A sling of a normal right inferior vena cava around the abdominal aorta.

Variations in the anatomy of inferior vena cava (IVC) may have important clinical implications. In-depth knowledge of its embryology and variations are of fundamental importance to prevent any potential medical complications related to anatomic variations of the IVC. In this article, we described a previously unreported, to the best of our knowledge, a variation of IVC. In the case we presented, the IVC was seen almost completely encircling the abdominal aorta. We decided to call this anatomic variation as "a sling of a normal right IVC around the abdominal aorta". Cross-sectional imaging is a prompt and highly reliable method to evaluate IVC anatomy and may have significant clinical importance to prevent any potential complications related to IVC during surgery or interventional radiology procedures.

Prostatitis, the Great Mimicker of Prostate Cancer: Can We Differentiate Them Quantitatively With Multiparametric MRI?

OBJECTIVE. The purpose of this study was to investigate the diagnostic performance of semiquantitative and quantitative pharmacokinetic parameters and quantitative apparent diffusion coefficient (ADC) values obtained from prostate multiparametric MRI (mpMRI) to differentiate prostate cancer (PCa) and prostatitis objectively. MATERIALS AND METHODS. We conducted a retrospective review of patients with biopsy-proven PCa or prostatitis who underwent mpMRI study between January 2015 and February 2018. Mean ADC, forward volume transfer constant (Ktrans), reverse volume transfer constant (kep), plasma volume fraction (Vp), extravascular extracellular space volume fraction (Ve), and time to peak (TTP) values were calculated for both lesions and contralateral normal prostate tissue. Signal intensity-time curves were analyzed. Lesion-to-normal prostate tissue ratios of pharmacokinetic parameters were also calculated. The diagnostic accuracy and cutoff points of all parameters were analyzed to differentiate PCa from prostatitis. RESULTS. A total of 138 patients (94 with PCa and 44 with prostatitis) were included in the study. Statistically, ADC, quantitative pharmacokinetic parameters (Ktrans, kep, Ve, and Vp), their lesion-to-normal prostate tissue ratios, and TTP values successfully differentiated PCa and prostatitis. Surprisingly, we found that Ve values were significantly higher in prostatitis lesions. The combination of these parameters had 92.7% overall diagnostic accuracy. ADC, kep, and TTP made up the most successful combination for differential diagnosis. Analysis of the signal intensity-time curves showed mostly type 2 and type 3 enhancement curve patterns for patients with PCa. Type 3 curves were not seen in any prostatitis cases. CONCLUSION. Quantitative analysis of mpMRI differentiates PCa from prostatitis with high sensitivity and specificity, appears to have significant potential, and may improve diagnostic accuracy. In addition, evaluating these parameters does not cause any extra burden to the patients.

Imaging findings of congenital anomalies of seminal vesicles.

The seminal vesicles are paired organs of the male reproductive tract, which produce and secrete seminal fluid. Although congenital anomalies of seminal vesicles are usually asymptomatic, they may lead to various urogenital symptoms, including infertility. Due to their embryologic relationship with other urogenital organs, congenital anomalies of seminal vesicles may accompany other urinary or genital anomalies. Congenital anomalies of seminal vesicles include agenesis, hypoplasia, duplication, fusion, and cyst. These anomalies can be diagnosed with various imaging techniques. The main purpose of this article is to summarise imaging findings and clinical importance of congenital anomalies of seminal vesicles with images of some rare and previously unreported anomalies.

A new technique for the diagnosis of acute appendicitis: abdominal CT with compression to the right lower quadrant.

OBJECTIVE: To determine the diagnostic accuracy of abdominal CT with compression to the right lower quadrant (RLQ) in adults with acute appendicitis. METHODS: 168 patients (age range, 18-78 years) were included who underwent contrast-enhanced CT for suspected appendicitis performed either using compression to the RLQ (n = 71) or a standard protocol (n = 97). Outer diameter of the appendix, appendiceal wall thickening, luminal content and associated findings were evaluated in each patient. Kruskal-Wallis, Fisher's and Pearson's chi-squared tests were used for statistical analysis. RESULTS: There was no significant difference in the mean outer diameter (MOD) between compression CT scans (10.6 ± 1.9 mm) and standard protocol (11.2 ± 2.3 mm) in patients with acute appendicitis (P = 1). MOD was significantly lower in the compression group (5.2 ± 0.8 mm) compared to the standard protocol (6.5 ± 1.1 mm) (P < 0.01) in patients without appendicitis. A cut-off value of 6.75 mm for the outer diameter of the appendix was found to be 100% sensitive in the diagnosis of acute appendicitis for both groups. The specificity was higher for compression CT technique (67.7 vs. 94.9%). CONCLUSION: Normal appendix diameter was significantly smaller in the compression-CT group compared to standard-CT group, increasing diagnostic accuracy of abdominal compression CT. KEY POINTS: • Normal appendix diameter is significantly smaller in compression CT. • Compression could force contrast material to flow through the appendiceal lumen. • Compression CT may be a CT counterpart of graded compression US.

