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.

Classification of noncalcified coronary atherosclerotic plaque components on CT coronary angiography: impact of vascular attenuation and density thresholds.

PURPOSE: The authors assessed the effect of vascular attenuation and density thresholds on the classification of noncalcified plaque by computed tomography coronary angiography (CTCA). MATERIALS AND METHODS: Thirty patients (men 25; age 59 ± 8 years) with stable angina underwent arterial and delayed CTCA. At sites of atherosclerotic plaque, attenuation values (HU) were measured within the coronary lumen, noncalcified and calcified plaque material and the surrounding epicardial fat. Based on the measured CT attenuation values, coronary plaques were classified as lipid rich (attenuation value below the threshold) or fibrous (attenuation value above the threshold) using 30-HU, 50-HU and 70-HU density thresholds. RESULTS: One hundred and sixty-seven plaques (117 mixed and 50 noncalcified) were detected and assessed. The attenuation values of mixed plaques were higher than those of exclusively noncalcified plaques in both the arterial (148.3 ± 73.1 HU vs. 106.2 ± 57.9 HU) and delayed (111.4 ± 50.5 HU vs. 64.4 ± 43.4 HU) phases (p<0.01). Using a 50-HU threshold, 12 (7.2%) plaques would be classified as lipid rich on arterial scan compared with 28 (17%) on the delayed-phase scan. Reclassification of these 16 (9.6%) plaques from fibrous to lipid rich involved 4/30 (13%) patients. CONCLUSIONS: Classification of coronary plaques as lipid rich or fibrous based on absolute CT attenuation values is significantly affected by vascular attenuation and density thresholds used for the definition.

Diagnostic accuracy of second-generation dual-source computed tomography coronary angiography with iterative reconstructions: a real-world experience.

PURPOSE: The authors evaluated the diagnostic accuracy of second-generation dual-source (DSCT) computed tomography coronary angiography (CTCA) with iterative reconstructions for detecting obstructive coronary artery disease (CAD). MATERIALS AND METHODS: Between June 2010 and February 2011, we enrolled 160 patients (85 men; mean age 61.2±11.6 years) with suspected CAD. All patients underwent CTCA and conventional coronary angiography (CCA). For the CTCA scan (Definition Flash, Siemens), we use prospective tube current modulation and 70-100 ml of iodinated contrast material (Iomeprol 400 mgI/ ml, Bracco). Data sets were reconstructed with iterative reconstruction algorithm (IRIS, Siemens). CTCA and CCA reports were used to evaluate accuracy using the threshold for significant stenosis at ≥50% and ≥70%, respectively. RESULTS: No patient was excluded from the analysis. Heart rate was 64.3±11.9 bpm and radiation dose was 7.2±2.1 mSv. Disease prevalence was 30% (48/160). Sensitivity, specificity and positive and negative predictive values of CTCA in detecting significant stenosis were 90.1%, 93.3%, 53.2% and 99.1% (per segment), 97.5%, 91.2%, 61.4% and 99.6% (per vessel) and 100%, 83%, 71.6% and 100% (per patient), respectively. Positive and negative likelihood ratios at the per-patient level were 5.89 and 0.0, respectively. CONCLUSIONS: CTCA with second-generation DSCT in the real clinical world shows a diagnostic performance comparable with previously reported validation studies. The excellent negative predictive value and likelihood ratio make CTCA a first-line noninvasive method for diagnosing obstructive CAD.

Computed tomography coronary angiography in asymptomatic patients.

