Correlation between appearance of the retroportal fat plane at preoperative CT and pathology findings in resected adenocarcinoma of the pancreatic head.

AIM: To correlate the appearance of the retroportal fat plane at preoperative computed tomography (CT) and the pathology findings in resected adenocarcinoma of the pancreatic head (PDAC). MATERIAL AND METHODS: Forty-eight patients with resected PDAC of the pancreatic head were included (24 men, 24 women, mean age 63 years, median BMI 24.1). All patients underwent CT <30 days before surgery. The state of the retroperitoneal resection margin and the presence of lymphatic or perineural invasion were obtained from pathology reports. CT images were reviewed independently by two radiologists for assessment of the retroportal fat plane and graded in two categories (clear/effaced). Inter-reader discrepancies were solved in consensus. Interobserver agreement was calculated and Fisher's test was used to assess the correlation between CT and pathology findings. Visceral fat areas were measured and correlated with CT findings. RESULTS: A clear retroportal fat plane was significantly associated with a negative retroperitoneal margin at pathology with 100% specificity and PPV (p=0.0001). No association was observed between the appearance of the fat plane at CT and the presence of lymphatic or perineural invasion (p=ns). Interobserver agreement for retroportal fat plane evaluation was good (0.741). False-positive cases had a significantly lower visceral fat area than the correctly classified patients (p=0.0480). CONCLUSIONS: A clear retroportal fat plane is significantly associated with negative retroperitoneal resection margins at pathology. The lack of visceral adipose tissue can lead to overestimation of retroportal fat plane involvement at preoperative CT.

Iodine Extravasation Quantification on Dual-Energy CT of the Brain Performed after Mechanical Thrombectomy for Acute Ischemic Stroke Can Predict Hemorrhagic Complications.

BACKGROUND AND PURPOSE: Intracerebral hemorrhage represents a potentially severe complication of revascularization of acute ischemic stroke. The aim of our study was to assess the capability of iodine extravasation quantification on dual-energy CT performed immediately after mechanical thrombectomy to predict hemorrhagic complications. MATERIALS AND METHODS: Because this was a retrospective study, the need for informed consent was waived. Eighty-five consecutive patients who underwent brain dual-energy CT immediately after mechanical thrombectomy for acute ischemic stroke between August 2013 and January 2017 were included. Two radiologists independently evaluated dual-energy CT images for the presence of parenchymal hyperdensity, iodine extravasation, and hemorrhage. Maximum iodine concentration was measured. Follow-up CT examinations performed until patient discharge were reviewed for intracerebral hemorrhage development. The correlation between dual-energy CT parameters and intracerebral hemorrhage development was analyzed by the Mann-Whitney U test and Fisher exact test. Receiver operating characteristic curves were generated for continuous variables. RESULTS: Thirteen of 85 patients (15.3%) developed hemorrhage. On postoperative dual-energy CT, parenchymal hyperdensities and iodine extravasation were present in 100% of the patients who developed intracerebral hemorrhage and in 56.3% of the patients who did not (P = .002 for both). Signs of bleeding were present in 35.7% of the patients who developed intracerebral hemorrhage and in none of the patients who did not (P < .001). Median maximum iodine concentration was 2.63 mg/mL in the patients who developed intracerebral hemorrhage and 1.4 mg/mL in the patients who did not (P < .001). Maximum iodine concentration showed an area under the curve of 0.89 for identifying patients developing intracerebral hemorrhage. CONCLUSIONS: The presence of parenchymal hyperdensity with a maximum iodine concentration of >1.35 mg/mL may identify patients developing intracerebral hemorrhage with 100% sensitivity and 67.6% specificity.

Uric acid versus non-uric acid renal stones: in vivo differentiation with spectral CT.

