Nuclear magnetic resonance proton imaging of bone pathology

Thirty-two patients with diversified pathology were examined with a supraconductive NMR imager using spin echo with different TR and TE to obtain T1 and T2 weighted images. They included 20 tumors (12 primary, eight metastasis), six osteomyelitis, three fractures, two osteonecrosis, and one diffuse metabolic (Gaucher) disease. In all cases except for the stress fractures, the bone pathology was clearly visualized in spite of the normal lack of signal from the compact cortical bone. Nuclear magnetic resonance (NMR) imaging proved to be at least as sensitive as radionuclide scintigraphy but much more accurate than all other imaging procedures including computed tomography (CT) and angiography to assess the extension of the lesions, especially in tumors extended to soft tissue. This is due both to easy acquisition of sagittal and coronal sections and to different patterns of pathologic modifications of T1 and T2 which are beginning to be defined. It is hoped that more experience in clinical use of these patterns will help to discriminate between tumor extension and soft-tissue edema. We conclude that while radionuclide scintigraphy will probably remain the most sensitive and easy to perform screening test for bone pathology, NMR imaging, among noninvasive diagnostic procedures, appears to be at least as specific as CT. In addition, where the extension of the lesions is concerned, NMR imaging is much more informative than CT. In pathology of the spine, the easy visualization of the spinal cord should decrease the need for myelography.     

Imagerie fonctionnelle du sein

In recent years, breast imaging has benefited from a number of new advances. The resulting new imaging methods mainly focus on the functional examination of tumours and aim to improve tumour detection and characterization, provide new prognosis criteria, and guide the therapeutic management of breast cancer. One of the most promising functional assessments — whether performed through the use of ultrasound, X-rays or MRI — is the analysis of tumour angiogenesis, which plays a major role in tumour development and metastatic potential. In this article, we discuss the major developments in functional imaging of the breast, including imaging methods such as X-rays, ultrasound, MRI and nuclear medicine. After a brief technology overview, we present the early clinical results and prospects of each of the techniques.     

Rheumatic fever

Rheumatic fever is a multisystem inflammatory disease that occurs as a delayed sequel to group A streptococcal pharyngitis. It is less common than it was 50 years ago but is still a major cause of heart disease in developing areas of the world. The relationship between the site of infection, the type of causative organism, and susceptibility of the host is essential in the development of the disease. Its major clinical manifestations include carditis, migratory polyarthritis, chorea, erythema marginatum, and subcutaneous nodules. It can manifest as an acute febrile illness consisting of migratory polyarthritis involving the large joints, as carditis and valvulitis, or as Sydenham’s chorea with involvement of the central nervous system. The disorder in its milder form resolves itself without sequelae. Carditis is the condition most associated with increased mortality and morbidity and may be fatal in its severe forms. Penicillin is the most appropriate primary and secondary prophylaxis. Antiinflammatory agents provide symptomatic relief but do not prevent rheumatic heart disease.     

Suppression of B cell activation by cyclosporin A, FK506 and rapamycin.

The effects of the immunosuppressants cyclosporin A (CsA), FK506 and rapamycin have been compared using murine B cells activated with a variety of mitogens. FK506 is a macrolide antibiotic that has been recently shown to inhibit T cell activation by a mechanism that appears similar to that of CsA. Rapamycin is a macrolide structurally related to FK506 whose mechanism of T cell suppression appears to be distinct from that of FK506 and CsA. While CsA and FK506 were found to preferentially inhibit B cell activation caused by stimuli which induce a rise in intracellular calcium, rapamycin partially inhibited activation by all stimuli tested, including those which are not associated with a calcium flux. All three compounds were found to inhibit cell cycle progression within the G1 phase; however, the rapamycin-sensitive event within G1 was completed earlier than the G1 events inhibited by CsA and FK506. In addition, inhibition of anti-IgM-activated B cells with CsA and FK506, but not with rapamycin, resulted in cell death. These data suggest that although CsA, FK506 and rapamycin are all inhibitors of B cell activation, the inhibitory activity of rapamycin can be clearly distinguished from that of CsA and FK506. Although the suppressive effects of CsA and FK506 on B cell proliferation were nearly identical in this study, their biological activities were distinguishable since FK506, but not CsA, could antagonize rapamycin-mediated suppression.     

Granular cell tumors of the esophagus

An unusual benign multicentric esophageal granular cell tumor (granular cell myoblastoma) associated with 16 other similar tumors in the skin, vulva, breast, and tongue of 1 patient is described. There was a family history of granular cell tumors in the patient's mother; this has not been previously described. The pathologic findings and controversial histogenesis of granular cell tumors are discussed in an effort to delete the erroneous term "myoblastoma" from the radiologist's vocabulary. Granular cell tumors of the esophagus are also specifically reviewed.     

Weight change adjusted equations for assessing resting metabolic rate in overweight and obese adults

BackgroundAlthough over one hundred equations have been developed to predict the energy expenditure of individuals, none are sensitive to weight change in assessment of resting metabolic rate (RMR) before and after weight loss.ObjectiveTo formulate adjusted equations for overweight and obese individuals and to compare their accuracy with existing prediction RMR equations before and after weight loss.Subjects/materialsThis is historical prospective study. Participants included 39 overweight and obese men and women before and after losing 10–20% from baseline weight on a diet and physical activity regimen for at least three months. Pre and post weight loss measured RMR results were compared to estimated RMR using several existing prediction equations: Harris and Benedict, Ravussin and Bogardus, and Mifflin et al. To improve the accuracy of these prediction equations, we suggest new equations adjusted for weight loss, based on measured RMR and evaluated their accuracy.ResultsPre and post weight loss data indicated: significant fat reduction in both genders; reduction in free-fat mass only in men, and a significant decrease in measured RMR only in women. Our suggested equations were the most accurate and closest to measured RMR in both genders, in comparison to the Harris and Benedict, Ravussin and Bogardus, and Mifflin et al equation results. Estimated RMR using the latter equations was significantly lower than measured RMR in both genders at pre and post weight loss (P < 0.01).ConclusionsThis study highlights the need for adjusting RMR equations before and after weight loss in overweight and obese individuals. Further research is needed to validate our suggested equations.     

Pyogenic liver abscess: Warning indicator of silent colonic cancer

PURPOSE: Carcinoma of the colon, manifested clinically as an enterococcal hepatic abscess, in the absence of liver metastases, is very uncommon. However, having treated a patient with such a condition, we would like to draw the attention of surgeons to this possibility. Most reports describe secondary infections of hepatic metastases only in patients with a known malignancy. However, increased awareness of colonic cancer as an underlying cause of pyogenic liver abscesses will afford earlier diagnosis and treatment. METHODS: The case was analyzed for history, presentation, laboratory data, radiologic studies, and bacteriology. RESULTS: A 66-year-old woman presented with abdominal pain, fever, and chills. Imaging scans revealed a solitary liver abscess, which was successfully treated with percutaneous drainage and broad-spectrum intravenous antibiotics. Pus cultures grew Streptococcus faecalis.A search for the underlying cause led to the discovery of an adenocarcinoma of the sigmoid colon. CONCLUSIONS: An aggressive search for the underlying cause of pyogenic liver abscesses should be an integral part of the definitive treatment of this disease. After prevailing etiologies have been excluded, silent colonic cancer should be considered.