Flocculus Herniation into the Internal Acoustic Canal in Incomplete Partition Type I: A Case Report.

In this study, we present the first case with cerebellar herniation into the internal acoustic canal in incomplete partition type I anomaly. Cerebellar herniation into the internal acoustic canal is very rare with only a few cases reported in the literature. Although it is a rare clinical situation, cerebellar herniation into the internal acoustic canal may be seen in patients with incomplete partition type I. We presented magnetic resonance imaging findings of a 3-year-old girl with a history of meningitis, middle ear effusion, and bilateral congenital sensorineural hearing loss. Magnetic resonance imaging showed bilateral incomplete partition type I malformation and an additional flocculus herniation into the right internal acoustic canal. In the presented case, predisposition to cerebrospinal fluid leak in incomplete partition type I anomaly may be the reason for cerebellar herniation into internal acoustic canal. Also, possible increased intracranial pressure due to meningitis may be a contributing factor.

Sacroiliac joint involvement in osteochondromatosis: identifying its prevalence and characteristics from cross-sectional imaging

PURPOSE: Apart from a few case reports, sacroiliac joint (SIJ) involvement in osteochondromatosis has not been studied. We aimed to determine the prevalence and characteristics of such involvement using cross-sectional imaging. METHODS: In this retrospective study, three observers (one junior radiologist and two musculoskeletal radiologists) independently reviewed computed tomography (CT) or magnetic resonance imaging (MRI) of patients in our database who had osteochondromatosis (≥2 osteochondromas across the skeleton) for SIJ involvement. The final decision was reached by the consensus of the two musculoskeletal radiologists in a later joint session. RESULTS: Of the 36 patients with osteochondromatosis in our database, 22 (61%) had cross-sectional imaging covering SIJs (14 females, 8 males; age range 7-66 years; mean age 23 years; 13 MRI, 9 CT). Of these, 16 (73%) had intra-articular osteochondromas. For identifying SIJ osteochondromas on cross-sectional imaging, interobserver agreement was substantial [κ = 0.67; 95% confidence interval (CI): 0.34, 1.00] between the musculoskeletal radiologists and moderate (κ = 0.59; 95% CI: 0.23, 0.94) between the junior radiologist and the final consensus decision of the two musculoskeletal radiologists. In the cohort with cross-sectional imaging, the anatomical variations of the accessory SIJ (n = 6, 27%) and iliosacral complex (n = 2, 9%) were identified in six different patients with (n = 2) and without (n = 4) sacroiliac osteochondromas. CONCLUSION: Cross-sectional imaging shows frequent (73%) SIJ involvement in osteochondromatosis, which, although a rare disorder, nevertheless needs to be considered in the differential diagnosis of such SIJ anatomical variants as the accessory SIJ and iliosacral complex. Differentiating these variants from osteochondromas is challenging in patients with osteochondromatosis.

Complete Cervicouterine Dissociation After Repeat Cesarean Sections: A Case Report.

INTRODUCTION: The number of cesarean deliveries (CDs) has extremely increased in the last decades. Although it is a common and relatively safe surgical procedure, there are several potential complications. To the best of our knowledge, complete cervicouterine dissociation after several CDs has not been reported before in the medical literature. CASE REPORT: A 28-year-old woman with a history of 6 CDs presented with abdominal pain and vaginal bleeding. The patient's most recent CD happened three weeks before the current presentation. Transabdominal ultrasonography examination and magnetic resonance imaging revealed the absence of continuity with the uterine cervix and corpus with associated pelvic hematoma. Laparotomy findings confirmed the imaging findings, and the displaced uterine corpus was removed with the evacuation of the associating pelvic hematoma. CONCLUSION: Uterine dehiscence and rupture are among the relatively common complications of CD. Uterine rupture and dehiscence are focal disorders, and complete cervicouterine dissociation has not been seen before. Multiple CDs are among the risk factors for complete cervicouterine dissociation, and abnormal uterine bleeding is the most common symptom. Imaging findings allow a quick and definitive diagnosis, and surgical intervention may be planned accordingly based on the imaging findings.

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.

Aneurysm of the left ascending lumbar communicating vein: Its prevalence and possible association with nutcracker phenomenon.

