Evaluation of peri-tumoral vessels surrounding colorectal liver metastases after intravenous injection of extruded magnetoliposomes in rats: correlation with 3T MRI and histopathology.

BACKGROUND: Magnetoliposomes have pronounced signal-enhancing effect on T1-weighted (T1w) images of the liver using qualitative analysis which may be benefical for demonstrating peritumoral vasculature. PURPOSE: To correlate peri-tumoral vasculature (ring-enhancement) surrounding colorectal liver metastases after injection of magnetoliposomes using T1-weighted (T1w) imaging with histopathology in a rat model. MATERIAL AND METHODS: All experiments were approved by the responsible Animal Care Committee. Three rats injected with CC531 coloncarcinoma cells in the portal vein were imaged at 3T using a small diameter four channel coil. The presence of liver metastases, signal intensity changes within intrahepatic vessels, peri-tumoral vasculature (ring-enhancement) surrounding liver metastases on T1w imaging and histopathology, and the histopathological distribution of iron particles were evaluated. SS SE-EPI and T1w GE sequences were used. Images were evaluated qualitatively and MRI findings were correlated with histopathology. RESULTS: Fifteen liver metastases were present which were all detected at MRI (mean diameter 2.4 mm (SD 0.8 mm, range 1.5-4.7 mm)). Ring-enhancement surrounding liver metastases at contrast-enhanced T1w GE sequences was present in all liver metastases. Correlation with histopathology showed the corresponding presence of dilated sinusoids filled with iron particles surrounding the liver metastases. CONCLUSION: Blood-pooling of iron oxide particles within magnetoliposomes was demonstrated with increased and hyperintensity of vessels after injection of magnetoliposomes. Qualitatively, ring-enhancement surrounding the liver metastases was seen on T1w imaging and corresponded histopathologically with the presence of iron particles (magnetoliposomes) within the dilated sinusoids surrounding the liver metastases.

An elderly woman with obstructed obturator hernia: a less common variety of external abdominal hernia.

Obturator hernia is a type of external abdominal hernia. Site of hemiation is the obturator canal, which is the superolateral aspect of the obturator foramen. The herniation sac exits the pelvis near the obturator nerve and vessels. Herniated loops of small bowel extend between the pectineus and obturator muscles. In this report, we present a case of obstructed obturator hernia.

Comparison of respiratory-triggered T2-weighted turbo spin-echo imaging versus breath-hold T2-weighted turbo spin-echo imaging: distinguishing benign from malignant liver lesions in patients with colorectal cancer.

T2-weighted turbo spin echo sequences are being used as a first sequence for abdominal magnetic resonance imaging in many cases. For oncological patients breath-hold imaging can be difficult. T2-weighted turbo spin echo sequences can be used during breath-hold or during respiratory-triggering. The purpose of our study is to compare a respiratory-triggered fat-suppressed and breath-hold T2-weighted Turbo Spin Echo (RT and BH FS T2w TSE) sequence for focal liver lesions. Prospectively, both T2w TSE sequences were acquired in 40 patients using 1.5T MRI. Qualitatively analysis was performed for image quality, lesion conspicuity, diagnostic confidence, artifacts using two-tailed Wilcoxon signed-ranks test. Quantitative analysis was performed for lesion-to-liver Contrast-to-Noise Ratio (CNR) using two-tailed Student's t-test. Qualitatively, RT FST2wTSE performed significantly (p < 0.05) better than BH FST2wTSE concerning image quality, lesion conspicuity, diagnostic confidence and artifacts. Seventy-eight metastases and 47 hemangiomas were detected on both FST2wTSE sequences. Seven liver metastases and 2 hemangiomas < 10 mm and 3 metastases between 10-20 mm detected on RT FS T2wTSE were only retrospectively detected on BH FS T2wTSE. Diagnostic confidence scores were best using RT FS T2w TSE compared with BH FS T2w TSE. Mean CNR of all lesions, mean CNR of all lesions < 10 mm and mean CNR between hemangiomas and metastases was significantly better using the RT sequence compared with the BH sequence. RT FST2wTSE might perform better than BH FST2wTSE for lesion detection and characterization in this study.

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.

Pneumatosis coli and multi-slice helical CT virtual colonoscopy.

Helical CT colography is improved by multislicing due to thinner slices. The case reported shows the potential of multislice HCT colography to demonstrate gas-filled cysts on axial images as well as on CT endoscopy, and consequently the extent of the disease exceeding the sigmoid, as was diagnosed by conventional coloscopy.

Cine-viewing of overlapping thin collimation images: an improved diagnostic tool in multislice helical CT of the bowel.

As compared to single slice helical CT, multislice helical CT does not only improve the quality of the individual images (in terms of slice sensitivity profile and image artifacts) and the range of scan coverage, it also enforces the CT postprocessing possibilities. The advantage of post-processing thin collimation bowel CT images with overlap and cine-viewing or paging is reported. The case report illustrates that cine-viewing of overlapping thin collimation images obtained with multislice helical CT, allows an excellent evaluation of the bowel loops resulting in the diagnosis of a perforated sigmoid carcinoma and its complications.

