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J D Laredo

Publications and source records attributed to J D Laredo.

At least 91 records · Page 5Linked to original sources
PubMed1990

Vertebral hemangiomas: fat content as a sign of aggressiveness.

Thirty-two vertebral hemangiomas (VHs) were evaluated with nonenhanced computed tomography (CT), T1-weighted magnetic resonance (MR) imaging, CT enhanced with contrast material, and selective spinal arteriography. The stroma between the osseous trabeculae was found to correspond to either fatty tissue or soft tissue or both. All 11 asymptomatic VHs showed complete fatty stroma at CT and increased signal intensity at MR imaging. In contrast, all four compressive VHs had soft-tissue attenuation at CT. Three compressive VHs showed low signal intensity on MR images. Predominantly fatty stroma at CT and increased signal intensity at MR imaging were associated with normal or only slightly increased vascularization at selective spinal arteriography or contrast-enhanced CT, while soft-tissue stroma at CT and low signal intensity at MR imaging were associated with distinct hypervascularization. The authors' experience suggests that fatty VHs may represent inactive forms of VH, while soft-tissue content at CT and low signal intensity at MR imaging may indicate a more active vascular lesion with potential to compress the spinal cord. CT and MR imaging may be especially valuable for evaluating patients with clinical signs or symptoms of uncertain origin and findings compatible with VH at plain radiography.

Adipose Tissue↗
PubMed1989

[Medical imaging and chronic backache].

The different procedures for imaging the lumbar spine are presented within a general review of chronic low back pain. Plain films still represent the main procedure: they are sufficient for common backache, the most frequent pattern of chronic low back pain. They help in determining further investigations in symptomatic low back pain, due either to spinal or non spinal conditions.

Arachnoiditis↗
PubMed1989

[Compressive vertebral hemangioma. The contribution of imaging technics to diagnosis and pretherapeutic evaluation].

From a serie of ten cases of compressive vertebral hemangiomas (H.V.C.), the interest of different imaging methods was evaluated. CT scan and M.R.I. were the best imaging modalities in most cases. A CT guided biopsy was necessary in three cases to differentiate from metastasis. Angiography permitted to establish the vascular patterns and to evaluate the usefulness of embolization performed in six cases.

Adolescent↗
PubMed1989

[Radiologic evaluation of an isolated vertebral hemangioma].

CT scan and M.R.I. features have been evaluated in case of compressive (H.V.C.) and asymptomatic (H.V.A.) vertebral hemangiomas. The main datas observed in H.V.C. are: 1) thoracic localization; 2) whole vertebral body involvement; 3) extension to the pedicles; 4) irregular trabeculation; 5) swelling of bone contours with 6) epidural and perivertebral extension. H.V.C. always exhibit at least three of these six datas while H.V.A. are associated with 2 or less. Also H.V.C. frequently present intravertebral contrast enhancement on CT and low signal intensity on T1 weighted and high signal intensity on T2 weighted M.R.I.

Hemangioma↗
PubMed1988

Solitary plasmacytoma of the spine. Long-term clinical course.

The data for 19 patients with solitary plasmacytoma of the spine were reviewed with regard to clinical course and prognosis (median follow-up, 96 months). Eight patients presented with spinal cord compression. A monoclonal immunoglobulin was initially detected in seven of 15 evaluable patients. Treatment included radiotherapy (18 of 19) and/or surgery (11 of 19) and chemotherapy (eight of 19). Spinal cord compression was reversed in every patient. The expected survival rate was 85% at 10 years after diagnosis. Local recurrence or dissemination was observed in 13 patients. It occurred within 5 years of diagnosis in 11 patients and was localized (that is, local recurrence or single bone metastasis) in eight patients. It was always associated with the appearance or an increase of the M component. Dissemination frequently had a "metastatic" pattern with no diffuse bone marrow plasmacytosis. The incidence of local recurrence (five patients) and leukemia (four patients) was high. Local recurrence and/or dissemination were significantly more frequent in patients with the M component at diagnosis than in those without it (P less than 0.05; relative risk, R = 4). The effectiveness of surgery and chemotherapy combined with radiotherapy is also discussed.

Combined Modality Therapy↗
PubMed1987

[Occult fractures of the sacrum in aged osteoporotic patients].