PURPOSE: To evaluate abdominal computed tomography (CT) studies in respect of the prevalence of the left ascending lumbar communicating vein (ALCV) and ALCV aneurysm and to identify possible causes of aneurysm development in the ALCV. METHODS: Contrast-enhanced abdominal CT examinations were retrospectively investigated for the prevalence of the ALCV in the adult population. In patients with ALCV, the diameters of the following vessels were measured: ALCV, left renal vein (LRV) at two levels, compression ratio of the LRV (CR), left gonadal vein, right and left ascending lumbar veins (ALVs). The aortomesenteric angle was also measured for preaortic LRVs. ALCV aneurysm was noted during the assessment. RESULTS: Evaluation was made of 500 patients. ALCV was found in 240 patients (48%), more common in patients with retroaortic LRV and circumaortic LRV than in patients with preaortic LRV (p = 0.003). The mean diameter of the ALCV was 3.85 ± 2.06 mm. ALCV and the left gonadal vein merged to form a common vein draining into the LRV in 23 patients with preaortic LRV (9.6%). Of the patients with ALCV, 19 (8%) had aneurysm. The diameter of the left ALV and CR were significantly greater in patients with aneurysm than in patients without (p = 0.001 and 0.032, respectively). Patients with ALCV aneurysm had a significantly narrower aortomesenteric angle (p = 0.004). CONCLUSION: The results of this study indicated that a narrower aortomesenteric angle and a greater CR might play a role in the development of ALCV aneurysm.

Different Attenuation Models of Diffusion-Weighted MR Imaging for the Differentiation of Benign and Malignant Musculoskeletal Tumors.

BACKGROUND: Several functional imaging techniques, including monoexponential diffusion-weighted imaging (m-DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis (DK) imaging, have been used in differentiating benign and malignant musculoskeletal tumors. Combining all three techniques in the same study population may improve differentiation. PURPOSE: To compare the diagnostic performance of m-DWI, IVIM, and DK models and their combinations in differentiating benign and malignant musculoskeletal tumors. STUDY TYPE: Prospective. POPULATION: Fifty patients with benign and malignant musculoskeletal tumors divided into nonmyxoid and nonchondroid and myxoid and/or chondroid subgroups. FIELD STRENGTH/SEQUENCE: A 1.5 T/m-DWI, IVIM, and DK single-shot spin-echo echo-planar sequences. ASSESSMENT: Minimum and volumetric values of apparent diffusion coefficient (ADC), pure molecular diffusion (Divim ), pseudodiffusion (D*), perfusion fraction (f), diffusion coefficient for kurtosis model (DK ), and Kurtosis (K) were compared between all benign and malignant tumors. Subgroup analysis was also performed for nonmyxoid and nonchondroid and myxoid and/or chondroid tumors. STATISTICAL TESTS: Independent samples t-test, Mann-Whitney U test, intraclass correlation coefficient, ROC analysis, and logistic regression analysis. A P value < 0.05 was considered statistically significant. RESULTS: ADCmin , Divim-min , D*vol , DK-min, Kvol, and Kmin values showed statistically significant differences between all benign and malignant tumors and nonmyxoid and nonchondroid tumor subgroup. Kmin showed the highest diagnostic performance in differentiating benign and malignant tumors with AUCs of 0.760 for "all tumors" and 0.825 for the nonmyxoid and nonchondroid tumor subgroup. No significant differences were detected in m-DWI-, IVIM-, and DK-derived parameters for differentiating benign and malignant myxoid and/or chondroid tumors. Only three of 63 combinations of prediction models demonstrated a higher diagnostic performance than Kmin ; however, improvements were not significantly different. DATA CONCLUSION: ADCmin , Divim-min , D*vol , DK-min , Kvol , and Kmin values can be used to differentiate benign and malignant musculoskeletal tumors. Our findings suggest that the added value of multiparametric approach in such differentiation is not significant. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

Assessment of 4DCT imaging findings of parathyroid adenomas in correlation with biochemical and histopathological findings.

