High Diffusion-weighted Imaging Signal Research Articles

Novel TBC1D8B variant causes neonatal nephrotic syndrome combined with acute kidney injury

BackgroundNephrotic syndrome (NPHS), characterized by proteinuria, hypoalbuminemia, and edema, can be caused by genetic variations. TBC1D8B was recently discovered as a novel disease-causing gene for X-linked NPHS. With only a few reported cases, the clinical manifestations associated with variants of this gene need to be further examined.MethodsWe recruited a newborn with NPHS complicated by acute kidney injury (AKI) and his parents and tested the potential genetic cause of the disease through trio-whole exome sequencing and Sanger sequencing. Western blotting (WB) was performed using a mutant plasmid to evaluate mutant protein expression levels. Since the TBC1D8B protein interacts with RAB proteins to catalyze the GTPase hydrolysis process, immunofluorescence (IF) can be used to verify the interaction between the TBC1D8B mutant protein and RAB11A/RAB11B, and thus to confirm its effect on the endocytosis and vesicle recycling functions of RAB proteins within the cell.ResultsThe child, at 1 month, showed severe edema and proteinuria and unexplained coma with epilepsy. Ultrasound examination revealed multiple organ enlargement, and MRI showed nonspecific high diffusion-weighted imaging signal characteristics in the splenium of the corpus callosum. Hematoxylin and eosin staining showed diffuse inflammatory cell infiltration in the renal interstitium and multifocal renal tubule lumen expansion. Diffuse fusion of podocyte foot processes was observed under electron microscopy, indicating glomerular podocyte lesions. Genetic testing revealed a maternally inherited novel hemizygous variant, NM_017752: c.628 A > T, p.Lys210Ter, in TBC1D8B. In vitro functional experiments showed that this variant may lead to TBC1D8B protein degradation. IF results showed disrupted interaction with RAB11A/RAB11B, that then affects the biological function of RAB proteins in the process of cell intimal vesicle formation and intracellular transport.ConclusionThis study will enrich the mutational and phenotypic spectra of TBC1D8B and demonstrate the potential of this gene variants to cause early-onset NPHS leading to severe kidney disease.

Impact of fat content on lumbar spine DWI performance: A sex-based comparative study

PurposeSex-based differences in lumbar spine's fat content in adults are minimal, but significant variations exist in diffusion-weighted imaging (DWI) signal characteristics. This study aimed to investigate fat content’s impact on DWI performance in lumbar spine and potential sex differences. MethodsA retrospective analysis was conducted on upper abdominal MRI examinations in asymptomatic adult. The lumbar 1 vertebral apparent diffusion coefficient (ADC) values and fat fraction were measured. Using DWI images (b = 800 s/mm2), the lumbar 1 vertebral signal was categorized into high and iso-low signal groups. A univariate and multivariate analysis was conducted to investigate the influence of fat fraction on DWI performance. Finally, the participants were divided into three groups to analyze sex differences in the effect of fat content on DWI performance. Results202 subjects, 99 men were included. Fat content significantly influenced lumbar spine DWI signal in both sexes (p < 0.05). The effect on ADC values was significant only in women (p < 0.001). Women demonstrated a significantly higher proportion of high DWI signal than men in the low (p = 0.002) and middle (p = 0.012) fat content groups. Additionally, women had higher ADC values in the low fat group (p = 0.004) but lower values in the high fat group (p = 0.004). ConclusionFat content significantly impacts the DWI signal of lumbar spine, with a slight sex difference observed. These sex differences suggest that DWI signals may provide valuable information about the bone marrow beyond fat content.

The utility of MRI for the preoperative differential diagnosis of uterine sarcoma and leiomyoma: a single-center study.

