Quantitative Analysis of the Olfactory System in COVID-19: An MR Imaging Study.

BACKGROUND AND PURPOSE: Anosmia or hyposmia, often accompanied by changes in taste, is recognized as a common symptom that can assist in the diagnosis of coronavirus disease 2019 (COVID-19). The pathogenesis of olfactory dysfunction in COVID-19 is not yet fully understood. MR imaging represents a useful anatomic imaging method for the evaluation of olfactory dysfunction associated with varying etiologies, including viral infection, trauma, and neurodegenerative processes. This case-control study was conducted to compare quantitative measurements of olfactory anatomic structures between patients diagnosed with COVID-19 associated with persistent olfactory dysfunction and healthy controls. MATERIALS AND METHODS: This study has a retrospective design. Cranial MR imaging was performed on all participants in both the patient and control groups. The bilateral olfactory bulb volume, olfactory tract length, and olfactory sulcus depth were measured in all patients. RESULTS: A total of 116 people aged 18-60 years, including 36 patients diagnosed with COVID-19 and 80 controls, were included in the study. All measured values were compared between the patient and control groups. The right, left, and total olfactory bulb volume values were significantly lower in the patient group than in the control group. The patient group also had significantly lower right and left olfactory sulcus depth and olfactory tract length values compared with those in the control group. CONCLUSIONS: MR imaging findings can be used to demonstrate olfactory injury in patients with COVID-19. The olfactory pathway may represent an alternative route for virus entry into the central nervous system.

Crohn's disease Activity: Abdominal Computed Tomography Histopathology Correlation.

PURPOSE: Crohn's disease is a type of inflammatory bowel disease affecting estimated 4 million people worldwide. Therapy stratification of Crohn's disease (CD) is mainly based on the inflammatory activity being assessed by endoscopic biopsy and clinical criteria. Cross-sectional imaging allows for the assessment of structural characteristics of the entire gastrointestinal tract including small bowel loops and may provide potential non-invasive image-based biomarkers for the inflammatory activity of CD. The aim of this study was to explore the predictive value of Computed Tomography-based morphologic patterns for inflammatory activity in CD. MATERIAL AND METHODS: 42 patients diagnosed with CD were included in a retrospective study (13 male, 29 female, median age 32 years). Abdominal CT imaging was carried out on symptomatic patients at a single institution 0-10 days prior to endoscopic biopsy or surgery using a protocol optimized for the characterization of structural bowel alterations. Image data were initially reviewed independently by three radiologists and discrepancies were settled in consensus with a focus on mesenteric fat stranding and combing, mesenteric adenopathy, mesenteric abscess, intraperitoneal free fluid, fistula, skip lesions, highest wall thickness and the localization of the affected bowel. The extent of inflammatory activity in the bowel wall was determined subsequently by histological analysis. RESULTS: All intestinal and extraintestinal CT findings except the mesenteric comb sign showed a tendency towards higher extent or prevalence in patients with high histological inflammatory activity score, especially median bowel wall thickness (6.0 mm vs. 3.5 mm), mesenteric abscesses (32% vs. 0%) and mesenteric adenopathy (94% vs. 45%). Spearman rank order correlation coefficient indicated a significant correlation of bowel wall thickness (r = 0.40, p < 0.05), mesenteric adenopathy (r = 0.54, p < 0.05), mesenteric abscess (r = 0.33, p < 0.05) and mesenteric fat stranding (r = 0.33, p < 0.05) with the histological inflammatory activity score. CONCLUSION: CT-based biomarkers including wall thickness, mesenteric fat stranding, mesenteric lymphadenopathy and mesenteric abscess positively correlated with the histological inflammatory activity score and therefore provided additional information for therapy stratification in symptomatic patients with CD, particularly as most of these biomarkers are hidden from endoscopy.

Xiphoid syndrome: an uncommon occupational disorder.

