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Biomedical subjects

A M De Schepper

Publications and source records attributed to A M De Schepper.

At least 91 records · Page 5Linked to original sources
PubMed1997

New concepts in understanding evolution of desmoid tumors: MR imaging of 30 lesions.

The objective of this study was to evaluate the appearance and the natural evolution of desmoid tumors on MR imaging, given histologic correlation. The MR images of 30 desmoids (20 primary and 10 recurrent) in 26 patients were scored for a multiplicity of morphological parameters, signal intensity (SI) on different pulse sequences, and behavior after contrast administration. Natural evolution was evaluated in 2 primary and 3 recurrent lesions, and correlated with evolution on histologic specimens. Desmoid tumors are mostly found in muscles of shoulder and hip girdle and are often fusiform with partially ill-defined margins. Rare subcutaneous desmoids have a more stellar morphology. Variable amounts of low-SI areas are present on all sequences. On T1-weighted images (T1-WI), most lesions are near homogeneous and isointense to muscle, whereas on T2-WI they are more heterogeneous with an overall SI equal to or slightly lower than fat. Histologic correlation reveals that SI on T2-WI cannot be explained solely by cellularity. After initial growth, spontaneous evolution of desmoids is characterized by shrinking and an increase in low-SI areas on T2-WI. While distal lesions shrink, the more recent lesions in asynchronous multicentric desmoids have a tendency to develop proximally in the same limb, and should not be confused with recurrences. Fast growth, extracompartmental spread, and bone involvement are often seen in recurrences. Follow-up MR imaging of desmoids indicates natural regression of desmoids and more aggressive behavior of recurrences, which may justify a more conservative therapeutic approach.

Adolescent↗
PubMed1997

Imaging findings in patients with failed back surgery syndrome.

The incidence of low back pain and leg pain related to the spine is very high in the Western population. As a result of conservative treatment failure there are roughly 200,000 lumbar disk operations performed annually. Unsuccessful surgical outcome is known as the failed back surgery syndrome (FBSS). FBSS is a complex and poorly understood syndrome, with as many different imaging findings as different possible etiologic mechanisms. Still we believe some imaging aspects deserve special attention. Firstly it is of particular importance to correctly differentiate residual disk herniation from epidural scar tissue since disk herniation can be an indication for repeat intervention. Secondly when residual disk herniation is present, one should keep in mind that it is not necessarily responsible for the patients complaints. Thirdly, late nerve root enhancement should be considered as pathological. Finally one should be aware of the mechanical back stress that may develop as a result of discectomy. One of the consequences can be secondary foraminal stenosis which is probably one of the most common causes of FBSS.

Cicatrix↗
PubMed1997

MR of the brain in Sjögren-Larsson syndrome.

Cerebral MR was performed in three patients with Sjögren-Larsson syndrome. In each case, a 1.5-T system was used, and the patient was under general anesthesia. The MR findings included confluent hyperintense white matter lesions in the periventricular and deep white matter of the centrum semiovale, with sparing of the subcortical U fibers. The topography of the white matter abnormalities correlated well with the clinical signs and symptoms.

Adult↗
PubMed1997

Shock bowel following massive pulmonary embolism.

Wide-spread abnormalities of the small bowel on CT scan after massive pulmonary embolism and acute hemodynamic collapse are described. These small bowel abnormalities are secondary to hypotension with prolonged hypoperfusion. They consist of diffuse thickening of the small-bowel wall, fluid-filled, dilated loops and increased contrast enhancement of the small-bowel wall (shock bowel). These abnormalities are reversible and should be distinguished from acute vascular occlusion.

Adult↗
PubMed1996

Magnetic resonance imaging of pilomatricoma.