Although uterine sarcoma is a rare disease, its prognosis is extremely poor;thus, it is important to differentiate it from uterine leiomyoma. In this retrospective study, we examined the association between preoperative MRI findings and postoperative pathology results in 170 patients with uterine tumors who underwent preoperative MRI examination at Fukushima Red Cross Hospital. In 4 cases of sarcoma / smooth muscle tumor of unknown malignant potential (STUMP), abnormal findings were found at a high frequency with T1-weighted imaging (T1WI) (75%), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and contrast enhancement (CE) (100%). In cases of ordinary leiomyoma, on the other hand, abnormal findings were less frequent. The rates of high DWI signal intensity for degenerated and cellular leiomyoma were 31% and 64%, respectively, and the CE-positive rates were 31% and 57%, respectively. Apparent Diffusion Coefficient (ADC) values appeared to be useful in differentiating degenerated leiomyoma from sarcoma. The relatively characteristic findings of uterine sarcoma on MRI images may overlap with those of degenerated leiomyoma and cellular leiomyoma, making it difficult to diagnose sarcoma on imaging alone. However, findings that distinguish sarcoma from ordinary, degenerated, and cellular leiomyoma cases are worthy of attention, to avoid overlooking sarcoma.

Magnetic resonance imaging features to evaluate the neonatal hypoglycemia brain injury and investigation of related risk factors under the fuzzy C‐means clustering intelligent algorithm

AbstractThis research was aimed to analyse the application value of magnetic resonance imaging based on Fuzzy C‐means (FCM) algorithm in neonatal hypoglycemia brain injury (HBI), and explore the risk factors related to the occurrence of brain injury in children, to provide guidance for clinical diagnosis and treatment. 114 children with hypoglycemia were divided into brain injury group (58 cases) and no brain injury group (56 cases) according to whether they had brain injury or not. The MRI image signal performance, general data, average minimum blood glucose value, duration of hypoglycemia, first feeding time, age of onset of hypoglycemia, and algorithm segmentation performance of the two groups of patients were observed and compared. Furthermore, the Logistic factor analysis was carried out to summarize the MRI characteristics and related risk factors of neonatal hypoglycemic brain injury. The results showed that the average minimum blood glucose (1.09 ± 0.53 mmoL/L) in the brain injury group was lower than that in the non‐brain injury group (1.75 ± 0.49 mmoL/L), and the duration of hypoglycemia (43.1 ± 21.07 h) was higher than that in the non‐brain injury group (13.79 ± 6.81 h), p &lt; 0.05. The first feeding time and age of hypoglycemia in the brain injury group were higher than those in the non‐brain injury group, showing a difference with p &lt; 0.05. In the brain injury group, all 58 cases showed high DWI (diffusion weighted imaging) signal at the damaged site at the early stage of MRI (magnetic resonance imaging), and 23 cases (39.66%) were involved in parieto‐occipital lobe. Image segmentation coefficient of Vpc increased significantly under FCM clustering algorithm (p &lt; 0.05). Late first feeding time, low blood sugar level, and long duration were high risk factors for hypoglycemic brain injury. In conclusion, MRI images based on FCM clustering algorithm had higher image quality. Late first feeding time, low blood sugar level, and long duration of hypoglycemia were high risk factors for hypoglycemic brain injury.

Factors associated with hearing outcomes after a middle fossa approach in 131 consecutive patients with vestibular schwannomas.

The middle fossa approach is an effective option for the treatment of small (Koos grade I and II) vestibular schwannomas (VSs) when the goal is hearing preservation. The authors evaluated the rates of hearing preservation and examined the factors associated with improved hearing outcomes after the middle fossa approach for VSs. In this retrospective, single-center cohort study evaluating the clinical outcomes after resection of small VSs using the middle fossa approach, consecutive adult patients (> 18 years) who underwent surgery between January 2000 and December 2021 were included. Clinical and imaging characteristics were analyzed, including baseline hearing status, duration of surgery, anesthetic parameters, and imaging characteristics of the surgically treated tumors. Among the 131 included patients, 102 had valid and discoverable pre- and postoperative audiology assessments. The mean follow-up was 26 months (range 1-180 months). There were 85 patients with serviceable hearing preoperatively, defined as American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) class A or B, of whom 78% retained class A or B hearing at the last follow-up. Binary logistic regression demonstrated that preoperative hearing AAO-HNS class (OR 0.19, 95% CI 0.05-0.77; p = 0.02), overlap between fundus and cochlea (OR 0.32, 95% CI 0.11-0.96; p = 0.04), and duration of anesthesia (OR 0.98, 95% CI 0.97-0.99; p = 0.03) were independent predictors of hearing outcomes. Additionally, 75% of patients with high diffusion-weighted imaging signal in the tumor (p = 0.009) and 67% of patients with the tumor originating at the modiolus of the cochlea (p = 0.004) had poor hearing outcomes. The hearing preservation rates after microsurgical resection of small VSs using the middle fossa approach are high, with 78% of patients maintaining AAO-HNS class A or B hearing. Poor hearing status at baseline, longer duration of anesthesia, and large overlap between the fundus of the internal auditory canal and the cochlea were independently associated with unfavorable hearing outcomes. Imaging characteristics can be used to stratify patients' risk of hearing loss.

