High Diffusion-weighted Imaging 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

Sex-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. A 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. 202 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). Fat 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.

Monoexponential and advanced diffusion-weighted imaging for hepatic fibrosis staging based on high inter-examiner reliability.

To determine the diagnostic efficiencies of multiple diffusion-weighted imaging (DWI) techniques for hepatic fibrosis (HF) staging under the premise of high inter-examiner reliability. Participants with biopsy-confirmed HF were recruited and divided into the early HF (EHF) and advanced HF (AHF) groups; healthy volunteers (HVs) served as controls. Two examiners analyzed intravoxel incoherent motion (IVIM) using the IVIM-DWI and diffusion kurtosis imaging (DKI) models. Intravoxel incoherent motion-DWI, DKI, and diffusion tensor imaging parameters with intraclass correlation coefficients (ICCs) of ≥0.6 were used to create regression models: HVs vs. EHF and EHF vs. AHF. We enrolled 48 HVs, 59 EHF patients, and 38 AHF patients. Mean, radial, and axial kurtosis; fractional anisotropy; mean, radial, and axial diffusivity; and α exhibited excellent reliability (ICCs: 0.80-0.98). Fractional anisotropy of kurtosis, f, and apparent diffusion coefficient showed good reliability (ICCs: 0.69-0.92). The real (0.58-0.67), pseudo- (0.27-0.76), and distributed diffusion coefficients (0.58-0.67) showed low reliability. In the HVs versus (vs.) EHF model, α (p=0.008) and ADC (p=0.011) presented statistical differences (area under curve [AUC]: 0.710). In the EHF vs. AHF model, α (p=0.04) and distributed diffusion coefficient (p=0.02) presented significant differences (AUC: 0.758). Under the premise of high inter-examiner reliability, DWI and IVIM-derived stretched-exponential model parameters may help stage HF.

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.

Rare Cortical and Intraparenchymal Epidermoid Cyst within the Right Occipital Lobe (P3-4.004)

<h3>Objective:</h3> N/A <h3>Background:</h3> The differential diagnosis for a diffusion-restricting cortical lesion on brain magnetic resonance imaging (MRI) is broad and includes acute ischemic stroke, abscess, demyelination, Creutzfeldt Jakob disease, encephalitis, and epidermoid cyst. <h3>Design/Methods:</h3> <h3>Case description:</h3> A 13-year-old boy with accelerated growth underwent MRI for pituitary assessment, which incidentally demonstrated a non-enhancing, T2 hyperintense right occipital lesion. No diffusion weighted imaging (DWI) sequences were obtained, and the lesion was suspected to represent encephalomalacia. Five years later, he developed left visual field difficulties and repeat MRI identified right occipital lesional growth with high DWI and low apparent diffusion coefficient (ADC) signal. The patient underwent resection of the right occipital lesion. Histopathology revealed keratin encapsulated by squamous epithelium, consistent with an epidermoid cyst. Our patient is currently doing well, and his left visual field vision is improved. <h3>Results:</h3> <h3>Discussion:</h3> Intracranial epidermoid cysts comprise 1% of primary intracranial tumors and are derived from ectodermal inclusions during neural tube closure. They usually present in middle age due to mass effect on adjacent structures. Epidermoid cysts most commonly occur at the cerebellopontine angle and parasellar region. A cortical location of an intracranial epidermoid cyst, as in our patient’s case, is very rare. The signal intensity of the epidermoid cyst on MRI is variable due to its composition of keratin and lipids and there is usually no associated edema. Total surgical excision is the mainstay of treatment for intracranial epidermoid cysts. Recurrence is not uncommon, but growth is usually slow over many years. <h3>Conclusions:</h3> Neurologists should include intraparenchymal epidermoid cysts in the differential diagnosis for a diffusion restricting lesion on MRI of the brain. <b>Disclosure:</b> Dr. Webb has nothing to disclose. The institution of Dr. Burns has received research support from NIH (NINDS, NCI), DOD, ABTA, Ivy foundation, insightec, Mayo Clinic, Abbvie, . Dr. Zhang has nothing to disclose. Dr. Sener has nothing to disclose.

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.

Uterine Sarcomas: Are There MRI Signs Predictive of Histopathological Diagnosis? A 50-Patient Case Series with Pathological Correlation.