Two patients (a 16-month-old boy and a 53-year-old man) were referred for MR imaging of a small, subcutaneous nodule at the forearm. Plain films were available in one patient and showed a non-specific well-circumscribed lesion. Upon ultrasonography (1 patient), a nodular, well-circumscribed, hyperechoic lesion was seen. In both cases spin-echo (SE) T1-weighted images (T1WI) showed homogeneous, intermediate signal intensity (SI). On gadolinium-enhanced T1WI (1 patient), no enhancement was observed. Both lesions showed predominant low-to-intermediate SI on T2WI. At histological examination characteristic findings of pilomatricoma were observed.

Contrast Media↗
PubMed1996

Deep cerebral invasion by basal cell carcinoma of the scalp.

We report recurrent basal cell carcinoma of the scalp with deep cerebral invasion in an 82-year-old man. Plain films and CT showed extensive, full thickness, skull destruction at the vertex. Gadolinium-enhanced MRI revealed neoplastic invasion of the meninges and left cerebral hemisphere, down to the lateral ventricle. We postulate that tumour extended into the brain along perivascular spaces of transcerebral vessels. This hypothesis is supported by the cleft-like contrast enhancement on MRI.

Aged↗
PubMed1996

Clinical usefulness of contrast-enhanced MP-RAGE of the brain.

Our purpose was to evaluate the usefulness of a 3D T1-weighted gradient-echo sequence (MP-RAGE) in clinical practice. We prospectively examined 200 patients with a variety of neurological disorders and symptoms. We compared lesion conspicuity and contrast enhancement on MP-RAGE images with conventional gadolinium-enhanced spin-echo (SE) T1-weighted images. Both the original MP-RAGE data and the reformatted images were characterised by improved differentiation between grey and white matter. More lesions were found on the 3D series, in both patients with neoplastic and non-neoplastic disease. Contrast enhancement of small oedematous lesions affecting the white matter in demyelinating disease was less obvious. Multiplanar reformatting, which can be realised in any desired plane and surface rendering with sophisticated segmentation algorithms superbly displayed the underlying anatomical relationships between lesions and normal brain structures. Excellent spatial resolution, the absence of posterior fossa artefacts and equivalent contrast enhancement resulted in an increased number of space-occupying lesions being found on the MP-RAGE images. Thus contrast-enhanced MP-RAGE is an alternative to conventional SE imaging in the investigation of intracranial masses. Although the total number of lesions found in patients with demyelinating disease was significantly higher on MP-RAGE, demonstration of blood-brain-barrier breakdown in active lesions was less obvious.

Adult↗
PubMed1996

MRI after successful lumbar discectomy.

Our aim was to establish the normal range of MRI findings after successful lumbar discectomy. We prospectively examined 34 consecutive patients with an excellent clinical outcome by MRI 6 weeks and 6 months after surgery. All examinations included sagittal and axial spin-echo (SE) T1-weighted images before and after intravenous gadolinium-DTPA and fast SE T2-weighted images. Contrast enhancement along the surgical tract was seen in all patients 6 weeks and 6 months after surgery. After 6 months minimal or no mass effect on the dural sac by epidural scar was seen. In 20% of patients there was recurrent disc herniation, with mass effect. Enhancing nerve roots were seen in 20% of patients 6 weeks postoperatively, and half of these were associated with recurrent disc herniation at the same side. None of these patients still showed nerve root enhancement 6 months after surgery. Postoperative MRI studies must be interpreted with great care since the features described in the failed back surgery syndrome are also found, to some extent, in asymptomatic postoperative patients.

Adolescent↗
PubMed1996

Magnetic resonance imaging of cartilaginous tumors: is it useful or necessary?

OBJECTIVE: A retrospective study was undertaken to compare the diagnostic accuracy of plain radiography and magnetic resonance (MR) imaging in the diagnosis of cartilaginous tumors. PATIENTS: The study population consisted of 68 patients with a histologically proven cartilaginous tumor. DESIGN: For each lesion, a comparative analysis of "plain radiography" versus "plain radiography together with MR study" was performed by two radiologists together. Recently reported literature data were used as criteria by which to define accuracy rating. RESULTS AND CONCLUSIONS: MR imaging improves accuracy in diagnosing low-grade chondrosarcomas. Since osteochondromas have a characteristic appearance on plain films, MR imaging contributes only in the diagnostic workup of cases in which malignant transformation is suspected.