Breaking with a dogma: persisting diffusion restrictions (pDWI) in follow-up after endovascular treatment for stroke

BackgroundPost-stroke diffusion weighted imaging (DWI) signal transformation of the infarct core, which results in high apparent diffusion coefficient (ADC) values and variable DWI signal intensity, is completed no later than...

DWI Combined With Hepatobiliary-Phase Enhanced Imaging Can Better Differentiate Cholangiocarcinoma From Atypical Liver Abscesses

ObjectiveTo investigate the value of diffusion-weighted imaging (DWI) combined with the hepatobiliary phase (HBP) Gd-BOPTA enhancement in differentiating intrahepatic mass-forming cholangiocarcinoma (IMCC) from atypical liver abscess.Materials and MethodsA retrospective analysis was performed on 43 patients with IMCCs (IMCC group) and 25 patients with atypical liver abscesses (liver abscess group). The DWI signal, the absolute value of the contrast noise ratio (│CNR│) at the HBP, and visibility were analyzed.ResultsA relatively high DWI signal and a relatively high peripheral signal were presented in 29 patients (67.5%) in the IMCC group, and a relatively high DWI signal was displayed in 15 patients (60.0%) in the atypical abscess group with a relatively high peripheral signal in only one (6.7%) patient and a relatively high central signal in 14 (93.3%, 14/15). A significant (P<0.001) difference existed in the pattern of signal between the two groups of patients. On T2WI, IMCC was mainly manifested by homogeneous signal (53.5%), whereas atypical liver abscesses were mainly manifested by heterogeneous signal and relatively high central signal (32%, and 64%), with a significant difference (P<0.001) in T2WI imaging presentation between the two groups. On the HBP imaging, there was a statistically significant difference in peripheral │CNR│ (P< 0.001) and visibility between two groups. The sensitivity of the HBP imaging was significantly (P=0.002) higher than that of DWI. The sensitivity and accuracy of DWI combined with enhanced HBP imaging were significantly (P=0.002 and P<0.001) higher than those of either HBP imaging or DWI alone.ConclusionIntrahepatic mass-forming cholangiocarcinoma and atypical liver abscesses exhibit different imaging signals, and combination of DWI and hepatobiliary-phase enhanced imaging has higher sensitivity and accuracy than either technique in differentiating intrahepatic mass-forming cholangiocarcinoma from atypical liver abscesses.

Diagnostic Algorithm to Differentiate Benign Atypical Leiomyomas from Malignant Uterine Sarcomas with Diffusion-weighted MRI.

