In nonspecific gall bladder (GB) wall thickening on ultrasonography (USG) or computed tomography (CT), the patient undergoes a more major surgery for a benign cause or a redo surgery for malignancy if diagnosed inaccurately.

To evaluate whether malignant and benign causes of nonspecific GB wall thickening can be accurately differentiated on multiparametric magnetic resonance imaging (MpMRI) and to propose MpMRI-based diagnostic criteria.

Thirty-six of 94 nonspecific GB wall thickening patients underwent MpMRI in a 1.5 T scanner. The MRI characterization was compared with histopathology. Statistical analysis calculated various MRI parameters' sensitivity, specificity, and accuracy in distinguishing benign and malignant lesions. The receiver operating curve analysis provided the apparent diffusion coefficient (ADC) cut-off value.

MpMRI had 100% sensitivity and 92.31% specificity in detecting malignant wall thickening. The sensitivity and specificity of various parameters like intact mucosa on T2-weighted imaging (T2WI), smooth-enhancing mucosa, identification of wall layers on T2WI, and diffusion-weighted imaging (DWI) were 100% and 84.62%, 100% and 92.31%, 100% and 96.15%, and 100% and 53.85%, respectively, in differentiating benign from malignant thickening. Malignancy showed lower ADC values; the cut-off was 1.107 × 10-3 mm2/s. Intramural nodule/cyst on T2WI, chemical shift imaging, and dynamic contrast-enhanced MRI (DCE-MRI) showed 100% positive predictive value for benign wall thickening.

MpMRI accurately differentiates benign from malignant GB wall thickening and is recommended when USG or CT are inconclusive. This will help decide the type of surgery, simple cholecystectomy for benign or radical surgery for a malignant cause. Accurate prediction by MpMRI will reduce patient morbidity and improve survival.

Gallbladder malignancies, especially gallbladder cancer, are aggressive lesions with a poor prognosis, and correct differentiation from benign lesions is crucial for improved outcomes. Recently, diffusion-weighted imaging (DWI) has demonstrated potential for this aim to evaluate suspicious lesions detected by initial imaging (e.g., ultrasound).

The protocol of this review was pre-registered at ( https://osf.io/ury4k ) PubMed, Web of Science, Embase, and Cochrane Library were searched. The performance of both qualitative (i.e., visual) and quantitative (i.e., apparent diffusion coefficient (ADC)) DWIs was assessed for visualized suspicious lesions detected on preliminary imaging. The added value of combining DWI with conventional magnetic resonance imaging (MRI) for this purpose was also evaluated.

After the screening, 27 studies were included. Qualitative analysis showed an area under curve (AUC) of 0.93 (95% confidence interval (CI) = 0.90 to 0.95), while AUC of quantitative analysis was 0.91 (95% CI = 0.89 to 0.94). Adding DWI to conventional MRI protocol added significant values of + 11.27% (95% CI = 0.78% to 21.76%) to sensitivity and + 9.64% (95% CI = 3.90% to 15.39%) to specificity for suspicious lesions on preliminary imaging.

DWI offers an accurate, noninvasive method for differentiating benign gallbladder lesions from malignant ones after preliminary imaging. While adding the DWI protocol to conventional MRI imaging does not require technical resources, it significantly improves performance.

The porcelain gallbladder condition describes gallbladder calcification. While gallbladder calcification is believed to increase the risk of developing gallbladder cancer, recent reports have shown that the malignancy risk is much lower than previously reported. Symptomatic patients with porcelain gallbladder should be recommended for cholecystectomy, but the management of asymptomatic patients is debatable. Based on recent evidence, prophylactic cholecystectomy is not routinely recommended in all patients with porcelain gallbladder. From the assessment of the current literature, there are three essential factors in the management of patients with porcelain gallbladder: (1) symptoms or complications of gallbladder disease, (2) calcification pattern and (3) patient age and comorbidities. Patients who do not undergo cholecystectomy should be educated about the symptoms of gallbladder diseases, and a thorough discussion is essential between patients and clinicians.

To assess the value of the ratio of signal intensities at high and low b-values (b800/b0 ratio) during diffusion-weighted imaging (DWI) for gallbladder cancer diagnosis.

All patients presenting with suspicious gallbladder lesions between January 2011 and December 2016 who underwent DWI and histopathological diagnoses of the lesions were assessed.