We report a case of a 45-year-old man, complaining of swelling and pain in his epigastric region for the last 3 years. According to his medical history, he had undergone various investigations and treatments for gastro-oesophageal reflux, without relief. He had had a history of chronic repeated microtraumas to his sternum during 9 years of working as a carpenter, as a result of placing wood against his anterior chest wall and pushing the former into a plank cutting machine. On examination, a tender swelling was palpable as an immobile, hard mass showing minimal protrusion under the skin on the xiphoid process. He was diagnosed as having xiphoid syndrome. We prescribed anti-inflammatory medication and advised him to avoid pressure on his anterior chest wall, especially on the sternum, while cutting wood. At follow-up, the symptoms were relieved. Xiphoid syndrome may be seen in people performing hard physical work who incur sustained pressure or friction on their anterior chest wall. The case emphasizes the importance of the occupational history as well as clinical and radiological investigation of unusual conditions as mentioned above.

Gastrointestinal tract wall visualization and distention during abdominal and pelvic multidetector CT with a neutral barium sulphate suspension: comparison with positive barium sulphate suspension and with water.

OBJECTIVE: When examining patients with contrast-enhanced multidetector-row CT, we determined if the stomach and small bowel were visualized and distended better with a neutral barium sulphate suspension than with positive barium sulphate suspension or water. MATERIALS AND METHODS: After obtaining approval from our institutional review board, 156 patients (women: 84; mean age: 54 yrs) with no history of gastrointestinal tract disease were randomized prospectively to receive orally either 900 ml of neutral (0.1% w/v) barium sulphate suspension (n = 53), 900 ml of positive (2.1% w/v) barium sulphate suspension (n = 53), or 900 ml of water (n = 50), prior to undergoing contrast-enhanced abdominal and pelvic multidetector-row CT. Two independent radiologists evaluated the stomach, and small bowel, for luminal distension and wall visualization, using a five point scale. Results were compared using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: The walls of the stomach, and small bowel were visualized better in patients who were administered neutral barium sulphate suspension than those who were administered either positive barium sulphate suspension (p < 0.01) or water (p < 0.01). In patients who received neutral barium sulphate suspension, the stomach and small bowel were distended better compared to patients administered water (p < 0.01); the stomach, duodenum, and ileum were distended better compared to patients administered positive barium sulphate suspension (p < 0.05). CONCLUSIONS: When examining patients with intravenous contrast-enhanced abdominal and pelvic multidetector-row CT, orally administered neutral barium sulphate suspension allows the gastrointestinal tract to be visualized and distended better than either positive barium sulphate suspension, or water.

Hepatic alveolar echinococcosis: a diagnostic challenge.

We report a case of alveolar echinococcosis involving the liver in a 61-year-old male. Alveolar echinococcosis is a rare chronic and progressive disease, which can involve mostly liver and in rare cases lung and brain. It is caused by Echinococcus multilocularis. In this report we describe the imaging findings of hepatic involvement of alveolar echinococcosis by ultrasonography, computed tomography and magnetic resonance imaging.

Role of low-mechanical index CEUS in the differentiation between low and high grade bladder carcinoma: a pilot study.

PURPOSE: To assess the efficacy of low-mechanical index contrast-enhanced ultrasonography (CEUS) in the differentiation of a series of histologically proven bladder lesions identified via conventional cystoscopy and biopsied. MATERIALS AND METHODS: 36 patients (mean age: 62 years; range 45 - 72 years) with bladder lesions previously detected by color power Doppler ultrasonography (CDUS) were prospectively examined with low-mechanical index contrast-enhanced US after bolus administration of 2.4 ml of Sonovue (Bracco, Milan, Italy). All lesions were evaluated in real-time continuous scanning for 2 minutes and the videos were registered. Two ultrasound (US) experts evaluated the videos by consensus and assigned a score to the enhancement pattern. Subsequently, a specific sonographic quantification software (Qontrast, Bracco, Milan, Italy) based on pixel by pixel signal intensity over time was used to obtain contrast-enhanced sonographic perfusion maps for each lesion. Time-intensity curves (TICs) of each lesion were then extracted from the region of interest positioned within the lesion and in the closest bladder wall. The sensitivity and specificity of CDUS and CEUS were compared using McNemar's test. All patients subsequently underwent conventional cystoscopy with biopsy or transurethral resection. RESULTS: 22 high-grade and 14 low-grade transitional cell carcinomas (TCCs) were histologically diagnosed (mean diameter 2.1 cm; range: 1 - 4.5 cm). The sensitivity and specificity of CDUS were 86.4% (19 / 22; 95% CI = 66.7 - 95.3%) and 42.9% (6 / 14; 95% CI = 21.4 - 67.4%), respectively. The sensitivity and specificity of CEUS were 90.9% (20 / 22; 95% CI = 72.2 - 97.5%) and 85.7% (12 / 14; 95% CI = 60.1 - 95.9%), respectively. The sensitivity and specificity of CEUS using TICs were 95.4% (21 / 22; 95% CI = 78.2 - 99.2%) and 85.7% (12 / 14; 95% CI = 60.1 - 95.9%), respectively. There was no significant difference between the sensitivity of CDUS versus CEUS, CDUS versus TIC, and CEUS versus TIC (p > 0.05; McNemar's test). The specificity of CEUS and TIC was significantly higher than that of CDUS (p < 0.05; McNemar test). CONCLUSION: CEUS is a reliable noninvasive method for differentiating low- and high-grade bladder carcinomas since it provides typical enhancement patterns as well as specific contrast-sonographic perfusion curves. However, further studies involving larger patient populations is mandatory to confirm these promising results.

