Differentiation between normal and metastatic lymph nodes in patients with skin melanoma: Preliminary findings using a DIXON-based whole-body MRI approach.

Purpose: Metastatic melanoma lymph nodes (MMLns) might be challenging to detect on MR-WBI, as both MMLns and normal lymph nodes (NLns) can show restricted water diffusion. Our purpose is to assess the potential contribution of the DIXON sequence in differentiating MMLns from NLns. Material and methods: We followed a cohort of 107 patients with stage IIIb/c and IV skin melanoma for 32 months using MR-WBI with DIXON, STIR, and DWI/ADC sequences. We compared signal intensity (SI) values of MMLns and NLns in the four series of the DIXON sequence (in/out-of-phase, fat_only, and water_only series). The fat fraction (SIfat_only/SIin) and the long:short axis ratio of MMLns were calculated. The fat fraction was also calculated in the fatty hila of NLns. Results: All MMLns (8 from 7 patients) showed SIout>SIin with a mean fat fraction of 10%. In 40 normal fatty hila (25 patients), the proportion of SIout>SIin was 100% and mean fat fraction was 89% (p<0.001 for fat fraction, Mann-Whitney U-test). In the cortex of NLns, a SIout>SIin pattern was identified in 41/113 cases from 19/40 patients. The median long:short axis ratio in MMLns was 1.13 (range 1.03-1.25). Conclusion: The combination of three features of MMLns (SIout>SIin, low-fat fraction and rounded shape) might hold promise in differentiating NLns from MMLns in patients with skin melanoma. Further research is warranted due to the small number of MMLns in our cohort.

Radiological assessment of peritoneal carcinomatosis: a primer for resident.

The imaging has critical responsibility in the assessment of peritoneal lesions along with estimating the overall extent. Valuing disease burden is crucial for selection of combining cytoreductive surgery (CRS) and intraperitoneal hyperthermic chemotherapy (HIPEC) treatment. An approach that combines the strength of several imaging tools and increases diagnostic accuracy, should be chosen, even if the preferred imaging tool in patients with suspected Peritoneal Carcinomatosis (PC) is CT. The outcomes of PC are mainly correlated to tumor spread, localization, and lesion size. Accurate assessment of these features is critical for prognosis and treatment planning. These data can be evaluated by Peritoneal Cancer Index (PCI), a quantitative index suggested by Harman and Sugarbaker. Additionally, precise predictive biomarkers should be established to predict PC in patients at risk. The radiomics analysis could predict PC throughout the evaluation of cancers heterogeneity.

Role of perfusion CT in the evaluation of metastatic nodal tumor response after radiochemotherapy in head and neck cancer: preliminary findings.

OBJECTIVE: To assess changes of CT perfusion parameters (ΔPCTp) of cervical lymph node metastases from head and neck cancer (HNC) before and after radiochemotherapy (RT-CT) and their association with nodal tumor persistence. PATIENTS AND METHODS: Eligibility criteria included HNC (Stage III-IV) candidates for RT-CT. Patients underwent perfusion CT (PCT) at baseline 3 weeks and 3 months after RT-CT. Blood volume (BV), blood flow (BF), mean transit time (MTT) and permeability surface (PS) were calculated. PET/CT examination was also performed at baseline and 3 months after treatment for metabolic assessment. RESULTS: Between July 2012 and May 2016, 27 patients were evaluated. Overall, only 3 patients (11%) experienced tumor persistence in the largest metastatic lymph node. A significant reduction of all PCTp values (p<0.0001), except MTT (from 6.3 to 5.7 s; p=0.089), was observed at 3 weeks post-RT-CT compared to baseline. All PCTp values including MTT were significantly lower at 3-month follow-up compared to baseline (p<0.05). Moreover, a statistically significant association was observed between nodal tumor persistence and high BF values (p=0.045) at 3 months after treatment that did not occur for the other parameters. CONCLUSIONS: Our preliminary findings show that all PCTp except MTT are significantly reduced after RT-CT. High BF values at 3 months post-RT-CT are predictive of nodal tumor persistence.

Assessment of radiation protection awareness and knowledge about radiological examination doses among Italian radiographers.

OBJECTIVES: To evaluate radiation protection basic knowledge and dose assessment for radiological procedures among Italian radiographers METHODS: A validated questionnaire was distributed to 780 participants with balanced demographic characteristics and geographic distribution. RESULTS: Only 12.1 % of participants attended radiation protection courses on a regular basis. Despite 90 % of radiographers stating to have sufficient awareness of radiation protection issues, most of them underestimated the radiation dose of almost all radiological procedures. About 5 % and 4 % of the participants, respectively, claimed that pelvis magnetic resonance imaging and abdominal ultrasound exposed patients to radiation. On the contrary, 7.0 % of the radiographers stated that mammography does not use ionising radiation. About half of participants believed that radiation-induced cancer is not dependent on age or gender and were not able to differentiate between deterministic and stochastic effects. Young radiographers (with less than 3 years of experience) showed a higher level of knowledge compared with the more experienced radiographers. CONCLUSIONS: There is a substantial need for radiographers to improve their awareness of radiation protection issues and their knowledge of radiological procedures. Specific actions such as regular training courses for both undergraduate and postgraduate students as well as for working radiographers must be considered in order to assure patient safety during radiological examinations. MAIN MESSAGES: • Radiographers should improve their knowledge on radiation protection issues. • Only 12.1 % of participants attended radiation protection courses on a regular basis. • Specific actions must be considered in order to increase knowledge and awareness.

iPad-based primary 2D reading of CT angiography examinations of patients with suspected acute gastrointestinal bleeding: preliminary experience.

