Ultra-low dose CT colonography with automatic tube current modulation and sinogram-affirmed iterative reconstruction: Effects on radiation exposure and image quality.

OBJECTIVE: To assess the radiation dose and image quality of ultra-low dose (ULD)-CT colonography (CTC) obtained with the combined use of automatic tube current (mAs) modulation with a quality reference mAs of 25 and sinogram-affirmed iterative reconstruction (SAFIRE), compared to low-dose (LD) CTC acquired with a quality reference mAs of 55 and reconstructed with filtered back projection (FBP). METHODS: Eighty-two patients underwent ULD-CTC acquisition in prone position and LD-CTC acquisition in supine position. Both ULD-CTC and LD-CTC protocols were compared in terms of radiation dose [weighted volume computed tomography dose index (CTDIvol ) and effective dose], image noise, image quality, and polyp detection. RESULTS: The mean effective dose of ULD-CTC was significantly lower than that of LD-CTC (0.98 and 2.69 mSv respectively, P < 0.0001) with an overall dose reduction of 63.2%. Image noise was comparable between ULD-CTC and LD-CTC (28.6 and 29.8 respectively, P = 0.09). There was no relevant difference when comparing image quality scores and polyp detection for both 2D and 3D images. CONCLUSION: ULD-CTC allows to significantly reduce the radiation dose without meaningful image quality degradation compared to LD-CTC.

Grading of aortic stenosis severity: a head-to-head comparison between cardiac magnetic resonance imaging and echocardiography.

AIM: To prospectively evaluate the accuracy of cardiac magnetic resonance (cMR) imaging for the assessment of aortic valve effective orifice area (EOA) by continuity equation and anatomical aortic valve area (AVA) by direct planimetry, as compared with transthoracic (TTE) and transesophageal (TEE) two-dimensional (2D) echocardiography, respectively. METHODS AND RESULTS: A total of 31 patients (21 men, 10 women, mean age 69 ± 10 years) with moderate-to-severe aortic stenosis (AS) diagnosed by TTE and scheduled for elective aortic valve replacement, underwent both cMR and TEE. AVA by cMR was obtained from balanced steady-state free-precession cine-images. EOA was computed from phase-contrast MR flow analysis. AVA at cMR (0.93 ± 0.42 cm2) was highly correlated with TEE-derived planimetry (0.92 ± 0.32 cm2) (concordance correlation coefficient, CCC = 0.85). By excluding 11 patients with extensively thickened and heavily calcified cusps, the CCC increased to 0.93. EOA at cMR (0.86 ± 0.30 cm2) showed a strong correlation with TTE-derived EOA (0.78 ± 0.25 cm2) (CCC = 0.82). CONCLUSIONS: cMR imaging is an accurate alternative for the grading of AS severity. Its use may be recommended especially in patients with poor transthoracic acoustic windows and/or in case of discordance between 2D echocardiographic parameters.

Aortic elasticity indices by magnetic resonance predict progression of ascending aorta dilation.

OBJECTIVES: Aortic distensibility and pulse-wave velocity (PWV) are under investigation as parameters by which to evaluate the indication for ascending aorta (AA) replacement. The maximum rate of systolic distension (MRSD) was proposed as a new index of aortic elasticity. The aim of this study was to assess the role of aortic elasticity parameters to predict AA growth rates in patients with AA dilation (AAD). METHODS: Magnetic resonance imaging (MRI) was performed annually in 65 patients with AA dilation (median follow-up 17 months; 25-75th percentile; range 12-30 months). A significant increase in AA diameter was defined as a ≥2-mm increase. RESULTS: An increase in AA diameter was found in 42 (68 %) patients (AAD+ group) and absent in 20. Median increase was 0.16 (25-75th percentile; range 0.32-0.7) mm/month. The AAD+ group had a lower MRSD (4.6 ± 2.2 vs 7.4 ± 2.0, p < 0.001) but the same PWV and distensibility. MRSD showed 93.7 % specificity and 75.6 % sensitivity for prediction of increase. Patients with MRSD ≤ 6 had lower progression-free survival times (p < 0.002). After a follow-up of 4.1 years, patients who underwent surgical therapy had lower MRSD and distensibility than others. CONCLUSIONS: MRSD is an index of aorta elastic properties and is a valuable predictor for progression in AAD. KEY POINTS: • MRI-derived parameters of aortic wall elasticity predict progression of ascending aorta dilation. • Maximal rate of systolic distension (MRSD) was the best predictor of progression. • Patients with MRSD ≤ 6 had lower progression-free survival (PFS) times. • Patients who underwent surgical therapy had lower MRSD and distensibility. • MRI-derived parameters identify patients with fast progression of Ascending Aorta Dilation.