Hepatobiliary Tuberculosis: Imaging Findings.

OBJECTIVE: Tuberculosis (TB) may present with highly variable imaging findings. The findings may vary from nonspecific hepatomegaly to abscesses or solid focal lesions, mimicking liver tumors. Biliary tract involvement may also be detected, which may manifest with ductal dilatations from underlying strictures. CONCLUSION: All cross-sectional imaging modalities, including sonography, CT, and MRI, may be used in the evaluation of patients with TB. Imaging findings may be perplexing to radiologists, particularly ones who practice in areas where TB is not endemic; thus, histopathologic diagnosis may be required.

CT and MRI of aortic coarctation: pre- and postsurgical findings.

OBJECTIVE. The purpose of this article is to summarize the roles of CT and MRI in the diagnosis and follow-up of patients with aortic coarctation. CONCLUSION. Aortic coarctation is a common congenital heart disease accounting for approximately 6-8% of congenital heart defects. Despite its deceptively simple anatomic presentation, it is a complex medical problem with several associated anatomic and physiologic abnormalities. CT and MRI may provide very accurate information of the coarctation anatomy and other associated cardiac abnormalities.

Ultralow-Dose Abdominal Computed Tomography: Comparison of 2 Iterative Reconstruction Techniques in a Prospective Clinical Study.

PURPOSE: To assess lesion detection and image quality of ultralow-dose (ULD) abdominal computed tomography (CT) reconstructed with filtered back projection (FBP) and 2 iterative reconstruction techniques: hybrid-based iDose, and image-based SafeCT. MATERIALS AND METHODS: In this institutional review board-approved ongoing prospective clinical study, 41 adult patients provided written informed consent for an additional ULD abdominal CT examination immediately after standard dose (SD) CT exam on a 256-slice multidetector computed tomography (iCT, Philips-Healthcare). The SD examination (size-specific dose estimate, 10 ± 3 mGy) was performed at 120 kV with automatic exposure control, and reconstructed with FBP. The ULD examination (1.5 ± 0.4 mGy) was performed at 120 kV and fixed tube current of 17 to 20 mAs/slice to achieve ULD radiation dose, with the rest of the scan parameters same as SD examination. The ULD data were reconstructed with (a) FBP, (b) iDose, and (c) SafeCT. Lesions were detected on ULD FBP series and compared to SD FBP "reference-standard" series. True lesions, pseudolesions, and missed lesions were recorded. Four abdominal radiologists independently blindly performed subjective image quality. Objective image quality included image noise calculation and noise spectral density plots. RESULTS: All true lesions (n, 52: liver metastases, renal cysts, diverticulosis) in SD FBP images were detected in ULD images. Although there were no missed or pseudolesions on ULD iDose and ULD SafeCT images, appearance of small low-contrast hepatic lesions was suboptimal. The ULD FBP images were unacceptable across all patients for both lesion detection and image quality. In patients with a body mass index (BMI) of 25 kg/m or less, ULD iDose and ULD SafeCT images were acceptable for image quality that was close to SD FBP for both normal and abnormal abdominal and pelvic structures. With increasing BMI, the image quality of ULD images was deemed unacceptable due to photo starvation. Evaluation of kidney stones with ULD iDose/SafeCT images was found acceptable regardless of patient size. Image noise levels were significantly lower in ULD iDose and ULD SafeCT images compared to ULD FBP (P < 0.01). CONCLUSIONS: Preliminary results show that ULD abdominal CT reconstructed with iterative reconstruction techniques is achievable in smaller patients (BMI ≤ 25 kg/m) but remains a challenge for overweight to obese patients. Lesion detection is similar in full-dose SD FBP and ULD iDose/SafeCT images, with suboptimal visibility of low-contrast lesions in ULD images.

