Matteo Bonatti

Autoimmune Pancreatitis: Pancreatic and Extrapancreatic MR Imaging―MR Cholangiopancreatography Findings at Diagnosis, after Steroid Therapy, and at Recurrence

PURPOSE To determine and describe the magnetic resonance (MR) imaging-MR cholangiopancreatographic pancreatic and extrapancreatic findings of autoimmune pancreatitis (AIP) and the probability, site, and MR features of recurrent AIP after steroid therapy. MATERIALS AND METHODS This retrospective study was approved by the institutional review board, and the requirement for informed patient consent was waived. The data of 27 patients with AIP were included in the study. All patients had undergone MR imaging with MR cholangiopancreatography before and after steroid treatment and during follow-up (median follow-up period, 45 months). Image analysis included assessment of pancreatic parenchyma enlargement, signal intensity on T1- and T2-weighted MR images, contrast enhancement, and presence of bile duct and/or renal involvement. The probability of AIP recurrence was assessed by using Kaplan-Meier curves and the unadjusted Cox model. RESULTS At the time of diagnosis, the AIP-affected pancreatic parenchyma showed diffuse enlargement in 14 (52%) of the 27 patients and segmental enlargement in 13 (48%). The pancreatic parenchyma appeared hypointense on T1-weighted images in all 27 (100%) patients, hyperintense on T2-weighted images in 25 (93%), and isointense in two (7%). During the pancreatic phase of the dynamic contrast material-enhanced study, the affected pancreatic parenchyma appeared hypointense in 25 (93%) patients and isointense in two (7%). During the portal venous and delayed phases, the images of 19 (70%) patients showed delayed enhancement. Bile duct involvement was observed in 10 (37%) patients, and renal involvement was observed in two (7%). After steroid treatment, six (22%) patients had recurrent AIP, with a median disease-free interval of 20.6 months. The sites of recurrence were the pancreas and the kidneys in three of the six patients, solely the pancreas in two patients, and the biliary ducts in one patient. CONCLUSION MR imaging with MR cholangiopancreatography enables the diagnosis of pancreatic and extrapancreatic AIP and the assessment of changes after steroid therapy.

Imaging techniques for the evaluation of cervical cancer.

Improvements in the treatment of cervical carcinoma have made it possible to offer optimal and personalised treatment. Cervical cancer staging is based on clinical examination and histological findings. Many diagnostic methods are used in clinical practice. Magnetic resonance imaging is considered the optimal method for staging cervical carcinoma because of its high accuracy in assessing local extension of disease and distant metastases. Ultrasound has gained increased attention in recent years; it is faster, cheaper, and more widely available than other imaging techniques, and is highly accurate in detecting tumour presence and evaluating local extension of disease. Magnetic resonance imaging and ultrasound are often used together with computed tomography or positron emission tomography combined with computed tomography to assess the whole body, a more accurate detection of pathological lymph nodes and metabolic information of the disease.

Which imaging technique should we use in the follow up of gynaecological cancer

Follow-up routines after gynaecological cancer vary. The optimal approach is unknown, and no randomised-controlled trials comparing surveillance protocols have been published. In this chapter, we summarise the diagnostic performance of ultrasound, computed tomography, and magnetic resonance imaging in the follow up of women treated for ovarian or uterine cancers. Computed tomography is today the standard imaging method for the follow up of women treated for endometrial, cervical, or ovarian cancer. Six-monthly or annual follow-up examinations have not been shown to positively affect survival. Instead, a combination of transvaginal and transabdominal ultrasound examination with clinical examination might be a more cost-effective strategy for early detection of recurrence. Positron-emission tomography might play a role in women with clinical or serological suspicion of recurrence but without evidence of disease at conventional diagnostic imaging. To create guidelines, more studies, preferably randomised-controlled trials, on follow-up strategies are needed.

