Is CT Radiomics Superior to Morphological Evaluation for pN0 Characterization? A Pilot Study in Colon Cancer.

The aim of this study was to compare CT radiomics and morphological features when assessing benign lymph nodes (LNs) in colon cancer (CC). This retrospective study included 100 CC patients (test cohort) who underwent a preoperative CT examination and were diagnosed as pN0 after surgery. Regional LNs were scored with a morphological Likert scale (NODE-SCORE) and divided into two groups: low likelihood (LLM: 0-2 points) and high likelihood (HLM: 3-7 points) of malignancy. The T-test and the Mann-Whitney test were used to compare 107 radiomic features extracted from the two groups. Radiomic features were also extracted from primary lesions (PLs), and the receiver operating characteristic (ROC) was used to test a LN/PL ratio when assessing the LN's status identified with radiomics and with the NODE-SCORE. An amount of 337 LNs were divided into 167 with LLM and 170 with HLM. Radiomics showed 15/107 features, with a significant difference (p < 0.02) between the two groups. The comparison of selected features between 81 PLs and the corresponding LNs showed all significant differences (p < 0.0001). According to the LN/PL ratio, the selected features recognized a higher number of LNs than the NODE-SCORE (p < 0.001). On validation of the cohort of 20 patients (10 pN0, 10 pN2), significant ROC curves were obtained for LN/PL busyness (AUC = 0.91; 0.69-0.99; 95% C.I.; and p < 0.001) and for LN/PL dependence entropy (AUC = 0.76; 0.52-0.92; 95% C.I.; and p = 0.03). The radiomics ratio between CC and LNs is more accurate for noninvasively discriminating benign LNs compared to CT morphological features.

Trans-vaginal repair of recurrent rectovaginal fistula with interposition of BIO-A Tissue Reinforcement.

Rectovaginal fistulas (RVFs) represent the majority of all symptomatic leakages after anterior and low anterior resection in women. Conservative management is useful in paucisymptomatic patients with small fistulas but is usually unsuccessful in all other cases. The surgical strategies are various and heavily dependent on the type and extent of anatomic involvement. We present a case of a 51-year-old female with a multi-recurrent rectovaginal fistula that occurred since a laparoscopic sigmoidectomy was performed for a complicated diverticular disease in May 2015. An attempt to close the fistula was undertaken three times. In July 2019, a transvaginal repair was performed with interposition in the rectovaginal septum of GORE® BIO-A® Tissue Reinforcement. The postoperative course was uneventful. There was no recurrence and functional outcome was good at 24-months follow-up. Rectovaginal fistula can be successfully treated using the interposition of a GORE® BIO-A® Tissue Reinforcement with significant economic savings and good functional outcomes even through a transvaginal approach. It represents a therapeutic option for an otherwise difficult-to-treat complex fistula.

Differential diagnoses of COVID-19 pneumonia: the current challenge for the radiologist-a pictorial essay.

BACKGROUND: COVID-19 pneumonia represents the most severe pandemic of the twenty-first century and has crucial clinical, social and economical implications. The scientific community has focused attention and resources on clinical and radiological features of COVID-19 pneumonia. Few papers analysing the vast spectrum of differential diagnoses have been published. MAIN BODY: Complexity of differential diagnosis lays in the evidence of similar radiological findings as ground-glass opacities, crazy paving pattern and consolidations in COVID-19 pneumonia and a multitude of other lung diseases. Differential diagnosis is and will be extremely important during and after the pandemic peak, when there are fewer COVID-19 pneumonia cases. The aim of our pictorial essay is to schematically present COVID-19 pneumonia most frequent differential diagnoses to help the radiologist face the current COVID-19 pneumonia challenge. CONCLUSIONS: Clinical data, laboratory tests and imaging are pillars of a trident, which allows to reach a correct diagnosis in order to grant an excellent allocation of human and economical resources. The radiologist has a pivotal role in the early diagnosis of COVID-19 pneumonia because he may raise suspicion of the pathology and help to avoid COVID-19 virus spread.

Magnetic Resonance of Rectal Cancer Response to Therapy: An Image Quality Comparison between 3.0 and 1.5 Tesla.

