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Biomedical subjects

J Frija

Publications and source records attributed to J Frija.

At least 19 recordsLinked to original sources
PubMed2000

Image-guided core-needle biopsy in patients with suspected or recurrent lymphomas.

BACKGROUND: It is now commonly admitted that the diagnosis of recurrence of lymphoma can be assessed by image-guided needle biopsy (IGNB). However, the means of obtaining tissue for the original diagnosis of lymphoma is often surgery. The aim of this study was to compare the accuracy of IGNB at the time of diagnosis and at the time of recurrence or progression. METHODS: The authors performed 212 IGNBs on 194 patients who eventually had a diagnosis of lymphoma. One hundred three IGNBs were obtained at original diagnosis and 109 at recurrence or progression. Large-cutting core-biopsy needles, ranging in size from 20 gauge to 14 gauge, were used. Immunohistochemistry studies were performed in all lymphoma cases. RESULTS: A diagnosis of lymphoma with subtyping was obtained in 88% of all cases, in 85% at initial diagnosis, and in 89% at follow-up. Therapy was initiated on the basis of IGNB in 93% of all cases, in 91% at initial diagnosis, and in 94% at follow-up. Benign complications occurred in 7.5% of cases and did not require specific treatment. IGNB was equally effective for making a specific diagnosis of lymphoma and initiating therapy at the time of original diagnosis and at follow-up. CONCLUSIONS: The authors recommend that IGNB be performed as the initial procedure for the diagnosis of lymphoma in the absence of peripheral lymph nodes, either at presentation or at recurrence.

Adolescent↗
PubMed2000

[Role of MRI in the diagnosis of breast diseases].

UNLABELLED: ADVANTAGES AND LIMITATIONS: Magnetic resonance imaging of the breast is probably the most sensitive method for detecting or ruling out breast disease. It is however not as specific as expected. TECHNIQUE: All examinations are performed with and without gadolinium intravenous administration, excepted in the case of silicone implant reconstruction mammoplasty. Dynamic contrast-enhanced MRI sequences are necessary with a permanent balance between temporal resolution, spatial resolution, and signal. MRI of the breast is not indicated as a routine examination in a screening program, neither to improve the specificity of infra-clinic lesions, nor in simply dense breasts without any known risk factor or in circumscribed masses. INDICATIONS: MRI is best used to improved the sensitivity of mammography and sonography in selected patients. The selected indications are: evaluation of the volume and extension of breast lesions evaluation of the therapeutic response after chemotherapy, and detection or exclusion of the local recurrence in patients with breast conservation therapy. PERSPECTIVES: The future indications and perspectives of MRI include interventional breast radiology (MRI-guided core biopsy), and thermocoagulation therapy. It may be interesting for the evaluation of patients with contrast enhanced MRI lesions with normal mammography and sonography, and also in woman with a genetically defined high breast cancer risk.

Biopsy↗
PubMed2000

[Techniques to improve the accuracy of CT-guided abdominal biopsy].

STUDY AIM: The aim of this paper is to present an overview of the various technical progresses made in the field of CT-guided abdominal biopsies. Recent improvements allowed to markedly increase the efficiency of biopsies and to decrease the number of complications. The main innovations concern the guidance technique itself with the availability of ultra-fast CT systems, the development of automated biopsy systems, which allow to improve the size and quality of tissue samples and numerous technical tricks, allowing an easier access to target lesions, either in patient positioning or in displacement of anatomical structures. A better management of tissue samples favored by a close collaboration with pathologists is also mandatory. The last section of the paper is an overview of the rare complications of CT-guided biopsies.

Abdomen↗
PubMed2000

Diagnostic imaging of choroid plexus disease.

Disorders of the choroid plexus, a central nervous system structure, are rare, but can pose diagnostic difficulties. The purpose of this review is to illustrate the computed tomography and magnetic resonance imaging findings of a wide spectrum of lesions that affect the choroid plexus. The areas covered include (1) neoplasms (papilloma, leukaemia, meningioma, lymphoma and metastases); (2) infections (bacterial, fungal and viral); (3) cysts; (4) haemorrhage; (5) congenital abnormalities (Sturge-Weber syndrome, Klippel-Trenaunay-Weber syndrome and vascular malformations); and (6) non-infectious inflammatory disorders (xanthogranulomas, inflammatory pseudotumour, neurosarcoidosis, rheumatoid nodule and villous hypertrophy). Few of the patterns of choroid plexus involvement are specific for a particular pathological process. Guermazi, A. (2000) Clinical Radiology 55, 503-516.

