Comparison of FDG-PET and dynamic contrast-enhanced MRI in the evaluation of suggestive breast lesions.

The aim of our study was a direct comparison of the ability of positron-emission tomography with FDG-PET and of magnetic resonance imaging (MRI) to determine whether breast lesions were benign or malignant and of the two imaging methods capability of depicting eventual multifocal disease. We performed both PET and MRI in 36 patients (40 lesions) who were scheduled for surgery because of suggestive mammographic, sonographic and/or clinical findings. A final histological classification was available for all lesions. Tumour size ranged from 5 to 45 mm (mean 16.7 mm). Sensitivity for lesions, sensitivity for patients, specificity for lesions and specificity for patients were 68.0%, 76.2%, 73.3%, and 73.3% for PET and 92.0%, 95.2%, 73.3%, and 73.3% for MRI, respectively. MRI was more sensitive than FDG-PET in disclosing malignant breast tumours and was also more accurate than FDG-PET in the assessment of multifocal disease. The lower sensitivity of FDG-PET than of MRI seems to be due to difficulties in reliable imaging of carcinomas smaller than 10 mm and of lobular carcinomas.

Small-bowel disease: comparison of MR enteroclysis images with conventional enteroclysis and surgical findings.

PURPOSE: To investigate if magnetic resonance (MR) enteroclysis can be performed routinely and to compare MR enteroclysis findings with those of conventional enteroclysis or surgery. MATERIALS AND METHODS: MR enteroclysis was prospectively performed in 30 patients with symptoms of inflammatory bowel disease or small-bowel obstruction (SBO). A methylcellulose-water solution was used to distend the small bowel. To monitor dynamic changes in the small bowel, a single-shot fast spin-echo T2-weighted sequence was applied. For morphologic assessment, breath-hold T2-weighted fast spin-echo and coronal T1-weighted gradient-recalled-echo MR images were obtained without and with gadolinium enhancement. Image quality and degree of small-bowel distention were graded. MR imaging findings and degree of SBO were compared with findings at conventional enteroclysis (n = 25) or surgery (n = 5). RESULTS: MR enteroclysis was well tolerated and provided adequate image quality and sufficient small-bowel distention. SBO grade based on MR enteroclysis images (n = 10) was identical to that based on conventional enteroclysis images (n = 6) or surgical findings (n = 4). There was exact agreement between MR enteroclysis and retrospective findings in all five patients who underwent surgery, and MR findings were identical to those at enteroclysis in 18 patients, superior in six patients, and inferior in one patient. CONCLUSION: MR enteroclysis can be performed routinely with adequate image quality and sufficient small-bowel distention. The functional information provided by MR enteroclysis is identical to that provided at conventional enteroclysis.

Intraspinal primitive neuroectodermal tumour: report of two cases and review of the literature.

Two patients with primary intraspinal primitive neuroectodermal tumour are presented. In a 32-year-old man, the tumour evolved intradurally from a sacral nerve root. Despite repeated surgery and radiochemotherapy, the patient suffered multiple intraspinal tumour relapses and intracranial seedings, and died 29 months after the first diagnosis. In a 17-year-old male adolescent, the tumour was located in the lumbar epidural space, extending into the paraspinal muscles. Following resection and radiochemotherapy, the patient is free from disease 23 months after the initial presentation. The clinical, radiological, histopathological and cytogenetic findings of both patients are presented and the relevant literature is reviewed. Particular attention is given to the histogenetic relationship between peripheral primitive neuroectodermal tumour and Ewing's sarcoma.

Scintimammography using Tc-99m tetrofosmin.

Breast cancer, the most common malignancy in women, still poses a challenge to diagnostic procedures and therapy. Despite low specificity routine mammography is the method of choice to screen women for breast cancer. In the last years other additional diagnostic procedures such as high frequency ultrasonography (US) and especially magnetic resonance imaging (MRI) have improved breast cancer diagnosis. However, all these imaging methods are lacking in specificity which makes biopsy or surgery necessary. The purpose of our study was to evaluate prospectively the sensitivity, specificity, PPV and NPV of scintimammography with a new cationic complex Tc-99m tetrofosmin in patients with suspicious mammographic lesions. One hundred and thirty seven patients in whom mammography and/or high resolution ultrasonography (10 MHz) revealed suspicious breast lesions were studied with Tc-99m tetrofosmin scintimammography. In 84 of them biopsy and/or surgery was performed for histological evaluation. After intravenous injection of 555 MBq Tc-99m tetrofosmin planar images in anterior and lateral projections (5 min.p.i.) and SPECT imaging including 3-D-reconstruction (20 min.p.i.) were performed. Scintimammography was evaluated as negative, equivocal (+), probably (+2) or definitely (+3) positive. Planar scintimammography with Tc-99m tetrofosmin was negative in 46 patients (43 true negative-f.n; 3 false negative-f.n.) and positive in 38 patients (27 true positive-t.p.; 11 false positive-t.p.). Using SPECT imaging Tc-99m scintimammography was negative in 43 cases (41 t.n.; 2f.n.) and positive in 41 cases (28 t.p.; 13 t.p). Sensitivity of Tc-99m tetrofosmin scintimammography in this prospective study was 90%, specificity 80%, PPV 71% and NPV 93% for planar imaging and 93%, 76%, 68% and 95% for SPECT, respectively. Scintimammographic results in patients with suspicious breast lesion show, that Tc-99m tetrofosmin accumulates in breast cancer as well as in some fibroadenoma with high cellularity. However, the high NPV of 93 and 95% respectively excludes breast cancer in suspicious mammographic lesions to a very high degree and therefore reduces the need of biopsy and/or surgery in most of these patients.

[MR mammography: current status and indications]. / MR-Mammographie: Aktueller Stand und Indikationen.

Several reports in the literature have demonstrated a promising role for MR imaging when used as an adjunct to mammography for the detection and diagnosis of breast cancer. There are many technical factors that must be considered, including dynamic imaging with subtraction, high resolution and fat suppression. Proven indications for MR mammography include patients suspicious of having cancer recurrence after breast conservation treatment and patients suspicious of having breast implant rupture. Potential clinical applications include differentiating benign from malignant lesions, detecting cancer when results of conventional imaging are equivocal, staging newly diagnosed breast cancer, detecting occult cancer in patients presenting with axillary node metastasis, determining chemotherapy induced tumor response, detecting residual tumor after incomplete surgical excision. Several investigators have demonstrated that MR imaging can provide extremely high sensitivity for detection of breast cancer. There are pitfalls, however, secondary to false positive and false negative contrast enhancement. Awareness of the strengths and limitations of MR imaging of the breast will facilitate integration of this technique into the work-up of patients with suspicious breast lesions.