OBJECTIVE: To evaluate the effectiveness of the iPad (Apple Inc., Cupertino, CA) for two-dimensional (2D) reading of CT angiography (CTA) studies performed for suspected acute non-variceal gastrointestinal bleeding. METHODS: 24 CTA examinations of patients with suspected acute gastrointestinal bleeding confirmed (19/24, 79.2%) or ruled out (5/24, 20.8%) by digital subtraction angiography (DSA) were retrospectively reviewed by three independent readers on a commercial picture archiving communication system (PACS) workstation and on an iPad with Retina Display® 64 GB (Apple Inc.). The time needed to complete reading of every CTA examination was recorded, as well as the rate of detection of arterial bleeding and identification of suspected bleeding arteries on both devices. RESULTS: Overall, the area under the receiver operating characteristic curve, sensitivity, specificity, positive- and negative-predictive values for bleeding detection were not significantly different while using the iPad and workstation (0.774 vs 0.847, 0.947 vs 0.895, 0.6 vs 0.8, 0.9 vs 0.944 and 0.750 vs 0.667, respectively; p > 0.05). In DSA-positive cases, the iPad and workstation allowed correct identification of the bleeding source in 17/19 cases (89.5%) and 15/19 cases (78.9%), respectively (p > 0.05). Finally, the time needed to complete reading of every CTA study was significantly shorter using the iPad (169 ± 74 vs 222 ± 70 s, respectively; p < 0.01). CONCLUSION: Compared with a conventional PACS workstation, iPad-based preliminary 2D reading of CTA studies has comparable diagnostic accuracy for detection of acute gastrointestinal bleeding and can be significantly faster. ADVANCES IN KNOWLEDGE: The iPad could be used by on-call interventional radiologists for immediate decision on percutaneous embolization in patients with suspected acute gastrointestinal bleeding.

How to build patient-specific synthetic abdominal anatomies. An innovative approach from physical toward hybrid surgical simulators.

BACKGROUND: According to literature evidence, simulation is of the utmost importance for training and innovative surgical strategies assessment. At present commercial physical simulators are limited to single or only a few anatomical structures and these are often just standard anatomies. METHODS: This paper describes a strategy to produce patient-specific abdominal silicone organs with realistic shapes and colors, starting from radiological images. Synthetic organs can be assembled in a complex physical simulator or, if paired with electromagnetic sensors, in a hybrid environment (mixed reality) to quantify deformations caused by surgical action. RESULTS: A physical trunk phantom with liver, gallbladder, pancreas and a sensorized stomach has been developed. It is coupled with consistent radiological images and a 3D model of the entire upper abdomen. The simulator has been evaluated in quantitative and qualitative terms to quantify its accuracy and utility, respectively. CONCLUSIONS: This simulator can be used in the field of abdominal surgery to train students and as a testing environment to assess and validate innovative surgical technologies.

Secretin-stimulated multi-detector CT versus mangafodipir trisodium-enhanced MR imaging plus MRCP in characterization of non-metastatic solid pancreatic lesions.

BACKGROUND AND AIM: Our study was aimed to compare multiphasic multi-detector computed tomography after secretin stimulation and mangafodipir trisodium-enhanced magnetic resonance imaging plus MR cholangiopancreatography in the characterization of solid pancreatic lesions. PATIENTS AND METHODS: Forty patients with ultrasound diagnosis of solid pancreatic lesion prospectively underwent both multi-detector computed tomography and magnetic resonance imaging. Three minutes after intravenous administration of secretin, post-contrast computed tomography scans were performed 40, 80, and 180 s after contrast medium injection. MR protocol included axial/coronal, thin/thick-slab, single-shot T2 w sequences and axial/coronal T1 w breath-hold spoiled gradient-echo images before and 30-40 min after intravenous infusion of manganese dipyri-doxal diphosphate. Different observers blindly evaluated the ability of computed tomography and magnetic resonance imaging to characterize focal pancreatic lesions. Surgery, biopsy, and/or follow-up were considered as our diagnostic gold standard. RESULTS: Thirty-five focal pancreatic lesions (adenocarcinoma, n=18; focal chronic pancreatitis, n=4; endocrine tumor, n=6; metastasis, n=1; cystic tumor, n=3; indeterminate cystic lesions, n=3) were present in 34 patients since the remaining 6 subjects showed no pathological finding. Both multi-detector computed tomography and magnetic resonance imaging showed a statistically significant correlation with the gold standard and between themselves in the characterization of 29 solid lesions of the pancreas (p<0.05). CONCLUSION: Both imaging techniques well correlate to final diagnosis of non-metastatic solid pancreatic lesions and particularly of adenocarcinomas with a slight advantage for mangafodipir trisodium-enhanced magnetic resonance imaging plus MR cholangiopancreatography.

