Superficial temporal artery pseudoaneurysm: what is the role of ultrasound?

PURPOSE: The superficial temporal artery (STA) is one of the terminal branches of the external carotid artery; STA pseudoaneurysms are uncommon vascular lesion, generally subsequent to blunt or penetrating trauma that could represent a trick for radiologist, especially when the only anamnestic information is "palpable superficial swelling". In this article, we describe our ultrasonographic experience about STA pseudoaneurysm reporting several cases with different etiopatogenesis. METHODS: Between January 2004 and March 2015 six patients (4F and 2M; aged 15-55 years, mean 36 year) presented at our department with superficial palpable swelling in temporal region (four with trauma history, two with iatrogenic cause) underwent to ultrasonographic study to assess the presence of STA pseudoaneurysm. Ultrasonographic findings suggestive of pseudoaneurysm was a well-defined, pulsatile, anechoic mass in B-mode, a swirling or disorganized pattern of blood flow in the lesion with demonstration of direct communication between arterial lumen and pseudoaneurysm at colour-Doppler and a typical to-and-fro waveform on pseudoaneurysm neck at pulsed-Doppler. RESULTS: B-mode proves the presence of anechoic mass in five on six patients. Colour-Doppler demonstrates the presence of flow inside the lesion in five patients and a direct communication in all patients. To-and-fro typical waveform has been demonstrated in five patients. Ultrasound made diagnosis in all patients with a sensibility and specificity of 100 %. CONCLUSION: US is the imaging modality of choice, since it can provide detailed information about vascular anatomy without incurring the risks of invasive methods like angiography or radiation.

Comparison of CE-FDG-PET/CT with CE-FDG-PET/MR in the evaluation of osseous metastases in breast cancer patients.

BACKGROUND: Despite improvements in treatments, metastatic breast cancer remains difficult to cure. Bones constitute the most common site of first-time recurrence, occurring in 40-75% of cases. Therefore, evaluation for possible osseous metastases is crucial. Technetium 99 ((99)Tc) bone scintigraphy and fluorodexossyglucose (FDG) positron emission tomography (PET)-computed tomography (PET-CT) are the most commonly used techniques to assess osseous metastasis. PET magnetic resonance (PET-MR) imaging is an innovative technique still under investigation. We compared the capability of PET-MR to that of same-day PET-CT to assess osseous metastases in patients with breast cancer. METHODS: One hundred and nine patients with breast cancer, who underwent same-day contrast enhanced (CE)-PET-CT and CE-PET-MR, were evaluated. CE-PET-CT and CE-PET-MR studies were interpreted by consensus by a radiologist and a nuclear medicine physician. Correlations with prior imaging and follow-up studies were used as the reference standard. Binomial confidence intervals and a χ(2) test were used for categorical data, and paired t-test was used for the SUVmax data; a non-informative prior Bayesian approach was used to estimate and compare the specificities. RESULTS: Osseous metastases affected 25 out 109 patients. Metastases were demonstrated by CE-PET-CT in 22 out of 25 patients (88%±7%), and by CE-PET-MR in 25 out of 25 patients (100%). CE-PET-CT revealed 90 osseous metastases and CE-PET-MR revealed 141 osseous metastases (P<0.001). The estimated sensitivity of CE-PET-CT and CE-PET-MR were 0.8519 and 0.9630, respectively. The estimated specificity for CE-FDG-PET-MR was 0.9884. The specificity of CE-PET-CT cannot be determined from patient-level data, because CE-PET-CT yielded a false-positive lesion in a patient who also had other, true metastases. CONCLUSIONS: CE-PET-MR detected a higher number of osseous metastases than did same-day CE-PET-CT, and was positive for 12% of the patients deemed osseous metastasis-negative on the basis of CE-PET-CT.

Contrast-enhanced ultrasound in the characterization of complex cystic focal liver lesions.

Complex cystic focal liver lesions (FLLs) found at non-contrast ultrasound (US) may turn out to be malignant. In this prospective, monocentric study we investigated the value of contrast-enhanced US (CEUS) in the differential diagnosis of complex cystic FLLs. In the past 3 years, all patients with complex cystic FLLs unclassifiable at US underwent CEUS with low-transmit insonation power. We evaluated 36 consecutive patients with 61 FLLs (1-6/patient, mean = 2). The diameter of the lesions ranged from 1.1 to 7.9 cm (mean = 3.9 cm). Sixteen patients had an extrahepatic malignancy. There were 42 malignant lesions and 19 benign lesions. No lesion had a certain diagnosis at conventional US, whereas 16 FLLs were classified as probable (benign or malignant) and 45 as uncertain. CEUS correctly categorized 95% of the malignant cases. CEUS was not able to differentiate the biliary cystadenoma from its malignant counterpart and misdiagnosed two abscesses. Complete non-enhancement throughout three phases or sustained enhancement in the portal/late phase was exhibited in most benign complex cystic FLLs, except for 1 (of the 3) cystadenomas and in 2 (of the 4) abscesses. On the other hand, all malignant lesions presented a contrast washout with a hypo-enhancing appearance. CEUS may provide added diagnostic value in all complex cystic FLLs found uncertain at conventional US, potentially avoiding the use of more invasive and expensive imaging modalities.

[Value of new MR techniques in MR-PET]. / Stellenwert neuer MR-Techniken in der MR-PET.