PURPOSE: To evaluate signal intensity (SI) differences between 3.0 T and 1.5 T on T2-weighted (T2w), diffusion-weighted imaging (DWI), and apparent diffusion coefficient (ADC) in rectal cancer pre-, during, and postneoadjuvant chemoradiotherapy (CRT). MATERIALS AND METHODS: 22 patients with locally advanced rectal cancer were prospectively enrolled. All patients underwent T2w, DWI, and ADC pre-, during, and post-CRT on both 3.0 T MRI and 1.5 T MRI. A radiologist drew regions of interest (ROIs) of the tumor and obturator internus muscle on the selected slice to evaluate SI and relative SI (rSI). Additionally, a subanalysis evaluating the SI before and after-CRT (∆SI pre-post) in complete responder patients (CR) and nonresponder patients (NR) on T2w, DWI, and ADC was performed. RESULTS: Significant differences were observed for T2w and DWI on 3.0 T MRI compared to 1.5 T MRI pre-, during, and post-CRT (all P < 0.001), whereas no significant differences were reported for ADC among all controls (all P > 0.05). rSI showed no significant differences in all the examinations for all sequences (all P > 0.05). ∆SI showed significant differences between 3.0 T and 1.5 T MRI for DWI-∆SI in CR and NR (188.39 ± 166.90 vs. 30.45 ± 21.73 and 169.70 ± 121.87 vs. 22.00 ± 31.29, respectively, all P 0.02) and ADC-∆SI for CR (-0.58 ± 0.27 vs. -0.21 ± 0.24P value 0.02), while no significant differences were observed for ADC-∆SI in NR and both CR and NR for T2w-∆SI. CONCLUSION: T2w-SI and DWI-SI showed significant differences for 3.0 T compared to 1.5 T in all three controls, while ADCSI showed no significant differences in all three controls on both field strengths. rSI was comparable for 3.0 T and 1.5 T MRI in rectal cancer patients; therefore, rectal cancer patients can be assessed both at 3.0 T MRI and 1.5 T MRI. However, a significant DWI-∆SI and ADC-∆SI on 3.0 T in CR might be interpreted as a better visual assessment in discriminating response to therapy compared to 1.5 T. Further investigations should be performed to confirm future possible clinical application.

Minimally invasive management of rare giant Bochdalek hernia in adults.

Bochdaleck hernia (BH) is a congenital diaphragmatic hernia that presents after birth with respiratory symptoms and needs surgical treatment in the neonatal period. However, there are some rare cases of adult presentation, which require surgery to avoid complications. BHs can be treated through several approaches, including laparoscopy. Laparoscopic treatment of a giant BH was successfully attempted on a woman affected by multiple myeloma, with severe dyspnoea and dysphagia. Preoperative work-up included chest X ray, CT-scan and MRI. The whole stomach, duodenum, the small bowel, the right and transverse colon, most descending colon and the pancreas were herniated into the thorax. The herniated viscera were totally reduced into the abdominal cavity and the large defect of the left diaphragm repaired with a biosynthetic web scaffold especially designed for diaphragmatic reconstruction. Finally, to avoid a compartment syndrome in an abdomen with not enough room for the reduced viscera, an extended right colectomy with extracorporeal anastomosis was carried out through a mini-laparotomy. At seven-month follow-up, the patient is symptomless and control CT scan showed no hernia recurrence. Laparoscopic repair of large symptomatic adult BHs can be performed successfully with significant clinical improvement, even in difficult cases and fragile patients.

Groove pancreatitis: a challenging imaging diagnosis.

Groove pancreatitis (GP) is an uncommon form of chronic pancreatitis (CP) involving the space between duodenum, pancreatic head and common bile duct (CBD) known as pancreatic-duodenal groove. Although an association with long-standing ethanol assumption is reported a definite etiology of GP is unknown. Since thickening of the duodenal wall, pancreatic head enlargement, CBD stricture and dilatation of pancreatic duct system are common findings the differential diagnosis with pancreatic head neoplasm by means of imaging can be challenging. However, some imaging findings such as fibrotic changes of the pancreatic groove and presence of duodenal wall cysts may suggest the correct diagnosis. In this paper we review clinical and imaging features of GP with emphasis on computed tomography (CT) and magnetic resonance imaging (MRI) findings.

Layered enhancement at magnetic resonance enterography in inflammatory bowel disease: A meta-analysis.