PURPOSE: This study assessed the accuracy of computed tomography coronary angiography (CT-CA) for detecting significant coronary artery disease (CAD; ≥50% lumen reduction) in intermediate/high-risk asymptomatic patients. MATERIALS AND METHODS: A total of 183 consecutive asymptomatic individuals (92 men; mean age 54±11 years) with more than one major risk factor (obesity, hypertension, diabetes, hypercholesterolaemia, family history, smoking) and an inconclusive or nonfeasible noninvasive stress test result (stress electrocardiography, stress echocardiography, nuclear stress scintigraphy) underwent CT-CA in an outpatient setting. All patients underwent conventional coronary angiography (CAG) within 4 weeks. Data from CT-CA were compared with CAG regarding the presence of significant CAD (≥50% lumen reduction). RESULTS: Mean calcium score was 177±432, mean heart rate during the CT-CA scan was 58±8 bpm and the prevalence (per-patient) of obstructive CAD was 19%. CT-CA showed single-vessel CAD in 9% of patients, two-vessel CAD in 9% and three-vessel CAD in 0%. Per-patient sensitivity, specificity, positive predictive value and negative predictive value of CT-CA were 100% (90-100), 98% (96-99), 97% (85-99), 100% (97-100), respectively. Positive and negative likelihood ratios were 151 and 0, respectively. CONCLUSIONS: CT-CA is an excellent noninvasive imaging modality for excluding significant CAD in intermediate/ high-risk asymptomatic patients with inconclusive or nonfeasible noninvasive stress test.

Coronary plaque burden in patients with stable and unstable coronary artery disease using multislice CT coronary angiography.

PURPOSE: We evaluated the multislice computed tomography (MSCT) coronary plaque burden in patients with stable and unstable angina pectoris. MATERIALS AND METHODS: Twenty-one patients with stable and 20 with unstable angina pectoris scheduled for conventional coronary angiography (CCA) underwent MSCT-CA using a 64-slice scanner offering a fast rotation time (330 ms) and higher X-ray tube output (900 mAs). To determine the MSCT coronary plaque burden, we assessed the extent (number of diseased segments), size (small or large), type (calcific, noncalcific, mixed) of plaque, its anatomic distribution and angiographic appearance in all available ≥2-mm segments. In a subset of 15 (seven stable, eight unstable) patients, the detection and classification of coronary plaques by MSCT was verified by intracoronary ultrasound (ICUS). RESULTS: Sensitivity and specificity of MSCT compared with ICUS to detect significant plaques (defined as ≥1-mm plaque thickness on ICUS) was 83% and 87%. Overall, 473 segments were examined, resulting in 11.6±1.5 segments per patient. Plaques were present in 62% of segments and classified as large in 47% of diseased segments. Thirty-two percent were noncalcific, 25% calcific and 43% mixed. Plaques were most frequently located in the proximal and mid segments. Plaque was found in 33% of segments classified as normal on CCA. Unstable patients had significantly more noncalcific plaques when compared with stable patients (45% vs. 21%, p<0.05). CONCLUSIONS: MSCT-CA provides important information regarding the coronary plaque burden in patients with stable and unstable angina.

Prognostic value of Morise clinical score, calcium score and computed tomography coronary angiography in patients with suspected or known coronary artery disease.

PURPOSE: Our aim was to determine the prognostic value of computed tomography coronary angiography (CTCA), coronary artery calcium scoring (CACS) and Morise clinical score in patients with known or suspected coronary artery disease (CAD). MATERIALS AND METHODS: A total of 722 patients (480 men; 62.7±10.9 years) who were referred for further cardiac evaluation underwent CACS and contrast-enhanced CTCA to evaluate the presence and severity of CAD. Of these, 511 (71%) patients were without previous history of CAD. Patients were stratified according to the Morise clinical score (low, intermediate, high), to CACS (0-10, 11-100, 101-400, 401-1,000, >1,000) and to CTCA (absence of CAD, nonsignificant CAD, obstructive CAD). Patients were followed up for the occurrence of major events: cardiac death, nonfatal myocardial infarction, unstable angina and revascularisation. RESULTS: Significant CAD (>50% luminal narrowing) was detected in 260 (36%) patients; nonsignificant CAD (<50% luminal narrowing) in 250 (35%) and absence of CAD in 212 (29%). During a mean follow-up of 20±4 months, 116 events (21 hard) occurred. In patients with normal coronary arteries on CTCA, the major event rate was 0% vs. 1.7% in patients with nonsignificant CAD and 7.3% in patients with significant CAD (p<0.0001). Three hard events (14%) occurred in patients with CACS≤100 and two (9.5%) in patients with intermediate Morise score; one revascularisation was observed in a patient with low Morise score. At multivariate analysis, diabetes, obstructive CAD and CACS >1,000 were significant predictors of events (p<0.05). CONCLUSIONS: An excellent prognosis was noted in patients with a normal CTCA (0% event rate). CACS ≤100 and low-intermediate Morise score did not exclude the possibility of events at follow-up.