Background Improving the differentiation of uterine sarcomas from atypical leiomyomas remains a clinical challenge and is needed to avoid inappropriate surgery. Purpose To develop a diagnostic algorithm including diffusion-weighted MRI criteria to differentiate malignant uterine sarcomas from benign atypical leiomyomas. Materials and Methods This case-control retrospective study identified women with an atypical uterine mass at MRI between January 2000 and April 2017, with surgery or MRI follow-up after 1 year or longer. A diagnostic algorithm including T2-weighted MRI and diffusion-weighted imaging (DWI) signal and apparent diffusion coefficient (ADC) values was developed to predict for sarcoma. The training set consisted of 51 sarcomas and 105 leiomyomas. Two external validation sets were used to evaluate interreader reproducibility (16 sarcomas; 26 leiomyomas) and impact of reader experience (29 sarcomas; 30 leiomyomas). Wilson confidence intervals (CIs) were calculated for sensitivity and specificity. Results Evaluated were 156 women (median age, 50 years; interquartile range, 44-63 years). Predictive MRI criteria for malignancy were enlarged lymph nodes or peritoneal implants, high DWI signal greater than that in endometrium, and ADC less than or equal to 0.905 × 10-3 mm2/sec. Conversely, a global or focal area of low T2 signal intensity and a low or an intermediate DWI signal less than that in endometrium or lymph nodes allowed readers to confidently diagnose as benign a uterine mass demonstrating one or more of these signs (P < .001) in 100% cases in all three data sets. The sensitivities and specificities of the algorithm for diagnosis of malignancy were 98% (50 of 51 masses; 95% CI: 90%, 100%) and 94% (99 of 105 masses; 95% CI: 88%, 98%) in the training set; 88% (14 of 16 masses; 95% CI: 64%, 97%) and 100% (26 of 26 masses; 95% CI: 87%, 100%) in the validation set; and 83% (24 of 29 masses; 95% CI: 65%, 92%) and 97% (29 of 30 masses; 95% CI: 83%, 99%) for the less experienced reader, respectively. Conclusion A diagnostic algorithm with predictive features including lymphadenopathy, high diffusion-weighted imaging signal with reference to endometrium, and low apparent diffusion coefficient enabled differentiation of malignant sarcomas from atypical leiomyomas, and it may assist inexperienced readers. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Méndez in this issue.

WITHDRAWN: Double primary carcinoid tumors of the kidney

Abstract Primary renal carcinoid tumor is extremely rare. Because of its similar presentation with other renal tumors, 14.5% were initially misdiagnosed. A 37-year-old female was referred to our department due to incidentally finding of left kidney tumor by sonography. She didn't present flank pain or gross hematuria, also absence of positive physical findings. The patient's general blood routine, urine routine, and renal function examination were all within normal limits. Abdomen computed tomography showed two soft tissue mass within left kidney. The larger renal tumor was about 3.8 cm in size, mild contrast enhancement and small cystic foci abutting renal sinus. The smaller renal mass was exophytic with same image characteristics. The subsequent kidney magnetic resonance imaging reported two lesions had persistent high diffusion-weighted imaging signal intensity, which strongly favor solid neoplasm. Differential diagnosis included renal cell carcinioma, benign adenoma and Wilm's tumor. Hence, frozen section of the smaller renal nodule was sent for pathologist, and it reported no evidence of obvious malignancy. We later performed open partial nephrectomy. The final pathology reported two well-differentiated grade 1 neuroendocrine (carcinoid) tumors. Immunohistochemistry showed these two lesions were strong positive for synaptophysin and neuron-specific enolase (NSE), but negative for WT-1 and vimentin, which were consistent with features of neuroendocrine tumor. Two weeks after operation, patient's serum creatinine was within normal limits. Abdomen computed tomography reported no specific lymph node involvement after 6 months. Primary renal carcinoid tumors are usually found incidentally, and nephron-sparing surgery whenever possible remains the standard treatment of choice.

Prediction of Recurrence in Parasagittal and Parafalcine Meningiomas: Added Value of Diffusion-Weighted Magnetic Resonance Imaging

