Imaging and Clinical Findings of Xanthogranulomatous Inflammatory Disease of Various Abdominal and Pelvic Organs: A Pictorial Essay.

Xanthogranulomatous (XG) inflammatory disease is a rare benign disease involving various organs, including the gallbladder, bile duct, pancreas, spleen, stomach, small bowel, colon, appendix, kidney, adrenal gland, urachus, urinary bladder, retroperitoneum, and female genital organs. The imaging features of XG inflammatory disease are nonspecific, usually presenting as a heterogeneous solid or cystic mass. The disease may also extend to adjacent structures. Due to its aggressive nature, it is occasionally misdiagnosed as a malignant neoplasm. Herein, we review the radiological features and clinical manifestations of XG inflammatory diseases in various organs of the abdomen and pelvis.

Ultrasonography of intrascrotal torsed appendages: size and interval between symptom onset and the ultrasonographic examination according to echogenicity.

PURPOSE: This study investigated the size of torsed appendages and the interval between symptom onset and the ultrasonographic examination according to the echogenicity of the torsed appendages. METHODS: This was a retrospective analysis of 54 cases in 46 patients with torsion of the testicular appendages between December 2008 and July 2021. Eight patients received follow-up ultrasonography 7-48 days after initial ultrasonography. The echogenicity of torsed appendages was classified into three groups: hypoechoic, hyperechoic, or isoechoic. RESULTS: The 54 torsed appendages were hypoechoic (n=40), hyperechoic (n=9), or isoechoic (n=5). The size of the torsed appendages ranged from 4 to 14 mm (8.0±3.1 mm) in hypoechoic torsed appendages and from 2.6 to 5.0 mm (3.7±0.9 mm) in hyperechoic torsed appendages. The interval between symptom onset and the ultrasonographic examination ranged from 0 to 17 days (4.2±4.4 days) in hypoechoic torsed appendages and from 8 to 48 days (29.8±16.0 days) in hyperechoic torsed appendages. The hyperechoic torsed appendages were smaller and had longer intervals between symptom onset and the ultrasonographic examination than the hypoechoic torsed appendages (P<0.05). Three hypoechoic torsed appendages and a single isoechoic torsed appendage on initial ultrasonography became hyperechoic on follow-up ultrasonography. CONCLUSION: The size of the torsed appendages and the interval between symptom onset and the ultrasonographic examination varied according to the echogenicity of the torsed appendages. The hyperechoic torsed appendages were smaller and had longer intervals until the examination than the hypoechoic torsed appendages.

Various Intratesticular Hypoechoic Lesions on Scrotal Sonography.

Sonography with a high-frequency transducer is the modality of choice for imaging the scrotum. Most intratesticular lesions are hypoechoic. Differentiation of intratesticular hypoechoic lesions as either malignant or benign is important because the treatment of these lesions vary. In this paper, we review the sonographic features of different types of intratesticular hypoechoic lesions, such as testicular cysts, testicular tumors, testicular inflammatory lesions, segmental testicular infarction, and testicular trauma.

Small testes: clinical characteristics and ultrasonographic findings.

The purpose of this pictorial essay is to describe the ultrasonographic and clinical findings of patients with small testes due to a wide range of causes. We retrospectively reviewed the ultrasonographic and clinical findings of various causes of small testes. We present various causes of small testes on ultrasonography including Klinefelter syndrome, testicular torsion, mumps orchitis, inguinal hernia, cryptorchidism, varicocele, and trauma. On ultrasonography, small testes in patients with testicular torsion, mumps orchitis, and trauma usually showed heterogeneous echogenicity. Atrophic testes were homogeneously hypoechoic in patients with cryptorchidism and inguinal hernia and were isoechoic to the normal testis in patients with varicocele. Klinefelter syndrome patients had small hyperechoic or hypoechoic nodules, but the echogenicity of the remnant portion of the testes was homogeneous. Ultrasonography is helpful for detecting small testes and for the differential diagnosis of the various possible causes of small testes.

Testicular atrophy after mumps orchitis: ultrasonographic findings.

