Portal vein thrombosis in patients with chronic liver diseases: From conventional to quantitative imaging

Portal vein thrombosis is a pathological condition characterized by the lumen occlusion of the portal vein and its intrahepatic branches, commonly associated to chronic liver diseases. Portal vein thrombosis is often asymptomatic and discovered as an incidental finding in the follow-up of chronic hepatopathy. Imaging plays a pivotal role in the detection and characterization of portal vein thrombosis in patients with hepatocellular carcinoma. Ultrasound and Color-Doppler ultrasound are usually the first-line imaging modalities for its detection, but they have limits related to operator-experience, patient size, meteorism and the restrained field-of view. Unenhanced cross-sectional imaging doesn't provide specific signs of portal vein thrombosis except under certain specific circumstances. Conventional contrast-enhanced imaging can depict portal vein thrombosis as an endoluminal filling defect best detected in venous phase and can differentiate between non-neoplastic and neoplastic thrombus based on the contrast enhanced uptake, but not always rule-out the malignant nature. Functional and quantitative imaging techniques and software seem to be more accurate. The purpose of this work is to provide the reader with an accurate overview focused on the main imaging features of portal vein thrombosis.

Proton magnetic resonance spectroscopy (H-MRS) in chronic schizophrenia. A single-voxel study in three regions involved in a pathogenetic theory

The cognitive dysmetria theory suggests a disconnectivity between the dorsolateral prefrontal cortex, thalami and vermis to explain the pathophysiology of schizophrenia. This study investigated the metabolic integrity of this neurologic circuit in patients with schizophrenia using proton magnetic resonance spectroscopy (H-MRS). Twenty-two patients with schizophrenia and twelve control subjects were studied. Metabolites concentrations were evaluated by a single-voxel technique in the prefrontal cortex, thalami and vermis. To our knowledge, this is the first H-MRS experience with concomitant evaluation of these regions in schizophrenic patients. We found no significant statistical difference in N-AA, Cho and Cr absolute concentrations and N-AA/Cho, N-AA/Cr and Cho/Cr ratios between the schizophrenic patients and control group. At the vermis, we found a constant spectrum with low levels of N-AA and higher levels of Cho and Cr. Our experience does not clearly support or refute the cognitive dysmetria theory. The consistency of metabolic findings in the cerebellar vermis could represent an important datum, highlighting the specificity of metabolic and functional activity in this region.

Usefulness and limits of near infrared spectroscopy monitoring during endovascular neuroradiologic procedures

BACKGROUND

Transcranial cerebral oximetry (TCCO) with near-infrared spectroscopy (NIRS) is a non-invasive, bedside technique, which allows the continuous measurement of regional cerebral oxygenation. The aim of this study was to evaluate TCCO monitoring during endovascular neuroradiologic procedures.

METHODS

Adult patients undergoing elective endovascular embolization of cerebral aneurysms, arteriovenous malformations, dural arteriovenous fistulas and meningiomas under general anesthesia were included in the study, over a period of 12 months. Twenty-eight procedures in 25 patients were analyzed.

RESULTS

Regional cerebral oxygenation rSO(2) readings were significantly different according to the different phases of the neuroendovascular procedure. An effect of the underlying cerebral pathology on regional cerebral oxygenation rSO(2) recording, in relation to the different stage of the interventional procedure, was also evident, the more invasive the procedure the greater the impact on rSO(2) reading. NIRS monitoring contributed to a prompt diagnosis and management of two adverse intraoperative events and helped in early evaluation of prognosis.

CONCLUSION

TCCO with NIRS is a promising monitoring tool to assess the balance between oxygen supply and demand during neuroradiologic procedures. Nevertheless, some limits should be acknowledged, such as the study of the posterior circulation and artefacts related to contrast agent injection. A careful understanding of the undergoing step of the procedure as well of the possible influence of intrinsic and extrinsic factors affecting recording is important for interpretation of data.

Endovascular Treatment of Cerebral Arteriovenous Malformation Bleeding during Pregnancy

Cerebral arteriovenous malformations (AVMs) represent congenital anomalies of blood vessels composed of a nidus of anomalous arterial and venous vessels without a capillary network. We describe a case of bleeding cerebral AVM in a pregnant women at the second quarter of gestation and diagnosed by digital subtraction angiography showing a large principal arterial nidus supply. The AVM was treated by endovascular embolization at the 27th week of gestation. The post-operative course was uneventful and a caesarean section was performed at the 37th week of gestation. The endovascular approach may represent a safe method in the treatment of this cerebral condition during pregnancy.

Arteriovenous fistula of the mandible simulating an odontogenic cyst. A case report

SUMMARY

We describe a rare case of mandibular highflow arteriovenous malformation (AVM) mimicking an odontogenic cyst in a young man. The diagnosis of mandibular AVM was made by CT angiography and confirmed by digital subtraction angiography. CT scan showed the extent of mandibular bone alteration and a double enlarged mandibular canal on the same side. An AVM containing a large aneurysm was demonstrated by CT angiography.The mandibular AVM was successfully treated by endovascular therapy with Guglielmi detachable coils. On panoramic radiogram, mandibular AVMs can appear as cystic lesions without pathognomonic features. Several benign and malignant tumours of this anatomical region must be considered in the differential diagnosis.We emphasize the radiological sign of double enlarged mandibular canal and the diagnostic role of CT, particularly CT angiography, to discriminate a mandibular AVM from neoplastic entities of this region, sparing the risks of a needle biopsy.