BACKGROUND: Documentation of disease activity in patients affected by Crohn's disease (CD) is mandatory in order to manage patients properly. Magnetic resonance imaging (MRI) is considered the reference cross-sectional technique for the assessment of CD activity. Among MRI findings, layered pattern (LP) of contrast enhancement seems to be one of the most significant signs of severe disease activity; however, it has also been associated with chronic disease and mural fibrosis. AIM: To systematically evaluate the accuracy of LP of contrast enhancement in the diagnosis of active inflammation in patients with CD. METHODS: In February 2019, we searched the MEDLINE and Cochrane Central Register of Controlled Trials databases for studies evaluating the diagnostic accuracy of LP of contrast enhancement on MRI for the detection of active inflammation in patients with CD. To be included, studies had to use histopathologic analysis (endoscopy or surgery) as the reference standard. Risk of bias and applicability concerns of the included studies were evaluated by using items from the Quality Assessment for Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Pooled sensitivity and specificity were determined using a bivariate random-effect model. Heterogeneity was quantified by using the I 2 statistic. Our meta-analysis received no funding, and the review protocol was not published or registered in advance. RESULTS: Of the 1383 studies identified, five articles were finally selected for quantitative and qualitative synthesis (245 patients, 238 of whom had histopathologically confirmed CD, 144 with active inflammation and 94 with inactive disease). The meta-analysis showed a pooled sensitivity of 49.3% (95%CI: 41%-57.8%; I 2: 90.7%) and specificity of 89.1% (95%CI: 81.3%- 94.4%; I 2: 48.6%). Pooled PLR and NLR were 3.3 (95%CI: 1.9-5.7; I 2: 6.1%) and 0.6 (95%CI: 0.5-0.9; I 2 70.5%), respectively. SDOR was 6.8 (95%CI: 2.6-17.6; I 2: 27.1%). The summary ROC curve showed an area under the curve (AUC) of 0.82 (SE 0.06; Q* 0.76). High risk of bias and applicability concerns were observed in the domains of patient selection for one included study. CONCLUSION: LP on contrast-enhanced MRI is a specific finding to rule out active inflammation in patients with CD. Further studies using a prespecified definition of LP on contrast-enhanced MRI are needed to support our findings.

Multidetector CT in emergency radiology: acute and generalized non-traumatic abdominal pain.

Multidetector CT (MDCT) is an imaging technique that provides otherwise unobtainable information in the diagnostic work-up of patients presenting with acute abdominal pain. A correct working diagnosis depends essentially on understanding the individual patient's clinical data and laboratory findings. In haemodynamically stable patients with acute severe and generalized abdominal pain, MDCT is now the preferred imaging test and gives invaluable diagnostic information, also in unstable patients after stabilization. In this descriptive review, we focus our attention on acute, severe and generalized or undifferentiated non-traumatic abdominal pain. The main differential diagnoses are acute pancreatitis, gastrointestinal perforation, ruptured abdominal aneurysm and acute mesenteric ischaemia. We will provide radiologist readers with a technical guide to optimize MDCT imaging protocols and list the major CT signs essential to reach a correct diagnosis and guide the best treatment.

MRI of hepatic epithelioid hemangioendothelioma (HEH).

PURPOSE: To investigate magnetic resonance imaging (MRI) characteristics of hepatic epithelioid hemangionendothelioma (HEH). MATERIALS AND METHODS: The study was exempted from formal Ethics Committee approval due to its retrospective and noninvasive nature. Eleven patients with histology-proven HEH were collected from six different institutions in a 5-year time period. In all patients a contrast-enhanced MR study was available. Two experienced reviewers in consensus retrospectively noted potential MR findings of HEH. Reviewers separately analyzed morphological findings, tumor signal intensity, HEH contrast enhancement pattern, and tumor appearance on hepatobiliary phase and diffusion-weighted imaging (DWI). The frequency of various findings was calculated. RESULTS: The most frequent presentation was a peripheral distribution of the lesions (72.7%), target appearance on T2-weighted images (63.6%), low signal intensity on T1-weighted images (63.6%), ring or target-like enhancement at dynamic study (63.6%), and coalescence of nodules and capsular retraction (45.4%). Lack of hepatobiliary enhancement (5/8 patients) or "entrapment" hepatobiliary enhancement (3/8 patients) as well as target appearance at DWI (5/6 patients) was also observed in our series. CONCLUSION: Although quite variable imaging appearances were seen, a target appearance on the T2-weighted image, ring or target enhancement at dynamic study, lack of enhancement or "entrapment" at hepatobiliary phase, and target appearance on DWI are frequent findings of HEH.

High concentration (400 mgI/mL) versus low concentration (320 mgI/mL) iodinated contrast media in multi detector computed tomography of the liver: a randomized, single centre, non-inferiority study.