PURPOSE: The purpose of this study was to describe the ultrasonographic findings of testicular atrophy after mumps orchitis. METHODS: We retrospectively reviewed the case files of eight patients (14 to 24 years old; mean, 17 years) with mumps orchitis and testicular atrophy who were treated between January 2011 and September 2017. On gray-scale and color Doppler, the ultrasonographic features of volume, shape, echogenicity, and degree of blood flow in the testes were analyzed as part of both initial and follow-up ultrasonography. The duration between the initial diagnosis of mumps orchitis and the ultrasonographic diagnosis of testicular atrophy after mumps orchitis ranged from 25 to 230 days (mean, 95.9 days). RESULTS: Of the eight patients with testicular atrophy after mumps orchitis, the testes were affected unilaterally in seven patients (6 right-sided and 1 left-sided) and bilaterally in one patient. The affected testes (n=9) were 23%-55% (mean, 44.7%) smaller in volume (mean, 6.3±2.0 mL) than the contralateral normal testes (n=7) (mean, 10.8±2.3 mL) on follow-up ultrasonography (P=0.001). The shape of the atrophic testes was oblong in seven cases and elliptical in two cases. The atrophic testes were either heterogeneously hypoechoic with multiple hyperechoic islands (n=7) or heterogeneously hyperechoic (n=2). On follow-up color Doppler ultrasonography, the degree of vascularity of the atrophic testis was either similar to (n=3) or lower than (n=6) that of the contralateral testis. CONCLUSION: On ultrasonography, atrophic testes after mumps orchitis tended to exhibit an oblong shape, heterogeneous low echogenicity with multiple hyperechoic islands, and decreased vascularity.

Gallbladder contraction at CT and sonography secondary to bowel preparation for colonoscopy.

PURPOSE: To investigate volume changes of the gallbladder at computed tomography (CT) following bowel preparation for colonoscopy and to evaluate the incidence of gallbladder contraction at abdominal sonography performed with colonoscopy on the same day. METHODS: During a 1-year period, 222 patients underwent abdominal CT (CT1) and colonoscopy on the same day. Among them, 123 patients had prior CT imaging without receiving colonoscopy in the past were enrolled. Manual estimates of 3D gallbladder volume were obtained from two CT scans to evaluate whether gallbladder volume changed as a result of bowel preparation for colonoscopy. During the same 1-year period, another 89 patients underwent abdominal sonography and colonoscopy on the same day (sonography group). The short-axis diameters of the gallbladder on the longitudinal scan of sonography from these patients were obtained. RESULTS: Gallbladder volume was significantly larger on prior CT without colonoscopy (31.7 ± 15.4 cm3) than on CT1 (20.3 ± 11.1 cm3) (p < 0.001). Gallbladder volume decreased by more than 50% in 41 of 123 patients (33%) who underwent abdominal CT and colonoscopy on the same day, compared with standard CT. In the sonography group (n = 89), the short-axis diameters of the gallbladder were less than 1.5 cm in 41 patients (46%) and less than 1.0 cm in 17 patients (19%). CONCLUSION: Contracted gallbladder secondary to bowel preparation can be seen on imaging when performed with same-day colonoscopy. Such a situation may lead to the incomplete or inadequate evaluation of the gallbladder on imaging with same-day colonoscopy.

Groin abnormalities: ultrasonographic and clinical findings.

Groin lesions can be classified as neoplastic or non-neoplastic. Neoplastic lesions include lipoma, epidermoid cyst, angiomyofibroblastoma-like tumor, liposarcoma, and synovial sarcoma, as well as metastases from lymphoma, neuroendocrine carcinoma, and carcinomas of the lung, breast, urinary bladder, ovary, vulva, and colon. Non-neoplastic lesions include hernias, round ligament varices, endometriosis, Kimura disease, Castleman disease, hematoma, and inflammation. Because the clinical implications and therapeutic strategies for groin lesions vary depending on the cause, the ability to noninvasively differentiate among etiologies is very important. Although there is substantial overlap in ultrasonographic findings across various groin lesions, some ultrasonographic features, along with clinical characteristics, may suggest a specific diagnosis. Familiarity with the ultrasonographic and clinical features of various groin lesions facilitates accurate diagnosis and treatment.

Tumors of the jejunum and ileum: a pattern-based imaging approach on CT.

Since a broad spectrum of tumors can occur in the small bowels, it is not easy to make a correct differential diagnosis among small bowel tumors on CT findings. Therefore, once a mass is detected on CT, the radiologist needs to analyze the mass based on presenting patterns such as location, multiplicity, morphology, and enhancement patterns. In this article, we will illustrate various kinds of small bowel tumors based on imaging patterns at CT to facilitate making a correct diagnosis.

Sonographic Diagnosis of a Colovesical Fistula Due to Sigmoid Colon Cancer.

Based on sonographic findings, colovesical fistula was diagnosed in a 71-year-old man with sigmoid colon cancer. Gray-scale sonography revealed an irregular thickening of the sigmoid colon wall abutting the urinary bladder which also showed thickening in the region of contact. Color Doppler sonography showed a twinkling artifact within the thickened bladder wall. Contrast-enhanced computed tomography scan showed luminal communication between the sigmoid colon and the bladder in the region of thickening.

Torsed appendix epididymis in an adult: misdiagnosis as tumor of tunica vaginalis on sonography.

