Magnetic resonance imaging of normal and pathologic fetal brain

A total of 78 pregnant patients who had previously been studied by ultrasound (US) underwent magnetic resonance (MRI) because of suspected fetal abnormality. The first 20 cases were performed using fetal curarization. Even in the 27 cases in which the MR examination concerned other body regions, a brain study was always performed to analyze the normal anatomy at different gestational ages. There is a brief discussion on normal MRI anatomy of the fetal brain. There were 45 studies that concerned central nervous system pathology, and the most frequent malformative and neoplastic disorders were revealed. A comparison between MRI and US is proposed for each. In conclusion, MRI can be regarded as a complementary method that can be helpful in the rare cases when the US diagnosis is doubtful.     

Mitochondrial neurogastrointestinal encephalomyopathy presenting with protein-losing gastroenteropathy and serum copper deficiency: a case report

OBJECTIVE: To evaluate ultrasonic and magnetic resonance imaging (MRI) and Doppler examination in fetal sacrococcygeal teratoma (SCT), in respect to the postnatal findings and histological type of the tumor. STUDY DESIGN: Nine pregnancies complicated by histologically mature fetal sacrococcygeal teratoma in four cases and by immature/malignant teratoma in five cases. Transabdominal ultrasonic imaging and Doppler velocity waveforms were recorded during the second or last trimester in all cases, first trimester ultrasound examination was carried out in six cases and last trimester MRI in five cases. These findings were compared with postnatal and operative findings of the children. RESULTS: Ultrasound examination did not reveal intrapelvic parts of SCT, but this was possible by MRI. Velocity waveforms of the tumor arteries were similar in all histological types and the resistance index varied from 60 to 70. The mean gestational age at antepartal diagnosis was 25.2 weeks. Large tumor size with relatively large proportion of solid components was often recognized in cases with malignant/immature histology. CONCLUSIONS: Antepartal MRI is useful for examination of fetal SCT, but reliable differentiation of mature and immature SCT is not possible antepartally.     

Clinically occult avascular necrosis of the hip in systemic lupus erythematosus

OBJECTIVE: To study the natural history of clinically occult avascular necrosis (AVN) of the hip in patients with systemic lupus erythematosus (SLE). METHODS: Sixty-six patients with SLE (without symptoms referable to the hip) receiving at least 5 mg/day prednisone for > or = 6 months were screened by magnetic resonance imaging (MRI) for AVN of the hip. A complete MRI evaluating class and percentage of femoral head involvement, AP and lateral radiographs of the hips, bone scan, and physical examination were performed for patients with positive MRI. Medical records were reviewed for serologic and clinical variables that might predict AVN. Repeat MRI were obtained at 3, 6, and 12 months to assess possible progression or resolution of the lesion. Patients with negative screening MRI underwent repeat screening after one year to assess the one year incidence rate. RESULTS: Eleven asymptomatic hips (8%) in 8 patients (12%) had MRI documented AVN. The percentage of femoral head involvement ranged from 1 to 46%. One lesion was MRI class B, the remaining lesions were class A. The radiographic stage of 10 hips was stage 1, the MRI class B hip was stage 2. Risk factors for clinically occult AVN included Afro-American origin, Raynaud's phenomenon, migraine headaches, and a maximal corticosteroid dose of at least 30 mg/day. After 12 months, 43 of 58 patients with an initially negative MRI underwent repeat screening examinations; no new lesions were observed. CONCLUSION: Clinically occult AVN of the hip is common in patients with SLE. The short term natural history of these lesions appears stable without spontaneous healing or clinical or radiographic progression. Risk factors for these asymptomatic lesions are similar to the risks for symptomatic AVN and surgical intervention appears not to be indicated in these patients.     

