[Nuclear magnetic resonance in the study of pathology of the whole body (III)].

Magnetic Resonance Imaging (MRI) is the most recent imaging modality introduced for the study of the body. The main clinical indications of this technique concern the pathology of the brain and spinal cord. Nevertheless, recent improvements in equipment technology have widened the field of applications to other regions of the body such as the chest, abdomen, pelvis, and the musculoskeletal system.

Assessment of male infertility: correlation between results of semen analysis and phosphorus-31 magnetic resonance spectroscopy.

To evaluate the usefulness of phosphorus-31 magnetic resonance spectroscopy (31P-MRS) in assessing male infertility, we compared it with conventional semen analysis. Specimens were obtained from otherwise healthy patient groups as follows: group A, 7 fertile control subjects; group B, 12 azoospermic men after vasectomy; and group C, 11 patients presenting for infertility evaluation. Correlations between established semen analysis parameters and the 31P-MRS-derived ratio of glycerylphosphorylcholine to total phosphate (GPC/TP) were investigated.

Gynecologic tumor imaging.

Anatomy of the female pelvis is superbly delineated by MRI due to excellent soft tissue contrast. In patients with infertility, MRI is the best technique to evaluate suspected myomata. Since tumors are directly visualized, MRI can be an effective technique for staging cervical, uterine, and vaginal malignancies.

Rapid, contrast-enhanced, diuretic magnetic resonance imaging of unilateral partial ureteral obstruction. An experimental study in micropigs.

The value of rapid, contrast-enhanced, diuretic magnetic resonance (MR) imaging (using ferrioxamine B and furosemide) in demonstrating partial unilateral ureteral obstruction and the potential of such MR imaging in differentiating obstructive from nonobstructive hydronephrosis was assessed in six micropigs. MR imaging (0.35 Tesla, partial-flip technique with repetition time [TR] of 125 milliseconds, echo-delay time [TE] of 20 milliseconds, and flip angle of 70 degrees) was performed before, and at 5, 12, and 19 days after partial ureteral obstruction.

Radiation-induced uterine changes: MR imaging.

To assess the capability of magnetic resonance (MR) imaging to demonstrate postirradiation changes in the uterus, MR studies of 23 patients who had undergone radiation therapy were retrospectively examined and compared with those of 30 patients who had not undergone radiation therapy. MR findings were correlated with posthysterectomy histologic findings. In premenopausal women, radiation therapy induced (a) a decrease in uterine size demonstrable as early as 3 months after therapy ended; (b) a decrease in signal intensity of the myometrium on T2-predominant MR images, reflecting a significant decrease in T2 relaxation time, demonstrable as early as 1 month after therapy; (c) a decrease in thickness and signal intensity of the endometrium demonstrable on T2-predominant images 6 months after therapy; and (d) loss of uterine zonal anatomy as early as 3 months after therapy.

Current status of MR imaging of the female pelvis.

Magnetic resonance imaging (MRI) has become an important diagnostic method for the study of the female pelvis. It provides a noninvasive means of evaluating uterine zonal anatomy and can reflect the variable appearance of the female genital tract in response to different hormonal stimuli. It is considered a problem-solving technique for evaluating benign uterine and adnexal masses and is the primary imaging modality for staging endometrial, cervical, and vaginal carcinoma.

Normal penile anatomy and abnormal penile conditions: evaluation with MR imaging.

The appearance of the normal penis and of a variety of penile abnormalities on magnetic resonance (MR) images was studied in 55 patients with either medium (0.35 T) or high (1.5 T) magnetic field strengths.

Advances in imaging.

The introduction of sonography, x-ray computed tomography, magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS) have enhanced the radiologist's ability to delineate and stage neoplasms in all parts of the human body. Images of excellent quality can be generated within a reasonable time frame and with minimal biologic risk. All of the more sophisticated imaging modalities are costly and none can, isolated from clinical data, provide histologic diagnoses.

Vagina: evaluation with MR imaging. Part II. Neoplasms.

The potential of magnetic resonance (MR) imaging in the detection of vaginal tumors and the assessment of their extent was evaluated retrospectively in 87 patients in whom primary, metastatic, or recurrent vaginal cancer was clinically suspected. MR findings were compared with the results of surgery and/or biopsy. Results of histopathologic study verified a normal vagina in 51 patients, benign cysts in two, primary tumor in four, metastatic cancer in 22, and recurrent tumor in eight.

Vagina: evaluation with MR imaging. Part I. Normal anatomy and congenital anomalies.

The appearance of the vagina was evaluated on magnetic resonance (MR) images of 65 subjects who were healthy or had disease unrelated to the vagina and 24 patients with suspected congenital anomalies of the vagina. MR imaging accurately demonstrated the presence of (n = 78) or complete (n = 7) or partial (n = 4) absence of the vagina in each case. Partial (n = 2) or complete (n = 2) duplication of the vagina was also correctly diagnosed.

Complete and partial ureteral obstruction: evaluation of renal effects with P-31 MR spectroscopy and Tc-DMSA scintigraphy.