We report the sonographic findings in a case of torsed appendix epididymis that occurred in an adult, which was misdiagnosed as a tunica vaginalis tumor such as cystic mesothelioma. Scrotal gray-scale sonography revealed an ovoid-shaped, heterogeneously hypoechoic mass with multiple tiny cystic foci and thick septa in the sac of the right tunica vaginalis, which abuts to the right epididymal head. Color Doppler sonography showed no blood flow within the mass. Pathological examination revealed torsion of the appendix epididymis.

The value of initial sonography compared to supplementary CT for diagnosing right-sided colonic diverticulitis.

PURPOSE: The purpose of the study was to assess the value of initial sonography in the diagnosis of right-sided colonic diverticulitis in comparison with supplementary CT. MATERIALS AND METHODS: A total of 183 consecutive adult patients with right lower quadrant pain (73 diverticulitis, and 110 non-diverticulitis) who underwent both initial sonography and subsequent CT within 24 h were enrolled in this study. Two reviewers retrospectively assessed imaging findings of diverticula, colonic wall thickening, inflammatory pericolic fat, and pericolic abscess for each sonography and CT and then classified each case as non-diverticulitis, simple diverticulitis or complicated diverticulitis. Sonography and CT were independently reviewed at 2-week intervals. The value of initial sonography was assessed through head-to-head comparison with CT results. RESULTS: Sensitivity, specificity and accuracy for diagnosing diverticulitis were not significantly different between the two modalities (p = 0.366, 0.605 and 0.259, respectively). In addition, the net sensitivity (97.26%) of both sonography and CT was not significantly different from the sensitivity (89.04%) of sonography alone (p = 0.101). Agreement between sonography and CT for the classification of diverticulitis and the four imaging findings was excellent (all κ > 0.8). CONCLUSION: Initial sonography can be as effective as CT for the diagnosis of right-sided colonic diverticulitis. Supplementary CT is only needed when sonography is inconclusive.

Diagnostic errors when interpreting abdominopelvic computed tomography: a pictorial review.

Diagnostic errors remain an inevitable occurrence during abdominopelvic CT (APCT) interpretation, despite advances in imaging technology. The main cause of error is failure to identify a lesion (i.e. perceptual error) and failure to recognize a finding's significance (i.e. interpretive or cognitive error). Awareness and understanding of the causes of errors can reduce their occurrence and may lead to a reduction in morbidity and mortality. This pictorial essay highlights various causes of error in interpreting APCT scans and briefly discusses possible solutions for minimizing these errors.

Comparison of Low- and Standard-Dose CT for the Diagnosis of Acute Appendicitis: A Meta-Analysis.

OBJECTIVE: A meta-analysis was performed to compare low-dose CT and standard-dose CT in the diagnosis of acute appendicitis with an emphasis on diagnostic value. MATERIALS AND METHODS: A systematic literature search for articles published through June 2016 was performed to identify studies that compared low-dose CT with standard-dose CT for the evaluation of patients suspected of having acute appendicitis. Summary estimates of sensitivity and specificity with 95% CIs were calculated using a bivariate random-effects model. Meta-regression was used to perform statistical comparisons of low-dose CT and standard-dose CT. RESULTS: Of 154 studies, nine studies investigating a total of 2957 patients were included in this meta-analysis. The pooled sensitivity and specificity of low-dose CT were 96.25% (95% CI, 91.88-98.31%) and 93.22% (95% CI, 88.75-96.00%), respectively. The pooled sensitivity and specificity of standard-dose CT were 96.40% (95% CI, 93.55-98.02%) and 92.17% (95% CI, 88.24-94.86%), respectively. In a joint model estimation of meta-regression, lowand standard-dose CT did not show a statistically significant difference (p = 0.71). Both lowand standard-dose CT seem to be characterized by high positive and negative predictive values across a broad spectrum of pretest probabilities for acute appendicitis. CONCLUSION: Low-dose CT is highly effective for the diagnosis of suspected appendicitis and can be considered a valid alternative first-line imaging test that reduces the potential risk of exposure to ionizing radiation.

A Case of Fibrovascular Polyp of the Stomach: Sonographic and Computed Tomographic Findings.

Fibrovascular polyps are rare, pedunculated, tumor-like lesions that are usually found in the esophagus; occurrence in the stomach is very rare. To our knowledge, sonographic and CT findings of a fibrovascular polyp in the stomach have never been reported. Here, we report a case of a fibrovascular polyp that was identified in the gastric antrum and prolapsed into the duodenal bulb. Sonography revealed a hyperechoic polypoid mass in the gastric antrum, which prolapsed into the duodenal bulb upon a change in the patient's position. CT also revealed a pedunculated polypoid mass with an inner fatty component.