The role of small bowel follow-through examination in the diagnosis of coeliac disease

A retrospective study of 105 barium follow-through examinations on 102 patients suspected of having malabsorption syndrome has been carried out to assess the usefulness of this technique in the diagnosis of coeliac disease. Comparison with histological and biochemical data has been made. Of the 34 examinations on 31 patients with a proven diagnosis of coeliac disease, 30 examinations showed both abnormal X-ray and biopsy findings, two examinations showed normal X-ray appearance but abnormal jejunal biopsy and two showed normal jejunal histology but abnormal X-ray findings. There were two cases with sensitivity, non-invasive nature, ease and cheapness of the technique, barium follow-through examination is suggested as the initial investigation in patients suspected of coeliac disease.     

Relation between fetal intrauterine growth retardation and anticardiolipin antibodies

OBJECTIVE: To investigate the relationship between fetal intrauterine growth retardation and anticardiolipin antibodies. METHODS: Serum anticardiolipin antibodies were detected with ELISA method in 5,330 cases of normal gravidas. Meanwhile, the observation of immunocomplex depositions in placentas in cases of positive anticardiolipin antibodies (ACA) were observed by immunofluorescence examination. RESULTS: The positive ACA rate in normal gravidas was 2.70%. The incidence of intrauterine growth retardation (IUGR) was 15.28% in cases of positive ACA, whereas was 1.77% in cases of negative ACA. There were significant differences between two groups (P < 0.001). Among children born in mothers with positive ACA, there were 5 cases of positive ACA. Immunocomplex depositions (Immunoglobulins & Complements) were all found in placenta of IUGR. CONCLUSIONS: ACA could be one of causes of IUGR. Determination of serum ACA would offer a new clue to diagnosis and treatment of IUGR.     

Correlation of MRI and histopathological findings in inflammatory skin diseases

PURPOSE: Can spatial and contrast resolution be achieved with currently available MR devices for the successful assessment of inflammatory diseases of the skin? METHOD: High resolution MRI was performed in 20 patients with non-malignant diseases of the dermis and subcutis. The skin biopsies subsequent to the MR examinations were indicated for clinical reasons. The MR examinations were done in the location of later performed skin biopsies using a 1.0 Tesla system (Gyroscan T10 NT, Philips, Best, the Netherlands) and a surface coil of 7.5 cm inner diameter. Conventional spin-echo (SE-Sequenz)- and gradient-echo (GRE)-sequences were optimised to obtain maximum spatial resolution with a sufficient signal-to-noise ratio within a tolerable examination time. MR visualisation of histopathology was assessed by four readers using a questionnaire. RESULTS: In 15 of 20 cases, high resolution MRI allowed a correct classification of the visualised dermal and subcutaneous patterns, in accordance with the histological work-up of the corresponding specimen. Due to the still only suboptimal spatial and contrast resolution the structure of the epidermis could not be assessed adequately. Determination of contrast enhancement or non-enhancement after administration of intravenous contrast agent provided information on the degree of tissue perfusion in 19 patients, which complemented the morphological assessment. CONCLUSION: High resolution MRI allows to identify non-invasively histological main patterns of inflammatory skin diseases. However, final diagnosis often depends on higher microscopic resolution and special staining.     

Pelvic and perineal complications of Crohn's disease: assessment using magnetic resonance imaging

This study evaluated the role of magnetic resonance imaging (MRI) in the demonstration of the pelvic and perianal complications of Crohn's disease. Twenty five patients with active Crohn's disease were studied (12 male; mean age 41.1 years). MRI examinations were performed using a 1.5 Tesla system, within 14 days after clinical assessment. T1 and T2 weighted fast spin echo sequences in two or three orthogonal planes were performed, with fat suppression in some cases. The MRI results were correlated with surgical and clinical findings. In 16 patients, cutaneous, deep perineal or enterovesical fistulas or abscesses were diagnosed at MRI which showed close correlation with findings at examination under anaesthetic. In eight patients no fistulas or abscesses were seen at MRI nor was there any evidence of complications on clinical examination and flexible sigmoidoscopy. There was one false negative examination in a patient who had a colovesical fistula. In conclusion, MRI can accurately show the pelvic and perineal complications of Crohn's disease and may render examination under anaesthetic unnecessary.     

