Magnetic resonance imaging findings of vulvar epithelioid sarcoma.

We describe here a case of vulvar epithelioid sarcoma. Epithelioid sarcoma is a malignant appendicular skin tumor that is rarely of vulvar origin. Magnetic resonance imaging (MRI) revealed a solid mass with an ulcer-like lesion and multilobulated contour. To our knowledge, this is the first case of vulvar epithelioid sarcoma described in the MRI literature.

MR findings of a giant Bartholin's duct cyst.

We describe the case of a 63-year-old woman with a large Bartholin's duct cyst that showed high signal intensity on T1- and T2-weighted magnetic resonance (MR) images. Although Bartholin's duct cyst is the most frequent cystic lesion of the vulva, such a giant cyst is rare.

Chronic expanding hematoma in the retroperitoneal space: a case report.

A case of retroperitoneal chronic expanding hematoma complicated with hydronephrosis, which was difficult to diagnose preoperatively, is reported. The patient was a 70-year-old man. An 18 cm mass was detected in the right retroperitoneal space on abdominal CT screening. There were small calcifications in the periphery of the mass that were strongly enhanced in the delayed phase of dynamic CT. The mass involved the right ureter and iliopsoas muscle, resulting in severe hydronephrosis. The histological diagnosis was chronic expanding hematoma.

[Histological changes in the rabbit kidney induced by transarterial injection of a hypertonic sodium chloride solution].

PURPOSE: To evaluate histological changes in normal renal tissue induced by the injection of a hypertonic liquid. MATERIALS AND METHODS: Transarterial injection was performed in 17 healthy rabbits at various rates of infusion and amounts of isotonic and hypertonic (7%) sodium chloride solutions. In group 1, 10 cc of isotonic sodium chloride solution was injected. In groups 2 and 3, 1-10 cc of hypertonic solution was injected at rates of 1.0 cc/sec and 0.05 cc/sec, respectively. After 20 minutes of hemostasis, renal weight measurements and histological examinations were performed. In three rabbits that received 10 cc of 7% sodium chloride, lung samples were also obtained, and histological changes were reviewed. RESULTS: There was no tissue injury in group 1, and in groups 2 and 3 the histological changes for infusions of 4-10 cc were greater than those of 1-3 cc. There was no vascular endothelial cell damage in any case. None of the histological changes were dose dependent, and the lungs showed no clear histological alterations. CONCLUSION: Higher doses of a hypertonic sodium chloride solution cause irreversible histological changes in the rabbit kidney.

CT and MRI findings of a solitary extramedullary plasmacytoma of the oropharynx: case report.

We report a case of solitary extramedullary plasmacytoma (SEP) of the oropharynx. A 53-year-old man presented who had had bloody phlegm and a sore throat for a few days. A mass was endoscopically detected in his right posterior oropharyngeal wall, and biopsy revealed a neoplasm consisting of a uniform population of plasma cells. Computed tomography (CT) showed a broad-based papillary soft tissue density mass projecting into the oropharynx from the right posterior wall of the pharynx, and post-contrast CT showed marked enhancement of the tumor. The tumor showed slightly higher signal intensity compared with surrounding muscle on MR Tl-weighted images (T1WI) and high signal intensity on MR T2-weighted images (T2WI). The mass showed homogeneous enhancement on post-contrast T1WI. Further clinical examination showed an absence of multiple myeloma (MM). The patient was diagnosed as having SEP. Following radiation therapy, a reduction in tumor size was observed. Although SEP is a rare tumor, it should be included in the differential diagnosis of tumors of the oropharynx because of its imaging similarities to other, more common malignant tumors, such as squamous cell carcinoma and lymphoma.

[Dual-phase chemical-shift imaging in the detection of diffuse bone metastasis].

Preliminary studies were performed to evaluate the usefulness of lumbar bone marrow MRI using the dual chemical-shift GRE sequence in the detection of diffuse bone metastasis. Two GRE images (TE = 2.3 msec and 4.6 msec) were obtained, and SIR was calculated. SIR was designated as the ratio of in-phase to out-of-phase signal intensity. Among 45 patients with suspicious lumbar bone metastases, diffuse bone metastases were present in 7. Mean SIRs were compared by unpaired t-test. SIRs of diffuse bone metastases had significantly higher signal intensities than those of non-diffuse bone metastases of vertebrae (p < 0.01).

Usefulness of early-phase helical CT for detecting recurrent rectal cancer.