Adult↗
PubMed1996

Whiplash injuries: is there a role for imaging?

Whiplash describes the manner in which a head is moved suddenly to produce a sprain in the neck and typically occurs after rear-end automobile collisions. It is one of the most common mechanisms of injury to the cervical spine. Although considered by some to be a form of compensation neurosis, evidence suggests that whiplash injuries are real and that they are a potential cause of significant impairment. Symptoms of cervical whiplash injury include neck pain and stiffness, interscapular pain, arm pain and/or occipital headache, and many whiplash patients have persistent complaints. Cervical roentgenography and conventional or computed tomography (CT) may show dislocations, subluxations and fractures in severely traumatized patients, but often fail to determine or visualize the cause for a whiplash syndrome. Magnetic resonance imaging (MRI), however, is able to assess different types of soft-tissue lesions related to whiplash injuries. Dynamic imaging may show functional disturbances. More widespread use of flexion/extension views, high-resolution static MRI and especially dynamic MRI should improve the correlation between imaging findings and patients' complaints.

Cervical Vertebrae↗
PubMed1996

Magnetic resonance imaging of pelvic bone tumors.

The aim of our study was to determine the value of magnetic resonance (MR) imaging in the diagnostic workup of pelvic bone tumors. We retrospectively evaluated the MR findings in 60 pelvic bone tumors. Owing to its high contrast resolution and multiplanar imaging capabilities, MR offers a clear depiction of cortical, medullar or soft tissue involvement, intratumoral necrosis, and relationship to neurovascular structures, and may be considered as the modality of choice for the staging of pelvic bone tumors. Since grading of bone tumors reaches a high accuracy on conventional radiography (CR), the value of MR imaging is rather complementary. Although the role of MR imaging in tissue characterization is mostly limited to recognition of tumoral components, accurate tissue characterization if often possible (e.g. in low-grade chondrosarcoma, eosinophilic granuloma, aneurysmal bone cyst, giant cell tumor, and chordoma). MR imaging in osteochondromas, metastases, and fibrous dysplasia remains of limited value since most of these lesions are well recognized on CR and/or CT. CR remains the first choice examination in diagnosis and grading of bone tumors, but MR imaging has significantly improved staging and tissue characterization in bone tumor imaging. The aim of our study is to determine the value of magnetic resonance (MR) imaging in the diagnostic workup of pelvic bone tumors, i.e. in staging, in differentiating benign from malignant tumors (grading), and in further characterization of tumors or tumoral components.

Adolescent↗
PubMed1996

Recurrent hepatic hydatid disease with secondary splenic infestation.

Hydatid disease caused by Echinococcus granulosus is a common problem throughout the world, but is rarely encountered in the Western Countries. The liver and lungs are the most frequently involved organs in hydatid disease. The cyst may become very large and rupture. Abdominal, pelvic and pleural dissemination due to spread of parasitic contents may follow. Splenic involvement in hydatid disease is uncommon, representing less than 2% of all human infestations by Echinococcus. We report a recurrent liver hydatidosis with secondary splenic infestation.

Adult↗
PubMed1996

Parinaud's syndrome in a patient with multifocal glioma.

We describe the clinical and neuroradiological findings in a 63-year-old man with Parinaud's syndrome. Magnetic resonance (MR) imaging showed a mass lesion within the quadrigeminal plate. Additional MR findings included a right frontoparietal subcortical lesion as well as periventricular white matter edema due to acute deterioration of hydrocephalus. On MR, the diagnosis of multifocal glioma was proposed. Neuropathological examination after resection of the supratentorial lesion revealed an oligodendroglioma, grade II.

Brain Neoplasms↗