Francesca Fornasa

Background: Diffusion-weighted magnetic resonance imaging (DWI) is increasingly used in the diagnosis of endometrial disease. No complete knowledge, however, exists yet of the influence of physiology on the endometrial apparent diffusion coefficient (ADC) values on which DWI is based. Purpose: To establish whether the ADC values measured with DWI in the endometrium of healthy reproductive-aged women significantly vary from the early proliferative to the periovulatory phase of the menstrual cycle and between the fundus and the isthmus of the uterus. Material and Methods: In 17 women the endometrial ADC values measured on the fifth menstrual day, both at the fundus and at the isthmus of the uterus, were compared to the values obtained on the 14th day before the subsequent cycle. In 81 women (menstrual day: fifth through 21st) the endometrial ADC values measured at the fundus were compared to the values obtained at the isthmus of the uterus. All examinations were performed with a 1.5 T magnet (b values: 0 and 800 mm/s²). The results were analyzed by means of Student's t-test per paired data. Results: The endometrial ADC values measured on the fifth day of the menstrual cycle were lower than those obtained in the periovulatory phase both at the fundus (mean 0.923 vs. 1.256 × 10⁻³ mm²/s) and at the isthmus (mean 1.297 vs. 1.529 × 10⁻³ mm²/s) of the uterus. The endometrial ADC values measured at the fundus of the uterus were lower than those obtained at the isthmus (mean 1.132 vs. 1.420 × 10⁻³ mm²/s) through the menstrual cycle. All these differences were highly significant ( P < 0.001) at statistical analysis. Conclusion: Physiological variations occurring in endometrial ADC values of healthy women should be considered by the radiologists when interpreting DWI examinations in patients with endometrial disease.

Objective: To assess the diagnostic accuracy of magnetic resonance imaging (MRI) in prospectively differentiating between fibrotic and active inflammatory small bowel stenosis in patients with Crohn's disease (CD). Materials and Methods: A total of 111 patients with histologically proven CD presenting with clinical and plain radiographic signs of small bowel obstruction underwent coronal and axial MRI scans after oral administration of polyethylene glycol solution. A stenosis was judged present if a small bowel segment had >80% lumen reduction as compared to an adjacent normal loop and mural thickening of >3 mm. At the level of the stenosis, both T2 signal intensity and post-gadolinium T1 enhancement were quantified using a 5-point scale (0: very low; 1: low; 2: moderate; 3: high; and 4: very high). A stenosis was considered fibrotic if the sum of the two values (activity score: AS) did not exceed 1. Results: A small bowel stenosis was identified in 48 out of 111 patients. Fibrosis was confirmed at histology in all of the 23 patients with AS of 0 or 1, who underwent surgery within 3 days of the MRI examination. In the remaining 25 patients (AS: 2–8), an active inflammatory stenosis was suspected and remission of the obstructive symptoms was obtained by means of medical treatment. One of these patients (AS: 2), however, underwent surgery after 14 days, due to recurrence. MRI had 95.8% sensitivity, 100% specificity, and 97.9% accuracy in the diagnosis of fibrotic stenosis. Conclusion: MRI is reliable in differentiating fibrotic from inflammatory small bowel stenosis in CD.

Diffusion-Weighted Magnetic Resonance Imaging (DWI) obtains information useful in diagnosing several diseases through the measurement of random, Brownian diffusion of water molecules in tissues. This pictorial essay illustrates the main factors, i.e., ratio between the volume occupied by cells and the extracellular space, composition of the extracellular space, and temperature, that determine the rate of the water diffusion. The mechanism through which these influencing factors affect water diffusion is explained. Clinical and experimental examples, derived both from physiology and from non-human models, are described.