Endovascular Treatment of Visceral Artery Pseudoaneurysms in Patients with Chronic Pancreatitis: Our Single-Center Experience.

BACKGROUND: To analyze our experience in endovascular treatment as first-line approach for severe and acute hemorrhage in patients with chronic pancreatitis. METHODS: From 2010 to 2016 at our institution, 12 males (mean age 66 years) with bleeding pseudoaneurysms (PSAs) underwent urgent visceral angiography and endovascular treatment. All patients had chronic pancreatitis. True visceral artery aneurysms and PSAs arising after surgery were excluded from the study. RESULTS: Pancreatitis was caused by alcohol abuse in 9 (9/12, 75%) patients and biliary lithiasis in 3 (3/12, 25%). Involved arteries were gastroduodenal (5/12, 50%), splenic (2/12, 16%), common hepatic (2/12, 16%), middle colic (1/12, 9%), and celiac trunk (1/12, 9%). All patients underwent computed tomography angiography (CTA) scan and visceral angiography followed by endovascular treatment using different devices. Technical success rate was 100%. Bleeding was stopped in all patients, and no one required reembolization. No major complications occurred. There were 2 complications associated with the endovascular procedure: in one case, a coil migration and in another case, in-stent restenosis at 6 months. Follow-up included CTA performed during hospitalization and at 6 months after the procedure. CONCLUSIONS: Our experience confirms the role of CTA and visceral angiography as diagnostic and therapeutic tool, respectively.

Delineating brachial plexus, cochlea, pharyngeal constrictor muscles and optic chiasm in head and neck radiotherapy: a CT-based model atlas.

BACKGROUND AND PURPOSE: Sparing of the organs at risk is one of the primary end-points of radiotherapy. The effects of organ-at-risk delineation on the dosimetric parameters can be critical and can influence treatment planning and outcomes. The aim of our study was to provide anatomical boundaries for the identification and delineation of the following critical organs at risk in the head and neck district: brachial plexus, cochlea, pharyngeal constrictor muscles and optic chiasm. PATIENTS AND METHODS: One patient was initially selected to elaborate our atlas. This patient was subjected to a planning computed tomography of the brain and head and neck district; axial images of 3-mm thickness at 3-mm intervals were obtained. In the same set-up a magnetic resonance imaging study was also performed. The obtained images were fused based on anatomical landmarks and used by a radiation oncologist, supported by a neuroradiologist, to provide anatomo-radiological limits for the identification of the brachial plexus, cochlea, pharyngeal constrictor muscles and optic chiasm. These limits were further verified on three consecutive patients. RESULTS: A computed tomography-based atlas was developed with definition of cranial, caudal, medial, lateral, anterior and posterior limits for each organ considered. CONCLUSIONS: This study allows improvement of definitions of anatomic boundaries for the brachial plexus, cochlea, pharyngeal constrictor muscles and optic chiasm. Our multidisciplinary experience led to the production of an institutional reference tool that could represent a useful aid for radiation oncologists in clinical practice.

Spectrum of phenotypic anomalies in four families with deletion of the SHOX enhancer region.