OBJECTIVES: To compare vascular and parenchymal contrast enhancement in multidetector computed tomography of the liver using two contrast media with different iodine concentration (Iodixanol 320 mgI/mL and Iomeprol 400 mgI/mL) and similar viscosity, using fixed total iodine volume (40 gI) and iodine delivery rate (1.6 gI/s). METHODS: 110 patients were prospectively randomized into two groups. Group A received 125 mL of Iodixanol 320 and group B 100 mL of Iomeprol 400. Attenuation values were measured at the level of the aorta, portal vein and liver parenchyma on unenhanced, arterial, portal and equilibrium phases. A non inferiority test was performed on the differences between the two groups. An independent reader evaluated image quality. RESULTS: The equivalence of the two CM was demonstrated in all measurements. Higher, but not statistically significant, attenuation values were obtained with Iomeprol 400 in the aorta during the arterial phase (305.3 HU versus 288.4 HU; P=0.32) and with Iodixanol 320 in the liver parenchyma, during both portal (59.8 HU versus 65.5 HU; P=0.78) and equilibrium (40.4 HU versus 41.8 HU; P=0.55) phases. CONCLUSIONS: Iodixanol 320 and Iomeprol 400 injected at the same iodine delivery rate (1.6 gI/s) and total iodine load (40 gI) did not provide statistically significant differences in liver parenchymal and vascular contrast enhancement.

The optimal contrast media policy in CT of the liver. Part II: Clinical protocols.

The advent of multidetector computed tomography (MDCT) revolutionized abdominal imaging. In particular, the definitive assessment of CT injection protocols, for the evaluation of the liver parenchyma, is still a critical issue for radiologists. Over the last years, this feature encouraged several authors to address their efforts to find the most accurate delay between the contrast medium injection and the effective scan-start, for the identification and characterization of liver lesions. Technological developments of the present century such as number of slices, submillimetric collimation, and the use of multiple dynamic post-contrast phases per single examination, may all contribute to increase the radiation exposure of single patients. The aim of this review is to propose liver imaging protocols, taking into consideration different clinical needs such as patients with chronic liver disease, healthy patients with focal liver lesion, and oncological patients to minimize radiation exposure. Finally, two recent innovations in MDCT which illustrate the potential application of multi-energy computed tomography (MECT) and perfusion computed tomography (CTp) when evaluating liver parenchyma will be discussed in a short closing paragraph.

The optimal contrast media policy in CT of the liver. Part I: Technical notes.

Latest developments of multidetector computed tomography (MDCT), which is today considered a real volumetric technique, have revolutionized abdominal imaging. Technological improvements such as higher spatial resolution, larger volume coverage and higher temporal resolution, have reduced scan times allowing CT studies of the abdomen within a single breath-hold. Furthermore, the increased number of slices, the submillimetric collimation, and the use of multiple dynamic post-contrast phases per single examination, may all contribute to increase the radiation exposure of single patients. The aim of this review is to discuss different parameters affecting contrast media enhancement, as vascular enhancement, parenchymal enhancement and timing, in order to minimize the amount of contrast medium injected and the radiation exposure.

Sixty-four-multidetector-row computed tomography angiography with bolus tracking to time arterial-phase imaging in healthy liver: is there a correlation between quantitative and qualitative scores?

PURPOSE: To determine the optimal 64-multidetector-row computed tomography scan delay from bolus-tracking trigger for the arterial phase and the evaluation of vascularization in healthy liver. MATERIALS AND METHODS: One hundred twenty patients are randomized into 3 groups according to scan delay (5-, 10-, 15-second arterial phase) and underwent CT of the liver. Images were evaluated on the basis of quantitative and qualitative scores. A correlation analysis between them was managed to find the most effective scan delay for best radiologists' diagnostically performances. RESULTS: Scanning too early results in images that are acquired before the vascular peak enhancement while scanning to late results in the increasing of liver parenchyma portal feeding. Good performances were obtained with a scan delay ranging between 10 and 19 seconds from the trigger. CONCLUSIONS: When a 64-multidetector-row computed tomography with a bolus-tracking program is used, only 1 arterial phase should be acquired, setting a scan delay of 10 to 19 seconds.

Dual energy CT (DECT) of the liver: conventional versus virtual unenhanced images.