Adolescent↗
PubMed2000

The clinical and radiological features of Fanconi's anaemia.

Fanconi's anaemia is a severe refractory anaemia, associated with congenital malformations in approximately two-thirds of cases. Although these malformations may involve every organ system, suggestive dysmorphic features include growth retardation, radial ray deformities and urinary malformations. These malformations are not specific for Fanconi's anaemia, but should be recognized during pregnancy, or later in childhood, and suggest the possibility of inherited haematopoiesis disorders.

Abnormalities, Multiple↗
PubMed1999

Imaging findings in patients with myelofibrosis.

The purpose of this review is to illustrate the wide range of radiological abnormalities in myelofibrosis. Myelofibrosis, also called myeloid metaplasia, is a myeloproliferative disorder of unknown etiology. The common imaging findings in patients with myelofibrosis are osteosclerosis, hepatosplenomegaly, and lymphadenopathies. In addition, extramedullary hematopoiesis may develop in multiple sites such as chest, abdomen, pelvis, and central nervous system, simulating malignant disease. Selected plain-film, CT, and MR images in patients with myelofibrosis are shown as pictorial essay to allow ready recognition of the most common imaging abnormalities of the disease.

Bone and Bones↗
PubMed1999

Prognostic value of vertebral lesions detected by magnetic resonance imaging in patients with stage I multiple myeloma.

We assessed the role of spinal magnetic resonance imaging (MRI) and bone densitometry as prognostic factors in patients with asymptomatic stage I multiple myeloma (MM) and negative skeletal survey. 55 consecutive patients underwent spinal MRI and 41 of them underwent bone densitometry by dual-energy X-ray absorptiometry (DEXA). Spinal MRI studies showed evidence of bone marrow involvement in 17/55 patients (31%). A diffuse pattern was present in three patients and a focal pattern in 14 patients, nine of them with only one nodular lesion. During a median follow-up of 25 months, 10 patients had disease progression, 8/17 patients with abnormal MRI and 2/38 patients with normal MRI. Median time to disease progression was not reached in both groups but was significantly different for patients with normal and those with abnormal patterns on MRI (P < 0.0001). Lumbar BMD was only slightly decreased compared with normal people (median lumbar Z score -0.43) and was not of prognostic value. Using a multivariate analysis the only two independent significant prognostic parameters were abnormal MRI (P<0.001, HR 30.4, 95% CI 4.3-213) and bone marrow plasmacytosis >20% (P=0.004, HR 16.4, 95% Cl 2.6-104). Thus, spinal MRI but not bone densitometry, appeared to be justified in patients with stage I asymptomatic MM and negative skeletal survey.

Absorptiometry, Photon↗
PubMed1999

[Scanner-guided biopsy technic with abdominal compression].

The aim of this study was to present a CT-guided biopsy technique using an abdominal compression device. With this system, the digestive structures (mainly the colon and the small bowel) can be displaced away from the needle track and the distance between the skin and the target lesion can be reduced by approximately one-third. The technique has been used in 29 patients and was successful in 28, allowing node biopsies in the mesenteric, retroperitoneal or pelvic areas. The compression system is easily mounted and used standard sterilizable material. The procedure is well tolerated by patients and complication rate is not raised compared with conventional biopsy techniques.

Abdomen↗
PubMed1999

[Fast imaging sequences].

Although conventional spin echo and gradient echo sequences are still in general use, the need to improve the temporal resolution of MRI and to study organ function has prompted to develop fast imaging techniques. These techniques are based on different approaches, but present common underlying principles which allow optimize k space fitting. As a result, both contrast and spatial resolution may be improved aside from the capability to reduce scan time. The selection of the most appropriate fast imaging technique will depend on the needed temporal resolution, spatial resolution and contrast. The aim of this paper is to review and explain the basic principles of fast imaging techniques, with emphasis on their advantages, limitations, and clinical applications.

Computer Systems↗
PubMed1998

Computed radiography.

In several medical centers computed radiography has almost completely replaced the use of conventional screen-film systems for general radiography. The aim of this paper is to explain the basic principles of the four most frequently numerical detectors used in the world, with emphasis on the phosphor plates, which are the most frequently used both in hospitals and by practitioners. The other two systems are based on a receptor with selenium. The fourth uses charged coupled device (CCD) detectors. The most important principles of digital processing are then described with concentration on unsharp mask filtering. In the future computed radiography will replace standard radiology and will create a system in medicine using the power of computers to archive--with more efficiency and less space--patient medical data. The transmission of data to workstations and the processing of this data is the topic of a new field in medicine.