BACKGROUND: SHOX alterations have been reported in 67% of patients affected by Léri-Weill dyschondrosteosis (LWD), with a larger prevalence of gene deletions than point mutations. It has been recently demonstrated that these deletions can involve the SHOX enhancer region, rather that the coding region, with variable phenotype of the affected patients.Here, we report a SHOX gene analysis carried out by MLPA in 14 LWD patients from 4 families with variable phenotype. CASE PRESENTATION: All patients presented a SHOX enhancer deletion. In particular, a patient with a severe bilateral Madelung deformity without short stature showed a homozygous alteration identical to the recently described 47.5 kb PAR1 deletion. Moreover, we identified, for the first time, in three related patients with a severe bilateral Madelung deformity, a smaller deletion than the 47.5 kb PAR1 deletion encompassing the same enhancer region (ECR1/CNE7). CONCLUSIONS: Data reported in this study provide new information about the spectrum of phenotypic alterations showed by LWD patients with different deletions of the SHOX enhancer region.

Extrapleural and cardiophrenic lymph nodes: prevalence, clinical significance and diagnostic value.

PURPOSE: The aim of this study was to evaluate the prevalence, clinical meaning and diagnostic value of extrapleural and cardiophrenic nodes occasionally observed on computed tomography (CT) scans of the chest. MATERIALS AND METHODS: We included 750 consecutive patients who underwent CT of the chest for different clinical purposes (340 nonneoplastic patients, 270 with extrathoracic neoplasms, 120 with intrathoracic neoplasms, 20 with pleural metastasis) and 91 patients with histologically proven malignant pleural mesothelioma (MPM). For each group of patients, we analysed the presence of extrapleural and cardiophrenic nodes, their number (single or multiple) and their size. RESULTS: The prevalence of cardiophrenic nodes between 6 and 10 mm and >10 mm was significantly higher in patients with MPM (28.6 and 26.4 %, respectively) than in all other categories of patients, except for patients with pleural metastasis (30 and 25 %, respectively). The prevalence of extrapleural nodes, independently from their size, was significantly higher in patients with MPM (68 %) compared with all other groups, including patients with pleural metastasis (5 %; p < 0.0001). CONCLUSIONS: Cardiophrenic nodes >5 mm and extrapleural nodes of any size have a significant diagnostic value in malignant pleural disease, either primary or secondary, whereas they are extremely rare in other neoplastic or nonneoplastic diseases.

Obscure and occult gastrointestinal bleeding: comparison of different imaging modalities.

Patients with persistent, recurrent, or intermittent bleeding from the gastrointestinal (GI) tract for which no definite cause has been identified by initial esophagogastroduodenoscopy, colonoscopy, or conventional radiologic evaluation are considered to have an obscure GI bleeding (OGIB). The diagnosis and management of patients with OGIB is challenging, often requiring extensive and expensive workups. The main objective is the identification of the etiology and site of bleeding, which should be as rapidly accomplished as possible, in order to establish the most appropriate therapy. The introduction of capsule endoscopy and double balloon enteroscopy and the recent improvements in CT and MRI techniques have revolutionized the approach to patients with OGIB, allowing the visualization of the entire GI tract, particularly the small bowel, until now considered as the "dark continent" . In this article we review and compare the radiologic and endoscopic examinations currently used in occult and OGIB, focusing on diagnostic patterns, pitfalls, strengths, weaknesses, and value in patients' management.

[Cough-induced intercostal lung herniation successfully diagnosed with imaging techniques]. / Ernia polmonare intercostale spontanea tosse-indotta: diagnosi mediante imaging.

We report the case of a 78-year-old man presenting with pain in right hemithorax that occurred suddenly after coughing. A palpable chest wall mass, soft in consistency, was noted on physical examination, and chest X-ray and CT allowed to make diagnosis of spontaneous lung hernia.