Imaging of hepatobiliary involvement in sarcoidosis.

Sarcoidosis is mainly a disease of the respiratory system; however, several other organ systems may be affected in the course of the disease. Liver is one of the most frequently affected organs in the setting of sarcoidosis after lungs and lymph nodes. Microscopic hepatic involvement is common in these patients but is mostly clinically silent. However, in a significant portion of these patients, macroscopic findings can be detected in the course of the disease, and these findings may easily be confused with other benign and malignant conditions of the liver. The purposes of this article are to briefly summarize the clinical findings and the underlying pathophysiology of sarcoidosis and detailed presentation of the radiologic findings of hepatic involvement in this disease. We subgrouped the imaging findings based on the location and the radiologic appearance of the hepatic involvement. We tried to provide images that would enable the readers to link the imaging findings with the underlying pathology and clinical symptoms.

Feasibility and effectiveness of image-guided percutaneous biopsy of the urinary bladder.

PURPOSE: To evaluate the indications, technique, results, and complications of image-guided percutaneous biopsy of the urinary bladder. METHODS: This retrospective study included 15 patients (10 male, 5 female) who underwent image-guided percutaneous biopsy of the urinary bladder between January 1999 and December 2013. The medical records, imaging studies, procedural details, and long-term follow-up of each patient were reviewed in detail to assess the feasibility of percutaneous bladder biopsy. RESULTS: Ten patients had focal bladder masses and 5 patients had asymmetric or diffuse bladder wall thickening. Eleven patients had either negative or unsatisfactory cystoscopies prior to the biopsy. Percutaneous biopsies were performed under computed tomography guidance in 12 patients and ultrasound in 3 patients. All procedures were technically successful and there were no procedural complications. Malignancy was confirmed in 8 patients, among whom 6 had transitional cell carcinoma, 1 cervical cancer, and 1 prostate cancer metastasis. Seven patients had a benign diagnosis, including 3 that were later confirmed by pathology following surgery and 2 patients with a false-negative result. The overall sensitivity was 80% and accuracy was 87%. CONCLUSIONS: Image-guided percutaneous biopsy of the urinary bladder is a safe and technically feasible procedure with a high sensitivity and accuracy rate. Although image-guided bladder biopsy is an uncommon procedure, it should be considered in selected cases when more traditional methods of tissue sampling are either not possible or fail to identify abnormalities detected by cross-sectional imaging.

Associations Between Hepatic and Pancreatic Steatosis with Lumbar Spinal Bone Marrow Fat: A Single-Center Magnetic Resonance Imaging Study.

BACKGROUND: To evaluate the associations between hepatic, pancreatic steatosis, and lumbar spinal bone marrow fat determined by magnetic resonance imaging-proton density fat fraction in patients with no known or suspected liver disease. METHODS: A total of 200 patients who were referred to our radiology department for upper abdominal magnetic resonance imaging between November 2015 and November 2017 were included in this study. All patients underwent a magnetic resonance imaging-proton density fat fraction on a 1.5-T magnetic resonance imaging system. RESULTS: The mean liver, pancreas, and lumbar magnetic resonance imaging-proton density fat fraction were 7.52 ± 4.82%, 5.25 ± 5.44%, and 46.85 ± 10.38% in the study population. There were significant correlations between liver and pancreas (rs = 0.180, P = .036), liver and lumbar (rs = 0.317, P < .001), and pancreas and lumbar magnetic resonance imaging-proton density fat fraction (rs = 0.215, P = .012) in female patients. A weak correlation was observed between liver and lumbar magnetic resonance imaging-proton density fat fraction (rs = 0.174, P = .014) in the total population. The prevalence of hepatic and pancreatic steatosis was 42.5% and 29%, respectively. The prevalence of pancreatic steatosis (42.9% vs. 22.8%, P = .004) was higher in male patients compared to female patients. In subgroup analysis, in patients with hepatic steatosis, there were higher pancreas magnetic resonance imaging-proton density fat fraction (6.07 ± 6.42% vs. 4.66 ± 4.53%, P = .036) and lumbar magnetic resonance imaging-proton density fat fraction (48.81 ± 10.01% vs. 45.40 ± 10.46%, P =.029) compared to patients without hepatic steatosis. In patients with pancreatic steatosis, there were higher liver (9.07 ± 6.08 vs. 6.87 ± 4.06, P = .009) and lumbar magnetic resonance imaging-proton density fat fraction (49.31 ± 9.13% vs.45.83 ± 10.76%, P = .032) in comparison with patients without pancreatic steatosis. CONCLUSION: Based on the results of the present study, fat accumulation in liver, pancreas, and lumbar vertebra have associations with more evident in females.