PURPOSE: To evaluate the usefulness of dynamic enhancement of helical CT in the detection of local recurrence of resected rectal cancer. MATERIALS AND METHODS: In 142 patients with a history of curatively resected T2 or T3 rectal cancer, follow-up plain CT indicated that they had a loco-regional recurrent tumor; consequently, they underwent follow-up pelvic helical CT providing accurate early-phase contrast enhancement in the lower pelvic region. The patients were divided into four groups according to the grade of contrast enhancement of the suspected mass-like lesion before and after contrast enhancement, and the correlation between groups and results obtained by biopsy and/or surgery were assessed. If no correlation was found, patients were followed up for a period lasting from 400 days to two years. As of June 2002, results had been obtained for 80 patients, and correlation between these results and grouping by contrast enhancement ratio was analyzed. RESULTS: All patients in the highest-grade group (n=10) had local recurrence. When only the highest-grade group was considered positive, there were no false positives and only one false negative. CONCLUSION: Our results suggest that early-phase contrast enhancement is useful for accurately detecting recurrent rectal cancer. This can be easily achieved using the SmartPrep function, and should be used to distinguish recurrent tumors from postsurgical scar tissue, because these two tissue types do not exhibit similar enhancement patterns.

Gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid interaction with clinical drugs in rats.

RATIONALE AND OBJECTIVES: To investigate whether the hepatic enhancement characteristics of Gd-EOB-DTPA are influenced by the preapplication of a variety of commonly used clinical pharmaceuticals (eg, antibiotics, antineoplastic drugs, corticosteroids, antiarrhythmia drugs, antianxiety drugs, scopolamine, and xanthine derivatives). MATERIALS AND METHODS: Eleven commercially available drugs (prednisolone, rifampicin, doxorubicin hydrochloride, cisplatin, propranolol hydrochloride, scopolamine butylbromide, theophylline, ampicillin, cefotaxime sodium, verapamil hydrochloride, and diazepam) were intravenously (IV) injected in rats at three to five times the clinical dose (n = 3 or 6 per drug). A control group of rats was given saline (n = 6). Gd-EOB-DTPA (25 micromol Gd/kg IV) was administered to rats 30 minutes after the injections of the clinical drugs. Liver MR imaging was performed with a 2.0 T animal imager before and up to 60 minutes after injection. Enhancement (ENH) (%) and area under the data from time versus enhancement curve (AUD) were calculated. RESULTS Rifampicin was the only drug that significantly decreased the hepatic enhancement by Gd-EOB-DTPA. Both the maximum enhancement of the liver and the AUD were significantly reduced when rifampicin was preinjected. Preinjection of prednisolone, doxorubicin hydrochloride, cisplatin or propranolol hydrochloride yielded a slightly but significant increased maximum enhancement of the liver. Furthermore, the enhancement declined more slowly when these drugs were preadministered, yielding a large AUD. None of the other drugs showed a significant effect on hepatic enhancement. CONCLUSION: Rifampicin exerted a clinically significant decrease on hepatic enhancement by Gd-EOB-DTPA. Prednisolone, doxorubicin hydrochloride, cisplatin, or propranolol hydrochloride slightly but significantly increased the hepatic enhancement by Gd-EOB-DTPA.

Detection of lung nodules on digital chest radiographs: potential usefulness of a new contralateral subtraction technique.

PURPOSE: To evaluate the potential usefulness of a contralateral subtraction technique developed for radiologists' performance in the detection of subtle lung nodules on chest radiographs. MATERIALS AND METHODS: Fifty chest radiographs (25 normal and 25 abnormal with a subtle lung nodule) that were digitized with a 0.175-mm pixel size and 4,096 gray levels were used. Twelve radiologists (10 attending and two residents) participated in observer tests and read both original and contralateral subtraction images with a sequential testing method. Radiologists' performance was evaluated by means of receiver operating characteristic analysis with use of a continuous rating scale. The beneficial and detrimental effects of the contralateral subtraction technique on the radiologists' performance were also evaluated. RESULTS: The area under the receiver operating characteristic curve values obtained without and with contralateral subtraction images were 0.926 and 0.962, respectively. Results indicated that the contralateral subtraction images significantly (P <.05) improved diagnostic accuracy, particularly for radiologists with limited experience. CONCLUSION: The contralateral subtraction technique can assist radiologists in the correct identification of subtle lung nodules on chest radiographs.

A case of testicular malignant lymphoma with extension to the epididymis and spermatic cord.

Findings of magnetic resonance imaging (MRI) in a case of testicular lymphoma are presented. The tumor was lower intensity than the normal testis on T2-weighted images. Coronal images clearly showed the tumor extending to the spermatic cord. Compared with seminoma, lymphoma more often invades the epididymis and spermatic cord. MRI is a useful method for differentiating between testicular lymphoma and seminoma because it clearly shows tumor extension to the epididymis and spermatic cord.