Cancer of the nasal cavity and paranasal sinuses and exposure to environmental tobacco smoke in pet dogs

PURPOSE: To evaluate dynamic MR imaging of the pituitary gland. MATERIAL AND METHODS: 19 patients with suspected mass lesions of the pituitary gland were examined at 1.5 Tesla with dynamic and standard MRI using a Turbo-FLASH sequence (1 image/s for 40 s). RESULTS: In 13/19 patients microadenomas were detected. One of the 13 microadenomas was detected using dynamic imaging and was not seen on standard MRI. The remaining 12 microadenomas were diagnosed with standard MRI. CONCLUSION: Dynamic imaging of the pituitary gland is a time-consuming and costly diagnostic technique. If laboratory results suggest the presence of a microadenoma and conventional MRI is unable to localise it, dynamic imaging should be performed.     

Etiology and epidemiology of anal incontinence

In twenty-five patients with a clinical diagnosis of suspected sacroiliitis conventional radiography, CT and MRI were performed. In ten patients no abnormalities were demonstrated. In thirteen cases CT and MRI revealed sacroiliitis. In two patients with normal plain films and CT para- and intraarticular changes of signal intensity suggested suspicious sacroiliitis. MRI can be considered as an important imaging modality for early diagnosis of sacroiliitis. In eighteen patients with a firm diagnosis of ankylosing spondylitis and plain films of the thoracolumbar junction suggesting destructive Romanus and Anderson inflammatory lesions MRI was done. Two distinct groups of inflammatory changes were found. In ten patients MRI findings compatible with active inflammatory enthesitis were revealed at the disco-vertebral junction. In eight cases focal and linear changes of signal intensity within the intervertebral disks suggested an active inflammation. Using MRI the spectrum of inflammatory changes in sero-negative spondylitis can be presented. In sixteen patients with definite clinical diagnosis (psoriatic arthritis--thirteen cases and Reiter's syndrome--three cases) plain films and MRI of small hand joints were performed. The patients fell into two distinct groups. In the first MRI findings could not be differentiated from those seen in rheumatoid arthritis. In nine cases the distribution and extent of soft tissue findings were different, similar to changes seen in enthesitis. Therefore, on the basis of MRI findings in small peripheral joints easier differential diagnosis between sero-negative spondyloarthritides and rheumatoid arthritis is possible. In five patients with a diagnosis of Reiter's syndrome having clinical signs of enthesitis plain films and MRI of calcaneus were done. MRI revealed findings compatible with active inflammation which resembled those seen at the attachment of the annulus fibrosus and collateral ligaments of the small hand joints.     

Glial tumourettes (glial microtumours): their clinical and histopathological manifestations

This study represents our experience with eight cases (males: 4; females: 4; 13-47 years old, average age 28.5 years) of a "glial tumourette" (minute glioma), which measured less than 15 mm in diameter on an MRI. Four tumours were located in the frontal lobe, one in the rostrum of the corpus callosum, two in the midbrain, and one in the thalamus. The symptoms and signs lasted from two days to 15 months prior to diagnosis, and they consisted of epileptic seizures in five patients and increased intracranial pressure due to hydrocephalus resulting from aqueductal stenosis in three. All patients had a CT scan and an MRI as a part of their initial neuroimaging evaluations. While the CT findings failed to show the lesion in four patients, MRI demonstrated it in all cases. Five tumours were either totally or subtotally removed while the remaining three were biopsied. Histological examinations revealed six tumours to be low-grade gliomas (fibrillary astrocytoma: 4; oligoastrocytoma: 2) and two to be high-grade gliomas (anaplastic astrocytoma: 1; anaplastic oligodendroglioma: 1). Regarding adjuvant therapy, three patients received radiation and/or chemotherapy. One of the patients with midbrain fibrillary astrocytoma died of the disease 38 months after the operation, however, no evidence of progression in the remaining seven has been observed in the follow-up period ranging from five to 65 months after the operation (average: 25.4 months). The histogenesis of benign and malignant gliomas and the importance of surgical exploration in the management of such patients with minute intracerebral tumours are also discussed.     