Humans↗
PubMed1998

Fat suppression techniques in MRI: an update.

Due to short relaxation times, fat has a high signal on magnetic resonance images (MRI). This high signal, easily recognized on MRI, may be useful to characterize a lesion. However, small amounts of lipids are more difficult to detect on conventional MRI. In addition, the high signal due to fat may be responsible for artifacts such as ghosting and chemical shift. Lastly, a contrast enhancing tumor may be hidden by the surrounding fat. These problems have prompted development of fat suppression techniques in MRI. Fat may be suppressed on the basis of its difference in resonance frequency with water by means of frequency selective pulses or phase contrast techniques, or on the basis of its short T1 relaxation time by means of inversion recovery sequences. Lastly, hybrid techniques combining several of these fat suppression techniques are also possible. The aim of this paper is to review the basic principles of all these fat suppression techniques and to exemplify their clinical use.

Adipose Tissue↗
PubMed1998

Surgical endoscopic techniques in the diagnosis and follow-up of patients with lymphoma.

BACKGROUND: In patients with lymphoma, tissue for histology can be obtained through image-guided techniques or by surgery. The aim of this study was to assess the efficacy of surgical endoscopic techniques in obtaining adequate tissue specimens. METHODS: Ninety-two patients with suspected or confirmed lymphoma were referred for a surgical biopsy of a deeply located intrathoracic or intra-abdominal mass or lymph node. The 86 patients who had surgery using a surgical endoscopic technique were included in this study. There were 54 men and 32 women, of mean age 34 (range 15-78) years. Most were selected directly for surgery while five previously had a failed computed tomography-guided biopsy. A total of 89 procedures were performed in 86 patients: laparoscopy (15 patients), thoracoscopy (61) and mediastinoscopy (13). RESULTS: No patient died. One intraoperative complication occurred during thoracoscopy (1 per cent). Two postoperative complications were noted (2 per cent). Three patients required conversion to open surgery (3 per cent). Adequate tissue for histology was obtained by surgical endoscopic procedures in 87 per cent. Twelve of 13 mediastinoscopies were successful. After thoracoscopy, the success rate was 92 per cent but only nine of 15 laparoscopies were considered successful. CONCLUSION: In patients with lymphoma, surgical endoscopic techniques have a high diagnostic yield and a low morbidity rate. Barring exceptional circumstances these should be favoured rather than conventional open surgery.

Adolescent↗
PubMed1998

[What is bright on T1 MRI scans?].

The list of entities associated with a high signal intensity on T1-weighted images is extensive and classically includes fat, proteins, hemorrhage, melanin and gadolinium. However, additional entities may be responsible for abnormally high signal intensity on T1-weighted images. These include ion deposition in metabolic disorders, free radicals, increased proton density, flow phenomena, some artifacts, and new contrast agents. The aim of this article is to display both the common and uncommon causes for a high T1 signal intensity and to discuss the underlying mechanisms or attributable pathophysiology for this phenomenon.

Artifacts↗
PubMed1997

Radiologic anatomy of the inferior lung margins as demonstrated on computed radiography with enhancement of low frequencies.

The aim of this work was to describe the radiologic anatomy of the inferior lung margins (ILMs). The method was to enhance the low frequencies of 50 normal chest computed radiographs. On each side, the anterior and posterior ILMs were divided into two halves. The frequency of visibility of each half of each ILM was calculated as their shape, lateral and medial continuities, depth, and vertebral level. The differences were compared by a paired Student t-test. The right posterior ILM was always visible and usually concave upward (94%). Its height was 8.7 +/- 1.6 cm. Its most inferior part faced L1 or L2 in 92% of cases. It was continuous medially inside with the azygo-esophageal recess in 96% of cases. The left posterior ILM was not visible laterally in 34% of cases and medially in 60% of cases. It was most often concave upward (82% of cases). Its height was 6.9 +/- 1.5 cm. Its most inferior part was at the level of L1 or L2. It was continuous medially with either the left paraspinal line or the paraaortic line. The right anterior ILM was visible in 76% of cases. It was most often oblique upward and medially (46%) or concave upward (33%) and often notched (38%). The left anterior ILM was visible in 64% of cases and more often oblique inward and upward (58%). It was continuous medially with the left inferior precardiac recess. The anterior ILMs were more variable than the posterior. The posterior ILMs were very similar in shape and inferior level and differed in depth only by the difference of height of the diaphragmatic cupolas.

Adult↗