Sara Mehrabi

MR imaging and MR cholangiopancreatography of multifocal intraductal papillary mucinous neoplasms of the side branches: MR pattern and its evolution

Purpose . This paper describes the magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) pattern of multifocal intraductal papillary mucinous tumours (IPMT) of the pancreatic side branches and its evolution during followupMaterials and methods . Twenty-six patients with multifocal IPMT of the side branches were included in this retrospective study. Inclusion criteria were ≥2 ectasic side branches, presence of communication with the main pancreatic duct, and ≥2 MRI/MRCP examinations after ≥6-12 months. Exclusion criteria were IPMT involving both the main pancreatic duct and its branch ducts, previous surgery and lack of follow-up MRI examinations. Median follow-up was 27 (range 6–59) months. Images were assessed qualitatively and quantitatively. Qualitative assessment considered: the number of cystic lesions of the branch ducts, morphology of the communication between the cystic lesion and the main duct (direct or neck), presence of intraluminal filling defects within the cystic lesions, presence of mural nodules and mural enhancement of the cystic lesion. Quantitative assessment considered mean maximal diameter of the cystic lesions and mean length of the communication neckResults . At diagnosis, the mean number of cystic lesions of the side branches was 7.5. A communication neck was detected in 16/26 patients (60%). Intraluminal filling defects in the side branches were present in 6/26 patients (23%). Mural nodules were seen in 1/26 patients (4%). The mean diameter of the cystic lesions was 18.8 mm. The mean length of the communication neck was 6.9 mm. At follow-up, the mean number of cystic lesions of the side branches was 8.4. A communication neck was detected in 20/26 patients (77%). Intraluminal filling defects in the side branches were detected in 7/26 patients (27%); mural nodules were seen in 2/26 patients (8%). Mural enhancement of the branch duct was detected in 2/26 patients (8%). The mean diameter of the cystic lesions increased to 22.3 mm ( p < 0.05), and the mean length of the communication neck was 8.6 mmConclusions . Multifocal IPMT of the side branches shows a constant but very slow progression over time. In our series, only 2/26 patients showed mural nodulesRiassuntoObiettivo . Descrivere le caratteristiche RM/CPRM dei tumori intraduttali papillari mucino-secernenti (TIPM), multifocali dei dotti pancreatici secondari (dotti II) e loro evoluzioneMateriali e metodi . Ventisei pazienti (Pz) con TIPM multifocali dei dotti II sono stati inclusi in questo studio retrospettivo. Criteri di inclusione: ≥2 dotti II ectasici, presenza di comunicazione con il dotto pancreatico principale (DPP), ≥2 RM/CPRM a distanza ≥6-12 mesi. Criteri di esclusione: TIPM coinvolgenti sia il DPP che i dotti II, pregressa chirurgia, assenza di controllo RM. Mediana del monitoraggio: 27 mesi (range 6–59 mesi). Analisi qualitativa: numero delle dilatazioni cistiche dei dotti II, morfologia della comunicazione tra ectasie dei dotti II e DPP (diretta/colletto), presenza di difetti di riempimento endoluminali delle dilatazioni dei dotti II, presenza di noduli parietali, impregnazione di contrasto parietale delle dilatazioni cistiche dei dotti II. Analisi quantitativa: diametro medio delle dilatazioni cistiche dotti II; lunghezza media del colletto di comunicazione tra dotti II e DPPRisultati . Diagnosi. Numero medio ectasie dei dotti II: 7,5. Un colletto di comunicazione era presente in 16/26 Pz (60%). Difetti endoluminali erano presenti in 6/26 Pz (23%). Noduli parietali erano presenti in 1/26 Pz (4%). Il diametro medio delle dilatazioni cistiche dei dotti II era di 18,8 mm. La lunghezza media dei colletti di comunicazione era 6,9 mm. Controllo. Numero medio ectasie dei dotti II: 8,4. Il colletto di comunicazione era presente in 20/26 Pz (77%). Difetti endoluminali erano presenti in 7/26 Pz (27%); noduli parietali in 2/26 Pz (8%); ed in 2/26 (8%) era presente impregnazione di contrasto parietale. Diametro medio delle ectasie dei dotti II: 22,3 mm (p<0,05). La lunghezza media dei colletti rilevati era 8,6 mmConclusioni . I TIPM multifocali dei dotti II presentano un’evoluzione molto lenta. Solo 2/26 Pz (8%) hanno dimostrato noduli parietali

Detection and localization of deep endometriosis by means of MRI and correlation with the ENZIAN score