Parasagittal and parafalcine (PSPF) meningiomas recur more frequently than other intracranial meningiomas owing to the difficulty in achieving gross total resection. The present study investigated the preoperative magnetic resonance imaging (MRI) features for the prediction of progression/recurrence (P/R) in benign PSPF meningiomas with an emphasis on the apparent diffusion coefficient (ADC) values. We retrospectively investigated the preoperative MRI features for the prediction of P/R in benign (World Health Organization grade I) PSPF meningiomas. Only patients who had undergone preoperative and postoperative MRI follow-up studies for ≥1 year were included. From October 2006 to December 2015, 48 patients with a diagnosis of benign PSPF meningioma were included (median follow-up period, 42.5 months). Of these 48 patients, 12 (25%) developed P/R (median time to P/R, 23 months). PSPF meningiomas in male patients, subtotal resection, large tumor diameter, high diffusion-weighted imaging signal, and lower ADC values or ratios were significantly associated with P/R (P < 0.05). The cutoff points of the ADC value and ADC ratio for the prediction of P/R were 0.83× 10-3 mm2/second and 0.99, with an area under the curve of 0.82 and 0.83, respectively (P= 0.001). On multivariate Cox proportional hazards analysis, male sex and low ADC values (<0.83× 10-3 mm2/second) were high-risk factors for P/R, with a hazard ratio of 12.37 and 30.2, respectively (P < 0.05). Kaplan-Meier analysis showed that lower ADC values and ratios predicted for significantly shorter progression-free survival (P < 0.05). The preoperative ADC values and ratios for the prediction of P/R offer additional valuable information for the treatment planning for PSPF meningiomas.

The role of diffusion-weighted MRI on the differentiation of complex adnexal masses

Background Conventional MRI has an established role in gynecologic imaging. However, increasing clinical demand for improved lesion characterization and disease mapping to optimize patient management has resulted in the incorporation of newer sequences, such as diffusion-weighted imaging (DWI), into routine protocols for pelvic MRI. DWI provides functional information on the microenvironment of water in tissues, hence augmenting the morphologic information derived from conventional MRIs. Objective The objective of this study was to highlight the role of DWI in differentiating benign from malignant complex adnexal masses. Patients and methods Twenty-five patients with adnexal masses underwent conventional MRI and DWI and the cases were proven by postsurgery pathological examination. Analysis of the pathological specimen with lesion morphology, signal characteristics, and correlation with the appearance at DWI followed by apparent diffusion coefficient values measurement were obtained. Results Twenty-five patients with adnexal mass lesions were included. Included masses proved benign in 18 (72%) and malignant in seven (28%). Restricted diffusion was observed in proved malignant masses (24%, n = 6/25). Benign tumors with high DWI signal intensity evidence at 24% also. The mean apparent diffusion coefficient value was 1.4+0.34×10−3 and 1.02+0.06×10−3 mm2/s, for benign and malignant masses, respectively. Conclusion DWI supported by conventional MRI data can confirm or exclude malignancy in suspicious ovarian masses. A combined analysis of quantitative and qualitative criteria and a knowledge of the sequence pitfalls are required.

Distinct magnetic resonance imaging features in a patient with novel RARS2 mutations: A case report and review of the literature

Pontocerebellar hypoplasia type 6 (PCH6) is a rare autosomal recessive disease that occurs due to mutations in the mitochondrial arginyl-tRNA synthetase 2 (RARS2) gene. To the best of our knowledge, 23 cases with relatively complete clinical data have been reported thus far. In the present study, a case with PCH6 caused by novel RARS2 mutations is described, in which distinct magnetic resonance imaging (MRI) features were identified. In addition, 23 PCH6 cases found in the literature were reviewed. Early onset hypotonia (43.48%), epileptic seizures (34.78%), encephalopathy (26.08%) and feeding difficulties (17.39%) were common initial symptoms of PCH6. During disease progression, the patients presented refractory epileptic seizures (94.12%), feeding problems (60.87%), severe developmental delay (100%), microcephaly (88.89%) and hyperlactacidemia (76.47%). The clinical features of the present patient were suggestive of PCH6, with early onset epilepsy, feeding difficulties, severe developmental delay, microcephaly, hearing loss and hyperlactacidemia. According to available MRI data from 20 reported cases with PCH6, the characteristic finding in MRI was pontocerebellar dysplasia or progressive cerebral/pontocerebellar atrophy in 16 cases, while 4 cases did not present pontocerebellar hypoplasia, and no basal ganglia involvement was observed in any of the cases. Distinctive MRI features were also identified in the present case, including pontocerebellar preservation after 1 year of age, as well as a high diffusion-weighted imaging signal suggesting intracellular edema in the cerebellar hemispheres, basal ganglia, thalamus and corpus callosum. Progressive loss of cerebral white matter and cortical volume were common features shared by all patients. In conclusion, in the present study, two novel heterozygous mutations were identified in RARS2, namely c.1718C>T(p.Thr573Ile) and c.991A>G (p.Ile331Val). Thus, the present case enriched the phenotypic and genotypic spectrum of the RARS2 mutations.

