Improved focal liver lesion detection: comparison of single-shot diffusion-weighted echoplanar and single-shot T2 weighted turbo spin echo techniques.

The purpose of this study was to compare diffusion-weighted respiratory-triggered single-shot spin echo echoplanar imaging (SS SE-EPI) sequence using four b-values (b = 0, b = 20, b = 300, b = 800 s mm(-2)) and single-shot T2 weighted turbo spin echo (T2W SS TSE) in patients with focal liver lesions, with special interest in small (<10 mm) lesions. Twenty-four patients underwent routine MRI. The five sequences were compared qualitatively for image quality, lesion conspicuity and artefacts. Quantitative analysis was performed for lesion identification and lesion-to-liver contrast-to-noise ratio (CNR). Subgroup analyses were performed for different types of lesions with different sizes. Sequences were compared by rank order statistic (RIDIT) and Kruskal-Wallis test. The best image quality (p<0.05) was achieved with T2W TSE and the best lesion conspicuity (p<0.05) with T2W TSE for biliary cysts and SE-EPI diffusion-weighted imaging (DWI) (b = 20 s mm(-2)) for haemangiomas and metastases. Image artefacts were lowest (p<0.05) with T2W TSE. T2W TSE was found to be the best protocol (p<0.05) for the identification of biliary cysts and SE-EPI DWI (b = 20 s mm(-2)) for haemangiomas and metastases. The lesion-to-liver CNRs were highest on T2W TSE for biliary cysts and on SE-EPI diffusion-weighted imaging (DWI) for haemangiomas and metastases (p<0.05). This study shows the potential of SS SE-EPI DWI (especially with a b-value of 20 s mm(-2)) as a promising technique for detecting small (<10 mm) focal liver lesions.

An unusual presentation of pancreatic serous cystadenoma with acute hemorrhage.

Pancreatic serous cystadenomas are benign cystic lesions without complication risks. They can be discovered after investigations for upper abdominal discomfort because of mass effect or incidentally. In rare cases they are detected because of biliary obstruction. Hemorrhagic complication is very unusual.

Collision tumor in the ileum: a rare combination of an adenocarcinoma and small cell neuroendocrine tumor.

We present a case of a rare small bowel tumor. A 73-year-old female patient presented at our department with vague abdominal pain. Ultrasound examination discovered an inhomogeneous vascularised mass originating from a small bowel loop, mesenteric enlarged lymph nodes and a nodule in the liver. Multislice Computed Tomography of the abdomen confirmed the ultrasonographic findings and found omental implants together with a left-sided ovarian mass. Surgery was performed. Pathology revealed a rare ileal collision tumor consisting of an adenocarcinoma and a small cell neuroendocrine tumor with peritoneal metastasis of neuroendocrine origin and coincidental benign lesions on both ovaries.

Omental infarction in childhood.

We present a case of right-sided omental infarction in a child documented with ultrasound and multislice computed tomography and confirmed by surgery and pathologic examination. Omental infarction is a rare cause of right-sided acute abdominal pain in a child. Differential diagnosis includes appendicitis. With different imaging modalities a diagnosis can be made and avoid unnecessary appendectomy.

Duodenal stromaltumor detected by CT-enteroclysis.

Gastro-intestinal stromal tumors can present with gastro-intestinal hemorrhage, often with an acute episode of abdominal pain, weight loss, nausea and vomiting. We present a case of a young man who presented with gastrointestinal bleeding. The patient previously presented with gastro-intestinal bleeding but several investigations like gastroscopy, coloscopy, Ectopic gastric mucosa-scan, and computed tomography were reported as negative. A well-circumscribed submucosal tumoral mass in the duodenum with maximal thickness of 15 mm was however detected by CT-enteroclysis. Microscopic examination confirmed the presence of a gastro-intestinal stromal tumor.

[Correlation between ultrasound and radiographic data for assessment of symphyseal bony callus maturation after distraction]. / Corrélation entre les données échographiques et radiographiques dans l'évaluation de la maturation du cal osseux symphysaire après distraction.

