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.

Splenic hamartoma presenting as an occasional asymptomatic finding.

We report a case of splenic hamartoma that was occasionally detected. Ultrasonography performed as a screening examination revealed a hypoechoic splenic lesion. A computed tomography and magnetic resonance examination were performed in order to characterize the lesion but failed to make a final diagnosis. An elective laparoscopic splenectomy with consecutive histologic examination revealed a splenic hamartoma. Splenectomy may be required for definite characterization of this type of splenic lesion.

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.

Non-traumatic giant aneurysm of a superficial temporal artery.

We present a case of giant aneurysm in the superficial temporal artery. A 59-year-old male was admitted to our hospital with a slowly growing swelling just in front of his right ear. Diagnosis was made by US and CT. CTA was able to provide accurate anatomic information and to eliminate the risks associated with diagnostic conventional angiography. A superselective embolization of the giant temporal aneurysm was performed.

Mri findings in primary non-Hodgkin's lymphoma of the liver.

Primary lymphoma of the liver is a very rare malignancy. Most often, these lesions consist of diffuse large B-cell non-Hodgkin's lymphoma that occurs mostly in immunodeficient patients. To prove the primary nature of a hepatic lesion, a systemic lymphoproliferative disease should be ruled out. Secondary liver involvement during Hodgkin's and non-Hodgkin's lymphoma is frequent. In advanced cases the incidence varies from 25% to 50%. The present case describes the MRI features of a primary lymphoma of the liver presenting as a solitary nodule. The primary lymphoma presents as a T2-hyperintense homogeneous nodule, with a signal intensity comparable with the signal intensity of the spleen. Signal intensity is comparable on in and out of phase imaging. The nodule is slightly T1-hypointense and doesn't show any arterial contrast uptake. In the late venous phase a slight increase in signal intensity is noted. Two and a half minutes after the administration of contrast agent, the lesion is iso-attenuating with the liver parenchyma. This case is rare because of the concomitant presence of heterozygous sickle cell anaemia and the presence of Gamna-Gandy bodies in the splenic parenchyma. It remains uncertain whether the presence of the Gamna-Gandy bodies is associated with the liver lymphoma or with the underlying sickle cell anaemia, or with a combination of both.

A new multislab 3D balanced turbo field echo technique for imaging of the renal arteries without contrast agent.

An 80-year-old female patient with arterial hypertension and slowly progressive deterioration of renal function was referred to our department for investigation of the renal arteries. Imaging of the renal arteries with ultrasound was inconclusive, due to obesity. Subsequently, imaging was performed with balanced turbo field echo which is a newly developed technique in our department. This new technique for the moment is still combined with contrast-enhanced magnetic resonance angiography. A therapeutic digital subtraction angiography was performed for stent placement.

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.

Appendicitis after appendectomy: CT diagnosis.

This article presents a case of appendicitis 7 years after open appendectomy. Together with the apparent CT findings we discuss the current literature of this issue.