Molecular MR imaging in oncology

The implementation and integration of systems biology approaches with the emerging nanosciences and microchip technology will revolutionize profoundly molecular imaging and fuel the drive toward a more predictive and individualized health care. In combination with informatics platforms, key gene and protein targets will be identified, and serve as more effective targets for diagnostic and therapeutic interventions. Drug development also will be expedited by the judicious selection of more appropriate molecular biomarkers that will serve as objective end points of treatment efficacy, in addition to facilitating the development of new target-specific therapeutics. Finally, with the more widespread proliferation of high-field magnets and advancements in imaging hardware; acquisition methods; and novel,"smart" MR agents, the ability to achieve higher resolution analyses of tumor biology, cell track-ing, and gene expression will be realized more fully. Although radiologists will continue to serve as diagnostic consultants and assist in management decisions, the contributions from new developments in the biologic and molecular sciences will significantly alter the scope of our profession. Radiologists will be required to participate more actively in the individualized care of the patient and cultivate a deeper understanding of the underlying molecular basis of disease and molecular pharmacology for facilitating selection of the most appropriate combination of imaging studies that address biologically relevant questions. These radical changes in our profession will necessitate the re-education and emergence of a small cadre of professionals that is educated broadly in multiple scientific disciplines, and demonstrate expertise in clinical care and the basic sciences. The optimistic view is that this already is happening.     

Correlation of proton MR spectroscopic imaging with gleason score based on step-section pathologic analysis after radical prostatectomy

PURPOSE: To determine whether hydrogen 1 magnetic resonance (MR) spectroscopic imaging can be used to predict aggressiveness of prostate cancer. MATERIALS AND METHODS: All patients gave informed consent according to an institutionally approved research protocol. A total of 123 patients (median age, 58 years; age range, 40-74 years) who underwent endorectal MR imaging and MR spectroscopic imaging between January 2000 and December 2002 were included. MR imaging and spectroscopy were performed by using combined pelvic phased-array and endorectal probe. Water and lipids were suppressed, and phase-encoded data were acquired with 6.2-mm resolution. Voxels in the peripheral zone were considered suspicious for cancer if (Cho + Cr)/Cit was at least two standard deviations above the normal level, where Cho represents choline-containing compounds, Cr represents creatine and phosphocreatine, and Cit represents citrate. Correlation between metabolite ratio and four Gleason score groups identified at step-section pathologic evaluation (3 + 3, 3 + 4, 4 + 3, and > or =4 + 4) was assessed with generalized estimating equations. RESULTS: Data from 94 patients were included. Pathologic evaluation was used to identify 239 lesions. Overall sensitivity of MR spectroscopic imaging was 56% for tumor detection, increasing from 44% in lesions with Gleason score of 3 + 3 to 89% in lesions with Gleason score greater than or equal to 4 + 4. There was a trend toward increasing (Cho + Cr)/Cit with increasing Gleason score in lesions identified correctly with MR spectroscopic imaging. Tumor volume assessed with MR spectroscopic imaging increased with increasing Gleason score. CONCLUSION: MR spectroscopic imaging measurement of prostate tumor (Cho + Cr)/Cit and tumor volume correlate with pathologic Gleason score. There is overlap between MR spectroscopic imaging parameters at various Gleason score levels, which may reflect methodologic and physiologic variations. MR spectroscopic imaging has potential in noninvasive assessment of prostate cancer aggressiveness.     

Imaging of transposed ovaries in patients with cervical carcinoma

OBJECTIVE: Lateral ovarian transposition is a surgical procedure performed in premenopausal women with pelvic malignancies in which the ovaries are surgically displaced from the pelvis, before radiation therapy. In this article, we present the imaging features of normal transposed ovaries as well as the spectrum of abnormalities associated with lateral ovarian transposition. CONCLUSION: After lateral ovarian transposition, it is important to recognize the ovaries to avoid confusing them with peritoneal implants. In addition, benign ovarian lesions must be distinguished from primary and secondary malignancies.     

Transient protein-losing enteropathy associated with Epstein-Barr virus infection in an immunocompetent child: a case report

Transient protein-losing enteropathy associated with acute Epstein-Barr virus infection in an immunocompetent 5-year-old girl is described. The child had a complete resolution of the disease without specific treatment. To the best of our knowledge this is the first report of Epstein-Barr virus infection associated protein-losing enteropathy in a previously healthy patient. Acute infection caused by Epstein-Barr virus infection should be considered in patients with symptomatic protein loss of gastrointestinal origin.     