Comparison of computed tomography histogram analysis and chemical-shift magnetic resonance imaging for adrenal mass characterization.

BACKGROUND: Computed tomography (CT) histogram analysis and chemical-shift magnetic resonance imaging (MRI) are currently used modalities for adrenal mass characterization. However, it is not yet clear which modality can be regarded as most sensitive in terms of adrenal mass characterization. PURPOSE: To prospectively compare CT histogram analysis and chemical-shift MRI in the characterization of adrenal masses. MATERIAL AND METHODS: Between May 2007 and November 2008, 93 patients (45 males, 48 females; mean age 56.7 years, range 22-85 years) with 109 adrenal masses prospectively underwent both unenhanced CT and chemical-shift MRI examinations. These masses consisted of 67 adenomas and 42 metastases. Histogram analysis was applied with a circular region of interest (ROI) that recorded mean attenuation, total number of pixels, number of negative pixels, and the percentage of negative pixels on unenhanced CT images for each adrenal mass. In the CT histogram analysis, a 10% negative pixel threshold for unenhanced CT was calculated. In chemical-shift MRI, signal intensity drop between in-phase and opposed-phase images was quantitatively calculated so that adrenal-to-spleen chemical-shift ratios and adrenal signal intensity indexes were determined for each of the adrenal masses. A mass was regarded as an adenoma if it contained more than 10% negative pixels by CT histogram analysis, showed an adrenal-to-spleen chemical-shift ratio of less than 0.71, and had an adrenal signal intensity index of more than 16.5% by chemical-shift MRI. The results were compared to reveal which method was most sensitive in the diagnosis of adrenal masses and whether or not a correlation exists between these two modalities. Final diagnoses were based on imaging follow-up of minimum 6 months, biopsy, surgery, and adrenal washout study. RESULTS: On unenhanced CT examinations, all of the 67 adenomas and 21 out of 42 metastases exhibited negative pixels. None of the metastases showed more than 10% negative pixels on CT histogram analysis. An increase in the percentage of negative pixels correlated well with a decrease in the mean CT attenuation. CT histogram analysis using a 10% negative pixel threshold gave a 91% sensitivity and 100% specificity for the diagnosis of an adenoma. On chemical-shift MRI, for an adrenal-to-spleen chemical-shift ratio of less than 0.71, a 97% sensitivity and 100% specificity were achieved, while a 97% sensitivity and 93% specificity were obtained for an adrenal signal intensity index of more than 16.5% for adenoma diagnosis. CONCLUSION: CT histogram analysis method using a 10% negative pixel threshold on unenhanced CT had a good sensitivity and perfect specificity for the differentiation of adrenal adenomas from non-adenomas. In spite of the good results obtained with the CT histogram analysis method, chemical-shift MRI using adrenal-to-spleen chemical-shift ratio and adrenal signal intensity index formulas had a higher sensitivity and could help in the characterization of adrenal masses appearing indeterminate by CT histogram analysis.

Is contrast-enhanced US alternative to spiral CT in the assessment of treatment outcome of radiofrequency ablation in hepatocellular carcinoma?