OBJECTIVE: To search for means of reducing ionizing radiation during treatment planning for transmandibular osteodistraction. MATERIAL AND METHODS: Eleven patients (6 female, 5 male) underwent combined bimaxillary osteodistraction at a mean age of 18 Years. The following investigations were performed to determine symphyseal callus maturation: occlusal radiographs (O-RX) preoperatively, after the active phase of distraction (mean 27 days); ultrasound investigations (US) after the active and consolidation phase. RESULTS: US showed calcification foci at the end of the active phase, when O-RX failed to do so. Both US and O-RX detected callus immaturity after 2 Months of consolidation in 1 patient. Both detected bridging ossification one Month later. DISCUSSION: US can replace radiography in the diagnosis of callus maturation related to distractor removal.

Doppler sonography in breast pathology.

Breast sonography has been a standard complementary procedure to mammography for more than 10 years. In recent years, a tremendous technological evolution has taken place both at the level of the equipment, electronics and software, and in probe technology. This has resulted in a substantial increase in image quality (contrast ans spatial resolution) and in Doppler sensitivity. The use of linear probes of at least 7 MHz is mandatory, and frequencies of over 10 MHz are becoming standard now. Sonography of the breast not only permits differentiation between solid and cystic lesion, but also gives additional morphological details which enable differentiation between benign and malignant lesions. US increases both sensitivity and specificity of the breast exam when combined with X-ray mammography. It is also the method of choice for guiding interventional procedures, such as hook wire placement, FNAC, or core biopsy. Doppler has been used since the seventies (continuous wave Doppler), but more recently the use of color Doppler has proven to be valuable in the study of the vascularity of breast lesions.

Contrast-enhanced MRI of the breast: technique and indications.

Magnetic Resonance Imaging of the breast is a recent promising technique. Today this technique is still dedicated to problematic cases or has very specific indications and cannot be regarded as a screening technique. However, MRI of the breast has already proved to be very reliable in the differentiation between tumor recurrence and scar formation, in the preoperative evaluation of tumor extension, the detection of a tumor recurrence adjacent to a breast prosthesis, the response of tumors to radiotherapy and/or chemotherapy, and can also be helpful in the differentiation between benign and malignant breast lesions. For these reasons, MR of the breast has already achieved a place in the diagnosis of breast tumors.

MR imaging of a diverticulum in a female urethra.

The case of a 44-year-old woman with urethral diverticulum is described. The lesion was initially detected by ultrasonography. MRI proved to be very sensitive in localising and delineating the urethral diverticulum and could differentiate it from lesions arising from the vagina or bladder.

Contribution of MRI and color Doppler sonography in breast cancer diagnosis.

Thirty female patients were examined with both MRI (30) and color Doppler sonography (24). MRI after injection of Gadolinium DTPA in combination with fast 3D FLASH sequences makes it possible to plot out signal-intensity changes over a certain period of time. Flow within a malignant breast lesion can be depicted with color Doppler sonography. The signal intensity increase pattern over a period of time, and the detection of color Doppler flow are of major importance for the differential diagnosis in breast cancer.

Pathology of the membranous labyrinth: comparison of T1- and T2-weighted and gadolinium-enhanced spin-echo and 3DFT-CISS imaging.

PURPOSE: To assess the value of unenhanced T1-weighted images, T2-weighted images, gadolinium-enhanced T1-weighted images, and three-dimensional Fourier transformation-constructive interference in steady state (3DFT-CISS) images in depicting lesions of the membranous labyrinth. METHODS: Six patients were studied using 1-T MR; both enhanced (gadolinium-tetraazacyclododecane tetraacetic acid) and unenhanced images were obtained and different sequences compared to determine which provided the most information. RESULTS: A combination of gadolinium-enhanced T1-weighted and 3DFT-CISS images could depict all membranous labyrinth pathology. Unenhanced T1-weighted images were necessary to exclude spontaneous hyperintensity in the membranous labyrinth. Gadolinium-enhanced T1-weighted images were needed to detect enhancing pathology such as labyrinthitis and tumors inside the membranous labyrinth. In these cases, 3DFT-CISS images allowed immediate differentiation between inflammation and tumor. In temporal bone tumors involving the bony and membranous labyrinth, unenhanced and enhanced T1-weighted images often sufficed to suggest the correct diagnosis. Only 3DFT-CISS images were able to demonstrate small structures (as fistulas) and to help us confirm or rule out obliteration of the labyrinthine fluid spaces. 3DFT-CISS images were necessary to detect small congenital malformations of the membranous labyrinth when only MR was performed. Uncalcified obliteration of the labyrinth fluid spaces could be reliably detected only on 3DFT-CISS images. Here also gadolinium-enhanced T1-weighted images had to be obtained because enhancement of the soft tissues inside the membranous labyrinth had been observed. CONCLUSION: The CISS sequence and enhanced T1-weighted sequence formed the best sequence combination for diagnosis of membranous labyrinth lesions; additional, unenhanced T1-weighted images can help one differentiate labyrinthitis, proteinaceous fluid, subacute hemorrhage, or tumor inside the labyrinth.