Prostate cancer: correlation of intravoxel incoherent motion MR parameters with Gleason score.

PURPOSE: To evaluate the potential of intravoxel incoherent motion (IVIM) imaging to predict histological prognostic parameters by investigating whether IVIM parameters correlate with Gleason score. MATERIALS AND METHODS: The institutional review board approved this retrospective study, and informed consent was waived. A total of 41 patients with histologically proven prostate cancer who underwent prostate MRI using a 3T MRI machine were included. For eight diffusion-weighted imaging b-values (0, 10, 20, 50, 100, 200, 500, and 800s/mm(2)), a spin-echo echo-planar imaging sequence was performed. D, f, D(⁎), and ADCfit values were compared among three groups of patients with prostate cancer: Gleason score 6 (n=9), 7 (n=16), or 8 or higher (n=16). Receiver operating characteristic (ROC) curves were generated for D, f, D(⁎), and ADCfit to assess the ability of each parameter to distinguish cancers with low Gleason scores from cancers with intermediate or high Gleason scores. RESULTS: Pearson's coefficient analysis revealed significant negative correlations between Gleason score and ADCfit (r=-0.490, P=.001) and Gleason score and D values (r=-0.514, P=.001). Gleason score was poorly correlated with f (r=0.168, P=.292) and D(⁎) values (r=-0.108, P=.500). The ADCfit and D values of prostate cancers with Gleason scores 7 or ≥8 were significantly lower than values for prostate cancers with Gleason score 6 (P<.05). ROC curves were constructed to assess the ability of IVIM parameters to discriminate prostate cancers with Gleason score 6 from cancers with Gleason scores 7 or ≥8. Areas under the curve were 0.671 to 0.974. ADCfit and D yielded the highest Az value (0.960-0.956), whereas f yielded the lowest Az value (0.633). CONCLUSIONS: The pure molecular diffusion parameter, D, was the IVIM parameter that best discriminated prostate cancers with low Gleason scores from prostate cancers with intermediate or high Gleason scores.

Diagnostic Usefulness of Low-Dose Nonenhanced Computed Tomography With Coronal Reformations in Patients With Suspected Acute Appendicitis: A Comparison With Standard-Dose Computed Tomography.

PURPOSE: The aims of the study were to evaluate the usefulness of low-dose (LD) nonenhanced CT (NECT) with coronal reformation in diagnosing acute appendicitis and to compare LD NECT with standard-dose (SD) NECT and SD contrast-enhanced CT (CECT). METHODS: A total of 452 patients suspected of having acute appendicitis underwent CT using a scan 1 (SD NECT and SD CECT1, n = 182) or a scan 2 protocol (LD NECT and SD CECT2, n = 270). The diagnostic performance and interobserver agreement for diagnosing acute appendicitis were compared. RESULTS: Although the area under the curves of both reviewers of LD NECT were lower than those of SD CECT2, area under the curves of both reviewers for SD NECT were not significantly different for SD CECT1 and LD NECT (all P > 0.05). The interobserver agreements within each scan were excellent (all κ > 0.8). CONCLUSIONS: Low-dose NECT with coronal reformation showed high diagnostic performance and can be used as the first-line imaging tool in the work-up of patients with suspected acute appendicitis.

Cystic Duct Enhancement: A Useful CT Finding in the Diagnosis of Acute Cholecystitis Without Visible Impacted Gallstones.

OBJECTIVE: The purpose of this study was to determine the incremental value of the presence of cystic duct enhancement for diagnosing acute cholecystitis without visible impacted gallstones. MATERIALS AND METHODS: CT scans of 63 patients with acute cholecystitis and 63 control subjects were retrospectively and independently reviewed by two radiologists to determine the presence of cystic duct enhancement or impacted stones. Two additional radiologists were then asked to independently evaluate all CT images using a 5-point scoring system for diagnosing acute cholecystitis. They conducted the evaluations both before and after being informed that cystic duct enhancement could be substituted for a CT finding of impacted gallstones. RESULTS: The prevalence of either cystic duct enhancement or stone impaction was observed to be significantly more common in the patient group (86-91%) than in the control group (6-14%) (p < 0.001) with good interobserver agreement (κ = 0.79). Diagnostic sensitivities increased significantly from 60.3% to 85.7% for reviewer 1 (p = 0.001) and from 71.4% to 87.3% for reviewer 2 (p = 0.028) after the reviewers were informed of the presence of cystic duct enhancement. Diagnostic accuracy increased significantly for the less experienced radiologist, from 75.4% to 87.3% (p = 0.015). CONCLUSION: The accuracy and sensitivity of CT for the diagnosis of acute cholecystitis improved significantly when cystic duct enhancement was used as an alternative to impacted gallstones as a diagnostic criterion.