OBJECTIVE: To compare image quality and noise of conventional unenhanced (CU) and virtual unenhanced (VU) images in patients who underwent hepatic dual energy computed tomography (DECT) and to assess potential radiation dose reduction. MATERIALS AND METHODS: Forty consecutive patients were studied. Mean CU and VU image quality and noise were analyzed by two blinded radiologists using a five-point grade scale. The effective radiation dose of a triple-phase protocol (CU, arterial and DE portal phases) were compared with that of a dual-phase protocol (arterial and DE portal phases). RESULTS: No significant difference in mean image quality was observed between VU (3.92 ± 0.85) and CU images (4.20 ± 0.72). A significant difference in mean image noise was observed between VU and CU (P < 0.01). The dose reduction achieved by omitting the unenhanced acquisition was 30.47 ± 7.07% (P < 0.01). In 6 patients, a complete VU liver image was not obtained. CONCLUSIONS: VU images can be obtained with similar image quality as CU. This approach favors a reduction in patient's radiation exposure. Nevertheless, a complete abdominal DECT is possible only in patients with a low body mass index, due technical limitations of the present DECT systems.

Anatomic variations of the hepatic arteries in 250 patients studied with 64-row CT angiography.

The aim of our study was to determine the frequency of different hepatic arterial variants identified on abdominal CT angiography (CTA) with a 64-row CT system and a high resolution protocol. A total of 250 consecutive abdominal CTAs performed on a 64-row CT system were evaluated. Two radiologists in consensus analyzed arterial phase images; the anatomical findings were grouped according to Michels' classification. An anomalous arterial pattern was observed in 34% of the cases. The most common anomaly was Michels type III (9.2%), followed by types II and V (5.2%), type VI (4.0%), types IV, VII, and IX (2.0%), and type VIII (0.6%). No cases of type X were detected. Unclassified variations were observed in 3.3% of the cases. The new generation of 64-row MDCT allows optimal visualization of splanchnic vascular anomalies with a minimally invasive examination. This visualization is extended to those vessels with a small caliber and slow flow resulting in difficult recognition by classic angiographic studies. The knowledge of anomalous arterial patterns could be very useful in the preoperative planning of surgical and interventional liver procedures.

Current status of MR imaging in the evaluation of IBD in a pediatric population of patients.

Diagnosis and follow-up of inflammatory bowel disease (IBD) in children represent a challenging issue for pediatricians. Nowadays MR studies of the bowel represent a valid diagnostic tool especially in the diagnosis and follow-up of ileal and perianal Crohn's disease in children as well as in adults. The lack of ionizing radiation of MRI enhances the interest of clinicians with respect to CT studies of the bowel in children. Thanks to recent technical development in terms of fast MR images acquisition a reasonable image quality can be easily achieved in scholar-age children. A majority of authors prefer MR-enterography approach in children with respect to the more invasive MR-enteroclysis in the assessment of ileal Crohn's disease. Using rigorous technique of MR-enterography represents a feasible and accurate test in the diagnosis of ileal Crohn's disease. Less experience is collected on MR-colonography in pediatric IBD while MRI of the pelvis represents the most accurate non-invasive diagnostic test in the assessment of perianal Crohn's disease in children as well as in adults.

Not all symptoms disappear after vascular ring division: a pathophysiological interpretation.

Vascular rings are a group of cardiovascular lesions due to faulty embryological development derived from an abnormality of neural crest cells (cephalic neurocristopathy). In addition to peculiar symptoms due to compression on the trachea and/or the esophagus, patients with vascular rings might present further features of neural crest-related defects. We report on a case of a child with complete vascular ring, affected both by compressive symptoms and by autonomic disturbances and minor facial anomalies. The autonomic disturbances are clinical features of maturational dysautonomia and tend to disappear with aging, whereas major compressive symptoms are solved by surgery.

Spectrum of normal findings, anatomic variants and pathology of ileocecal valve: CT colonography appearances and endoscopic correlation.

Knowledge of the potential variants of ileocecal valve, the most frequent pathologic conditions as well as some pitfalls encountered during the analysis of CT Colonography images are thus indispensable for radiologists who perform and interpret such examinations and for general practitioners who are approaching this technique. Awareness of these different diagnostic possibilities is mandatory for radiologists evaluating CT Colonography datasets. Combined analysis of 2D axial and reformatted slices and 3D endoluminal views provides the highest level of diagnostic accuracy. We present the multidetector CT Colonography findings with endoscopic correlation and discuss the possible pathologies and the practical implications.