M Motton

Main pancreatic duct intraductal papillary mucinous neoplasms: accuracy of MR imaging in differentiation between benign and malignant tumors compared with histopathologic analysis.

PURPOSE To retrospectively determine the accuracy of magnetic resonance (MR) imaging combined with MR cholangiopancreatography (CP) in differentiating benign from malignant intraductal papillary mucinous neoplasms (IPMNs) involving the main pancreatic duct (MPD), with histopathologic analysis as the reference standard. MATERIALS AND METHODS The informed consent requirement was waived for this institutional review board-approved study. A total of 51 patients with histopathologically proved IPMNs (MPD IPMN, n = 29; mixed type IPMN, n = 22), underwent MR imaging, MR CP, and surgery, with a mean interval of 2.6 months between MR examination and surgery. Qualitative image analysis included assessment of the site of MPD dilatation (head of the pancreas, body and/or tail of the pancreas, or diffuse), presence or absence of duct wall nodules, and contrast enhancement of the MPD walls. Quantitative image analysis included measurement of the maximum diameter of the MPD. A comparison of adenomas and borderline IPMNs with cancerous IPMNs was performed with the Student t test or the Mann-Whitney U test for continuous variables. RESULTS At histopathologic analysis, 27 IPMNs were classified as carcinomas; 13, as borderline tumors; and 11, as adenomas. MPD wall nodules were observed in 16 carcinomas involving the MPD and one adenoma or borderline neoplasm (P < .00001). Duct wall enhancement was observed in 20 MPD or mixed type carcinomas and five adenomas or borderline neoplasms (P = .0001). The median maximal diameter of the MPD was 18 mm in malignant MPD or mixed type IPMNs and 11 mm in benign borderline IPMNs (P = .038). No significant difference in the overall 5-year survival rate of patients with MPD IPMNs and those with mixed type IPMNs was observed (P = .813). CONCLUSION Duct wall nodules and enhancement of the MPD walls are signs of malignant MPD or mixed type IPMNs. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2531080604/-/DC1.

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

Thyroid volumetric quantification: comparative evaluation between conventional and volumetric ultrasonography.

Objective. Thyroid volume quantification is an important parameter for radiotherapy dosing in cases of major thyroid diseases such as thyroiditis and carcinoma. In clinical practice, this calculation is performed by means of ultrasonography on the basis of an ellipsoid formula obtained from the 3 axes. The aim of our study was to compare the accuracy of volume calculation between B‐mode ultrasonography and volumetric ultrasonography (VUS). Methods. Between April and May 2007, 27 consecutive patients selected for thyroidectomy were prospectively evaluated. One expert ultrasound operator calculated each thyroid volume with standard B‐mode ultrasonography on the basis of the 3 axes of each lobe, and then the patients were analyzed with an offline workstation equipped with volumetric probes (VUS). On the offline workstation, 2 separate blinded operators (VUS1 and VUS2) calculated the thyroid volume with virtual organ computer‐aided analysis. Data acquired were then compared with pathologic anatomy (PA). Results. The mean time for B‐mode analysis was 6 minutes, whereas VUS analysis needed a mean time of 16.5 minutes. Interobserver variability between the median VUS1 and VUS2 measurements was 0.36 mL (interquartile range [IQR], −0.79 to 0.37 mL; P < .156). The median variability between B‐mode ultrasonography and PA was −9.6 mL (IQR, −16.7 to 1.5 mL; P < .001), and that between VUS and PA was −2.87 mL (IQR, −11.97 to 9.51 mL; P = .019). The overall performance of B‐mode ultrasonography in comparison with PA was −29.1% (IQR, −47.5% to −5.9%), and that of VUS in comparison with PA was −6.3% (IQR, −26.3 to 13.7%; P < .001). Conclusions. Volumetric ultrasonography is a valid tool that compares better with PA than does B‐mode ultrasonography.

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).