Evaluation of MRI criteria (1.5 T) for the diagnosis of hippocampal sclerosis in healthy subjects.

PURPOSE: The presence of hippocampal sclerosis (HS) on MRI has a great impact on the clinical evaluation and counselling of patients with temporal lobe epilepsy (TLE) and is considered as a key criterion for the decision to recommend epilepsy surgery. However, neuropathological studies describe evidence of HS in up to 10% of non-epileptic individuals, questioning the impact of this MRI finding in patients with TLE. We evaluated the prevalence of HS on MRI in the general population. METHODS: 100 healthy subjects and 10 patients with TLE due to HS were investigated in a prospective study using a specific protocol for the detection of hippocampal pathology (coronal FLAIR, coronal T2 TSE and a T1 weighted 3D SPGR sequence). RESULTS: HS was detected in none of the healthy subjects (95% confidence interval=0-3.6%), but in all patients. Inter-rater agreement was perfect for presence of HS. Thirty-three subjects had an unilaterally enlarged temporal horn as an isolated secondary criterion for HS and inter-rater agreement was slight for this point. Incidental pathological findings were detected in two patients (2%): one had a low grade astrocytoma (1%), one an aneurysm of the posterior communicating artery (1%). CONCLUSIONS: HS was not diagnosed in healthy subjects, supporting its impact on the evaluation of patients with temporal lobe epilepsy. An unilateral enlarged temporal horn that occurred in one third of the healthy subjects should not be considered as a pathologic finding or even as a marker for HS.

[Changes in MR images in pre-eclampsia and eclampsia]. / MR-tomografische Veränderungen bei Präeklampsie und Eklampsie.

BACKGROUND: Pre-eclampsia affects 2% of pregnancies. This multisystem disorder is a major cause of maternal, foetal and neonatal mortality and morbidity. Neurological manifestations of eclampsia are headache, nausea, vomiting, cortical blindness and recurrent seizures. OBJECTIVE: The purpose of this study was to determine whether the neurological symptoms correlate with MR imaging findings. RESULTS: In a patient with eclamptic seizure and another one with blindness due to pre-eclampsia, the white matter hyperintensities on T (2)-weighted MR and FLAIRsequence images could be demonstrated in the occipital region and in the basal ganglia. Within 3-5 days all neurological symptoms and radiological abnormalities had resolved. CONCLUSION: These cerebral lesions could be classified as posterior reversible encephalopathy syndrome (PRES) or as reversible leukoencephalopathy syndrome (PLES). Thus, MRI supports differential diagnosis regarding non pregnancy-related cerebral disease and can be helpful for therapy planning in cases of pre-eclampsia.

[Validity of the breast imaging reporting and data system BI-RADS(TM) for clinical mammography in men]. / Anwendbarkeit des Breast Imaging Reporting and Data System (BI-RADS(TM)) auf die klinische Mammographie des Mannes.

AIM: The implementation of diagnostic standards enhances quality assurance. The American College of Radiology's Breast Imaging-Reporting and Data System (BI-RADS(TM)) is intended to standardize terminology in the mammography report, the assessment of the findings, and the recommendation af action to be taken. The purpose of this study was to assess the value of the standardized system for clinically apparent male breast tumors. Do the special male anatomy and physiology limit the applicability of an evaluation system designed for female screening mammograms? METHODS: 4 investigators with different degrees of experience retrospectively evaluated 160 male mammograms. Our study was based on the 36 cases which could be correlated to histopathological findings: gynecomastia in the majority of cases, but also 4 invasive ductal carcinoma, 1 leiomyosarcoma and 1 ductal carcinoma in situ. RESULTS: Assessment of the mammograms by BI-RADS(TM) (3(rd) Edition 1998) correctly placed all cases of malignancy into categories 4 and 5 without respect to the investigators's level of experience. CONCLUSION: Therefore, we conclude that the BI-RADS(TM)-classification can successfully be used to classify male mammograms with a high positive predictive value for malignancy. Knowledge of gender-specific imaging characteristics increases the specificity at a constant high level of sensitivity.

[Sonographic variability of lactating adenoma demonstrated by a longitudinal evaluation of 4 cases]. / Sonographische Variabilität laktierender Adenome am Beispiel von 4 langzeitüberwachten Fällen.

AIM: Lactating adenoma are circumscribed benign breast lesions developing during pregnancy or lactation due to overall enhanced proliferation of steroid hormone dependent tissue. Sonography is the method of choice for imaging mainly because of the physiologically dense breast tissue. Which is the predictive value of sonography in the diagnosis of lactating adenoma? Are sonographic characteristics dependent on age of gestation or time of lactation? Which diagnostic procedure should be recommended? METHOD: We report the long time course of four patients with histologically proven (core-needle biopsy, 16 Gauge) lactating adenoma, first diagnosed during pregnancy, which were followed up sonographically (1997-2000) with real-time B-mode, panorama-mode (Siescape) and colour-sonography. RESULTS: Demonstrating a high inter- and intraindividual variability the tumors were biggest around parturitation. Despite ongoing lactation tumors regressed in size, but did not vanish completely even after definite termination of breast feeding. Evaluation of sonographical characteristics did not allow to rule out malignancy. CONCLUSION: Three percent of all breast cancers at childbearing age coincide with pregnancy and lactation, therefore, an early histologic diagnosis is absolutely necessary. Sonographically guided core-needle biopsies allow to exclude malignancy without negative effects on breast feeding.