[Posterior reversible encephalopathy syndrome: description of a case in the setting of severe infection]. / Encefalopatia posteriore reversibile: descrizione di un caso associato a stato infettivo.

Posterior reversible encephalopathy syndrome (PRES) is a well recognized neurotoxic state coupled with a unique neuroradiological appearance. This syndrome is associated with a broad spectrum of complex conditions (preeclampsia/eclampsia, bone marrow/organ transplantation, chemotherapy, autoimmune disease). We report the case of a female patient who developed PRES in the setting of severe infection, and we discuss the possible mechanisms underlying the development of cerebral edema by describing the inherent neuroradiological features.

[Orbital non-Hodgkin's lymphoma: description of a case diagnosed with magnetic resonance imaging]. / Linfoma non-Hodgkin bilaterale dell'orbita: descrizione di un caso studiato con RM.

Orbital non-Hodgkin's lymphoma is a rare tumor. Correct diagnosis and accurate staging are of paramount importance for timely treatment and better outcome. We report the case of a female patient with bilateral orbital lymphoma, and describe the clinical-pathological aspects of the disease and its neuroradiological features.

[Role of CT in the preoperative diagnosis of a giant benign solitary fibrous tumor of the pleura]. / Ruolo della TC nella diagnosi preoperatoria del tumore solitario fibroso gigante della pleura.

The authors emphasize the role of CT in the preoperative diagnosis of a giant benign solitary fibrous tumor of the pleura. CT can provide evidence of complete resection of the lesion, showing a pedunculated stalk. Aspiration cytology is not a reliable diagnostic approach.

Contrast-enhanced ultrasound versus color duplex ultrasound imaging in the follow-up of patients after endovascular abdominal aortic aneurysm repair.

PURPOSE: This study assessed the negative predictive value, sensitivity, specificity, and diagnostic accuracy of real-time contrast-enhanced ultrasound imaging (CEUS) in the detection of endoleaks in patients with abdominal aortic aneurysm (AAA) who underwent endovascular repair (EVAR) compared with unenhanced ultrasound imaging. Computed tomography angiography (CTA) was the gold standard. The secondary objective was to define the optimal dose of the second-generation contrast agent to routinely use in the CEUS examinations for endoleak detection. METHODS: The study enrolled 84 patients with unruptured AAA who were treated with EVAR and underwent CTA follow-up. In the same day, CTA (4- x 1-mm collimation, 1.25-mm slice width), unenhanced US imaging and CEUS imaging was performed in all patients. The CEUS studies were performed after an intravenous bolus injection of 1.2 mL and 2.4 mL of a second-generation contrast agent with continuous low-mechanical index (range, 0.01-0.04) real-time tissue harmonic imaging. The unenhanced US and CEUS studies were interpreted separately by two independent experienced readers to detect the presence of endoleaks by viewing recorded videotapes according to a five-point confidence scale. The standard of reference was represented by the consensus reading of CTA performed by two experienced radiologists not involved in the image analysis. Qualitative analysis as well as sensitivity, specificity, negative predictive value, and diagnostic accuracy in detecting endoleaks of each reading session were compared. RESULTS: CEUS imaging significantly improved the diagnostic performance of unenhanced US studies in the detection of endoleaks in terms of sensitivity (97.5% vs 62.5%), negative predictive value (97.3% vs 65.1%), accuracy (89.3% vs 63.1%), and specificity (81.8% vs 63.6%). The optimal dose of contrast agent to detect and characterize endoleaks was 2.4 mL. No adverse events were recorded during the study. CONCLUSIONS: The results showed CEUS imaging is a fast, noninvasive, reliable, and valid alternative to multislice CTA for endoleak detection in endovascular aortic stent graft patients, and is superior to unenhanced US imaging. Contrast-enhanced ultrasound imaging should be performed using a recommended contrast medium dose of 2.4 mL.