The unparalleled soft tissue contrast of magnetic resonance imaging (MRI) and the functional information obtainable with 18-F fluorodeoxyglucose positron emission tomography (FDG-PET) render MR-PET well-suited for oncological and psychiatric imaging. The lack of ionizing radiation with MRI also makes MR-PET a promising modality for oncology patients requiring frequent follow-up and pediatric patients. Lessons learned with PET computed tomography (CT) over the last few years do not directly translate to MR-PET. For example, in PET-CT the Hounsfield units derived from CT are used for attenuation correction (AC). As 511 keV photons emitted in PET examinations are attenuated by the patient's body CT data are converted directly to linear attenuation coefficients (LAC); however, proton density measured by MRI is not directly related to the radiodensity or LACs of biological tissue. Thus, direct conversion to LAC data is not possible making AC more challenging in simultaneous MRI-PET scanning. In addition to these constraints simultaneous MRI-PET acquisitions also improve on some solutions to well-known challenges of hybrid imaging techniques, such as limitations in motion correction. This article reports on initial clinical experiences with simultaneously acquired MRI-PET data, focusing on the potential benefits and limitations of MRI with respect to motion correction as well as metal and attenuation correction artefacts.

Rationale, design and methods of CTCA-PRORECAD (Computed Tomography Coronary Angiography Prognostic Registry for Coronary Artery Disease): a multicentre and multivendor registry.

PURPOSE: This study was done to assess the prognostic value of computed tomography coronary angiography (CTCA) in a large multicentre population of patients with suspected coronary artery disease (CAD) and, in particular, its incremental value compared with traditional methods for risk stratification. MATERIALS AND METHODS: This is a retrospective observational study that began in January 2003 conducted on patients with suspected CAD assessed with CTCA on the basis of symptoms (chest pain, dyspnoea) and/or abnormal or equivocal stress test and/or a high cardiovascular risk profile. The participating centres will provide data obtained with CTCA performed with 16-slice or higher equipment. Exclusion criteria are renal insufficiency, allergy to iodinated contrast material, pregnancy and previous myocardial infarction or revascularisation (percutaneous coronary intervention and/or coronary artery bypass graft). All patients are stratified by means of clinical assessment and/or data retrieved from a clinical database. Risk factors considered are hypertension, dyslipidaemia, diabetes mellitus, smoking, family history and obesity. Symptoms are classified as absent, typical chest pain, atypical chest pain and dyspnoea. Primary endpoints are death, major adverse cardiovascular events (cardiac death, unstable angina requiring hospitalisation, acute myocardial infarction) and shifting of cardiovascular risk category on the basis of coronary plaque burden. The secondary endpoint is coronary revascularisation. Telephone interviews and/or clinical databases are used for the follow-up. The study will be conducted on a population >1,000 patients. CONCLUSIONS: The information collected from the Prognostic Registry for Coronary Artery Disease (PRORECAD) will provide insight into the prognostic value of CTCA in addition to demographic and clinical features. The results will allow for better use and interpretation of CTCA for prognostic purposes.

Questions and answers: what can be said by diagnostic imaging in neuroendocrine tumors?

The neuroendocrine tumors (NET) of the gastro-entero-pancreatic area (GEP) represent a heterogeneous group of malignancies from the histologic, clinico-laboratoristic (functioning and non-functioning variants), and therapeutic point of view. It is an issue becoming more frequent for the diagnostic imager, being radiologist as well as nuclear physician. Imaging (together with biopsy) plays a key role in the diagnostic assessment and staging (including grading and prognostic definition), in evaluating response to treatment, and in follow-up of GEP-NET. Multislice computed tomography (MSCT), octreoscan and PET-CT are the most widely diffuse and accurate imaging modalities employed in this setting. Other methods, such as Magnetic Resonance and Endoscopic Ultrasound, may also play a significant role.

Utility of positron emission tomography/CT in the evaluation of small bowel pathology.

We describe the management principles and different roles of positron emission tomography (PET)/CT in the evaluation of patients with small bowel tumours (adenocarcinoma, gastrointestinal stromal tumour, lymphoma, metastases) from initial staging, monitoring response to treatment, to detection of recurrent disease. We also discuss the various non-malignant aetiologies of small bowel fludeoxyglucose (FDG) PET uptake, and other pitfalls in FDG PET/CT interpretation. Awareness of the imaging appearances of small bowel tumours, patterns of disease spread and potential PET/CT interpretation pitfalls are of paramount importance to optimise diagnostic accuracy.

Can high-resolution ultrasound avoid the sentinel lymph-node biopsy procedure in the staging process of patients with stage I-II cutaneous melanoma?

PURPOSE: The objective of our study was to define the diagnostic accuracy of high-resolution ultrasound (US) in detecting nodal involvement before sentinel lymph node biopsy (SLNB) in patients with cutaneous melanoma, to define the sonographic criteria used to assess nodal metastases, and to establish if high-resolution US can directly select patients to radical lymphadenectomy, sparing selective lymphadenectomy. MATERIALS AND METHODS: 623 patients underwent high-resolution US of the regional lymph nodes, 24 hours prior being submitted to the sentinel lymph node biopsy procedure. The US findings were compared with histological findings. RESULTS: In 14.7 % out of 122 excised lymph nodes, high-resolution US showed sonographic features consistent with malignant involvement before the surgical step. US scan sensitivity and specificity were 15 and 100 %, respectively, since positive and negative predictive values were 100 and 87 % respectively. CONCLUSION: US is an effective modality in the presurgical detection of subclinical deposits within sentinel lymph nodes. However, preoperative staging work-up with high-resolution US cannot substitute the SLNB, mainly because of low sensitivity due to missing many micrometastases.