We are reporting 4 cases of unnoticed sacral fractures in osteoporotic women. Their mean age was 73 years. Only in one case the fracture was seen on a standard X-Ray. On the other hand, hyperfixation with isotopes on the sacrum formed a very characteristic H-shaped image. In two of these patients, the sacral fracture was confirmed by tomodensitometry, but this examination was unavailing in the third patient. In the 4th case, hyperfixation of the isotope was not significant. Only a guided bone biopsy and the favorable evolution of the disease enabled the diagnosis of sacral fracture.

Aged↗
PubMed1986

Lumbar posterior marginal intra-osseous cartilaginous node.

This report concerns 12 patients, eight young adults and four adolescents, presenting with lumbar or sciatic pain. This was associated with an unusual defect of the inferior and posterior edges of the vertebral bodies of L4 or L5, together with a small bony ridge protruding into the spinal canal. We found 11 similar cases in the literature, all involving adolescents except for one young adult. It has been considered to be the result of a fracture of the posterior ring apophysis in association with a herniated disc. In our cases, in the absence of any known previous trauma, the radiological features and surgical results and the similarity and frequent association with typical lesions of Scheuermann disease, all suggest a posterior marginal cartilaginous node. The inferior lumbar location and frequent association with herniated disc and sciatic nerve root compression in young patients are discussed.

Adolescent↗
PubMed1986

Vertebral hemangiomas: radiologic evaluation.

Radiologic studies of 57 solitary vertebral hemangiomas (VHs) were reviewed to find radiographic and computed tomographic (CT) criteria by which to distinguish asymptomatic lesions from those compressing the spinal cord. Six features were seen significantly more often in those compressing the cord: location between T-3 and T-9, involvement of the entire vertebral body, extension to the neural arch, an expanded cortex with indistinct margins, an irregular honeycomb pattern, and soft-tissue mass. Contrast material-enhanced CT scans and selective spinal angiograms demonstrated extension into the spinal canal. In patients with a VH and back pain of uncertain origin, the presence of three or more of these signs may indicate a potentially symptomatic VH. In such patients, spinal angiography and, in some cases, embolization, are indicated.

Adolescent↗
PubMed1985

[Vertebral compression with intrasomatic vacuum images. Apropos of 2 cases with histological control by trocar biopsy].

The significance of a gas shadow, known as an intra-somatic space, seen in cases of vertebral compression is discussed in relation to two cases with histological confirmation by means of trocar aspiration biopsy of the vertebra. The presence of this image is in favour of a neoplastic or infectious aetiology; however, in view of the limited experience, histological confirmation by aspiration biopsy of the vertebra is indicated in the presence of one or more reasons for suspecting a neoplastic aetiology. The most satisfactory pathophysiological hypothesis to explain the appearance of an intra-somatic space is that this image generally appears in cases of osteoporotic vertebral compression complicated by a certain degree of osseous ischaemia.

Aged↗
PubMed1984

[Value of a new apparatus for percutaneous vertebral bone biopsy].

Percutaneous vertebral trephine biopsy is a valuable investigation. A new type of trephine needle for vertebral biopsy is described in this paper. This trephine needle is introduced on the thin needle used for local anesthesia, following a procedure similar to vascular catheterism. Thus, the same puncture is used for local anesthesia and bone biopsy. Therefore, local anesthesia is more effective and the biopsy procedure is much safer, particularly at the thoracic level where vital organs are very close to the spine. A very practical handle design for advancing the trephine needle on the guide wire makes the biopsy procedure easy and precise. This trephine needle enhance indications of this potentially valuable procedure.

Biopsy, Needle↗
PubMedDate not supplied

[A diagnosis to consider: insufficiency fracture of the sacrum].

The authors report a case of insufficiency fracture of the sacrum in an 81-year old woman. The fracture was related to disjunction of the pubic symphysis consecutive to curettage of the pubic bones for septic osteitis developed after vulvectomy for cancer. The diagnosis was suspected on the results of bone scintigraphy and was confirmed by computerized tomography with frontal sections and contrast inversion, showing the characteristic H-shaped fracture.

Aged↗
PubMedDate not supplied

A method of radio-frequency inhomogeneity correction for brain tissue segmentation in MRI.

An automatic method of correcting radio-frequency (RF) inhomogeneity in magnetic resonance images is presented. The method considers that image intensity variation due to radio-frequency inhomogeneity contains not only low frequency components, but also high frequency components. The variation is regarded as a multiplication of low frequency (capacity variation of coil) and the frequency of object (true image). The efficiency of the proposed method is illustrated with the aid of both phantom and physical images. The impact of the inhomogeneity correction on brain tissue segmentation is studied in detail. The results show significant improvement of the tissue segmentation after inhomogeneity correction.

Brain↗