Brain proton magnetic resonance spectroscopy. Indications for diagnosis and follow-up of HIV-related encephalopathy in the adult

NONINVASIVE EXPLORATION: Proton localized magnetic resonance spectroscopy (MRS) is a noninvasive human neurochemistry method based on the magnetic resonance phenomenon. ADVANTAGES: This exploration of brain metabolism, performed without any injection, detects neuronal, glial, and membrane markers, and can be performed after an MRI examination without moving the patient. INDICATIONS: In vivo brain MRS plays a major role (i) in early diagnosis of HIV-related encephalopathy, (ii) in differential diagnosis of HIV-related encephalopathy versus psychiatric symptoms or occurring in AIDS patients, (iii) in differential diagnosis of HIV-related encephalopathy versus other brain lesions related to AIDS, and (iv) in the follow-up of patient response to therapy. In these indications, MRS is frequently more reliable than neuropsychologic testing and more sensitive than MRI.     

Acute hemorrhagic leukoencephalitis: recovery and reversal of magnetic resonance imaging findings in a child

A case of acute hemorrhagic leukoencephalitis (AHLE) in a 6-year-old girl is reported. The presentation was typical for acute hemorrhagic leukoencephalitis, with acute onset of a rapidly progressive neurologic disorder with asymmetric involvement of brain, with polymorphonuclear predominant peripheral leukocytosis and cerebrospinal fluid pleocytosis. Cerebrospinal fluid findings not previously reported included elevation of IgG and the presence of myelin basic protein. Additional previously unreported findings were striking abnormalities on magnetic resonance imaging (MRI) of the brain, in contrast to normal findings on computed tomography (CT). The child was treated with high dose intravenous steroids and made a full recovery, with a parallel disappearance of all of her cerebrospinal fluid abnormalities and almost all of her abnormalities on MRI. Detailed examination of cerebrospinal fluid and MRI of brain should facilitate early diagnosis in other cases of suspected acute hemorrhagic leukoencephalitis and high-dose steroid therapy may lead to improved clinical outcomes.     

Fetal intracranial hemorrhage. Imaging by ultrasound and magnetic resonance imaging

OBJECTIVE: To describe the magnetic resonance imaging (MRI) findings associated with fetal intracranial hemorrhage and to compare them with ultrasound findings. STUDY DESIGN: In four pregnancies complicated by fetal intracranial hemorrhage, fetal imaging was carried out using T2-weighted fast spin echo sequences and T1-weighted fast low angle shot imaging sequences and by transabdominal ultrasonography. RESULTS: An antepartum diagnosis of hemorrhage was made by ultrasound in one case and by MRI in two. Retrospectively, the hemorrhagic area could be identified from the MRI images in an additional two cases and from the ultrasound images in one case. In the cases of intraventricular hemorrhage, the MRI signal intensity in the T1-weighted images was increased in the hemorrhagic area as compared to the contralateral ventricle and brain parenchyma. In a case with subdural hemorrhage, T2-weighted MRI signals from the hemorrhagic area changed from low-to high-intensity signals during four weeks of follow-up. Better imaging of the intracranial anatomy was possible by MRI than by transabdominal ultrasonography. CONCLUSION: MRI can be used for imaging and dating fetal intracranial hemorrhages. Variable ultrasound and MRI findings are associated with this complication, depending on the age and location of the hemorrhage.     

