external bleeding was still low with 16 mL (5–80 mL). In 3 of 61 lesions, it was not possible to gain representative tissue as a result of displacement of the lesion after introducing or shooting the needle. The average time needed for all biopsies was 28.2 minutes for all but 5 very complicated biopsies, which took 16.1 minutes. The histologic findings with further operative workup were: 10 ductal carcinomas in situ (DCIS), 4 atypical ductal hyperplasias, 1 atypical lobular hyperplasias (ALH), 3 lobular carcinomas in situ (LCIS), and 6 invasive ductal carcinomas. In 7 of 12 of the initial DCIS histologies, the operative histology was also DCIS, whereas in 4 of 12, no residual malignant tumor was found. In 1 of 12 patients with an initial DCIS histology, operative histology revealed invasive ductal cancer (8.3%). The cases with lobular lesions (ALH, LCIS) did not show any evidence for residual tissue in the operative workup. Most frequent benign histologies were mastopathy (13), ductal hyperplasia (9), fibroadenoma (8), and sclerosing adenosis (5). The control examinations (maximum 1 year) did not show any signs for a false-negative biopsy. Conclusion:The 11-G SVAB has proven to be a perfect adjunct to the existing breast biopsy methods. The new 8G SVAB speeds up the method when used for the same size of lesions and enables the user to representatively biopsy lesions up to 3 cm in diameter. The method is still minimally invasive; however, the amount of hematomas as well as clinically relevant complications is increased.

Galactography: an important and highly effective procedure

Abstract. Galactography should only be performed if there is spontaneous bloody or serous discharge from a single lactiferous duct of one breast. If this is observed, only pathologic processes instead of normal breast tissue are removed upon surgery and there is a close correlation between radiologic results and pathologic findings. Galactography localizes intraductal pathologic processes precisely and thus contributes to minimal volume surgery.

Efficacy of Daily Bedside Chest Radiography as Visualized by Digital Luminescence Radiography

To determine the diagnostic impact of daily bedside chest radiography in comparison with digital luminescence technique (DLR; storage phosphor radiography) and conventional film screen radiography, a prospective randomized study was completed in 210 mechanically ventilated patients with a total of 420 analysed radiographs. The patients were allocated to two groups: 150 patients underwent DLR, and 60 patients underwent conventional film screen radiography. Radiological analysis was performed consensually and therapeutic efficacy was assessed by the clinicians. There was no statistical significant difference between the frequency of abnormal findings seen on DLR and conventional film screen radiography. In total, 448 abnormal findings were present in 249 of 300 DLR and 97 of 120 conventional film screen radiographs. The most common findings were signs of overhydration (41%), pleural effusion (31%), partial collapse of the lung (11%) and pneumothorax (2%). One hundred and twenty-three of 448 (27%) of these abnormal findings were thought to have a considerable impact on patient management. The high rate of abnormal findings with significant impact on patient management suggests that the use of daily bedside chest radiography may be reasonable.

Pseudolesions in mammography

The mediolateral oblique view is one of the two standard mammographic views [1, 2, 3] and has replaced the mediolateral view; however, much more so than any other view, the mediolateral oblique view is susceptible for the appearance of pseudolesions. Pseudolesions are defined as regions of attenuation that are not caused by physiological or pathological findings but by fortuitous superimposition of normal breast tissue or innocuous overlapping shadows [4]. There are two types of pseudolesions: one is a stellate configuration of tissue (Figs. 1, 2) and the other one is an ill-defined density (Figs. 3, 4). Both types only have questionable or no correlates in the craniocaudal view. Nevertheless, very often they are considered to be suspicious of malignancy and cause further evaluation by MRI or even biopsy of the breast.

Notched ureter sign

The “notched ureter sign” is the radiographic appearance of various pathologies. An extrinsic compression by enlarged retroperitoneal lymph nodes can be easily detected by ultrasound or computed tomography (Figs 1, 2, 3). If enlarged lymph nodes are not detectable, this sign might also be caused by expanded and tortuous collateral arteries or veins. For example, a stenosis of the renal artery can lead to formation of collateral arteries around the ureter, thus leading to the “notched ureter sign”. On the other hand, obstruction of the suprarenal inferior vena cava can lead to an increased flow in the ureteral, ovarian or spermatic veins [1] which can also account for notching of the ureter [2]. An obstruction of the distal inferior vena cava, e.g. because of thrombosis [3], pregnancy [4] or a tumour can lead to pronounced collateral circulation via ovarian or periureteral veins [5]. Even an enlarged ovarian vein due to a flow inversion in nutcracker’s syndrome may cause this radiological symptom (Fig. 4) [6].

Stellenwert der kernspintomographie bei der epiphysiolysis capitis femoris

ZusammenfassungDie Diagnose der im Jugendalter spontan auftretenden Epiphysiolysis capitis femoris wurde bislang anhand der klinischen Beschwerden sowie der Bestimmung des Abrutschwinkels in konventionellen Aufnahmen (Beckenübersicht, Aufnahme nach Rippstein) gestellt. Für die Diagnose der Frühformen der Epiphysiolysis capitis femoris exsistiert kein allseits akzeptierter Goldstandard. Ziel der vorliegenden Arbeit war es herauszuarbeiten, inwieweit die Epiphysiolysis capitis femoris charakteristische Zeichen in der Kernspintomographie bietet und ob die MRT in der Lage ist, früher Veränderungen als die konventionellen Methoden zu erkennen.Die Kernspintomographien (1,5-T-, T1- und T2-SE-Sequenzen koronar, sagittal, paraaxial, fakultativ STIR-, TIRM-, FLASH-2D-Sequenzen) von fünf gesunden Kindern wurden standardisiert analysiert und mit den magnetresonanztomographischen Untersuchungen von neun Patienten mit vermuteter Epiphysiolysis capitis femoris verglichen. Bei den neun Patienten lagen zusätzlich konventionelle Röntgenaufnahmen nach Rippstein vor. Im Normalkollektiv stellte sich die Epiphysenfuge homogen signalarm bzw. signalfrei dar. Sie wies eine konstante Weite bis zu 3 mm auf und war gegenüber den angrenzenden knöchernen Strukturen scharf abgegrenzt. Das Grenzflächensignal erschien homogen und gezähnelt. Patienten mit vermuteter Epiphysiolysis capitis femoris zeigten eine Erweiterung der Epiphysenfuge auf mehr als 3 mm in sechs von neun Fällen. Bei allen klinisch verdächtigen Fällen konnte ein Gelenkerguß abgegrenzt werden. Es fand sich zusätzlich eine Verschiebung oder Abflachung der Verzähnelung. Ein Signalanstieg im Bereich des Knorpels fand sich kernspintomographisch in nur zwei Fällen.AbstractDiagnosis and determination of severity of chronic slipped capital femoral epiphysis (SCFE) is usually made from clinical history, physical examination and radiographic measurement of the degree of slippage. Aim of the present study is to evaluate the diagnostic impact of magnetic resonance imaging in early detection of SCFE.We evaluated magnetic resonance imaging of the hips of 5 healthy children in comparison to the findings in conventional radiographs and magnetic resonance imaging of 9 patients with suspected SCFE.The growth plate of healthy objects shows homogenous low signal intensity, constant width up to 3 mm, and is clearly defined against the surrounding osseous structures. The adjacent surface appears homogenous. Patients with suspected SCFE showed widened growth plate (> 3 mm) in 6 of 9 cases. Articular effusion was seen in all cases of clinical suspected disease. Incongruence of the ondulate surfaces was seen. Here we found flattening of denticulation of the growth plate in addition. Growth plate showed increase of signal intensity in 2 cases.