Prenatal planning of placenta previa: diagnostic accuracy of a novel MRI-based prediction model for placenta accreta spectrum (PAS) and clinical outcome.

PURPOSE: To investigate the diagnostic accuracy of MRI for placenta accreta spectrum (PAS) and clinical outcome prediction in women with placenta previa, using a novel MRI-based predictive model. METHODS: Thirty-eight placental MRI exams performed on a 1.5T scanner were retrospectively reviewed by two radiologists in consensus. The presence of T2 dark bands, myometrial thinning, abnormal vascularity, uterine bulging, placental heterogeneity, placental protrusion sign, placental recess, and percretism signs was scored using a 5-point scale. Pathology and clinical intrapartum findings were the standard of reference for PAS, while intrapartum/peripartum bleeding and emergency hysterectomy defined the clinical outcome. Receiver-operating characteristic (ROC) analysis and discriminant function analysis were performed to test the predictive power of MRI findings for both PAS and clinical outcome prediction. RESULTS: Abnormal vascularity and percretism signs were the two most predictive MRI features of PAS. The area under the curve (AUC) of the predictive function was 0.833 (cutoff 0.39, 67% sensitivity, 100% specificity, p = 0.001). Percretism signs and myometrial thinning were the two most predictive MRI features of poor outcome. AUC of the predictive function was 0.971 (cutoff - 0.55, 100% sensitivity, 77% specificity, p < 0.001). CONCLUSION: The diagnostic accuracy of MRI, especially considering the combination of the most predictive MRI findings, is higher when the target of the prediction is the clinical outcome rather than the PAS.

Endovascular treatment of thoracic aortic diseases: Follow-up and complications with multi-detector computed tomography angiography.

Endovascular procedures with placement of stent-graft has become an accepted alternative to traditional open surgery for treatment of descending thoracic aortic aneurysms, ulcers, post-traumatic rupture, or complications of type-B dissection, due to significant reduction in perioperative mortality, rate of complications and length of hospitalization. Moreover, increasing operator experience and continuous advances in stent-graft technology are making treatment of a wider range of cases possible with redefinition of guidelines for endovascular stent-graft. The feasibility of endovascular stent-graft is mainly dependent on anatomic factors which represent the important predictors of the success of this procedure as well as on strictly follow-up in order to obtain early detection and treatment of eventual complications. Multi-detector CT-angiography is a fast, safe, and minimally invasive imaging technique that represents the standard of reference in the follow-up of patients who have undergone endovascular stent-graft, as it is effective and specific in the detection of procedure-correlated complications. The purpose of this article is to give a brief review of those techniques most commonly used for endovascular treatment of thoracic aortic diseases together with a more detailed description of post-procedural complications and their appearance on multi-detector CT-angiography.

Four-detector row computed tomographic angiography in the evaluation of infrarenal aorta and peripheral arterial occlusive disease: influence of contrast medium concentration.