Thirty-two patients (24 men, eight women) were identified. Eighteen patients had benign gallbladder lesions while 14 had malignant lesions. The mean apparent diffusion coefficient (ADC) value was 1.62 (±0.57)×10^-3 mm²/s for benign cases and 1.27 (±0.39)×10^-3 mm²/s for malignant cases; this difference was not significant (p=0.0773). The mean b800/b0 ratio was 0.31 (±0.19) for benign cases and 0.48 (±0.13) for malignant cases; this difference was significant (p=0.007). The ROC curve for b800/b0 had an AUC of 0.782 (95% confidence interval [CI]: 0.616-0.947) with a sensitivity and specificity of 85.7% and 72.2%, respectively, at a cut-off point of 0.33.

The b800/b0 ratio can help differentiate benign and malignant gallbladder lesions and may be more reliable than ADC values in quantitative DWI assessments.

Gallbladder (GB) wall thickening is a frequent finding caused by a spectrum of conditions. It is observed in many extracholecystic as well as intrinsic GB conditions. GB wall thickening can either be diffuse or focal. Diffuse wall thickening is a secondary occurrence in both extrinsic and intrinsic pathologies of GB, whereas, focal wall thickening is mostly associated with intrinsic GB pathologies. In the absence of specific clinical features, accurate etiological diagnosis can be challenging. The survival rate in GB carcinoma (GBC) can be improved if it is diagnosed at an early stage, especially when the tumor is confined to the wall. The pattern of wall thickening in GBC is often confused with benign diseases, especially chronic cholecystitis, xanthogranulomatous cholecystitis, and adenomyomatosis. Early recognition and differentiation of these conditions can improve the prognosis. In this minireview, the authors describe the patterns of abnormalities on various imaging modalities (conventional as well as advanced) for the diagnosis of GB wall thickening. This paper also illustrates an algorithmic approach for the etiological diagnosis of GB wall thickening and suggests a formatted reporting for GB wall abnormalities.

Gallbladder (GB) wall thickening is a relatively common finding on imaging. While there are clear recommendations for the management of gallstones, GB wall thickening presents a significant challenge. Despite advances in radiological as well as endoscopic techniques, the ability to characterize GB wall thickening is still limited.

This review summarizes the currently available literature on various imaging investigations to characterize GB wall thickening. This review also summarizes the differences between benign and malignant GB wall thickening based on available imaging modalities. Transabdominal ultrasonography is the first-line investigation for evaluation of GB wall thickening. However, further characterization requires additional imaging tests. Magnetic resonance imaging (MRI) with the use of gadolinium and diffusion-weighted sequence is the preferred modality for GB wall characterization.

The accurate characterization of GB wall thickening is a challenging task. The available imaging criteria allow differentiation of benign and malignant GB wall thickening with moderate accuracy. The advanced imaging techniques, including contrast enhanced ultrasound, contrast-enhanced endoscopic ultrasound, and shear wave elastography, continue to evolve. There is a need for a well-designed reporting system for GB wall thickening to ensure uniformity of reporting of imaging tests, especially in regions with a high prevalence of GB cancer.

Although diffusion-weighted imaging (DWI) has been characterized as an alternative imaging modality for gallbladder (GB) lesions, it has not been routinely used in clinical practice because of relatively low signal-to-noise ratio.

To assess the sensitivity and specificity of the diagnostic performance of DWI for differentiating benign and malignant GB lesions.

Meta-analysis.

Patients with GB lesions.

DWI at 3.0T or 1.5T.

PubMed and EMBASE were searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy guidelines.

Bivariate modeling and hierarchical summary receiver operating characteristic (HSROC) modeling were performed to compare the overall diagnostic performance of DWI. Subgroup analyses were performed for qualitative and quantitative assessment of the DWI. Meta-regression analyses were performed according to the characteristics of the patients, study, and MRI.

Eight studies (including 557 patients) were included. The DWI exhibited a pooled sensitivity of 91%, a pooled specificity of 87%, and HSROC of 0.95. In subgroup analyses, qualitative assessment (sensitivity, 90%; specificity, 87%; HSROC, 0.94) was more accurate than quantitative assessment (sensitivity, 82%; specificity, 86 %; HSROC, 0.88). On meta-regression analysis, studies that used 3.0T field strength and thinner slices (≤5 mm) reported a significantly higher sensitivity (P ≤ 0.02) than those using only 1.5T field strength and thicker slices (>5 mm).

