Autoimmune pancreatitis: multidetector-row computed tomography (MDCT) and magnetic resonance (MR) findings in the Italian experience

CT, MRI and PET/CT features of abdominal manifestations of cutaneous melanoma: a review of current concepts in the era of tumor-specific therapies

Abdominal manifestations in patients with cutaneous melanoma include involvement due to metastatic spread and immune checkpoint inhibitor induced adverse events. The purpose of this review is to provide a critical overview of abdominal manifestations in patients with cutaneous melanoma and highlight the current imaging challenges in the era of tumor-specific therapies. Immune checkpoint inhibitors represent a treatment with demonstrated efficacy in the treatment of advanced cutaneous melanoma but are associated with several abdominal adverse events that must be recognized. CT has a role in the identification of colitis, enteritis and pancreatitis, whereas MRI has an important role in the diagnosis of autoimmune pancreatitis. Current evidence demonstrates that MRI should be the preferred imaging technique for the detection and characterization of hepatic and splenic metastases from cutaneous melanoma. The role of ¹⁸F-FDG-PET/CT should be further evaluated but current literature suggests an efficacy in the detection of pancreatic metastases not seen on CT and MRI.

Atypical enhanced computed tomography signs of pancreatic cancer and its differential diagnosis from autoimmune pancreatitis

Background

To analyze the atypical enhanced computed tomography (CT) signs of pancreatic cancer (PC) and compare them with those of autoimmune pancreatitis (AIP) to explore the differential diagnosis value of CT.

Methods

The clinical data of 36 AIP (AIP group) and 38 PC patients (PC group), who were admitted to our hospital from January 2013 to June 2020 and confirmed by surgical biopsy or hormone therapy, were retrospectively analyzed. Participants in both groups were examined by CT, the imaging signs of the 2 groups were analyzed, and the results of CT examination were compared.

Results

In the PC group, the density of the lesions on the CT scan was mostly reduced, the pancreas was not swollen, and the kidneys were not involved. The bile duct wall was thickened with a sausage-like appearance, enveloped edges were rare, blood vessels were invaded, lymph nodes were enlarged, and the pancreatic duct was truncated. The findings of the AIP group were the opposite. The difference in the proportion of participants with the above-mentioned CT features between the 2 groups was statistically significant (P<0.05). The shape of the lesions in the AIP group was mainly elongated, of uneven density, and the density of enhanced scanning was medium to high. The predominant shape of the lesions in PC participants was spherical, and the density was uniform. The enhanced scan was mainly low-density. The difference in shape and density between the 2 groups was also statistically significant (P<0.05). The CT values of the plain scan, intravenous phase, and delayed phase in the AIP group were significantly higher than those in the PC group (P<0.05).

Conclusions

The imaging signs of AIP and PC overlap. Examination with CT is of great value in the differential diagnosis between AIP and PC. Familiarity with and mastery of the CT signs of AIP and PC can help to improve the accuracy of clinical diagnosis and provide a reliable basis for patients' follow-up treatment.

Differential diagnosis of solid pancreatic masses

Solid pancreatic lesions include mainly adenocarcinoma, neuroendocrine tumors pancreatic cystic neoplasms with solid component, solid pseudopapillary tumor, pancreatoblastoma, pancreatic lymphoma, and pancreatic metastasis. The most frequent pancreatic lesion is the adenocarcinoma, representing between 70% and 95% of all solid pancreatic neoplasm. The diagnosis of these lesions can be a challenge and currently, there are different imaging techniques such as CT scan, EUS and MRI with high sensitivity and specificity. The most widely used technique for the initial evaluation is the CT scan with a sensitivity between 76% and 92% for the diagnosis of pancreatic cancer. The EUS has a sensitivity for the detection of pancreatic lesions of around 98% and is accepted to be the most sensitive technique for the detection of small pancreatic tumors (<2 cm). The MRI, with a very high soft-tissue contrast resolution, provides an accuracy in the detection and staging of adenocarcinoma of 90-100%. A multimodality approach is usually necessary in patients with clinical suspicion of pancreatic lesion. The EUS is required for the local evaluation of the relation of the lesion with vessels and for tissue acquisition and the CT scan and/or MRI is usually required for the local and distance staging in case of pancreatic cancer. The purpose of this review is to provide an overview of solid pancreatic lesions and the role of the different imaging techniques in their evaluation.

[Hepatopancreaticobiliary diseases in IgG4-associated autoimmune diseases]

BACKGROUND

IgG4-related diseases are rare systemic multiorgan diseases and can thus affect any organ system. The incidence of diagnosis has significantly increased due to increasing awareness.