[MRI or arthroscopy in the diagnosis of scapholunate ligament tears in fractures of the distal radius?]. / Magnetresonanztomographie oder Arthroskopie in der Diagnostik skapholunärer Bandschäden bei distalen Radiusfrakturen?

In a prospective study, 45 patients with fractures of the distal radius and radiologically suspected tears of the scapholunate interosseous ligament were examined. Magnetic resonance imaging was performed prior to wrist arthroscopy. The latter examination gave the definite diagnosis. MRI was performed in conventional technique (without contrast medium) in 25 cases and after additional intravenous injection of contrast medium in the remaining 20 patients. The images were obtained with a 1.0-T clinical imager using a T(2)-weighted turbo spin echo sequence (slice 3 mm, transversal) and a FLASH 2D sequence (slice 2 mm, oblique/coronal). Three independent observers assessed the MRI scans before arthroscopy was performed. The correct diagnosis was made by MRI in 76 %. Overall sensitivity and specificity came to 71 % and 86 %, respectively. The use of intravenously applied contrast medium did not improve MRI accuracy. In conclusion, MRI is not recommended for the diagnosis of scapholunate ligament tears. Presumably, the results of MRI could be improved by a more sophisticated technique.

MRI versus arthroscopy in the diagnosis of scapholunate ligament injury.

In a prospective study 103 patients with clinically or radiologically suspected tears of the scapholunate interosseous ligament were investigated with magnetic resonance imaging (MRI) and wrist arthroscopy. MRI was performed with the conventional technique in 72 cases and after intravenous injection of contrast medium in the remaining 31 patients. The correct diagnosis was made by MRI in 75% of cases and its overall sensitivity and specificity were 63% and 86% respectively. There was no statistical difference in the accuracy of MRI for acute or chronic tears and the use of intravenous contrast medium did not improve its accuracy. In conclusion, MRI is not recommended for the diagnosis of scapholunate ligament injury.

[Epiphyseal injuries of the distal tibia. Does MRI provide useful additional information?]. / Epiphysenfugenverletzungen der distalen Tibia. Sinnvolle Mehrinformation durch die MRT?

Plain film radiography often underestimates the extent of injury in children with epiphyseal fracture. Especially Salter-Harris V fractures (crush fracture of the epiphyseal plate) are often primarily not detected. MRI of the ankle was performed in 10 children aged 9-17 (mean 14) years with suspected epiphyseal injury using 1.0-T Magnetom Expert. The fractures were classified according to the Salter-Harris-Rang-Odgen classification and compared with the results of plain radiography. In one case MRI could exclude epiphyseal injury; in four cases the MRI findings changed the therapeutic management. The visualisation of the fracture in three orthogonal planes and the possibility of detection of cartilage and ligamentous injury in MR imaging makes this method superior to conventional radiography and CT. With respect to radiation exposure MRI instead of CT should be used for the diagnosis of epiphyseal injuries in children.

[Reactive thymus dysplasia following therapy for ACTH-producing tumors]. / Reaktive Thymushyperplasie infolge der Therapie ACTH-produzierender Tumoren.

UNLABELLED: Surgical or conservative treatment of ACTH-producing tumors results in acute drop of the previously excessively high cortisol levels. The following associated pathophysiological changes also occur in the organism's recovery from stress, such as trauma, operation or chemotherapy of tumors. Both cases result in a regeneration of the immune system, which might even be exalted. The corresponding radiographic feature is the "rebound" enlargement of the thymus occurring about six months after remission of hypercortisolism. Histological examination reveals benign thymus hyperplasia. Especially in cases of still unknown primary tumor the appearance of this anterior mediastinal mass can lead to misdiagnosis. We present the cases of two patients with diffuse thymic hyperplasia following surgical and medical correction of hypercortisolism. One patient suffered from classic Cushing's disease responding to transsphenoidal resection of an ACTH-secreting pituitary microadenoma. Six months later CT of the chest incidentally demonstrated an anterior mediastinal mass known as thymic hyperplasia. The second patient presented with an ectopic, still unkown source of ACTH-production. Six months after medical correction of hypercortisolism CT of the thorax showed an enlargement of the anterior mediastinum. Thymectomy was performed in order to exclude thymus carcinoid. Histological examination revealed benign thymus hyperplasia with negative immunostaining. CONCLUSION: Radiologists and clinicians should be familiar with the pathophysiological changes resulting from precipitously dropping cortisol levels in order to prevent diagnostic errors and unnecessary operations.