Role of MRI in the diagnosis of insufficiency fractures of the sacrum and acetabular roof

OBJECTIVE: To review the risk factors and the radiological appearance of insufficiency fractures of the sacrum and acetabular roof. DESIGN AND PATIENTS: Twenty patients with sacral and acetabular roof insufficiency fractures were reviewed retrospectively. There were 16 women (80%) and 4 males (age range 48-86 years, excluding an 8-year-old boy). Thirteen patients had a known tumour, and nine had received pelvic irradiation. All patients, except one who was asymptomatic, presented with low back or hip pain. In patients with a known tumor, metastases were suspected. Plain radiography (20), bone scintigrams (16), MR examinations (20), and bone densitometry (14) were performed. Nine patients also each had a CT scan. RESULTS AND CONCLUSIONS: In three cases the CT scan performed 10-25 days after onset of symptoms was interpreted as normal. MR examination performed a few days after the CT scan showed in each of these three patients a fracture line with a band of edema. Scintigraphy was very sensitive, but the H-shaped pattern of sacral uptake, specific for an insufficiency fracture, was detected in only three of 16 cases. The earliest MR sign was medullary edema, seen as early as 18 days after the onset of symptoms. On spin echo (SE) T1-weighted images (T1WI), the hypointense signal of edema could mask a fracture line. On SE T2WI the fracture line could be detected within the hyperintense edema (10 of 17 patients with examinations including SE T2WI). However, in four patients a fracture of the sacrum was not seen on T2WI, these having been obtained in the axial plane. For this reason, intravenous gadolinium was injected, revealing a fracture line in 12 of 14 examinations, or fat suppression sequences were performed, revealing a fracture line in five of five cases. The total number of fractures detected was 17 [15 fractures of the sacrum (bilateral in 10 cases) and two of the acetabular roof]. At a later stage, the edema resolved and the fracture was clearly seen. The two cases of fracture of the acetabular roof were easily recognized at MRI, particularly in the sagittal plane.     

Significance of inhalation and perfusion scintigraphy for the diagnosis of pulmonary embolism (author's transl)

Inhalation and perfusion scintigrams, general radiological examination of the thorax and an EKG were done on 43 patients with clinically suspected pulmonary embolism. In 11 cases, the clinical diagnosis could be confirmed on the basis of the scintigraphic examination. In the remaining 32 patients, an embolich event could be excluded by pulmonary scintigram, radiological examination and later the clinical course. A synopsis of clinical observations, X-ray and scintigraphy, therefore, permitted a basically reliable diagnosis of pulmonary embolism; selective pulmonary angiography should be used only in exceptional cases.     

Ultrasonographically-guided fine-needle aspiration cytology in the diagnosis of colonic lesions

BACKGROUND: The use of fine-needle aspiration cytology (FNAC) in the diagnosis of colonic lesions was investigated. METHODS: Some 22 patients (median age 71 years) with a colonic lesion identified on abdominal ultrasonography underwent ultrasonographically-guided FNAC using a 21-G needle. The sample was checked immediately by a cytopathologist for adequacy. RESULTS: Eighteen patients had colonic carcinoma; aspiration cytology detected malignant epithelial cells consistent with colonic carcinoma in 17 patients and severely dysplastic cells in one patient. The sensitivity and specificity of ultrasonographically-guided FNAC in the diagnosis of colonic carcinoma was 94 and 100 per cent respectively. The remaining four patients had a diagnosis of ileocaecal tuberculosis, ileocaecal Crohn's disease, and metastatic adenocarcinoma in the liver with no identifiable primary (two patients). One demonstrated granulomata, grew acid-fast bacilli and the patient was treated for tuberculosis. One had inflammatory cells and the patient was found to have Crohn's disease on histology. The remaining two patients had confirmed metastatic adenocarcinoma in the liver on aspiration cytology but suspected colonic lesions were found to be benign on cytological examination and no primary lesion was subsequently demonstrated. There were no complications of FNAC and patients complained of minimal discomfort. There has been no evidence of tumour recurrence with a median follow-up of 12 (range 1-25) months. CONCLUSION: Ultrasonographically-guided FNAC is a valid method for the diagnosis of colonic tumours.     