AIM: To differentiate uric acid from non-uric acid renal stones based on their spectral attenuation values. MATERIALS AND METHODS: The present study was approved by the institutional review board and the need for informed consent was waived. Thirty-three consecutive patients (21 men, 12 women; mean age 55 years) with symptomatic urolithiasis underwent dual-energy computed tomography (DECT) using a second-generation dual-source CT system. Stone composition was assessed by means of chemical analysis after extraction or spontaneous expulsion. The composition of one stone was considered to represent all remaining stones in patients presenting with more than one stone. Image-domain virtual monoenergetic images were generated from the dual-energy datasets. One radiologist evaluated stone attenuation values from 40 to 190 keV; attenuation curves were created and 40/190 keV attenuation ratios calculated. Qualitative evaluation of the spectral attenuation curves was also performed. Imaging findings were compared with laboratory results. RESULTS: Sixty-two stones were considered in 33 patients (mean diameter 6.5 mm). Fifteen of the 62 stones were mainly composed of uric acid and 47/62 of cysteine or calcium oxalates/phosphates. Forty to 190 keV attenuation ratios were significantly lower for uric acid stones (mean 0.87±0.3) than for non-uric acid stones (mean 3.80±0.6; p<0.0001). Accuracy was 100% with a cut-off value of 1.76. Qualitative analysis of spectral attenuation curves showed unique shapes for uric acid and non-uric acid stones. CONCLUSIONS: Spectral CT quantitatively and qualitatively differentiates uric acid from non-uric acid stones.

MDCT of blunt renal trauma: imaging findings and therapeutic implications.

OBJECTIVES: To show the wide spectrum of computed tomography (CT) findings in blunt renal trauma and to correlate them with consequent therapeutic implications. METHODS: This article is the result of a literature review and our personal experience in a level II trauma centre. Here we describe, discuss and illustrate the possible CT findings in blunt renal trauma, and we correlate them with the American Association for the Surgery of Trauma (AAST) classification and their therapeutic implications. RESULTS: CT findings following blunt renal trauma can be grouped into 15 main categories, 12 of them directly correlated with the AAST classification and 3 of them not mentioned in it. Non-operative management, which includes the "watchful waiting" approach, endourological treatments and endovascular treatments, is nowadays widely adopted in blunt renal trauma, and surgery is limited to haemodynamically unstable patients and a minority of haemodynamically stable patients. CONCLUSIONS: The interpretation of CT findings in blunt renal trauma may be improved and made faster by the knowledge of their therapeutic consequences. TEACHING POINTS: • The majority of blunt renal injuries do not require surgical treatment. • CT findings in blunt renal injury must be evaluated considering their therapeutic consequences. • Some CT findings in blunt renal trauma are not included in the AAST classification.

Incidentally discovered benign pancreatic cystic neoplasms not communicating with the ductal system: MR/MRCP imaging appearance and evolution.

PURPOSE: The authors sought to determine magnetic resonance/magnetic resonance cholangiopancreatography (MR/MRCP) imaging features of incidentally discovered benign, noncommunicating cystic neoplasms (BNCNs) of the pancreas to assess their evolution over time and identify MR/MRCP imaging features predictive of tumour growth. MATERIAL AND METHODS: This was a retrospective study, so informed consent was waived. Sixty-two patients with a diagnosis of BNCN were assessed. Inclusion criteria were incidentally discovered cystic neoplasm of the pancreas with nonmeasurable walls, no mural nodules and no communication with the pancreatic ductal system and who underwent ≥ 1 MR/MRCP examination. Image analysis, performed at diagnosis and during follow-up, included macroscopic pattern (microcystic/macrocystic/mixed), number of cysts (unicystic/oligocystic/multicystic), BNCN maximum diameter and tumour growth rates. RESULTS: A total of 64 BNCNs was detected. Macroscopic pattern was mixed in 31/64 (48%), microcystic in 28/64 (44%) and macrocystic in 5/64 (8%). BNCNs appeared multicystic in 38/64 (59%) cases, oligocystic in 22/64 (35%) and unicystic in 4/64(6%). All qualitative parameters remained unchanged during follow-up. At diagnosis, the median maximum BNCN diameter was 35.0 mm and 38.0 mm at the final examination (p<0.001). BNCNs showed a tumour growth rate of 2 mm/year. CONCLUSIONS: Mixed and microcystic patterns were the most common, accounting for 48% and 44% of cases, respectively, and showed no change over time. MR/MRCP features predictive of lesion enlargement were a mixed/ macrocystic pattern, and lesion size was >3 cm (both p<0.001).

Multiple pilomatrixomas and myotonic dystrophy: a case report.

Clinical and histopathological data of a patient affected by myotonic dystrophy (Steinert Disease) and multiple pilomatrixomas (calcifying epithelioma of Malherbe) are reported. This association has been previously reported in other 16 cases. The prevalence of pilomatricoma in myotonic dystrophy results much greater than in general population. This association affects females as well as males. This tumour, when associated with myotonic dystrophy, is more frequently multiple than single.