Long-term follow-up results of multiparametric prostate MRI and the prognostic value of PI-RADS: a single-center retrospective cohort study.

PURPOSE: We aim to examine the long-term outcomes of patients who underwent multiparametric prostate magnetic resonance imaging (mp-MRI) for suspected prostate cancer (PCa), specifically based on their initial Prostate Imaging Reporting and Data System (PI-RADS) categories and various clinical factors. Our secondary aim is to evaluate the prognostic value of the PI-RADS through the National Comprehensive Cancer Network (NCCN) risk group distribution. METHODS: This research was conducted as a single-center retrospective cohort study in a tertiary care hospital. A total of 1,359 cases having at least one histopathological examination after the initial mp-MRI and/or adequate clinical/radiological follow-up data were included in the clinically significant PCa (cs-PCa) diagnosis-free survival analysis. Initial mp-MRI dates were accepted as the start of follow-up for the time-to-event analysis. The event was defined as cs-PCa diagnosis (International Society of Urological Pathology ≥2). Patients who were not diagnosed with cs-PCa during follow-up were censored according to predefined literature-based criteria at the end of the maximum follow-up duration with no reasonable suspicion of PCa and no biopsy indication. The impact of various factors on survival was assessed using a log-rank test and multivariable Cox regression. Subsequently, 394 cases diagnosed with PCa during follow-up were evaluated, based on initial PI-RADS categories and NCCN risk groups. RESULTS: Three main risk factors for cs-PCa diagnosis during follow-up were an initial PI-RADS 5 category, initial PI-RADS 4 category, and high MRI-defined PSA density (mPSAD), with average hazard ratios of 29.52, 14.46, and 3.12, respectively. The PI-RADS 3 category, advanced age group, and biopsy-naïve status were identified as additional risk factors (hazard ratios: 2.03, 1.54-1.98, and 1.79, respectively). In the PI-RADS 1-2 cohort, 1, 3, and 5-year cs-PCa diagnosis-free survival rates were 99.1%, 96.5%, and 93.8%, respectively. For the PI-RADS 3 cohort, 1, 3, and 5-year cs-PCa diagnosis-free survival rates were 94.9%, 90.9%, and 89.1%, respectively. For the PI-RADS 4 cohort, 1, 3, and 5-year cs-PCa diagnosis-free survival rates were 56.6%, 55.1%, and 55.1%, respectively. These rates were found to all be 24.2% in the PI-RADS 5 cohort. Considering the 394 cases diagnosed with PCa during follow-up, PI-RADS ≥4 cases were more likely to harbor unfavorable PCa compared to PI-RADS ≤3 cases (P < 0.001). In the PI-RADS 3 subgroup analysis, a low mPSAD (<0.15 ng/mL2) was found to be a protective prognostic factor against unfavorable PCa (P = 0.005). CONCLUSION: The PI-RADS category has a significant impact on patient management and provides important diagnostic and prognostic information. Higher initial PI-RADS categories are associated with decreased follow-up losses, a shorter time to PCa diagnosis, increased biopsy rates, a higher likelihood of developing cs-PCa during follow-up, and a worse PCa prognosis. Combining mPSAD with PI-RADS categories could enhance diagnostic stratification in the identification of cs-PCa.

Infarcts and ischemia in the abdomen: an imaging perspective with an emphasis on cross-sectional imaging findings.