Traumatic pseudo-aneurysm and dissection of the thoracic aorta in the presence of an aberrant right subclavian artery: value of multi-slice helical CT.

A case of traumatic pseudo-aneurysm and dissection of the proximal descending thoracic aorta in association with an aberrant right subclavian artery and a common trunk for both common carotid arteries is presented. The diagnosis of this traumatic pseudo-aneurysm and dissection in association with these congenital anomalies by means of a multi-slice helical CT is discussed. To our knowledge, this is the first such case reported in the literature.

Pulmonary vein varix: diagnosis with multi-slice helical CT.

The diagnosis of a pulmonary vein varix with a recently introduced new CT technology, multi-slice helical CT, is discussed. The advantage of multi-slice helical CT lies in increased thin-slice coverage during a single breath hold, which is the predominant factor limiting scan time. This CT technique facilitates the diagnosis of vascular pulmonary pathology.

A one year experience with the multislice helical CT.

New detector morphology and increased computer power have led to a second leap in CT technology. With multislice helical CT, four slices per rotation are reconstructed resulting in a 3 to 6 times reduction of the examination time. During our one-year experience with the multislice CT, we have learnt that the major advantage of the technique is the possibility to cover a large volume with thin slices. Combination of both makes it possible to scan an entire anatomic region during the optimal enhancement phase (after i.v. contrast injection) with a high spatial resolution. New diagnostic possibilities can be explored by CT together with improved and more detailed post-processing tools.

Transient focal fatty liver infiltration mimicking liver metastasis.

The case of a 76-year-old woman presenting with focal liver lesions suggesting liver metastasis on CT is reported. A control CT performed one week later showed a normal liver. Biopsy revealed the diagnosis of focal liver steatosis. The final diagnosis of transient focal steatosis is proposed.

A semi-automated program for volume measurement in focal hepatic lesions: a first clinical experience.

The value of a semi-automated program for volumetric measurements was tested in 53 patients with liver lesions. Three different radiologists performed 10 measurements on a liver lesion in each patient. The variances of the measurements were calculated. There was no difference in intra- and interoperator variance of the measurements. If the diameter of the liver lesion exceeded the slice thickness, the different measurements became more reliable and more reproducible. The semi automation of the volume measurements makes its use in daily clinical practice possible. Volume measurement can be interesting in the follow-up and evaluation of the treatment on tumor reduction. However further and more thorough investigation is needed to test the clinical usefulness of the program.

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.

Detection of small mucosal and submucosal polyps with helical CT scanning in a patient with intestinal neurofibromatosis.

The detection of small (diameter 5-12 mm) mucosal jejunal polyps and small (diameter 14-26 mm) submucosal rectal polyps with helical C.T.-scanning in a patient with neurofibromatosis is described. Because a volume is scanned with helical CT, overlapping image reconstructions can be made allowing to produce a contiguous image set for cine mode display. The combination of 'volume scanning' with cine mode display helps in the dynamic visualization of the course of the intestinal loops. This might result in a better depiction of small lesions within the bowels and in a better differentiation between mucosal folds and the lesions.

Imaging of polypoid endoluminal growing bile duct tumors.

We reviewed the radiological documents and protocols of 196 cases of bile duct tumors examined over a period of 12 years: 20 of them (10.2%) presented with a polypoid endoluminal growth. The aim of this study was to provide a better knowledge about the radiological features of this less frequent kind of tumor. In these 20 cases, the correct diagnosis of bile duct lesion was provided in 100% by E.R.C.P., P.T.C., U.S. as well as C.T., and in 42% by arteriography. The correct diagnosis of tumor was made by E.R.C.P. in 86%, by P.T.C. in 88%, by U.S. in 61%, by C.T. in 63%, and by arteriography in 25%. A correct diagnosis of tumor could be reached in all cases by combination of several examination techniques. The anatomopathological diagnosis was: bile duct adenocarcinoma (7 cases), adenocarcinoma of the ampulla of Vater (4), villous adenoma of Vater's ampulla (2), cystadenoma (1), cystadenocarcinoma (1), hepatocellular carcinoma (1), apudoma (1), and metastases (3).

Sonographic diagnosis of ischemic colitis.

An abdominal ultrasound examination performed on two patients with abdominal pain showed segmental wall thickening of the colon that proved to be due to ischemic colitis. In one case, the typical "target lesion" was recognized. These findings could be confirmed with computed tomography, whereas a single contrast enema was unable to demonstrate the ischemic disease. In the second case, a typical five-layered structure of the bowel wall could be demonstrated. It is concluded that US can be useful in the early diagnosis of colonic ischemia.

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.

[Meigs' syndrome]. / Meigs syndroom.

Ascites and pleural effusion associated with "fibroma-like ovarian" benign tumor is described as Meigs syndrome. Tumor extirpation resulted in ascites and pleural effusion resorption. This rather unusual syndrome, should not be overlooked.