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.

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.

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.

Does the Degree of Perihepatitis Have Any Relevance to the Severity of the Manifestations of Pelvic Inflammatory Disease on Multidetector Computed Tomography?

PURPOSE: This study aimed to evaluate the relationship between the degree of perihepatitis and the severity of pelvic inflammatory disease (PID) on multidetector computed tomography (MDCT). METHODS: A total of 177 women with PID who underwent biphasic abdominal computed tomography (CT) scans were enrolled. Two reviewers retrospectively reviewed the CT scans with consensus and subjectively categorized the severity of PID into 4 grades (normal, mild, moderate, and severe). Another reviewer independently assigned the extent (grades 0 to 4) and the depth (grades 0 to 4) of hepatic surface enhancement in terms of the degree of perihepatitis. Relationships between the degree of perihepatitis and the CT severity as well as each CT manifestation of PID were evaluated using the χ test or a cumulative logistic regression analysis. RESULTS: Of the 177 patients, 99 (55.9%) showed hepatic surface enhancement. The severity of PID on MDCT was significantly related with the degree of perihepatitis (all P < 0.001). Salpingitis, oophoritis, pelvic fat haziness, complicated ascites, and omental/mesenteric fat infiltration were significantly related with the degree of perihepatitis (all P < 0.05). Among these variables, omental/mesenteric fat infiltration (odds ratio = 10.9) and salpingitis (odds ratio = 6.0) were the CT manifestations that were most associated with the presence of perihepatitis in PID. CONCLUSIONS: The degree of perihepatitis seems to show a relationship with the severity of PID on MDCT. Omental/mesenteric fat infiltration and salpingitis can be strongly related with perihepatitis in PID.

A case of intussusception of the appendix secondary to endometriosis: US and CT findings.

Intussusception of the appendix is an uncommon condition that is difficult to diagnose with radiology. Endometriosis causing appendiceal intussusception is a rare condition that has only been reported a few times in the literature. Here, we report a case of appendiceal intussusception caused by endometriosis in a 33-year-old woman who presented with intermittent right lower abdominal pain. Sonography revealed a hypoechoic mass invaginating into the cecum, which was covered by echogenic cecal wall with central dimpling indicating the appendiceal orifice. On CT, the mass was identified as an enhancing mass invaginating into the cecum at the level the appendiceal orifice.

Gastrointestinal tract perforation: evaluation of MDCT according to perforation site and elapsed time.

OBJECTIVES: To evaluate multidetector computed tomography (MDCT) for the prediction of perforation site according to each gastrointestinal (GI) tract site and elapsed time. METHODS: One hundred and sixty-eight patients who underwent MDCT before laparotomy for GI tract perforation were enrolled and allocated to an early or late lapse group based on an elapsed time of 7 h. Two reviewers independently evaluated the perforation site and assessed the following CT findings: free air location, mottled extraluminal air bubbles, focal bowel wall discontinuity, segmental bowel wall thickening, perivisceral fat stranding and localised fluid collection. RESULTS: The overall diagnostic accuracy was 91.07 % and 91.67 % for reviewers 1 and 2, respectively, with excellent agreement (kappa 0.86). Accuracies (98.97 % and 97.94 %) and agreements (kappa 0.894) for stomach and duodenum perforation were higher than for other perforation sites. Strong predictors of perforation at each site were: focal bowel wall discontinuity for stomach, duodenal bulb and left colon, mottled extraluminal air bubbles for retroperitoneal duodenum and right colon, and segmental bowel wall thickening for small bowel. The diagnostic accuracy was not different between the early- and late-lapse groups. CONCLUSIONS: MDCT can accurately predict upper GI tract perforation with high reliability. Elapsed time did not affect the accuracy of perforation site prediction. KEY POINTS: Perforation of the stomach and duodenum can be accurately predicted with MDCT. Knowledge of CT findings predicting perforation site can improve diagnostic accuracy. Elapsed time does not significantly affect accuracy in predicting perforation sites.

Sonographic findings of tuberculous vasitis.

The purpose of this series was to describe the sonographic findings of tuberculous vasitis. We conducted a retrospective analysis of 3 cases of tuberculous vasitis. The following grayscale and color Doppler sonographic features were analyzed: location, echogenicity of the lesion, epididymal or testicular involvement, presence of hydrocele, and blood flow within the lesion. All 3 patients had focal (n = 2) or multifocal (n = 1) involvement of the scrotal segment of the vas deferens. The sonographic findings for tuberculous vasitis were heterogeneously hypoechoic in all of the cases. On color Doppler sonography, no blood flow was identified within the lesions of the vas deferens. All 3 patients had tuberculous epididymitis in addition to tuberculous vasitis. Tuberculous vasitis presents with infection along with tuberculous epididymitis, and it appears as a heterogeneously hypoechoic lesion in the scrotal segment of the vas deferens adjacent to the epididymal tail.