Phosphorus-31 magnetic resonance (MR) spectroscopy was used to study the effects of partial and complete ureteral obstruction on the porcine kidney; results were compared with renal tubular function as determined with technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy. Twenty-seven pigs were used: nine as sham-operated controls, six with partial ureteral obstruction, and 12 with complete ureteral obstruction. P-31 MR spectra and Tc-DMSA scintiscans were obtained weekly over 3 weeks.

Müllerian duct cyst: diagnosis with MR imaging.

The value of magnetic resonance (MR) imaging in diagnosing clinically suspected müllerian duct cysts was assessed in six patients. MR imaging correctly demonstrated the abnormality to be intraprostatic, consistent with the diagnosis of müllerian duct cysts in four patients, and allowed the diagnosis to be excluded in the other two. The demonstration of prostatic zonal anatomy, the ability to obtain direct images in all three orthogonal planes, and a large field of view make MR imaging valuable in the study of suspected müllerian duct cysts.

Imaging the testis: comparison between MR imaging and US.

The potential role of magnetic resonance (MR) imaging in the diagnosis and local staging of testicular tumors was evaluated in 23 patients who subsequently underwent surgery or biopsy. Findings at MR imaging were compared with those at ultrasonography (US) and were correlated with the surgical-histologic findings. At surgery, three patients were found to have extratesticular and 20 patients intratesticular abnormalities.

Use of an agonistic analog of gonadotropin-releasing hormone (nafarelin) to treat leiomyomas: assessment by magnetic resonance imaging.

The purposes of this study were to investigate the effect of a superactive agonistic analog of gonadotropin-releasing hormone, nafarelin, on uterine leiomyomas and to assess the use of magnetic resonance imaging in monitoring uterine and myoma size. Eleven women with uterine leiomyomas were treated with 800 micrograms of nafarelin per day for 6 months. Serum gonadotropin and estradiol concentrations were suppressed during treatment.

Detection and staging of renal neoplasms: a reassessment of MR imaging.

The use of magnetic resonance (MR) imaging in the detection and staging of renal neoplasms was investigated in 104 patients with 106 renal cell carcinomas confirmed at surgery or autopsy. Overall, MR imaging demonstrated 101 of 106 lesions (95%), including all 93 tumors that were larger than 3 cm in diameter but only eight of the 13 smaller tumors (62%). MR imaging enabled accurate staging of 82% of all detected lesions but led to the understaging of nine lesions and the overstaging of nine.

Invasive cervical carcinoma: comparison of MR imaging and surgical findings.

The accuracy of magnetic resonance (MR) imaging in staging invasive carcinoma of the cervix was determined retrospectively in 57 consecutive patients in whom the extent of disease was surgically confirmed. MR images were analyzed for (a) location and size of the primary tumor; (b) tumor extension to the uterine corpus, vagina, parametria, pelvic sidewall, bladder, or rectum; and (c) pelvic lymphadenopathy. The accuracy of MR imaging in determination of tumor location was 91% and for determination of tumor size within 0.

Pelvic lipomatosis: diagnosis and characterization by magnetic resonance imaging.

While the number of reported cases of pelvic lipomatosis has been relatively small, this entity's prevalence is probably underestimated. Disease progression can cause hydroureteronephrosis and renal failure, and clinical follow-up is mandated after diagnosis. Diagnosis is based on detection of characteristic findings in conventional radiographs and computed tomographic (CT) images.

Noninvasive imaging for staging of prostate cancer: magnetic resonance imaging, computed tomography, and ultrasound.

The diagnosis of prostate carcinoma by imaging is still fraught with problems, even with the advent of highly sophisticated techniques. Despite enthusiastic preliminary reports, no one imaging method reliably screens for this condition. The staging of prostate carcinoma is feasible, but the best imaging method remains a subject of debate.

Magnetic resonance imaging in genital anomalies.

Magnetic resonance imaging, a new radiographic modality that is not dependent on ionizing radiation or intravenous contrast agents, was used to identify undescended testes in 11 patients. Of 14 undescended testes 13 were identified and the only testis that was not seen was in a patient with surgically proved unilateral anorchism. We also used magnetic resonance imaging in 9 patients with various types of intersex.

MR in renal disease: importance of cortical-medullary distinction.

The diagnostic value of MR contrast between renal cortex and medulla (CMC) as an indicator of renal disease was retrospectively studied in 51 patients (9 patients with obstructive disease, 7 with inflammatory disease, 12 with various noninfectious parenchymal medical disease, 5 with vascular disease, 2 with diffuse neoplastic disease, 7 with hemosiderosis, and 10 with renal trauma [blunt trauma and 9 postlithotripsy]). Additionally, normal kidneys from 20 control subjects were studied. On T1-weighted spin-echo images (SE 500/30), CMC was visible in all the normal kidneys (19% contrast +/- 2% SD).

Urologic cancer. Methods of early detection and future developments.

Technologic advances in diagnostic imaging have significantly improved the detection and staging accuracy of urologic cancer. Intravenous urography (IVU) is not sensitive for the detection of renal lesions, and a normal IVU does not exclude the presence of renal cancer. At this time, computed tomography (CT) is the method of choice for the detection of renal tumors.