DWI can discriminate malignant from benign GB lesions with excellent diagnostic performance in both qualitative and quantitative assessments. To enhance the diagnostic ability of DWI, images obtained with thinner slices (≤5 mm) with 3T field strength and qualitative assessment are recommended.

3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1375-1388.

Gallbladder calcification, also referred to as porcelain gallbladder, has received significant attention in the medical literature due to its perceived role in increasing the risk of developing a gallbladder carcinoma. However, recent reports raise questions challenging this purported high risk. While previous studies reported a concomitant incidence of gallbladder cancer in porcelain gallbladder ranging from 7-60%, more recent analyses indicate the incidence to be much lower (6%). Based on evidence in the current literature, a prophylactic cholecystectomy is not routinely recommended for all patients with porcelain gallbladder and should be restricted to those with conventional indications, such as young patients. However, it is important to note that a nonoperative approach may require prolonged follow-up. A laparoscopic cholecystectomy is a feasible therapeutic option for patients with porcelain gallbladder, although some researchers have indicated a higher incidence of complications and conversion due to technical difficulties.

To assess the use of diffusion-weighted imaging (DWI) for differentiating acute from chronic cholecystitis, in comparison with conventional magnetic resonance imaging (MRI) features.

Liver MRI including DWI (b-values 0/500/1000s/mm(2) ) was performed at 1.5T ≤30 days before cholecystectomy in 83 patients with abdominal pain. Two radiologists assessed cases for conventional (gallstones, wall thickening, pericholecystic fluid, pericholecystic fat changes, gallbladder distension, pericholecystic liver enhancement, mural T2 -hyperintensity, mural hyperenhancement, mural striations, abscess, intraluminal membranes, and mural defect) and DWI (increased mural signal on high b-value images, visually low apparent diffusion coefficient [ADC], and ADC values) features.

Acute cholecystitis was present in 43%; chronic cholecystitis was present in 57%. Nine of 12 conventional features were more frequent in acute cholecystitis for both readers (P ≤ 0.003). Increased mural signal on high b-value images was more frequent (P < 0.001) in acute than chronic cholecystitis for R1 (92% vs. 32%) and R2 (83% vs. 30%). Sensitivity and specificity of increased signal on high b-value images were: R1, 92%/68%; R2, 83%/70%. Visually low ADC was more frequent in acute cholecystitis for R2 (P < 0.001) but not R1 (P = 0.406); ADC values were not different between groups for either reader (P = 0.104-0.139). Among conventional and DWI features, only increased signal on high b-value DWI was independently associated with acute cholecystitis for both readers (P = 0.006-0.012).

Visually increased mural signal on high b-value DWI was highly sensitive and moderately specific for acute cholecystitis, being an independent predictor relative to conventional features for both readers. Although requiring larger studies, DWI (particularly the high b-value images) may have additive value relative to conventional MRI-suspected acute cholecystitis. J. Magn. Reson. Imaging 2016;44:89-97.

The aim of this meta-analysis was to assess the efficacy of the apparent diffusion coefficient (ADC) value of diffusion-weighted MRI (DWI) for differentiating biliary tract cancer (BTC) from benign biliary tract diseases in Asians.

We systematically searched Embase and PubMed prior to December 2014. Eight studies conducted in Asians met our predetermined inclusion criteria.

Our meta-analysis results showed that ADC values in BTC tissues were significantly lower than in benign biliary tract tissues (SMD = -1.54, 95%CI: -1.75~-1.33, P<0.001). Subgroup analysis based on the MRI machine type showed that the ADC values were consistent, accurate and reliable in the diagnosis of BTC when comparing cancer tissue vs. benign tissue under the Siemens 1.5 T/3.0 T, Philips 1.5 T/3.0 T, GE 1.5 T, and Toshiba 1.5 T types, respectively (all P<0.05). Further, ADC values were still consistent and accurate in the differential diagnosis of BTC under the b value of 800 and 1000 s/mm2 (all P<0.05).

Our findings supported potential clinical applications of DWI ADC values in differentiating BTC from benign biliary tract diseases in Asians.