High-resolution magnetic resonance tomography of the lesser pelvis using an endorectal coil

Spatial resolution of MRI within the true pelvis can be increased by a factor of 12 using an endorectal coil. The value of this new method for demonstrating the prostate, the rectum, the cervix and vagina and of pathological processes of these organs was examined in 89 patients and the results compared with conventional body coil MRI. In 25 patients who underwent radical surgery the results of the preoperative studies were compared with the histological findings. Detailed recognition of anatomical structures was markedly improved by using the endorectal coil. Diagnosis of carcinoma of the prostate and extension of the tumour was accurately assessed in 33 patients. Preoperative staging was correct in 87%, compared with 73% when using a body coil. The difference was less marked in examinations for carcinomas of the rectum, the cervix and vagina. Nevertheless, staging was more accurate in a few cases with a better recognition of recurrences. MRI with endorectal coils will have an important role in diagnosis of carcinomas of the prostate in the future. Its use in the diagnosis of carcinomas of the rectum and cervix must be subject to further studies.     

Indications for surgery to determine the etiology of subcortical hemorrhage

We studied the etiology of subcortical hemorrhage in 55 patients (30 males, 25 females), aged 19-83 years (mean 60 years). CT scan was made in all patients on admission, with the use of intravenous infusion of contrast agent in 35 patients. Cerebral angiography was performed in 37 patients and MRI was performed in 22 patients. Forty-one patients underwent surgery and the other fourteen patients were treated conservatively. The cause of bleeding had been discovered before surgery in 12 cases; 10 arteriovenous malformations and 2 brain tumors. They were discovered by meticulous neuroradiological investigations including cerebral angiography, MRI, dynamic MRI, MRA and enhancing CT. The cause of bleeding was newly discovered after surgery in 7 cases; all of amyloid angiopathy. It remained unknown in the other 22 surgical cases although hypertensive angiopathy was suspected in eleven of them. Among the 14 patients who received conservative therapy, hemorrhagic diathesis including the use of Warfarin and DIC was the cause of bleeding in four cases and the etiology remained unknown in other ten, although hypertensive angiopathy was suspected in eight of them. The 32 patients in whom the etiology remained unknown had been observed as long as 12-120 months (mean, 40 months) and although bleeding has occurred at different locations in two of these patients, there has been no recurrence of bleeding at the same location in any of them. In conclusion, surgery is not indicated to determine the etiology of subcortical hemorrhage when meticulous neuroradiological investigations fail to disclose any vascular or tumorous lesions.     

MRI in the diagnosis of osteoid osteoma

INTRODUCTION: Osteoid osteoma (OO) is a frequently encountered benign bone tumor, seen in young adults with male predominance. MATERIALS AND METHODS: Nine patients complaining of nonspecific extremity pain underwent MRI examination. The sequences obtained were T1 and T2 weighted spin-echo and T2 weighted gradient echo. A CT scan examination followed in all cases, exploring the region of the abnormal signal seen on MRI. The results of both examinations were compared. RESULTS: In six of the nine patients (66.6%) MRI showed evidence suggestive of osteoid osteoma, comparable that seen on CT scan. In three patients (33.3%), MRI showed a nonspecific and ill-defined bone marrow signal abnormality. CT cuts focused on those areas of signal abnormality showed the nidus. DISCUSSION: MRI is more sensitive than CT scan in detecting soft tissue and bone marrow abnormalities adjacent to an osteoid osteoma. This may produce a misleading aggressive appearance on MR images. CT scanning is more specific than MRI, by showing the nidus. In three patients studied, the nidus was only seen by CT, the other six osteoid osteomas were equally seen by CT and by MRI. In our study, MRI revealed abnormalities in all the cases. It was also highly specific for osteoid osteoma in 66.6%. CONCLUSION: MRI is very sensitive in detecting bone marrow and soft tissue abnormalities, and can suggest the diagnosis of OO in a good number of patients. In the remainder cases MRI guides the CT-scan. CT is more accurate and remains the definite examination for the diagnosis of OO, by showing the nidus.