Dropped omental fat post laparoscopy-assisted distal gastrectomy with omentectomy mistaken for malignant peritoneal seeding on sonography.

We report the sonographic findings in a case of dropped omental fat post laparoscopy-assisted distal gastrectomy with omentectomy for stomach cancer mistaken for malignant intraperitoneal seeding. Gray-scale sonography revealed an ovoid-shaped hyperechoic mass with central poorly defined hypoechoic portion in the right perihepatic space. Color Doppler sonography showed no blood flow within the mass. Contrast-enhanced CT scan of the liver revealed an oval-shaped fatty mass with a CT number of -100 HU

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.

Does computed tomography have any additional value after sonography in patients with suspected acute appendicitis?

OBJECTIVES: The purpose of this study was to evaluate the additional value of supplementary computed tomography (CT) after sonography for diagnosing acute appendicitis. METHODS: Among 140 consecutive patients with suspected acute appendicitis who underwent both initial sonography and supplementary CT within 12 hours, 88 patients whose appendices could not be visualized on sonography were excluded. The remaining 52 patients (mean age, 37.3 years; range, 15-98 years) were enrolled in this study. Two radiologists retrospectively reviewed the findings of 52 sonographic and CT examinations, and the appendix of each patient was classified as normal, equivocal appendicitis, nonperforated acute appendicitis, or perforated appendicitis. Causes of right lower quadrant pain other than appendicitis were also recorded. The additional value of supplementary CT was evaluated by performing head-to-head comparisons between CT and sonographic results. RESULTS: No patients with a normal appendix on sonography showed appendicitis on CT. In addition, there were no patients with a sonographic diagnosis of appendicitis who had a normal appendix on CT. Ten patients (19.2%) were determined to have additional value gained from CT. Among these 10 patients, however, the additional information from CT affected treatment modality decisions in only 5. CONCLUSIONS: Initial sonography can be as effective as CT in patients with suspected acute appendicitis when the results are definite. Supplementary CT should only be performed when sonography is inconclusive.

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.

Reassessment of CT images to improve diagnostic accuracy in patients with suspected acute appendicitis and an equivocal preoperative CT interpretation.

OBJECTIVES: To identify CT features that discriminate individuals with and without acute appendicitis in patients with equivocal CT findings, and to assess whether knowledge of these findings improves diagnostic accuracy. METHODS: 53 patients that underwent appendectomy with an indeterminate preoperative CT interpretation were selected and allocated to an acute appendicitis group or a non-appendicitis group. The 53 CT examinations were reviewed by two radiologists in consensus to identify CT findings that could aid in the discrimination of those with and without appendicitis. In addition, two additional radiologists were then requested to evaluate independently the 53 CT examinations using a 4-point scale, both before and after being informed of the potentially discriminating criteria. RESULTS: CT findings found to be significantly different in the two groups were; the presence of appendiceal wall enhancement, intraluminal air in appendix, a coexistent inflammatory lesion, and appendiceal wall thickening (P < 0.05). Areas under the curves of reviewers 1 and 2 significantly increased from 0.516 and 0.706 to 0.677 and 0.841, respectively, when reviewers were told which CT variables were significant (P = 0.0193 and P = 0.0397, respectively). CONCLUSIONS: Knowledge of the identified CT findings was found to improve diagnostic accuracy for acute appendicitis in patients with equivocal CT findings. KEY POINTS: • Numerous patients with clinically equivocal appendicitis do not have acute appendicitis • Computed tomography (CT) helps to reduce the negative appendectomy rate • CT is not always infallible and may also demonstrate indeterminate findings • However knowledge of significant CT variables can further reduce negative appendectomy rate • An equivocal CT interpretation of appendicitis should be reassessed with this knowledge.

Imaging findings of ruptured abdominal and pelvic tumors.

A variety of abdominal and pelvic tumors can present with rupture leading to hemoperitoneum/hemoretroperitoneum or peritonitis. Imaging plays an important role in the diagnosis of hemorrhage or peritonitis as well as in the detection of ruptured tumors or organs. In this article, we illustrate the imaging findings of ruptured tumors arising in the abdominal and pelvic organs while excluding those of ruptured tumors arising in the stomach and intestines. It is important for the radiologists to understand the mechanisms involved in tumor rupture and recognize the imaging features of ruptured tumors according to the organs involved because this will permit the exact diagnosis of ruptured tumors, thereby facilitating prompt and effective treatment.

Color Doppler twinkling artifacts in small-bowel bezoars.