Human leukocyte antigen-G expression after kidney transplantation is associated with a reduced incidence of rejection.

UNLABELLED: HLA-G is a non-classic Human Leukocyte Antigen (HLA-G) Class I of low polymorphism and restricted tissue distribution that displays tolerogenic functions. In heart transplantation and in combined liver/renal allograft transplantation, the expression of HLA-G has been associated with a lower incidence of acute graft rejection episodes and absence of chronic dysfunction. Since the expression of HLA-G in renal biopsies has been investigated only in few patients who received a combined kidney and liver transplant, in this study we performed a cross-sectional study, systematically comparing the expression of HLA-G in post-transplanted renal grafts, stratifying patients according to the presence or absence of rejection. PATIENTS AND METHODS: Seventy-three renal specimens (10 with acute rejection and 13 with chronic allograft nephropathy, and 50 with no signs of rejection) were immunohistochemically evaluated for HLA-G expression. RESULTS: In the group as a whole, HLA-G molecules were detected in 40 cases (54.8%). Among specimens that presented HLA-G expression, 2 out of 40 (5%) exhibited acute rejection, 2 (5%) exhibited chronic allograft nephropathy, and the remaining 36 (90%) exhibited no signs of rejection. The comparison between patients with rejection and those without rejection showed that the expression of HLA-G was significantly increased in specimens exhibiting no signs of rejection (p<0.0001). Considering only patients with acute rejection, 8 out of 10 patients showed no HLA-G expression in their kidney biopsies when compared to patients exhibiting no signs of rejection and absence of HLA-G was observed in 14 out of 50 (p=0.0032). Similarly, considering only patients with chronic allograft nephropathy, absence of HLA-G expression was observed in 11 out of 13 specimens, whereas in patients without rejection absence of HLA-G was observed in 14 out of 50 (p=0.003). Therapy with tacrolimus was significantly associated with the expression of HLA-G and a better graft prognosis. CONCLUSIONS: Our results suggest that HLA-G expression in the kidney allograft and the use of tacrolimus are associated with a lower frequency of acute renal rejection and chronic allograft nephropathy.

Assessment of midbrain atrophy in patients with progressive supranuclear palsy with routine magnetic resonance imaging.

OBJECTIVES: To assess midbrain atrophy through morphometric (linear, surface and volumetric) measurements in patients with clinically diagnosed progressive supranuclear palsy (PSP) and to establish the most accurate measure to be implemented in routine magnetic resonance (MR) protocol in distinguishing PSP from healthy subjects and MSA-p (multiple system atrophy, parkinsonian form) patients. MATERIALS AND METHODS: We studied 15 patients with the diagnosis of probable PSP, seven patients with the diagnosis of probable MSA-p and 14 age-matched healthy volunteers. MR protocol includes a sagittal SE T1-weighted sequence for cross-sectional area and linear brainstem measurements and a 3D-FSPGR sequence for brainstem volume measurements. RESULTS: A highly significant difference in the antero-posterior midbrain diameter, area and volume in PSP compared with control subjects was found. Only a measurement of the midbrain area and pons area enabled one to distinguish between PSP and MSA-p. Receiver operating characteristic analysis revealed that the midbrain area has the highest diagnostic accuracy in distinguishing between PSP and other conditions, with a sensitivity of 100% and specificity of 90.5%. The addition of the midbrain area/pons area ratio (A(ms)/A(pn) ratio) measurement improves the specificity in distinguishing between PSP and MSA. CONCLUSIONS: Morphological indexes indicate midbrain atrophy in PSP patients The combination of the A(ms) and A(ms)/A(pn) ratio measurements allows to discriminate between PSP and other conditions.

Microchimerism evaluation in recipients of living-related or unrelated deceased allograft renal transplants.

The presence of microchimerism in the peripheral blood of solid organ graft recipients has been associated with long-term solid organ acceptance, immunologic tolerance, and less aggressive immunosuppressive therapy. Molecular biology assays are among the most sensitive methods to detect microchimerism, primarily to evaluate Y chromosome sequences in females as indirect evidence of circulating male nucleated donor cells. We screened for the presence of the SRY sequence region in peripheral blood of 13 female recipients of male kidney grafts: 5 living-related and 8 deceased grafts. Only patients who received grafts from related living donors exhibited microchimerism. Five of 13 patients studied exhibited better graft outcomes, including the 4 who were positive for the SRY sequences.