PURPOSE: The present study was conducted to assess the efficacy of contrast-enhanced ultrasound with low mechanical index in evaluating the response of percutaneous radiofrequency ablation treatment of hepatocellular carcinoma by comparing it with 4-row spiral computed tomography. MATERIALS AND METHODS: 100 consecutive patients (65 men and 35 women; age range: 62 - 76 years) with solitary hepatocellular carcinomas (mean lesion diameter: 3.7 cm +/- 1.1 cm SD) underwent internally cooled radiofrequency ablation. Therapeutic response was evaluated at one month after the treatment with triple-phasic contrast-enhanced spiral CT and low-mechanical index contrast-enhanced ultrasound following bolus injection of 2.4 ml of Sonovue (Bracco, Milan). 60 out of 100 patients were followed up for another 3 months. Contrast-enhanced sonographic studies were reviewed by two blinded radiologists in consensus. Sensitivity, specificity, NPV and PPV of contrast-enhanced ultrasound examination were determined. RESULTS: After treatment, contrast-enhanced ultrasound identified persistent signal enhancement in 24 patients (24 %), whereas no intratumoral enhancement was detected in the remaining 76 patients (76 %). Using CT imaging as gold standard, the sensitivity, specificity, NPV, and PPV of contrast enhanced ultrasound were 92.3 % (95 % CI = 75.9 - 97.9 %), 100 % (95 % CI = 95.2 - 100 %), 97.4 % (95 % CI = 91.1 - 99.3 %), and 100 % (95 % CI = 86.2 - 100 %). CONCLUSION: Contrast-enhanced ultrasound with low mechanical index using Sonovue is a feasible tool in evaluating the response of hepatocellular carcinoma to radiofrequency ablation. Accuracy is comparable to 4-row spiral CT.

Cysts of the canal of Nuck: ultrasound and magnetic resonance imaging findings.

Cyst of the canal of Nuck is a rare cause of inguinal swelling in woman. We report a case of a cyst of the canal of Nuck in which sonography showed a tubular cystic structure with internal septae localized within the inguinal canal. Magnetic resonance examination demonstrated that the mass was hypointense on T1-weighted and hyperintense on T2-weighted series and that there were fine hypointense septae inside the mass on the T2-weighted sequence. Diagnosis of cyst of the canal of Nuck was confirmed by surgery and subsequent histopathologic evaluation.

Effect of duration of contrast material injection on peak enhancement times and values of the aorta, main portal vein, and liver at dynamic MDCT with the dose of contrast medium tailored to patient weight.

AIM: To investigate the effects of contrast material injection duration on peak enhancement times and attenuation values of the aorta, main portal vein, and liver at MDCT when the dose of contrast material is adjusted to patient weight. MATERIAL AND METHODS: Seventy-five patients were randomly assigned to one of five groups, with durations of injection of 25, 30, 35, 40, or 45 s. All patients were injected with 2 ml/kg iodine (300 mg/ml). Attenuation values and peak enhancement times for the aorta, main portal vein, and liver were determined. The relationship between patient weight and enhancement times and values, the differences regarding peak enhancement times, and the relationship between injection duration and enhancement values were investigated using Pearson correlation, analysis of variance (ANOVA), and Spearman rank correlation, respectively. RESULTS: No significant correlations were seen between patient weight and peak enhancement times or values. Mean peak enhancement times for the aorta, main portal vein, and liver were 9-11 s, 18-22 s, and 30-34 s, respectively (p>0.05). The correlations between injection duration and peak enhancement values were significant and negative. CONCLUSIONS: Regardless of patient weight and injection duration, peak enhancement times of aorta, main portal vein and liver were approximately 10, 20, and 30 s, respectively. The enhancement values tended to be higher for shorter injection durations.

US, CT and MRI findings in a case of diffuse lymphangiomatosis and cystic hygroma.

Lymphangiomatosis is a rare disease with multifocal lymphatic proliferation that typically occurs during childhood and involves multiple parenchymal organs including the lung, liver, spleen, bone, and skin. Lymphangiomatosis may occur synchronously or metachronously with cystic hygroma of the neck. We present US, CT, and MRI findings of cystic hygroma of the neck associated with generalized lymphangiomatosis affecting bones and spleen in a 2-year-old girl.