This study assessed the usefulness of magnetic resonance diffusion-weighted imaging (DWI) in distinguishing between benign and malignant breast lesions. Gadolinium-enhanced magnetic resonance imaging (MRI) and DWI with determination of the apparent diffusion coefficient (ADC) were performed on 78 women, each with a focal breast lesion at least 7 mm in diameter, which was studied by cytology or histology. Final diagnoses were obtained by cytology in 29 cases and histology in 49 (11 percutaneous biopsies and 38 surgical specimens). There were 43 benign lesions (13 fibrocystic disease, eight fibroadenoma, seven adenosis, five normal breast tissue, four inflammatory lesions, three intramammary lymph nodes, two scleroelastosis and one fat necrosis) and 35 malignant lesions (30 invasive ductal carcinoma, two invasive lobular carcinoma, one ductal carcinoma in situ, one carcinomatous mastitis and one metastasis from neuroendocrine carcinoma). The mean ADC values were 1.677±0.151 for benign lesions and 1.298±0.129 for malignant lesions (p<0.001). With an ADC cutoff value of 1.48, DWI had 88.6% sensitivity [confidence interval (CI) 78.1%–99.1%] and 95.3% specificity (CI 88.9%–100%), with 31 true positives, four false negatives (three invasive ductal carcinoma and one carcinomatous mastitis), 41 true negatives and two false positives (one fat necrosis and one fibroadenoma). With the cutoff value set at 1.52, DWI sensitivity (35 true positive, no false negative) was 100% and specificity was 86% (CI 75.7%–96.3%) due to 37 true negatives and six false positives (an additional two fibroadenoma and two fibrocystic disease compared with those recorded with the cutoff set at 1.48). The overall accuracy of DWI considering both cutoff values (72 correct evaluations out of 78 cases) was 92.3% (CI 86.4%–98.2%). DWI is a reliable tool for characterising focal breast lesions. Scopo del nostro lavoro è stato stabilire l’utilità dell’imaging in risonanza magnetica (RM) pesata in diffusione (DWI) nel distinguere le lesioni mammarie benigne da quelle maligne. La RM con mezzo di contrasto e la DWI, con misurazione del coefficiente di diffusione apparente (ADC), sono state eseguite in 78 pazienti di sesso femminile, ognuna portatrice di una lesione focale della mammella con diametro di almeno 7 mm sottoposta ad indagine citologica o bioptica. La diagnosi finale è stata ottenuta mediante citologia in 29 casi ed istologia in 49 (11 biopsie percutanee e 38 pezzi operatori). 43 lesioni sono risultate benigne (13 casi di mastopatia fibrocistica, 8 di fibroadenoma, 7 di adenosi, 5 di tessuto mammario normale, 4 di lesioni flogistiche, 3 di linfonodi intramammari, 2 di scleroelastosi ed 1 di steatonecrosi) e 35 maligne (30 carcinomi duttali infiltranti, 2 carcinomi lobulari infiltranti, 1 carcinoma duttale in situ, 1 mastite carcinomatosa ed 1 metastasi da carcinoma neuroendocrino). I valori medi di ADC sono risultati di 1,677±0,151 per le lesioni benigne e di 1,298±0,129 per quelle maligne (p<0,001). Ponendo il cut off di ADC pari a 1,48, la DWI ha raggiunto una sensibilità (31 veri positivi; 4 falsi negativi, rappresentati da 3 carcinomi duttali infiltranti e da una mastite carcinomatosa) dell’88,6% (intervallo di confidenza [IC]: 78,1%–99,1%) ed una specificità (41 veri negativi; 2 falsi positivi, dovuti ad un caso di steatonecrosi e ad un fibroadenoma) del 95,3% (IC: 88,9%–100%). Con il cut off di 1,52, la sensibilità (35 veri positivi; nessun falso negativo) è risultata del 100% e la specificità (37 veri negativi; 6 falsi positivi, per l’aggiunta ai due falsi positivi riscontrati con cut off di 1,48 di 2 fibroadenomi e 2 casi di mastopatia fibrocistica) dell’86% (IC: 75,7%–96,3%). Con entrambi i cut off l’accuratezza globale della DWI (72 risultati esatti su 78 casi) è stata del 92,3% (IC: 86,4%–98,2%). La DWI è uno strumento affidabile nella tipizzazione delle lesioni focali mammarie.

Hepatoid adenocarcinoma (HAC) is a rare type of extrahepatic cancer, whose pathologic features are indistinguishable from those of hepatocellular carcinoma. About thirty cases, nearly half of which occurring in the lung, have been described in patients with a normal liver. No imaging features are typical enough to allow a correct diagnosis.A localization of HAC in the soft tissues of the shoulder with invasion of the scapula in a woman without other symptoms is reported in this paper; soft-tissue HACs have never been described to date. An associate pulmonary HAC was eventually found in this patient.