PURPOSE: To prospectively compare the diagnostic accuracy and quality of vascular enhancement of 2 contrast agents with different iodine concentrations in 4-detector row computed tomographic angiography of abdominal aorta and lower-extremity arteries. MATERIALS AND METHODS: Forty consecutive patients with peripheral arterial occlusive disease referred for conventional angiography (digital subtraction angiography [DSA]) of the lower extremity were prospectively enrolled in the study and underwent multidetector row computed tomographic angiography (CTA) receiving either 90 mL of iomeprol 400 (Iomeron 400, group A; Bracco Imaging S.p.A., Milan, Italy) or 120 mL of iomeprol 300 (Iomeron 300, group B; Bracco Imaging). Resultant images, both axial, maximum intensity projection, multiplanar reformatted, and volume-rendered 3-dimensional images, were independently evaluated by 2 clinically competent and experienced blinded radiologists for the presence of stenotic and occluded arterial segments using DSA as the standard of reference. Computed tomographic images were also evaluated quantitatively for maximum arterial and venous enhancement, and qualitatively for vascular opacification, venous overlap, and diagnostic efficacy. Quantitative and qualitative results of the 2 study agent groups were statistically compared. Both contrast media were evaluated for safety and tolerability. RESULTS: From 760 segments, 722 arterial segments were effectively evaluated in the comparative analysis of CTA and DSA. In the evaluation of significant stenoses (>70%) and occluded segments, multidetector row CTA obtained a sensitivity, specificity, and accuracy of 97.1%, 96%, and 96.3%, and 98.9%, 100%, and 99%, respectively. Iomeprol 400 demonstrated an increased arterial enhancement in aortoiliac and femoral districts in comparison to iomeprol 300 (mean increase in opacification, 37.3 Hounsfield units) and a significant better qualitative assessment in the aortoiliac segments without an increase in venous opacification or the presence of venous overlap. No significant differences were found for sensitivity and specificity for the diagnosis of significant stenoses (>70%) and occluded segments. Both agents were well tolerated, and no adverse events were recorded. CONCLUSIONS: The use of a small volume of a high-concentration contrast material yielded higher arterial enhancement from the abdominal aorta down to the femoral arteries with absent or minimal venous overlap and without significant differences in diagnostic ability.

Multidetector-row computed tomography angiography in abdominal aortic aneurysm treated with endovascular repair: evaluation of optimal timing of delayed phase imaging for the detection of low-flow endoleaks.

PURPOSE: To evaluate the optimal timing of delayed phase imaging for detecting low-flow endoleaks. MATERIALS AND METHODS: Fifty-eight patients with unruptured abdominal aortic aneurysm treated with endovascular repair underwent 1- and 6-month follow-up multidetector row computed tomography (CT) performed during unenhanced, arterial, and delayed phase. At 6-month follow-up, delayed phase imaging, focused on stent graft, was performed with a delay of 60 (early delayed enhanced phase) and 300 seconds (late delayed enhanced phase) after intravenous injection of 120 mL of iodinated nonionic contrast medium (iomeprol 300 mgI/mL, Iomeron), at a flow rate of 3 mL/s via an antecubital vein, with a detector-row configuration of 4 x 1-mm, a 1.25-mm slice width, and a pitch of 6. Six-month follow-up CT images were independently evaluated by 2 readers during 2 different reading sessions: sets A (unenhanced, arterial, and early delayed phase images) and B (unenhanced, arterial, and late delayed phase images). Sensitivity and diagnostic accuracy of both reading sessions were compared. The standard of reference was represented by the combined evaluation of 1- and 6-month CT scans. RESULTS: At standard of reference, 24 of 58 patients had an endoleak classified as type 1 in 2 cases, type 2 in 21 cases, and type 3 in the last 1 case. Seven of 21 type 2 endoleaks were classified as low-flow endoleaks. Set A reading session, including early delayed enhanced phase, allowed the detection of 19 of 24 endoleaks (5 false-negative cases represented by low-flow endoleaks), whereas all endoleaks were detected during set B reading session, including late delayed enhanced phase. Differences between sets A and B in terms of sensitivity and diagnostic accuracy were statistically significant (P < 0.05). CONCLUSIONS: For optimal multidetector CT detection of low-flow endoleaks in patients who underwent endovascular repair, delayed phase should be acquired 300 seconds after injection of contrast medium.

Embolization of Bleeding Pulmonary Arterial Pseudoaneurysm in a Woman With Infective Endocarditis.

Pulmonary arterial pseudoaneurysm is a rare but life-threatening complication of infective endocarditis. This report describes a case of bleeding pulmonary arterial pseudoaneurysm in a young, drug-addicted woman with tricuspid annuloplasty after infective endocarditis that was promptly identified by computed tomography pulmonary angiography and successfully treated using coil embolization. Perfusion scintigraphy at 30 days confirmed the safety of endovascular treatment.