PURPOSE To determine the accuracy of ENZIAN score, as detected on MR imaging, compared to surgical-pathologic findings. MATERIALS AND METHODS This retrospective study was approved by the investigational review board and the requirement for informed patient consent was waived. 115 patients were included according to following criteria: tubo-ovarian and/or deep endometriosis suspected at physical examination and transvaginal ultrasound; availability of MR examination; histopathological results from laparoscopic or surgical treatment. EXCLUSION CRITERIA lack of available MR examination, and/or (b) lack of a definitive histopathological results. Histopathological findings from bioptic specimens obtained during laparoscopic or laparotomic treatment were considered as reference standard. For all detected lesions a score according to ENZIAN score (revised 2010) was assigned both for MRI and histopathological findings. By comparing MRI-ENZIAN score and histopathological-ENZIAN score the overall sensitivity, specificity, accuracy, positive and negative predictive values in relation to presence/absence of deep endometriosis in each patient were calculated. k-Cohen to evaluate the degree of concordance between MRI-ENZIAN score and histopathological-ENZIAN score was also measured. Moreover the sensitivity, specificity, accuracy, positive and negative predictive values for each specific localization provided by ENZIAN score were also calculated. RESULTS At histopathology, the diagnosis of deep endometriosis was confirmed in 82/115 (71.3%) patients. The sensitivity, specificity, accuracy, PPV and NPV of MRI were 94%, 97%, 95%, 99%, 86%, respectively. The highest accuracy was for adenomyosis (100%) and endometriosis of utero-sacral ligaments (USLs) (98%), slightly lower for vagina-rectovaginal septum an colo-rectal walls (96%), and the lowest for bladder endometriosis (92%). The concordance between histopathological and MRI ENZIAN score was excellent (k=0.824); in particular it was 0.812 for lesions in vagina-rectovaginal space, 0.890 for lesions in USL, 0.822 for lesions in rectum-sigmoid colon, 1.000 for uterine adenomyosis, and 0.367 for lesions located in the bladder wall. CONCLUSION MRI correlates with the ENZIAN score and has an accuracy of 95% in the detection and localization of deep endometriosis, allowing to minimize false negative results (4%) in patients with deep endometriosis and to obtain a correct preoperative staging.

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).

Pancreatic duct stenosis: Differential diagnosis between malignant and benign conditions at secretin-enhanced MRCP

PURPOSE To define imaging criteria of benign and malignant nature in patients with main pancreatic duct (MPD) stenosis. MATERIALS-METHODS S-MRCPs of 35 patients with pancreatitis and 14 with adenocarcinoma were evaluated. RESULTS Adenocarcinoma caused higher prevalence of complete stenosis (14/14-100% vs 17/35-49%), dilated side-branches (14/14-100% vs 18/35-51%) and lower prevalence of duct-penetrating sign (0/14-0% vs 31/35-89%). The number of stenoses was higher in benign conditions (mean 1.4 Vs 1). Upstream MPD diameter was higher in cancer-induced stenoses (4.5 vs 2.9mm). CONCLUSIONS Single complete stenosis with dilated side branches, increased MPD caliber and absent duct-penetrating sign are suggestive of malignancy.

Pancreatic mucinous cystoadenomas and cystoadenocarcinomas: differential diagnosis by means of MRI

OBJECTIVE To determine the accuracy of MRI in differentiating mucinous cystoadenomas (MCAs) from mucinous cystoadenocarcinomas (MCACs) of the pancreas, with histopathological analysis as the reference standard, for better surgical planning. METHODS A total of 65 patients with histopathologically proven mucinous cystic neoplasms (MCNs) underwent MRI and surgery. Quantitative image analysis included size, septa and wall thickness and number of loculations. Qualitative image analysis included nodules; hyperintensity of the cystic content on T1 weighted images; compression and/or infiltration of adjacent vessels or organs; and metastases. A comparison between MCAs and MCACs was performed with Students t-test for quantitative variables and with Fisher test for qualitative variables. Receiver operating characteristic analysis was performed to determine the accuracy in the differential diagnosis between MCAs and MCACs on the basis of a score system obtained by giving 1 point for each quantitative and qualitative variable observed in each patient. RESULTS At histopathology, 43 lesions were MCAs and 22 lesions were MCACs. A statistically significant difference was observed for size >7cm (<0.001), septa and wall thickness >3 mm (<0.0001), number of loculations >4 (<0.0001), nodules (<0.0001), hyperintensity of the cystic content on T1 weighted images (<0.0001), compression (<0.01) and/or infiltration (<0.01) of adjacent vessels or organs and metastases (<0.05). The best cut-off value to discriminate MCAs from MCACs was the presence of three features (p < 0.001), with an accuracy of 91%. CONCLUSION MRI has an accuracy of 91% in the differential diagnosis between MCA and MCAC, helping in identifying forms that could undergo parenchyma-sparing surgery (MCAs), reducing post-surgical morbidity and mortality. ADVANCES IN KNOWLEDGE In this study, the differentiation between MCAs and MCACs of the pancreas by means of MRI is addressed. The differential diagnosis allows selecting benign forms, susceptible of parenchyma-sparing surgery, with the advantage of reducing post-surgical morbidity and stratifying prognosis of MCNs.