Infarcts and ischemia of abdominal organs may present with acute abdominal pain, and early diagnosis is crucial to prevent morbidity and mortality. Unfortunately, some of these patients present in poor clinical conditions to the emergency department, and imaging specialists are crucial for optimal outcomes. Although the radiological diagnosis of abdominal infarcts is often straightforward, it is vital to use the appropriate imaging modalities and correct imaging techniques for their detection. Additionally, some non-infarct-related abdominal pathologies may mimic infarcts, cause diagnostic confusion, and result in delayed diagnosis or misdiagnosis. In this article, we aimed to outline the general imaging approach, present cross-sectional imaging findings of infarcts and ischemia in several abdominal organs, including but not limited to, liver, spleen, kidneys, adrenals, omentum, and intestinal segments with relevant vascular anatomy, discuss possible differential diagnoses and emphasize important clinical/radiological clues that may assist radiologists in the diagnostic process.

Evaluation of abdominal computed tomography findings in patients with COVID-19: a multicenter study

PURPOSE: To evaluate the frequency of abdominal computed tomography (CT) findings in patients with coronavirus disease-2019 (COVID-19) and interrogate the relationship between abdominal CT findings and patient demographic features, clinical findings, and laboratory test results as well as the CT atherosclerosis score in the abdominal aorta. METHODS: This study was designed as a multicenter retrospective study. The abdominal CT findings of 1.181 patients with positive abdominal symptoms from 26 tertiary medical centers with a positive polymerase chain-reaction test for severe acute respiratory syndrome coronavirus 2 were reviewed. The frequency of ischemic and non-ischemic CT findings as well as the association between CT findings, clinical features, and abdominal aortic calcific atherosclerosis score (AA-CAS) were recorded. RESULTS: Ischemic and non-ischemic abdominal CT findings were detected in 240 (20.3%) and 328 (27.7%) patients, respectively. In 147 patients (12.4%), intra-abdominal malignancy was present. The most frequent ischemic abdominal CT findings were bowel wall thickening (n = 120; 10.2%) and perivascular infiltration (n = 40; 3.4%). As for non-ischemic findings, colitis (n = 91; 7.7%) and small bowel inflammation (n = 73; 6.2%) constituted the most frequent disease processes. The duration of hospital stay was found to be higher in patients with abdominal CT findings than in patients without any positive findings (13.8 ± 13 vs. 10.4 ± 12.8 days, P < 0.001). The frequency of abdominal CT findings was significantly higher in patients who did not survive the infection than in patients who were discharged after recovery (41.7% vs. 27.4%, P < 0.001). Increased AA-CAS was found to be associated with a higher risk of ischemic conditions in abdominal CT examinations. CONCLUSION: Abdominal symptoms in patients with COVID-19 are usually associated with positive CT findings. The presence of ischemic findings on CT correlates with poor COVID-19 outcomes. A high AA-CAS is associated with abdominal ischemic findings in patients with COVID-19.

Proton density fat fraction: magnetic resonance imaging applications beyond the liver.

Magnetic resonance imaging-proton density fat fraction (MRI-PDFF) is an emerging quantitative imaging biomarker that accurately measures the fat fraction of tissue by correcting factors influencing magnetic resonance signal intensity. Beyond fat quantification, it also measures R2* which is a direct measure of iron concentration. The utilization of MRI-PDFF in liver diseases is well established. In the present review, we focused on applications of MRI-PDFF in different body areas including pancreas, bone, muscle, spleen, testis, visceral, and subcutaneous adipose tissue. Future studies can enable tracking of quantitative fat fraction changes in different organs simultaneously, which can be critical in understanding fat metabolism.

Imaging findings of spontaneous intraabdominal hemorrhage: neoplastic and non-neoplastic causes.

Contrary to traumatic and iatrogenic intraabdominal hemorrhages, spontaneous intraabdominal hemorrhage is a challenging clinical situation. A variety of neoplastic and non-neoplastic conditions may cause spontaneous intraabdominal bleeding. Imaging findings vary depending on the source of bleeding and the underlying cause. In this article, we aim to increase the awareness of imagers to the most common causes of spontaneous intraabdominal hemorrhage by using representative cases.

Multiparametric MRI with MR elastography findings in patients with sinusoidal obstruction syndrome after oxaliplatin-based chemotherapy.