Purpose To make clear distinction between two radiological types of uterine sarcomas. Methods 50 preoperative MRI were analyzed retrospectively, blinded to histopathology: 11 endometrial stromal sarcomas (ESS), 19 leiomyosarcomas (LMS), 18 carcinosarcomas/malignant mixed Mullerian tumors (MMMT), and 2 smooth muscle tumors of uncertain malignant potential (STUMP). Results According to their locations, two radiological types of sarcomas were identified: type 1: intracavitary (ESS, MMMT) and type 2: intramyometrial (LMS, STUMP). In both types, all tumors displayed intermediate T2-weighted signal (p < 0.001) and high diffusion-weighted imaging (DWI) b1000 signal (p < 0.001). Dynamic contrast-enhanced (DCE) MRI showed intratumoral pathologic vessels (98%) and heterogeneity at venous phase (p < 0.001). In the type 1 subgroup, all tumors displayed local spread: invasion of junctional zone on T2-weighted imaging (T2WI), irregular margins on DWI, and disruption of arcuate arteries subendometrial ring on DCE-MRI. In the type 2 subgroup, all tumors displayed irregular margins on T2WI, DWI, and DCE-MRI. Tumor heterogeneity was due to necrosis (p < 0.001). Most commonly the tumor was single (61%). In both types, apparent diffusion coefficient (ADC) lesser than or equal to 0.86 × 10−3 mm2/s (sensitivity = 73%, specificity = 92%) was suggestive of malignancy. Conclusion It may be feasible to get close to histological type of a uterine sarcoma based on our topographic classification into two radiological subgroups, corresponding to two kinds of diagnostic difficulties. Advances in knowledge. MRI signs suggestive of histopathological malignancy are identifiable, considering the triad T2WI/DWI/DCE-MRI, easily for type 1 but less easily for type 2; the threshold value for ADC is 0.86 × 10−3 mm2/s.

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 solid nonfunctioning pituitary macroadenomas: additional benefits of diffusion-weighted MR imaging.

A subset of benign, nonfunctioning pituitary macroadenomas (NFMAs) has been shown to undergo early progression/recurrence (P/R) during the first years after surgical resection. The aim of this study was to determine preoperative MR imaging features for the prediction of P/R in benign solid NFMAs, with emphasis on apparent diffusion coefficient (ADC) values. We retrospectively investigated the preoperative MR imaging features for the prediction of P/R in benign solid NFMAs. Only the patients who had undergone preoperative MRI and postoperative MRI follow-ups for more than 1 year (at least every 6-12 months) were included. From November 2010 to December 2016, a total of 30 patients diagnosed with benign solid NFMAs were included (median follow-up time 45 months), and 19 (63.3%) patients had P/R (median time to P/R 24 months). Benign solid NFMAs with cavernous sinus invasion, failed chiasmatic decompression, large tumor height and tumor volume, high diffusion-weighted imaging (DWI) signal, and lower ADC values/ratios were significantly associated with P/R (p < 0.05). The cutoff points of ADC value and ADC ratio for prediction of P/R are 0.77 × 10-3 mm2/sec and 1.01, respectively, with area under the curve (AUC) values (0.9 and 0.91) (p < 0.01). In multivariate Cox proportional hazards analysis, low ADC value (< 0.77 × 10-3 mm2/sec) is a high-risk factor of P/R (p < 0.05) with a hazard ratio of 14.07. Benign solid NFMAs with low ADC values/ratios are at a significantly increased risk of P/R, and aggressive treatments accompanied by close follow-up with imaging studies should be considered.

Genotypic Spectrum and Natural History of Cavitating Leukoencephalopathies in Childhood

We aimed to delineate the pattern of natural course, neuroimaging features, and the genotypic spectrum of cavitating leukoencephalopathies. Children (age of onset ≤16years) who met the criteria for cavitating leukoencephalopathies from January 2009 to October 2018 were identified. Whole-exome sequencing and prospective follow-up study of the natural history and brain magnetic resonance imaging (MRI) were performed. Thirty-seven children were clinically diagnosed with cavitating leukoencephalopathies. Pathogenic or likely pathogenic mutations in eight genes were identified in 31 individuals (83.78%): IBA57 (17/37), NDUFS1 (5/37), NDUFV1 (2/37), NDUFV2 (3/37), NDUFAF5 (1/37), LYRM7 (1/37), NDUFB8 (1/37), and GLRX5 (1/37). All genes were engaged in mitochondrial function. IBA57 was identified in half of children. Mutations in NDUFV2, NDUFAF5, NDUFB8, or GLRX5 were first found to be related to cavitating leukoencephalopathies. Follow-up with a median of 23.5months (four to 107months) was available. The median age at disease onset was 11months. All cases presented acute or subacute onset, and the initial presentation was rapid motor regression in 35 cases. Thirty-five children (35/37) exhibited a stabilized or improved pattern. Cavities and high-intensity diffusion-weighted imaging signals were the common MRI features during the acute stage. Although clinically stable, 21 children had reserved high diffusion-weighted imaging signals for a long time. Patients with different gene mutations show different MRI patterns. The study expands the number of genes involved in cavitating leukoencephalopathies to 22. IBA57 is the most common candidate gene. Most cases showed a stabilized or improved pattern after an acute or subacute onset, which is different from most other inherited metabolic diseases or leukodystrophies. More cases and a longer follow-up period are needed.

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.

Diagnostic performance of diffusion-weighted imaging for prostate cancer: Peripheral zone versus transition zone.

