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A study was conducted at the University of Virginia Health Sciences Center to examine the effectiveness of magnetic resonance imaging in detecting rupture or deflation of in situ mammary prostheses. Thirty-three women with 59 prostheses were included in the study. Fifteen of the 33 patients had undergone surgery for removal or replacement of 21 implants. Positive findings for rupture were accurately predicted for 15 implants and confirmed at surgery. Negative findings for rupture were accurately predicted in the remaining 6 implants and confirmed at surgery. Although it is a more costly procedure than either mammography or ultrasonography, we believe that magnetic resonance imaging is also more accurate in detecting damaged implants, particularly when they are contained within an intact capsule or when the implants are stacked. Unlike mammography, magnetic resonance imaging requires no ionizing radiation or breast compression. Magnetic resonance imaging of the in situ breast prosthesis may be a useful adjunct when other modalities yield inconclusive results or when a contained rupture is suspected.

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We have implemented an MR technique that employs a rapid gradient echo sequence, preceded by magnetization preparation pulses to provide T1- and T2-weighted tissue contrast. With this technique, which can be identified as a member of a new family of pulse sequences, generically named Magnetization Prepared RApid Gradient Echo (MP-RAGE), very short repetition times are used, allowing acquisition times of less than one second and images virtually free of motion-induced artifacts during quiet respiration. Fifteen patients with known liver lesions (metastases, hemangiomas, and cysts) were examined using T1- and T2-weighted 2-dimensional MP-RAGE sequences, and the images were compared with conventional T1- and multi-echo T2-weighted spin-echo (SE) sequences. Signal difference-to-noise ratios (SD/Ns) of the lesions were calculated for all pulse sequences using corresponding axial images and were normalized for voxel volume. The mean normalized SD/Ns of the MP-RAGE sequences were generally comparable to those for the SE sequences. In addition, there were no noticeable respiratory artifacts on the MP-RAGE images whereas these were clearly present on the T2-weighted SE images and to a lesser degree on the T1-weighted SE images. It is concluded that the MP-RAGE technique could become an important method for evaluating the liver for focal disease.

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Accurate preoperative assessment of renal and perirenal tumors is crucial in determining the type of therapy and/or in planning the operative approach. Computed tomography has been used extensively to stage renal cancer by defining the extent of disease within and outside the kidney, demonstrating patency of the renal vein and inferior vena cava, and depicting sites of lymph node involvement. Recent studies have shown magnetic resonance imaging to be comparable or superior to computed tomography in staging renal carcinoma. Because of its multiplanar imaging capabilities, MRI has also proven useful in evaluating perirenal masses that may obstruct, displace, or invade the kidney. The advantages and limitations of MRI and CT are discussed and their current roles in the evaluation of renal and perirenal abnormalities are reviewed.

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Thirteen patients' status post repair of thoracic aortic dissection were studied with both magnetic resonance and angiography. MRI was an accurate modality in identifying residual dissection when aortography was used as the gold standard. MRI can be used as a noninvasive modality for the follow-up of these patients.

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Changes in uterine zonal anatomy in six women during a cycle of treatment with clomiphene citrate is studied by magnetic resonance imaging. There was a rapid rate of increase in endometrial thickness during the periovulatory period that was similar to the pattern seen in a prior study of women with normal (nonstimulated) cycles. Junctional zone thickness did not parallel the endometrial pattern and differed from the response seen in nonstimulated cycles. Results of large scale studies may help to further understand the effects of these medications.

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Tuberculous abscess of the pancreas is a rare complication of disseminated tuberculosis. The computed tomographic appearance of a tuberculous pancreatic abscess in a patient with acquired immune deficiency syndrome (AIDS) is described. One should consider this diagnosis whenever a patient with AIDS has diffuse abdominal lymphadenopathy.

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In the absence of trauma or descending thoracic aortic dissection, abdominal aortic dissection is rare. This report presents a case of "isolated" abdominal aortic dissection. Magnetic resonance imaging may reliably diagnose and characterize these dissections without the use of contrast material.

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A prospective study was undertaken to assess the ability of magnetic resonance imaging (MRI) to stage cervical carcinoma. Compared to computed tomography (CT), MRI showed a high degree of accuracy in correctly demonstrating involvement of the vagina, parametria and sidewalls, bladder, and lymph nodes but tended to overestimate disease in all of the categories studied. Large-scale studies comparing the two modalities are necessary because the most accurate staging of cervical carcinoma is crucial for selecting the best treatment protocols.