The use of MRI in the diagnosis and management of a bulky cervical carcinoma

BACKGROUND: In the treatment of gynecologic cancer, surgical planning depends on the site and extent of disease. The evaluation of the origin of a large pelvic mass with combined pelvic examination and ultrasound is often adequate. However, the following case report illustrates the utility of magnetic resonance imaging (MRI) when sonographic findings are indeterminate and the origin of a pelvic mass is unclear. CASE: A 73-year-old woman presented for her first gynecologic exam in over 40 years. On speculum examination the cervix was not visible. A large, mobile pelvic mass was palpated during physical examination. Pelvic ultrasound revealed a large, cystic pelvic mass thought to be ovarian in origin. Surgery for presumed ovarian carcinoma was planned. Because a vaginal Pap smear revealed squamous-cell carcinoma, MRI was performed for further evaluation. MRI demonstrated a blood distended uterus with a large cervical tumor obstructing the endocervical os. After cervical dilatation under sonographic guidance, evacuation of the hematometrium was performed. Multiple biopsies of the cervix confirmed the diagnosis of a bulky Stage IIA squamous-cell carcinoma of the cervix. The patient was subsequently treated with concomitant chemotherapy and radiation therapy. Follow-up MRI demonstrated an excellent treatment response. Modified radical hysterectomy was performed demonstrating very small residual tumor. CONCLUSIONS: Magnetic resonance imaging, through multiplanar capabilities and high-contrast resolution, is a valuable tool that can assist the clinician in the evaluation, diagnosis, and management of challenging gynecologic malignancies.     

IgE antibodies to Plasmodium falciparum and severity of malaria in children of one ethnic group living in Burkina Faso

Plasmodium falciparum malaria infection induces elevated blood levels of both total immunoglobulin and anti-plasmodial antibodies belonging to different isotypes. We have previously shown that donors living in areas of malaria transmission develop malaria-specific IgE antibodies that are present at highest concentrations in patients with severe disease, suggesting a role for this isotype in malaria pathogenesis. To establish the possible importance of IgE in the course and severity of this disease, we have analyzed a large and homogenous group of African children (age range = 6 months to 15 years) belonging to one ethnic group (Mossi) living in identical epidemiologic conditions in the same urban area (Ougadougo) of Burkina Faso. While IgG antibodies to P. falciparum increased to high concentrations in very young children and then remained at these levels in older patients, IgE antibodies increased with age, becoming most significantly elevated in children more than four years of age. In older children, those with severe malaria had significantly higher IgE antibody levels than those with non-severe disease. No significant differences between the patient groups were seen for IgG antibodies to P. falciparum. However, when the patients with severe malaria were divided into two groups distinguished by the presence of absence of coma, both IgG and IgE antibodies against malaria were lower in the comatous patients than in the non-comatous patients. The results support the conclusion that IgE antibodies against malaria, regardless of their possible protectivity, also contribute to disease severity in this large and homogenous group of African children.     

Blood loss during radical retropubic prostatectomy: relationship to morphologic features on preoperative endorectal magnetic resonance imaging

Objectives. To determine whether morphologic features at preoperative magnetic resonance imaging (MRI) are related to intraoperative blood loss during radical retropubic prostatectomy.Methods. Endorectal MRI was performed in 143 patients with newly diagnosed prostate cancer before radical retropubic prostatectomy. Two independent readers rated the prominence of the periprostatic veins (on the basis of number and size) at four anatomic sites on a 3-point scale. Other features analyzed were prostate volume and interspinous diameter.Results. A prominence of the anterior and posterior apical periprostatic veins was positively associated with blood loss (correlation coefficient = 0.22 and 0.17 and P <0.01 and <0.05, respectively). Blood loss was not related to prostate volume (correlation coefficient = 0.02, P = 0.8) or interspinous diameter (correlation coefficient = 0.01, P = 0.9). The site-specific scores of both readers demonstrated positive agreement, with Pearson’s correlation coefficients of 0.51 to 0.65 (P <0.01).Conclusions. A marked prominence of the apical periprostatic veins on preoperative MRI is associated with greater intraoperative blood loss during radical retropubic prostatectomy. Other morphologic factors appear unrelated to the amount of intraoperative blood loss.     

Lysosomal enzyme studies after endotoxin administration in normothermia and hypothermia

The LD₅₀ dose of endotoxin results in a considerable increase in the plasma level of acidic phosphatase and -glucuronidase. The endotoxin decreases the quantity of -globulin fraction of sera as an effect of neutral lysosomal proteases. In hypothermic rabbits the activity of lysosomal enzymes is increased only slightly after administration of endotoxin and the change in the -globulin level is also more less than in the normothermic animals. The importance of our results in the pathogenesis of inflammation induced by endotoxin is discussed.