PURPOSE: To assess polar vessel presence and enhancement 4DCT imaging and their relation with biochemical and histopathological features. METHODS: Patients with primary hyperparathyroidism and preoperative 4DCT imaging were screened retrospectively and those with histopathologically proven diagnosis of PA were included. Biochemical findings, densitometric measurements (HUprecontrast, HUarterial, HUvenous, HUwash-in, HUwash-out, HUretained) and CTvolume of PA on 4DCT, presence of a polar vessel (PV), and histopathological features were recorded. Correlations between serum PTH, calcium levels and densitometric measurements of PA on 4DCT were investigated. Differences between subgroups created according to PV presence were also evaluated. RESULTS: Thirty-nine patients were enrolled (F/M = 32/7, median age = 57, interquartile range = 50-62 years). In all patients, serum PTH levels positively correlated with CTvolume (r = 0.398, p = 0.012) but negatively correlated with HUarterial (r = - 0.366; p = 0.022), HUvenous (r = - 0.452; p = 0.004) and HUretained (r = - 0.421; p = 0.008). In PV (-) PAs, PTH levels were positively correlated with CTvolume (r = 0.608, p ≤ 0.002) and negatively with HUarterial (r = - 0.449, p ≤ 0.028), HUvenous (r = - 0.560, p = 0.004), HUwash-in (r = - 0.460, p = 0.024), and HUretained (r = - 0.539, p = 0.007). No correlation between PTH levels and densitometric measurements was found in PV (+) PAs. HUwash-in and HUwash-out were significantly higher in PV (+) PAs compared to PV (-) PAs (p = 0.021 and p = 0.033, respectively). Histopathologic features revealed no difference according to the presence of PV. CONCLUSION: PTH levels might have an association with imaging findings of PAs, especially when categorized with respect to PV presence. PTH levels were negatively correlated with degree of enhancement in PV (-) PAs. Therefore, radiologists should be aware that in patients with high serum PTH levels and without a discernible PV, PA might be difficult to localize.

Radiation dose levels of thoracic-lumbar spine CT in pediatric trauma patients and assessment of scan parameters for dose optimization.

BACKGROUND: CT is frequently used for assessing spinal trauma in children. OBJECTIVE: To establish the local diagnostic reference levels of spine CT examinations in pediatric spinal trauma patients and analyze scan parameters to enable dose optimization. MATERIALS AND METHODS: In this retrospective study, we included 192 pediatric spinal trauma patients who underwent spine CT. Children were divided into two age groups: 0-10 years (group 1) and 11-17 years (group 2). Each group was subdivided into thoracic, thoracolumbar and lumbar CT groups. CT acquisition parameters (tube potential, in kilovoltage [kV]; mean tube current-time product, in milliamperes [mAs]; reference mAs; collimated slice width; tube rotation time; pitch; scan length) and radiation dose descriptors (volume CT dose index [CTDIvol] and dose-length product [DLP]) were recorded. The CTDIvol and DLP values of spine CTs obtained with different tube potential and collimated slice width values were compared for each group. RESULTS: CTDIvol and DLP values of thoracolumbar spine CTs in group 1 and lumbar spine CTs in group 2 were significantly lower in CTs acquired with low tube potential levels (P<0.05). CTDIvol and DLP values of thoracolumbar spine CTs in both groups and lumbar spine CTs in group 2 acquired with high collimated slice width values were significantly lower than in corresponding CTs acquired with low collimated slice width values (P<0.05). CONCLUSION: Pediatric spine CT radiation doses can be notably reduced from the manufacturers' default protocols while preserving image quality.

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.

Rare Pulmonary Tumors and Carcinoma Mimickers; Experience from an Interventional Radiology Unit with Radiologic-pathologic Correlation- A Pictoral Essay.

BACKGROUND: Although imaging findings along with patients' clinical history may give a clue for the etiology of a pulmonary lesion, the differentiation of benign pulmonary lesions from lung cancer could be challenging. OBJECTIVE: The aim of this review article was to increase the awareness of carcinoma mimicking lung lesions. METHODS: This paper was designed to illustrate rare pulmonary tumors and carcinoma mimickers with emphasis on radiologic-pathologic correlation. Pitfalls encountered on CT images and also false positivity of PET-CT scans were also presented. CONCLUSION: Several benign pulmonary lesions may grow in size on follow-up and some may show pathologic FDG (18F-fluorodeoxyglucose) uptake, which makes them indistinguishable from lung carcinoma by imaging. In addition, some slow-growing malignant lesions, such as carcinoid, may be false-negative on PET/CT scans.