Prognostic value of computed tomography coronary angiography in patients with chest pain of suspected cardiac origin.

PURPOSE: The authors sought to determine the prognostic value of computed tomography coronary angiography (CTCA) in patients with acute chest pain (ACP). MATERIALS AND METHODS: A total of 145 consecutive patients (75 men; 64±12 years) with ACP were referred from the Emergency Department for CTCA, which was performed with a standard protocol using a 64-slice scanner. Patients were stratified according to the Morise clinical score (low, intermediate, high) and to the CTCA findings [absence of coronary artery disease (CAD), nonobstructive CAD, obstructive CAD]. Patients were followed up for the occurrence of major events: cardiac death, nonfatal myocardial infarction, unstable angina and revascularisation. RESULTS: One hundred and twenty-seven (87.6%) patients were without a history of CAD, and 18 (12.4%) patients had a history of CAD. Obstructive CAD (>50% luminal narrowing) was detected in 35 (24%) patients; nonobstructive CAD (≤ 50% luminal narrowing) in 62 (43%) and absence of CAD in 48 (33%) patients. During a mean follow-up of 20 ± 3 months, 20 events occurred (four hard events). Sixteen events (three hard events) occurred in patients without a history of CAD, and four events (one hard event) occurred in patients with a history of CAD. In patients with absence of CAD as detected by CTCA, the rate of events was 0%. At multivariate analysis, hypercholesterolaemia and obstructive CAD were significant predictors of events (p<0.05). CONCLUSIONS: An excellent prognosis was observed in patients with ACP and normal CTCA. CTCA shows the potential for optimal stratification of patients with ACP.

Source and clinical motivation of orders for contrast-enhanced sonography (CEUS) of the liver: A prospective single-center survey.

Contrast-enhanced sonography (CEUS) has become a routine part of diagnostic imaging of the liver. Its possibilities, limitations, and indications have been defined in adequately large clinical series and in guidelines and recommendations. We prospectively evaluated physicians' orders for hepatic CEUS received in the radiology department of a large oncology center in Naples, Italy from May 2009 to April 2010. Radiologists performing the CEUS examinations filled out a form that included patient demography, source and type of patient referral, and clinical indications for the examination. During the study period, 564 patients aged 17-86 years (mean, 58 years) were referred to our department for CEUS liver studies (total: 644; 491 outpatient studies, 153 inpatient studies). This included 4 examinations that were ordered by the patient's physician but not performed by our staff. The majority of the CEUS examinations (n = 583; 90.5%) were regularly scheduled procedures ordered by clinical specialists from our center (77.3%) or other centers (11.8%); by general practitioners (on their own initiative) (0.8%); or by other figures (0.6%). The remaining 61 examinations (9.5%) were unscheduled procedures done on the initiative of a radiologist following conventional sonography (US). Fewer than half (47.8%) of the examinations were requested as first-line assessments. The others were ordered to clarify inconclusive findings generated by conventional US (30%) or by a more sophisticated imaging study (CT, MRI, PET) (16.1%) or to resolve discrepancies between CT, MRI, and/or PET findings (6%). CEUS is a relatively noninvasive, low-cost imaging study that is simple to perform and requires no particular patient preparation. This may explain its increasing use to clarify doubts raised by conventional US and other more sophisticated imaging studies.