Noninvasive multidetector computed tomography enterography in patients with small-bowel Crohn's disease: is a 40-second delay better than 70 seconds?

BACKGROUND: Multidetector computed tomography (MDCT) enterography combines neutral enteric contrast with intravenously administered contrast material. The optimal intravenous (IV) contrast material protocol has still not been established. PURPOSE: To determine the optimal delay time to image patients with small-bowel Crohn's disease during MDCT enterography. MATERIAL AND METHODS: After oral administration of 1350 ml of neutral contrast medium, 26 patients with small-bowel Crohn's disease underwent MDCT enterography;scans were obtained 40 s (enteric phase) and 70 s (parenchymal phase) after IV administration of 100 ml of iodinated contrast material. Three radiologists, blinded to clinical and pathological findings, independently and retrospectively evaluated each scan in two separate reading sessions for the presence or absence of CT features of Crohn's disease activity. The interobserver agreement was evaluated, and the efficacy of each phase in detecting active disease in the terminal ileum for each reader was determined. The gold standard was pathology (n=13), endoscopy (n=3), and clinical evaluation (n=10). RESULTS: No statistically significant difference was present between the enteric and the parenchymal phase for each reader in each segment regarding the presence or absence of CT features of Crohn's disease. The interobserver agreement for the presence of five main features of active Crohn's disease in the terminal ileum ranged from poor to excellent.The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for active Crohn's disease in the terminal ileum ranged from 40 to 90%, 88 to 100%, 70 to 94%, 44 to 100%, and 69 to 96%, respectively. There was no statistical difference between the two phases for each reader. CONCLUSION: MDCT enterography in patients with suspected active Crohn's disease can be obtained at either 40 s or 70 s after IV contrast material.

Benign and malignant breast lesions: efficacy of real time contrast-enhanced ultrasound vs. magnetic resonance imaging.

PURPOSE: To assess the efficacy of low mechanical index (MI) real time grey scale contrast-enhanced US (CEUS) in the differentiation of breast lesions in comparison to Magnetic Resonance Imaging (MRI). MATERIALS AND METHODS: 50 lesions previously detected at mammography or conventional US were evaluated by means of CEUS and MRI. Contrast-enhanced examinations were performed with a dedicated equipment (Esatune, Esaote, Genoa, Italy), before and after injection of 4.8 ml of Sonovue (Bracco, Milan, Italy). MRI was conducted with a 1.5 T equipment (Siemens Vision Plus, Erlangen, Germany) with bilateral dedicated superficial coil, on T2w STIR and 3D Flash T1w before and 1, 2, 3, 4, 5 minutes after the administration of contrast agent (Gd-DTPA, 1.5 ml/kg). Wash-in and wash-out curves were assessed for both procedures. A specific sonographic quantification software (Qontrast, Bracco, Milan, Italy), based on pixel by pixel signal intensity over time, was used to obtain contrast-enhanced sonographic perfusion maps for each lesion. Mc Nemar test was then calculated. RESULTS: 24 invasive ductal carcinomas, 18 fibroadenomas, 4 fibro-cystic dysplasias, 1 mucinous carcinoma, 1 invasive ducto-lobular carcinoma, 1 intraductal florid papillomatosis and 1 phylloides tumour were diagnosed. Contrast-enhanced sonographic patterns correlated well with those provided by MRI. Sensitivity, specificity, and accuracy of US were: 69.2 %, 66.7 %, and 68 %, respectively. According to the different contrast enhancement patterns and the resulting perfusion maps, all the malignant lesions and 9 out of 12 benign lesions were correctly diagnosed, thus resulting in 87.5 % of specificity and 100 % of sensitivity. Regarding the specificity, there is no difference between US and CEUS with McNemar (p = 0.18). Regarding sensitivity, the difference between contrast-enhanced US and US is significant as calculated with McNemar test (p = 0.013). The three lesions which were incorrectly classified as malignant were two hypervascularised fibroadenomas in young women and a phylloides tumour. CONCLUSION: CEUS seems to be a reliable method to differentiate breast lesions, since it provides typical enhancement patterns. Contrast sonographic perfusion curves correlate well with MRI wash in--wash out curves.