Can we differentiate neoplastic and non-neoplastic spontaneous adrenal bleeding? Imaging findings with radiopathologic correlation.

Spontaneous adrenal bleeding is a rare clinical event with non-specific clinical features. Life-threatening bleeding in the adrenal glands may be promptly diagnosed with imaging. Computed tomography (CT) is generally the first imaging modality to be used in these patients. However, in the acute phase of bleeding, it may be difficult to detect the underlying mass from the large hematoma. In these patients, additional imaging studies such as magnetic resonance imaging or positron emission tomography/CT may be utilized to rule out a neoplastic mass as the source of bleeding. In patients where an underlying neoplastic mass could not be identified at the time of initial diagnosis, follow-up imaging may be helpful after the acute phase subsides.

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.

Persistent left superior vena cava: clinical importance and differential diagnoses.

Persistent left superior vena cava (PLSVC) is the most common thoracic venous anomaly and may be a component of the complex cardiac pathologies. While it is often asymptomatic, it can lead to significant problems such as arrhythmias and cyanosis. Besides, it can cause serious complications during vascular interventional procedures or the surgical treatment of cardiac anomalies (CA). The clinical significance of PLSVC depends on the drainage site and the accompanying CA. In this article, we will describe the epidemiology, embryology, and anatomic variations of PLSVC. Possible accompanying CA and heterotaxy spectrum will be reviewed with the help of multidetector computed tomography (MDCT) images. Radiological pitfalls, differential diagnoses, and the clinical importance of PLSVC will be highlighted.

Congenital and hereditary cystic diseases of the abdomen.

Congenital and hereditary cystic lesions of the abdomen are relatively rare. Correct diagnosis is critical as they may simulate several other benign and malignant acquired diseases of the abdomen. With the correct and appropriate use of imaging, diagnosis may be relatively straightforward and clinical management may be implemented appropriately. The purpose of this article is to describe imaging findings of common and uncommon congenital and hereditary cystic disease of the abdominal organs.

Parasitic diseases as a cause of acute abdominal pain: imaging findings.

Acute abdominal pain can be seen in cases with parasitic diseases delivered to emergency departments. The diagnosis of the parasitic disease can be delayed because of the similar clinical signs encountered in other frequently seen causes of acute abdomen. Nevertheless, the features detected in imaging scans can be helpful in the diagnosis. The present study aims to raise awareness about abdominal parasitosis in emergency conditions and also to underline the association between imaging findings and the life cycle of parasites with illustrative cases.

Axial pulmonary trunk diameter variations during the cardiac cycle.

PURPOSE: Previous studies have shown a correlation between axial pulmonary trunk diameter (PTD) on chest computed tomography (CT) and pulmonary artery pressure. However, it is not known whether the PTD slices measured on chest CT have been recorded during the systolic or diastolic phase. The aim of this study was to demonstrate the variations in PTD during the cardiac cycle by measuring coronary CT angiography (CCTA) images. METHODS: A retrospective analysis was made of 101 patients who underwent CCTA for coronary artery disease assessment. CCTA images were reconstructed during a full cardiac cycle and measurements were taken of the systolic and diastolic PTD and ascending aorta diameter (AAD) from the same slice by two independent observers. RESULTS: Inter-observer agreement was excellent (intraclass correlation coefficient = 0.99) for all CT measurements. The mean systolic PTD of all patients was 26.3 ± 3.6 mm and the mean diastolic PTD was 22.8 ± 3.2 mm (p < 0.001). The mean difference between systole and diastole was found to be 3.5 ± 1.2 mm for PTD, 1.2 ± 0.7 mm for AAD, and 0.1 ± 0.04 for the PTD/AAD ratio (p values < 0.001). There was no statistical significance of PTD variations according to gender, age, height, weight, body mass index, and body surface area. CONCLUSION: When an increased PTD is detected in a chest CT compared to normal limits or a previous CT scan, this may be the result of the variation in PTD due to the cardiac cycle.