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This study examines the ability of magnetic resonance imaging (MRI) to monitor follicular and endometrial development during the menstrual cycle. MR scans, sonograms and hormonal levels of estradiol (E2) and progesterone (P) obtained from five ovulatory volunteers were evaluated on approximately days 4, 8, 12, 16, 20 and 24 of the cycle. MRI reliably demonstrated folliculogenesis in all of the volunteers. Changes depicted in the endometrial and junctional zones of the uterus reflected physiologic events occurring during the normal cycle. Important implications exist for infertile women undergoing stimulated cycles and/or in-vitro fertilization.

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A patient undergoing treatment for abdominal lymphoma presented with a superior vena cava (SVC) syndrome. The presence of a wide mediastinum and "nodular" mediastinal densities on CT presented a diagnostic problem, necessitating thoracotomy. The thoracotomy was negative for tumor or infection. We believe that the presence of an indwelling catheter and mediastinal lipomatosis resulted in the SVC syndrome. The "nodular" densities represented an unusual set of mediastinal collaterals that must be distinguished from adenopathy.

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A prospective study was undertaken to evaluate and compare magnetic resonance imaging (MRI) and ultrasound (U/S) in monitoring follicular and endometrial development during the normal menstrual cycle. Results of MRI, U/S, estradiol (E2), and progesterone were obtained from five ovulatory volunteers on days 4, 8, 12, 16, 20, and 24 of the cycle. On U/S, all the women had only one dominant follicle, whereas MRI was able to detect a secondary cohort of follicles in three of five volunteers. Endometrial development on U/S and MRI showed similar patterns of growth with an increase on MRI from 5.8 +/- 1.1 mm on day 4 to a mean peak of 10.3 +/- 1.7 mm on day 24. A distinct feature of MRI was the demonstration of a junctional zone (JZ), which has a pattern of growth that resembles that of the endometrium, with accelerated growth from day 8 to day 16 (5.1 +/- .7 mm to 6.7 +/- .7 mm). The JZ corresponds anatomically to the distribution of the arcuate vessels and may therefore represent changes in blood supply to the endometrium. MRI, similar to U/S, is noninvasive and does not involve any radiation exposure but provides new information on uterine changes in the normal cycle. At present, its clinical applications are limited.

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Small tumors of the breast, both benign and malignant, may remain clinically silent for some time before they become large enough to be palpable. In many cases the tumor is revealed on a mammogram that is performed only as part of a routine check-up. The spectrum of radiographic appearances of these "occult" tumors is described and correlated with histological findings. In a significant number of cases there is an overlap in mammographic appearance of these nonpalpable benign and malignant lesions and a biopsy is necessary. The techniques of spot localization are discussed, and the importance of this procedure prior to biopsy is stressed as an aid to the surgeon in localizing the abnormality. Results of studies and attempting to analyze and classify high risk radiographic patterns are reviewed. Reduction in mortality lies in detection of breast cancer in as early a stage as possible.

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During the period between 1977 and 1979, mammographic spot localizations were performed in 52 patients for evaluation of suspected occult neoplasms. Twenty-eight patients were found on biopsy to have a malignancy; on the remaining 24 patients the finding proved to be benign. The mammographic abnormalities were divided into two groups: (a) those associated with microcalcification and (b) those in which the abnormality was manifested by a small mass or localized distortion of the breast parenchyma. In many instances it was not possible to differentiate benign disease from malignancy on the mammogram. None of the 28 patients with malignant tumour had axillary node involvement at surgery.

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Ultrasound has become an accepted diagnostic modality since the late 1950s. Since its introduction as a soft-tissue imaging method, ultrasound has broadened and assumed many research and clinical roles in medicine. Yet, despite the growing enthusiasm for ultrasound, there has been little written about its growth that brings together the latest areas of clinical utilization and research. To gather this data, we personally researched 32 leading medical centers in the United States. This paper shows where ultrasound stands not and where it is likely to go in the near future.

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Fetal intracranial anatomy can now be visualized as early as the 13th to 15th menstrual week using commercially available ultrasound equipment. It has consequently become possible to diagnose hydrocephalus early in pregnancy, often in the second trimester. We present a case of unsuspected hydrocephalus diagnosed in utero which demonstrated marked undulation of the midline echo. The significance of the midline echo and the diagnostic criteria in evaluating hydrocephalus are discussed.

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