Denta Scan: CT software program used in the anatomic evaluation of the mandible and maxilla in the perspective of endosseous implant surgery.

A radiological technique, using a new CT software program for the evaluation of alveolar process height and width, is presented. Irradiation is kept within acceptable limits when this technique is used. Measurements obtained with this technique were compared with those obtained on panoramic radiographs in 40 "half-jaws" (21 maxillar and 19 mandibular). We found that new indications for implantation emerge in the mandibular region because 'Denta Scan' can sometimes show possibilities to place implants on the buccal side of the canal (2 of 19 mandibular cases) when no possibilities are present above the canal on both the panoramic radiographs and Denta Scan images. In the maxillar region Denta Scan avoids unnecessary interventions by demonstrating the insufficient width of the alveolar ridge, often missed on panoramic radiographs (4 of 21 maxillar cases). Moreover the use of Denta Scan allows the use of implants with optimal length and diameter (23 of the 40 cases), giving better long-term results.

Tissue characterization of atheromatous plaques: correlation between ultrasound image and histological findings.

Fifty-four atheromatous plaques of carotid arteries, obtained at autopsy, were scanned with a high-resolution real-time instrument, then histologically examined. Comparison between atherogenesis assessed first by histology then by ultrasonography allowed us to differentiate young from old plaques. An old plaque is characterized by a dense heterogeneous echo pattern and irregular borders or ulceration. Previous studies have shown a correlation between the presence of hemorrhage and ulceration of atheromatous plaques in the carotid, and the frequency of cerebral complications. Since these characteristics were mainly found in older plaques, we consider them to be the most important ones clinically.

Ultrasonographic findings in peptic ulcer: a report on 24 cases proven endoscopically.

A series of 24 patients is presented who had routine upper abdominal sonography for reason of atypical abdominal pain; in all cases the sonographically suggested diagnosis of a mucosal ulceration was proved by a following endoscopy. The ultrasonic findings were localized thickening of the gastric wall in combination with presence of liquid intragastrically in a fasting patient.

Herniography in adults: review and personal studies.

In 120 adults (87 men, 33 women) with suspicion of a hernia but with normal physical examination, herniography disclosed 125 positive findings correlated with the clinical manifestations. There were no false positive or false negative herniographic diagnoses among 25 patients who underwent surgery. Herniography is a useful examination to evaluate patients with an uncertain or normal physical examination and with clinical manifestations suggestive for hernia. This relatively simple technique and the use of a non-ionic contrast medium are well tolerated.

Giant angiomyolipoma with atypical arteriovenous shunting: CT and angiographic studies.

The advent of both ultrasound and computerized tomography made the pre-operative diagnosis of angiomyolipoma much easier. However, differentiation from retroperitoneal, perinephric space and especially intrarenal liposarcoma remains difficult or impossible. Angiographic findings are atypical and often do not allow differentiation from renal cell carcinoma. Early filling of the renal vein in renal cell carcinoma is sometimes used to distinguish renal cell carcinoma from angiomyolipoma. A case of a giant angiomyolipoma with arteriovenous shunting and early filling of the renal vein is described.

[Dynamic MRI of temporomandibular joint: technique and application]. / L'IRM dynamique de l'articulation temporo-mandibulaire: technique et application.

Internal derangements or disk dysfunctions represent the most frequent pathology of the temporomandibular joint (TMJ). The radiological study of TMJ dysfunction was, for a long time, restricted to arthrography. More and more MR is used to study the TMJ, because MR, allows non-invasive visualisation of without the use of X-rays. Moreover a "dynamic" MR technique can be used to study disk movements during mouth opening. A lot of the internal derangement problems can be solved with this technique and arthrography can often be avoided. This dynamic MR technique is described and some cases are discussed.