Diagnosis of lateral pelvic lymph node metastasis of T1 lower rectal cancer using diffusion-weighted magnetic resonance imaging: A case report with lateral pelvic lymph node dissection of lower rectal cancer.

The present study presented a 35-year-old female patient in whom fecal occult blood was detected in a medical check-up. Colonoscopy revealed a superficial elevated-type tumor with central depression in the lower rectum. The tumor was diagnosed as T1 deep invasive cancer. No swollen lymph nodes or distant metastasis were found on computed tomography or [18F]-fluorodeoxyglucose-positron emission tomography with computed tomography. However, a swollen right lateral pelvic lymph node (LPLN; short axis 4 mm) was revealed on magnetic resonance imaging (MRI). This lymph node exhibited high intensity on diffusion-weighted imaging (DWI), suggesting metastasis. Low anterior resection, regional lymph node dissection and right LPLN dissection (LPLD) were performed. Histological analysis revealed metastasis in the right LPLN, as suggested by the high DWI intensity. The indication for LPLD in the current Japanese guidelines is based on the tumor location and depth of invasion (≥T3), however, not on the status of LPLN metastasis in pre-operative evaluation. The present case was cT1, which is not included in this indication. DWI is sensitive for the diagnosis of lymph node metastasis of colorectal cancer, although inflammation-induced swelling of lymph nodes in advanced rectal cancer may cause a false-positive result, which is uncommon in T1 cases. Therefore, an LPLN with a high intensity DWI signal in T1 cases is likely to be metastasis-positive. Pre-operative DWI-MRI may be useful for identifying LPLN metastasis when planning the treatment strategy in these cases. The present study suggested reinvestigation of the indication for LPLD with inclusion of LPLN status on pre-operative imaging.

Diffusion‐weighted imaging and magnetic resonance spectroscopy findings in a case of neonatal hypoglycaemia

Rachel E Musson MBCHB MRCP, Ruth Batty MBBS MRCP FRCR, Santosh R Mordekar MD MRCP MRCPCH, Iain D Wilkinson PHD ARCP FIPEM, Paul D Griffiths PHD FRCR, Daniel JA Connolly BSC MRCP FRCR 1 Radiology Department, Royal Hallamshire Hospital, Sheffield, UK. 2 Department of Neurology, Sheffield Children's Hospital, Sheffield, UK. 3 Academic Unit of Radiology, University of Sheffield, Sheffield, UK. 4 Radiology Department, Sheffield Children's Hospital, Sheffield, UK. Correspondence to: rachel.musson@sth.nhs.uk

Persistent high signal on diffusion-weighted MRI in the late stages of small cortical and lacunar ischaemic lesions.

Diffusion-weighted imaging (DWI) is very sensitive to early brain infarcts. However, the late stages have been insufficiently studied. Infarcts in small vessel disease are often multiple and of different ages, and differentiation between new and old lesions might be difficult. We have therefore studied the change with time in DWI of small (< 3 ml) ischaemic lesions. We imaged 21 patients with an acute lacunar syndrome and a lesion visible on early DWI. They all had three MRI examinations 12-58 h (early), 7-16 and 54-144 days after the onset of stroke; 10 patients with high DWI signal on the third examination had a fourth examination 12-28 months after the stroke. MRI was performed at 1.5 T, using echo-planar DWI with 7 b-values from 0 to 1200 x 10(6) s/m2 and conventional T2-weighted imaging. After 7-16 days 18 of 21 lesions gave high signal on DWI, and 12/16 measurable lesions had a decreased apparent diffusion coefficient (ADC). After 54-144 days ten lesions still gave high DWI signal and two still had an ADC below normal. On the fourth examination there was no remaining high DWI signal and all ADC were higher than normal.