MR in Cystic Tumors of the Pancreas

Cystic neoplasms of the pancreas are rare pancreatic tumors; nowadays they are diagnosed more frequently due to the spread of accurate imaging techniques.

Evolution of ventriculomegaly: comparison between foetal MR imaging and postnatal diagnostic imaging.

PurposeWe evaluated the evolution of ventriculomegaly (VM) by comparing foetal magnetic resonance imaging (MRI) with postnatal transcranial ultrasonography (US) and/or encephalic MRI.Materials and methodsBetween January 2006 and April 2011, 70 foetuses with a mean gestational age of 28 weeks and 4 days (range, 18–36) weeks with VM on foetal MRI were assessed in this prospective study. Half-Fourier rapid acquisition with relaxation enhancement (RARE) T2-weighted, T1-weighted and diffusion-weighted (DWI) images along the three orthogonal planes according to the longitudinal axis of the mother, and subsequently of the foetal brain, were acquired. Quantitative image analysis included the transverse diameter of lateral ventricles in axial and coronal planes. Qualitative image analysis included searching for associated structural anomalies.ResultsThirty-four of 70 patients with a diagnosis of VM on foetal MRI underwent postnatal imaging. Twenty-five of those 34 (73%) had mild, four (12%) had moderate and five (15%) had severe VM on MRI. Normalisation of the diameter of lateral ventricles was observed in 16 of the 34 (47%) newborns. Among these 16, 13 (81%) had mild and three (19%) had moderate VM (two isolated and one associated VM). VM stabilisation was observed in 16 of the 34 (47%) babies. Among them, 11 (69%) had mild (eight isolated and three associated), one (6%) had moderate associated and four (25%) had severe associated VM. Progression from mild to severe (associated) VM was observed in two of the 34 (6%) babies.ConclusionsThe absence of associated anomalies and a mild VM are favourable prognostic factors in the evolution of VM.RiassuntoObiettivoScopo del presente lavoro è stato valutare l’evoluzione della ventricolomegalia (VM), confrontando la risonanza magnetica (RM) fetale con le indagini diagnostiche post-natali ottenute mediante ecografia transfontanellare e/o RM encefalo.Materiali e metodiTra gennaio 2006 e aprile 2011, 70 feti di età gestazionale media di 28 settimane e 4 giorni (range 18-36 settimane) con VM alla RM fetale sono stati inclusi in questo studio prospettico. Sono state eseguite immagini T2-dipendenti Half Fourier RARE lungo i tre piani ortogonali all’asse longitudinale materno e all’encefalo fetale, immagini T1-dipendenti e sequenze in diffusione. L’analisi quantitativa ha compreso la misura del diametro trasversale dei ventricoli laterali sui piani assiale e coronale. L’analisi qualitativa ha compreso la ricerca di eventuali anomalie strutturali associate.RisultatiTrentaquattro pazienti su settanta presentavano diagnosi di VM alla RM fetale e avevano effettuato un controllo post-natale. Alla RM fetale 25/34 (73%) neonati presentavano VM lieve, 4/34 (12%) VM moderata, 5/34 (15%) VM severa. In 16/34 (47%) neonati c’è stata una normalizzazione dei ventricoli laterali. In 13/16 (81%) neonati la RM fetale aveva mostrato la presenza di VM lieve. Tre su sedici (19%) neonati presentavano VM moderata alla RM fetale (2/3 isolata, 1/3 associata). In 16/34 (47%) neonati è stata riscontrata una stabilità della VM. In 11/16 (69%) neonati la RM fetale aveva mostrato VM lieve (8/11 isolata, 3/11 associata), 1/16 (6%) neonato VM moderata associata, 4/16 (25%) neonati VM severa associata. In 2/34 (6%) neonati c’è stata una progressione della dilatazione dei ventricoli laterali da lieve a severa (associata).ConclusioniL’assenza di anomalie associate alla VM e la presenza di una VM di basso grado sono fattori prognostici favorevoli per l’evoluzione della VM.

Preoperative Noninvasive Imaging

The liver is divided into the left and right lobes, and each lobe is divided into segments on the basis of its vascular anatomy and biliary drainage. The in trahepatic bile ducts generally follow the internal hepatic segmental anatomy (Figs. 6.1, 6.2). In the left lobe, a left medial segment duct and a left lateral segment duct normally join to form the main left hepatic duct. The right hepatic duct branches near its origin at the common hepatic duct. Frequently, the right hepatic duct has a dorso-caudal branch, draining the posterior segment of the right lobe, and a ventro-cranial branch, draining the anterior segment of the right lobe (Fig. 6.1). Ductal drainage of the caudate lobe is variable and may be related to the left or right ductal system. The left and right hepatic ducts unite just outside the liver to form the common hepatic duct, which is usually 3–4 cm in length (Figs. 6.3, 6.4).