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

PurposeThe 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 methodsThis 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.ResultsA 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.ConclusionsMixed 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).RiassuntoObiettiviScopo del presente lavoro è stato determinare gli aspetti in risonanza magnetica (RM)/colangiopancreatografia (CP)RM delle neoplasie cistiche pancreatiche benigne non comunicanti con il sistema duttale (BNCNs) scoperte incidentalmente, valutare la loro evoluzione nel tempo e ricercare aspetti RM/CPRM predittivi di crescita.Materiali e metodiAbbiamo svolto uno studio retrospettivo; non è stato necessario l’ottenimento di un consenso informato. Sono stati inclusi nello studio 62 pazienti affetti da BNCN. Criteri di inclusione sono stati neoplasia cistica pancreatica scoperta incidentalmente con setti sottili, priva di nodulazioni parietali, non comunicante con il sistema duttale pancreatico, sottoposta ad ≥1 esame di RM/CPRM. L’analisi delle immagini, alla diagnosi e durante il follow-up, ha incluso: aspetto macroscopico (micro-, macro-cistico, misto), numero di cisti (uni-, oligo-, multi-cistico), diametro massimo della neoplasia. Sono stati calcolati i tassi di crescita.RisultatiSono state identificate 64 BNCNs in 62 pazienti. Trentuno/64 (48%) presentavano aspetto misto, 28/64 (44%) microcistico e 5/64 (8%) macrocistico. Trentotto/64 (59%) BNCNs erano multicistiche, 22/64 (34%) oligocistiche e 4/64 (6%) unicistiche. I parametri qualitativi sono rimasti invariati durante il follow-up. Alla diagnosi il diametro massimo mediano delle BNCNs era 35,0 mm; all’ultimo esame 38,0 mm (p<0,001). Il tasso di crescita è risultato di 2 mm/anno.ConclusioniI pattern misto e microcistico sono i più comuni, 48% e 44% rispettivamente, e non variano nel tempo. Aspetti RM/CPRM predittivi di crescita sono l’aspetto misto o macrocistico e le dimensioni >3 cm (entrambi p<0,001).

MDCT of blunt renal trauma: imaging findings and therapeutic implications

ObjectivesTo show the wide spectrum of computed tomography (CT) findings in blunt renal trauma and to correlate them with consequent therapeutic implications.MethodsThis 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.ResultsCT 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.ConclusionsThe 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.

Gallbladder adenomyomatosis: imaging findings, tricks and pitfalls

Gallbladder adenomyomatosis (GA) is a benign alteration of the gallbladder wall that can be found in up to 9% of patients. GA is characterized by a gallbladder wall thickening containing small bile-filled cystic spaces (i.e., the Rokitansky–Aschoff sinuses, RAS). The bile contained in RAS may undergo a progressive concentration process leading to crystal precipitation and calcification development. A correct characterization of GA is fundamental in order to avoid unnecessary cholecystectomies. Ultrasound (US) is the imaging modality of choice for diagnosing GA; the use of high-frequency probes and a precise focal depth adjustment enable correct identification and characterization of GA in the majority of cases. Contrast-enhanced ultrasound (CEUS) can be performed if RAS cannot be clearly identified at baseline US: RAS appear avascular at CEUS, independently from their content. Magnetic resonance imaging (MRI) should be reserved for cases that are unclear on US and CEUS. At MRI, RAS can be identified with extremely high sensitivity, but their signal intensity varies widely according to their content. Positron emission tomography (PET) may be helpful for excluding malignancy in selected cases. Computed tomography (CT) and cholangiography are not routinely indicated in the suspicion of GA.Teaching points1. Gallbladder adenomyomatosis is a common benign lesion (1–9% of the patients).2. Identification of Rokitansky–Aschoff sinuses is crucial for diagnosing gallbladder adenomyomatosis.3. Sonography is the imaging modality of choice for diagnosing gallbladder adenomyomatosis.4. Intravenous contrast material administration increases ultrasound accuracy in diagnosing gallbladder adenomyomatosis.5. Magnetic resonance is a problem-solving technique for unclear cases.