Small-bowel bezoars usually form in the stomach and may subsequently cause small-bowel obstruction. Bezoars associated with small-bowel obstruction have been accurately diagnosed by computed tomography, although some case reports have described the specific sonographic findings of small-bowel bezoars. Bezoars can be overlooked by sonographic examination if a dilated small-bowel loop contains a large amount of air. Twinkling artifacts on color Doppler images appear as rapidly fluctuating red and blue signals behind certain strongly reflecting structures. In this series, we hypothesize that twinkling artifacts might appear in small-bowel bezoars, and we describe the presence of twinkling artifacts in 3 cases of small-bowel bezoars presenting as small-bowel obstruction.

Sonographic evaluation of anterosuperior hip labral tears with magnetic resonance arthrographic and surgical correlation.

OBJECTIVES: The purpose of this study was to retrospectively evaluate the sonographic findings compared with magnetic resonance (MR) arthrographic and arthroscopic findings in diagnosis of anterosuperior labral tears of the hip. METHODS: The Ethics Committees of our institution did not require patient approval or informed consent for this retrospective study. Sixteen symptomatic patients (4 male and 12 female; mean age, 43 years) with sonography, MR arthrography, and arthroscopy were enrolled. At arthroscopy, 11 patients were shown to have anterosuperior labral tears. We evaluated the findings of the anterosuperior acetabular labrum on sonography, with an emphasis on the presence or absence and types of labral tears, and correlated the findings with MR arthrography and arthroscopy. The types of tears were classified into radial flap, radial fibrillated, and longitudinal peripheral (base) tears. We calculated the sensitivity, specificity, and accuracy of sonography and MR arthrography. RESULTS: On sonography, 12 of 16 patients (75%) had a correct diagnosis of the presence or absence of an anterosuperior labral tear. On MR arthrography, 14 of 16 patients (88%) had a correct diagnosis of the presence or absence of a tear. The sensitivity, specificity, and accuracy for the diagnosis of tears by sonography and MR arthrography were 82%, 60%, and 75% and 91%, 80%, and 88%, respectively. CONCLUSIONS: When the arthroscopic results were used as the reference standard, our preliminary study revealed that sonography managed to show anterosuperior labral abnormalities, although it had a lesser diagnostic ability than MR arthrography in diagnosing anterosuperior labral tears. Additional investigations including larger numbers of patients are required to determine whether sonography can be an alternative or adjunctive imaging technique for diagnosis of hip labral tears, especially in patients who decline or are unable to undergo MR arthrography.

Sonographic findings of fibrous pseudotumor of the tunica vaginalis.

We report the sonographic findings in a case of fibrous pseudotumor of the tunica vaginalis. Scrotal gray-scale sonography revealed a well-margined, hypoechoic mass with an onion ring appearance and central calcifications in the left scrotum. Color Doppler sonography showed no blood flow within the mass. The pathological examination revealed a fibrous pseudotumor with a paucicellular and fibroblastic proliferation of cells within a hyalinized collagenous stroma.

Uterus-like mass involving the appendix: US and CT findings.

Uterus-like mass is a rare extrauterine mass composed of a central cavity lined by endometrium and surrounding smooth muscle. Uterus-like mass has frequently been reported in the ovary, but has rarely been found in extraovarian regions. We report a case of uterus-like mass involving the appendix in a woman who presented with right lower abdominal pain indistinguishable from acute appendicitis. Sonography revealed a heterogeneous mass of mixed echogenicity with inner cystic change, abutting the appendix. CT depicted an enhanced mass with inner cystic change abutting the appendix. Histopathologic examination confirmed the diagnosis.

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.

Optimization of a double inversion recovery sequence for noninvasive synovium imaging of joint effusion in the knee.

PURPOSE: We wanted to optimize a double inversion recovery (DIR) sequence to image joint effusion regions of the knee, especially intracapsular or intrasynovial imaging in the suprapatellar bursa and patellofemoral joint space. METHODS: Computer simulations were performed to determine the optimum inversion times (TI) for suppressing both fat and water signals, and a DIR sequence was optimized based on the simulations for distinguishing synovitis from fluid. In vivo studies were also performed on individuals who showed joint effusion on routine knee MR images to demonstrate the feasibility of using the DIR sequence with a 3T whole-body MR scanner. To compare intracapsular or intrasynovial signals on the DIR images, intermediate density-weighted images and/or post-enhanced T1-weighted images were acquired. RESULTS: The timings to enhance the synovial contrast from the fluid components were TI1 = 2830 ms and TI2 = 254 ms for suppressing the water and fat signals, respectively. Improved contrast for the intrasynovial area in the knees was observed with the DIR turbo spin-echo pulse sequence compared to the intermediate density-weighted sequence. CONCLUSIONS: Imaging contrast obtained noninvasively with the DIR sequence was similar to that of the post-enhanced T1-weighted sequence. The DIR sequence may be useful for delineating synovium without using contrast materials.