OBJECTIVE: To evaluate the magnetic resonance elastography (MRE)-derived liver stiffness measurement (LSM), T1 and T2 relaxation times, and hepatobiliary phase images in patients, who developed sinusoidal obstruction syndrome (SOS) after oxaliplatin-based chemotherapy. METHODS: Thirty-four patients (M/F:22/12) who underwent liver MRI-MRE and received oxaliplatin for colorectal, gastric, and pancreas cancer were included in the study. SOS was diagnosed by Gd-EOB-DTPA-enhanced MRI in 18 patients. MRE-LSM and T1-T2 maps were evaluated. Patients with SOS were grouped according to the amount of reticular hypointensity on the hepatobiliary phase images. RESULTS: The mean MRE-LSM in the patients with SOS was 3.14 ± 0.45 kPa, and the control group was 2.6 ± 0.5 kPa (p = 0.01). The mean-corrected T1 (cT1) relaxation time was 1181 ± 151 ms in the SOS group and 1032 ± 129 ms in the control group (p = 0.005). The mean T2 relaxation time was 50.29 ± 3.6 ms in the SOS group and 44 ± 3.9 ms in the control group (p = 0.01). Parenchymal stiffness values were 2.8 ± 0.22 kPa, 3 ± 0.33 kPa, and 3.65 ± 0.28 kPa in patients with mild, moderate, and advanced SOS findings, respectively (p = 0.002). Although cT1 and T2 relaxation times increased with increasing SOS severity, no statistical significance was found. CONCLUSIONS: We observed increased MRE-LSM in patients with SOS after chemotherapy compared to control group. T1 and T2 relaxation times were also useful in diagnosing SOS but were found inadequate in determining SOS severity. MRE is effective in diagnosing SOS and determining SOS severity in patients who cannot receive contrast agents, and it may be useful in the follow-up evaluation of these patients.

Aneurysm of the Communicating Vein Between the Left Renal Vein and Left Ascending Lumbar Vein Mimicking Retroperitoneal Lymphadenopathy: A Case Report.

INTRODUCTION: Aneurysm of the communicating vein between the left renal vein and left ascending lumbar vein is extremely rare, with only anecdotal reported cases. Unless detected and recognized promptly, this rare condition may give rise to severe bleeding in patients undergoing retroperitoneal surgery. It may also closely mimic enlarged retroperitoneal lymph nodes, paragangliomas, adrenal masses, or renal artery aneurysms. CASE REPORT: In this case study, we reported the imaging findings of this rare entity, which was falsely diagnosed as an enlarged retroperitoneal lymph node in an outside medical center, reported to be consistent with metastatic disease in a patient with newly diagnosed testicular cancer. CONCLUSION: The aneurysm of the communicating vein should be considered in the differential diagnosis in patients with testicular cancer and other disease processes where lymph nodes are commonly affected.

Anatomy of testicular artery: A proposal for a classification with MDCT angiography.

PURPOSE: Knowledge of normal anatomy and variations of testicular arteries are critical for planning before minimally invasive surgery. In this article, we aimed to evaluate the morphological characteristics of testicular arteries by MDCT and propose a new classification system. METHOD: A total of 400 adult patients (total of 819 testicular arteries) who underwent abdominal CT angiography examination for several unrelated reasons were enrolled in this study. Testicular arteries (TAs) were evaluated in terms of number, origin, course, and caliber. Based on our findings, we also proposed a novel anatomical classification for the TAs according to their origin (divided into 5 types-type 1-5-) and course (divided into three types-type a-c-). Type 4 origin and type a course are the expected normal origin and course of bilateral TAs. RESULTS: The most common type based on the origin was type 4, with the testicular artery originating from the abdominal aorta, inferior to the level of the renal artery within 5 cm distal to the renal arteries. 70.7% of the right and 75.6% of the left testicular arteries were type 4. The most common type of the vessel course was the normal expected trajectory (type a) with an incidence of 76.3% for the right and 82.6% for the left testicular arteries. CONCLUSION: Normal anatomy and variations of testicular arteries may be effectively evaluated by CT angiography in a non-invasive manner.

Imaging findings of diseases affecting the gastrohepatic ligament: not as acquiscent as it seems.

The gastrohepatic ligament, a major part of the lesser omentum with hepatoduodenal ligament, is an important anatomic structure connected to several other intraabdominal organs and ligaments. It is at the crossroads of several different anatomic structures and may be affected by different diseases. In this article, we aim to increase the awareness of imagers to this small anatomic structure and provide clues for correct diagnosis and assessment of diseases that may affect this area. We will examine various diseases involving the gastrohepatic ligament in detail and try to address its importance using representative cases.