Dual-energy CT of the brain: Comparison between DECT angiography-derived virtual unenhanced images and true unenhanced images in the detection of intracranial haemorrhage.

ObjectiveTo evaluate the diagnostic performance of virtual non-contrast (VNC) images in detecting intracranial haemorrhages (ICHs).MethodsSixty-seven consecutive patients with and 67 without ICH who underwent unenhanced brain CT and DECT angiography were included. Two radiologists independently evaluated VNC and true non-contrast (TNC) images for ICH presence and type. Inter-observer agreement for VNC and TNC image evaluation was calculated. Sensitivity and specificity of VNC images for ICH detection were calculated using Fisher’s exact test. VNC and TNC images were compared for ICH extent (qualitatively and quantitatively) and conspicuity assessment.ResultsOn TNC images 116 different haemorrhages were detected in 67 patients. Inter-observer agreement ranged from 0.98–1.00 for TNC images and from 0.86–1.00 for VNC images. VNC sensitivity ranged from 0.90–1, according to the different ICH types, and specificity from 0.97–1. Qualitatively, ICH extent was underestimated on VNC images in 11.9% of cases. Haemorrhage volume did not show statistically significant differences between VNC and TNC images. Mean haemorrhage conspicuity was significantly lower on VNC images than on TNC images for both readers (p < 0.001).ConclusionVNC images are accurate for ICH detection. Haemorrhages are less conspicuous on VNC images and their extent may be underestimated.Key points• VNC images represent a reproducible tool for detecting ICH.• ICH can be identified on VNC images with high sensitivity and specificity.• Intracranial haemorrhages are less conspicuous on VNC images than on TNC images.• Intracranial haemorrhages extent may be underestimated on VNC images.

Imaging techniques for evaluation of uterine myomas

Due to their high prevalence and related morbidity, uterine myomas constitute a group of gynecological pathologies largely studied in all clinical, diagnostic, and therapeutic aspects. They have been widely evaluated with a large series of imaging techniques. In fact, ultrasound (also saline infusion sonohysterography) and magnetic resonance imaging (MRI) are considered the optimal methods to assess uterine fibroids in terms of number, volume, echostructure, location, relation with endometrial cavity and uterine layers, vascularization, and differential diagnosis with other benign (adenomyosis) and malignant myometrial pathologies. Nevertheless, further studies are required to fill some gaps such as the absence of a common and sharable sonographic terminology and methodology to scan the myometrium, as well as imaging parameters for differentiation of typical myomas from smooth tumors of unknown malignant potential (STUMP) and leiomyosarcomas.

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

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. Thirteen of 85 patients 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. 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. The authors conclude that the presence of parenchymal hyperdensity with a maximum iodine concentration of greater than 1.35 mg/mL may identify patients developing intracerebral hemorrhage with 100% sensitivity and 67.6% specificity. 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.

Blunt diaphragmatic lesions: Imaging findings and pitfalls

Blunt diaphragmatic lesions (BDL) are uncommon in trauma patients, but they should be promptly recognized as a delayed diagnosis increases morbidity and mortality. It is well known that BDL are often overlooked at initial imaging, mainly because of distracting injuries to other organs. Sonography may directly depict BDL only in a minor number of cases. Chest X-ray has low sensitivity in detecting BDL and lesions can be reliably suspected only in case of intra-thoracic herniation of abdominal viscera. Thanks to its wide availability, time-effectiveness and spatial resolution, multi-detector computed tomography (CT) is the imaging modality of choice for diagnosing BDL; several direct and indirect CT signs are associated with BDL. Given its high tissue contrast resolution, magnetic resonance imaging can accurately depict BDL, but its use in an emergency setting is limited because of longer acquisition times and need for patient’s collaboration.