OBJECTIVE

In the abdomen the hepatopancreaticobiliary system provides an essential organ system for the expression of IgG4-associated autoimmune diseases. The focus here is autoimmune pancreatitis type 1 but IgG4-associated sclerosing cholangitis and IgG4-associated hepatopathy, which can also occur in combination are less well-known.

METHODS

Various mostly Asiatic, histologically-based diagnostic systems, such as HISORt or international consensus diagnostic criteria (ICDC) are available for the diagnostics of hepatopancreaticobiliary IgG4-related autoimmune diseases, in which imaging techniques playing an increasingly important role.

RESULTS

In addition to generalized organ swelling further morphological and also functional imaging criteria have become increasingly well-known for autoimmune pancreatitis, such as late enhancement or the imaging response to steroid therapy. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERP) can provide valuable information for the diagnostics of IgG4-related diseases in the hepatopancreaticobiliary system.

CONCLUSION

IgG4-related autoimmune diseases of the hepatopancreaticobiliary system are a rare group of diseases in which increasing knowledge of the radiological appearance also leads to an increasingly frequency of diagnosis. IgG4-related diseases must be distinguished from non-necrotizing pancreatitis and pancreatic cancer, which is often difficult but has significant therapeutic consequences for the patients.

Uncommon neoplasms of the biliary tract: radiological findings

OBJECTIVE

To report our cancer centre experience in the biliary tumours incidence other than cholangiocellular-carcinoma, emphasizing the radiological features.

METHODS

197 patients with biliary disease undergoing Gd-EOB-DTPA-enhanced MRI were reviewed. Four radiologists evaluated retrospectively size, structure, anatomical site and signal intensity of lesions on MRI. Enhancement-pattern during the arterial-, portal- and late-phase on ultrasound, CT and MR study was assessed as well as the enhancement pattern during the hepatobiliary-phase on MRI.

RESULTS

23 patients were selected. The lesion was intraductal in 5 cases, periductal in 14 and intrahepatic in 4. 16 lesions were solid, 5 uniloculated cystic and 2 complex cystic. In five patients the lesion was simple cyst, with a signal intensity in T₁ weighted (T1W) and T₂ weighted (T2W) similar to the gallbladder. In two patients with complex cystic lesion, the solid component was heterogeneously hypointense in T₁ W, hyperintense in T₂ W with a restricted diffusion. The solid component showed heterogeneous contrast-enhancement on CT, MR and ultrasound. The tumour was intrahepatic in two patients, with signal hypointense in T₁ W and hyperintense in T₂ W. Diffusion was restricted. The lesions showed heterogeneous contrast-enhancement. The periductal lesions were hypointense in T₁ W, hyperintense in T₂ W with restricted diffusion. The lesion showed progressive contrast-enhancement. Peribiliary melanoma was hyperintense in T₁ W, hyperintense in T₂ W with restricted diffusion and progressively contrast-enhanced.

CONCLUSION

Biliary tumours can have a wide spectrum of radiologic appearances and consequently represent a diagnostic challenge for the radiologist. Advances in knowledge: MRI is the technique of choice in diagnosing biliary tumours, including rare (non-CCC) tumours.

Differentiating Mass-Forming Autoimmune Pancreatitis From Pancreatic Ductal Adenocarcinoma on the Basis of Contrast-Enhanced MRI and DWI Findings

OBJECTIVE

The purpose of this study was to assess value of contrast-enhanced MRI, MRCP, and DWI for differentiating mass-forming autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

This study included 15 patients with mass-forming AIP and 79 with PDAC who underwent gadoxetic acid-enhanced MRI with DWI and MRCP. Two radiologists evaluated the MRI findings in consensus. Statistically significant imaging findings were identified through univariate and multivariate analyses, and their diagnostic performance for predicting mass-forming AIP was analyzed.

RESULTS

In the univariate analysis, multiplicity, similar or high signal intensity on portal phase and 3- and 20-minute delayed phase images, homogeneous enhancement, no peripancreatic fat infiltration, no internal cystic or necrotic portion, capsulelike rim, no upstream pancreatitis, no vascular invasion, and duct penetrating sign were more frequently observed (p < 0.05) in mass-forming AIP. The apparent diffusion coefficient (ADC) value was also significantly lower for mass-forming AIP than for PDAC (0.96 ± 0.14 versus 1.13 ± 0.23 × 10(-3) mm(2)/s; p < 0.001). The optimal cutoff value of ADC for differentiating mass-forming AIP from PDAC was 0.9407 × 10(-3) mm(2)/s. In multivariate analysis, homogeneous enhancement (p = 0.001), duct penetrating sign (p < 0.001), and ADC value less than 0.9407 × 10(-3) mm(2)/s (p < 0.001) were significant for differentiating mass-forming AIP from PDAC. When two of these three criteria were combined, 80% (12/15) of mass-forming AIPs were identified with specificity of 98.7%. When all three criteria were satisfied, specificity was 100%.