ObjectivesDiffusion-weighted imaging (DWI) has been shown to be an important component of multiparametric magnetic resonance imaging (mpMRI). We compared performance of DWI for detection of prostate cancer (PCa) in peripheral zone (PZ) and transition zone (TZ) of prostate.Materials and methodsWe reviewed data of 460 subjects who underwent preoperative 3.0-Tesla mpMRI and subsequently radical prostatectomy. Level of suspicion for PCa was graded using 5-grade Likert-scale from DWI. Topographic analyses were performed for location of tumor foci at each surgical specimen. Among those with DWI grade ≥ III, we analyzed concordance rate on the location of radiologic and pathologic index lesions between DWI and surgical specimens.ResultsAmong 460 patients, 351 (76.3%) patients showed suspicious DWI lesions (57.5% in PZ, 42.5% in TZ). Multivariates regression analyses revealed significant associations between high DWI grade and adverse pathologic outcomes including pathologic stage, Gleason score, tumor volume and extracapsular extension (all p < 0.05). Overall concordance rates between DWI and surgical specimen were 75.8%, significantly higher in PZ than TZ (82.2% vs. 67.1% p = 0.002). Such concordance rate showed a positive linear association with increase in DWI grading (p < 0.001). Among 109 patients with DWI grade I-II, 28 (25.7%) harbored high grade disease (pathologic Gleason score ≥ 4 + 3).ConclusionsDWI detects tumors in PZ of prostate more accurately than those in TZ. Such accuracy of DWI was shown to be more evident with higher DWI grade. Meanwhile, a negative DWI did not guarantee absence of high grade PCa.

High Signal in Bone Marrow on Diffusion-Weighted Imaging of Female Pelvis: Correlation With Anemia and Fibroid-Associated Symptoms.

The diffusion-weighted imaging (DWI) signals of the female pelvic bone marrow show great variability and are usually high in female patients with fibroid-associated symptoms and anemia. To ascertain clinical factors contributing to high signal intensity in the bone marrow of the female pelvis on DWI. Retrospective case-control study. A single-institution review of 221 female patients underwent a pelvic magnetic resonance study from December 2012 to July 2014. 1.5T/DWI (b = 0 and 1000) and apparent diffusion coefficient (ADC). The ADC of pelvic bone marrow and the muscle-normalized signal intensity (SI) on DWI (mnDWI) were measured. A brightness grading scale ranging from 0 to 4 was used for pelvic bone assessment. Clinical factors, namely, age, the lowest hemoglobin level in the last 6 months, the presence of large uterine fibroids, and/or adenomyosis and fibroid-associated symptoms were recorded. The relationships between the brightness grade and clinical factors were evaluated through multinomial logistic regression, and correlations of mnDWI and the ADC with the clinical factors were analyzed through the Kruskal-Wallis test, Jonckheere's trend test, and the Mann-Whitney U-test with Bonferroni correction. Age and the hemoglobin level were inversely associated with the bone marrow brightness grade on DWI (both P < 0.05), whereas the presence of fibroid-associated symptoms showed a positive association (P = 0.028). The ADC and mnDWI in women younger than 50 years were significantly higher than those in older women (both P < 0.0001). The ADC had no significant correlation with anemia (P = 0.511), whereas mnDWI increased as the severity of anemia increased (P = 0.00154). Our study showed an association of high DWI SI of pelvic bone marrow with anemia in premenopausal women. 4 Technical Efficacy Stage 3 J. Magn. Reson. Imaging 2018;48:1024-1033.

Phenotypic spectrum of mutations in IBA57, a candidate gene for cavitating leukoencephalopathy.

IBA57 is involved in the biogenesis of mitochondrial [4Fe-4S] proteins. Eighteen cases with IBA57 mutations have been reported to date. We described a novel phenotype in 11 children with cavitating leukoencephalopathy and summarized the phenotypic spectrum of IBA57 mutations. The median age of onset was 9 months, with an initial presentation of motor regression. Deterioration of neurological function reached its peak within 4 months. The median interval between onset and last follow-up was 2.9 years (0.4-10.0). All cases survived and remained stable. Severe motor handicap was observed in 50.0% of the patients, 52.9% to 71.4% had a delay in communication, problem solving or personal-social skills, and 20.0% had mild symptomatic fluctuations. In the peak phase, magnetic resonance imaging (MRI) lesions were mainly observed in the periventricular/central white matter, and cavitating lesions and patchy high diffusion-weighted imaging (DWI) signals were observed. The numbers and extent of restricted diffusional lesions were reduced, and atrophy was prominent in the recovery phase. Eight novel mutations in IBA57 were identified in our study. This study provided more information about the natural history and evolution of neuroimaging. Combined with previously reported patient studies, our findings suggest that defects in IBA57 can produce diverse phenotypes. IBA57 should be considered a candidate gene for cavitating leukoencephalopathy.

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.