CONCLUSION

Contrast-enhanced MRI with MRCP and DWI may be helpful for differentiating mass-forming AIP from PDAC.

Recent developments in steroid-responsive pancreatitides (autoimmune pancreatitis)

PURPOSE OF REVIEW

There are two distinct steroid responsive chronic fibro-inflammatory diseases of the pancreas, called type 1 and type 2 autoimmune pancreatitis (AIP). We review recent progress in this field.

RECENT FINDINGS

It has recently been suggested that the term AIP be used to describe type 1 AIP and the term idiopathic duct-centric chronic pancreatitis (IDCP) be used for type 2 AIP. Clinical features and long-term outcomes of AIP and IDCP are well characterized and prognosis of both diseases is excellent. Diagnostic strategies tailored to regional practice patterns have emerged with the application of International Consensus Diagnostic Criteria for AIP. Although corticosteroids remain the mainstay of treatment, management of relapses and strategies for preventing multiple relapses are better understood, including the role of maintenance therapy and B-cell depletion therapy with rituximab. Association studies with malignancies have yielded conflicting results regarding risk of cancer in AIP.

SUMMARY

The treatment, follow-up guidelines and associations continue to evolve with our increasing experience with both AIP and IDCP. In AIP, rituximab can be used for both induction and maintenance of remission. IDCP responds to steroids without need for maintenance therapy. Both AIP and IDCP have excellent prognosis.

Value of multi-slice CT perfusion imaging in patients with acute pancreatitis

AIM: To explore the value of multi-slice computed tomograohy (CT) perfusion imaging in patients with acute pancreatitis (AP).

METHODS: Thirty patients with severe AP (SAP), 30 patients with mild AP (MAP), and 30 healthy volunteers were included in this study. All subjects underwent multi-slice CT perfusion imaging. The blood flow (BF), blood volume (BV), time to peak (TTP), permeability surface (PS), time to abdominal pain relief, and hospital stay were compared for different groups.

RESULTS: The levels of BF and BV for the MAP group and SAP group were significantly lower than those for the control group [123.79 mL/(100 mg•min) ± 55.35 mL/(100 mg•min), 63.55 mL/(100 mg•min) ± 36.76 mL/(100 mg•min) vs 214.55 mL/(100 mg•min) ± 98.41 mL/(100 mg•min); 11.35 mL/100 mg ± 5.45 mL/100 mg, 7.43 mL/100 mg ± 2.45 mL/100 mg vs 18.13 mL/100 mg ± 14.56 mL/100 mg, P < 0.05]. The levels of PS for the MAP group and SAP group were also significantly lower than that for the control group [26.84 mL/(100 mg•min) ± 10.33 mL/(100 mg•min), 35.66 mL/(100 mg•min) ± 12.45 mL/(100 mg•min) vs 16.48 mL/(100 mg•min) ± 8.67 mL/(100 mg•min), P < 0.05]. The levels of BF and BV for the SAP group were significantly lower than those for the MAP group [63.55 mL/(100 mg•min) ± 36.76 mL/(100 mg•min) vs 123.79 mL/(100 mg•min) ± 55.35 mL/(100 mg•min), 7.43 mL/100 mg ± 2.45 mL/100 mg vs 11.35 mL/100 mg ± 5.45 mL/100 mg, P < 0.05]. The level of PS for the SAP group was significantly lower than that for the MAP group [35.66 mL/(100 mg•min) ± 12.45 mL/(100 mg•min) vs 26.84 mL/(100 mg•min) ± 10.33 mL/(100 mg•min), P < 0.05]. There was no significant difference in the level of TTP between the three groups (140.44/0.1 s ± 23.44/0.1 s vs 142.41/0.1 s ± 13.95/0.1 s vs 146.58/0.1 s ± 29.46/0.1 s, P > 0.05), although the time to abdominal pain relief and the hospital stay for the SAP group were longer than those for the MAP group (64.55 h ± 21.35 h vs 11.55 h ± 8.76 h, 78.35 d ± 46.45 d vs 20.43 d ± 8.45 d, P < 0.05).

CONCLUSION: Patients with AP have lower pancreatic perfusion, and the disease severity has relation with the levels of BF, BV, and PS. CT perfusion imaging has important clinical value in patients with AP.