Clinical utility of single-shot echo-planar diffusion-weighted imaging using L1-regularized iterative sensitivity encoding in prostate MRI.

We investigated the ability of echo-planar imaging with L1-regularized iterative sensitivity encoding-based diffusion-weighted imaging (DWI) to improve the image quality and reduce the scanning time in prostate magnetic resonance imaging. We retrospectively analyzed 109 cases of prostate magnetic resonance imaging. We compared variables in the quantitative and qualitative assessments among 3 imaging groups: conventional parallel imaging-based DWI (PI-DWI) with an acquisition time of 3 minutes 15 seconds; echo-planar imaging with L1-regularized iterative sensitivity encoding-based DWI (L1-DWI) with a normal acquisition time (L1-DWINEX12) of 3 minutes 15 seconds; and L1-DWI with a half acquisition time (L1-DWINEX6) of 1 minute 45 seconds. As a quantitative assessment, the signal-to-noise ratio (SNR) of DWI (SNR-DWI), the contrast-to-noise ratio (CNR) of DWI (CNR-DWI), and the CNR of apparent diffusion coefficient were measured. As a qualitative assessment, the image quality and visual detectability of prostate carcinoma were evaluated. In the quantitative analysis, L1-DWINEX12 showed significantly higher SNR-DWI than PI-DWI (P = .0058) and L1-DWINEX6 (P < .0001). In the qualitative analysis, the image quality score for L1-DWINEX12 was significantly higher than those of PI-DWI and L1-DWINEX6. A non-inferiority assessment demonstrated that L1-DWINEX6 was non-inferior to PI-DWI in terms of both quantitative CNR-DWI and qualitative grading of image quality with a <20% inferior margin. L1-DWI successfully demonstrated a reduced scanning time while maintaining good image quality.

A case of breast angiosarcoma clearly delineated by contrast-enhanced ultrasonography.

We present a case of breast angiosarcoma. Although B-mode ultrasonography did not indicate a tumor, contrast-enhanced ultrasonography (CEUS) was successfully delineated it. CEUS helped identify the tumor and its extent.

Prostatic urinary tract visualization with super-resolution deep learning models.

In urethra-sparing radiation therapy, prostatic urinary tract visualization is important in decreasing the urinary side effect. A methodology has been developed to visualize the prostatic urinary tract using post-urination magnetic resonance imaging (PU-MRI) without a urethral catheter. This study investigated whether the combination of PU-MRI and super-resolution (SR) deep learning models improves the visibility of the prostatic urinary tract. We enrolled 30 patients who had previously undergone real-time-image-gated spot scanning proton therapy by insertion of fiducial markers. PU-MRI was performed using a non-contrast high-resolution two-dimensional T2-weighted turbo spin-echo imaging sequence. Four different SR deep learning models were used: the enhanced deep SR network (EDSR), widely activated SR network (WDSR), SR generative adversarial network (SRGAN), and residual dense network (RDN). The complex wavelet structural similarity index measure (CW-SSIM) was used to quantitatively assess the performance of the proposed SR images compared to PU-MRI. Two radiation oncologists used a 1-to-5 scale to subjectively evaluate the visibility of the prostatic urinary tract. Cohen's weighted kappa (k) was used as a measure of agreement of inter-operator reliability. The mean CW-SSIM in EDSR, WDSR, SRGAN, and RDN was 99.86%, 99.89%, 99.30%, and 99.67%, respectively. The mean prostatic urinary tract visibility scores of the radiation oncologists were 3.70 and 3.53 for PU-MRI (k = 0.93), 3.67 and 2.70 for EDSR (k = 0.89), 3.70 and 2.73 for WDSR (k = 0.88), 3.67 and 2.73 for SRGAN (k = 0.88), and 4.37 and 3.73 for RDN (k = 0.93), respectively. The results suggest that SR images using RDN are similar to the original images, and the SR deep learning models subjectively improve the visibility of the prostatic urinary tract.

Distribution of human papilloma virus genotypes and treatment outcomes in definitive radiotherapy for cervical cancer.

Most oncogenic human papilloma virus (HPV) genotypes stratify into two species, α-7 HPV and α-9 HPV. There are several studies that evaluate the relationship between HPV species and treatment outcomes and reports that HPV species is prognostic. The HPV genotyping was conducted using biopsy specimens which had been stored in these studies. We conducted the study using the HPV test performed by cytology specimens which is less invasive and more useful in clinical settings. This study enrolled 46 patients who received HPV genotyping before the definitive radiotherapy. The results of the HPV genotyping were classified into HPVα-7, HPVα-9 and negatives. Of the 46 patients, 10 were positive for HPVα-7, 21 positive for HPVα-9 and 15 were negative. The median follow-up period was 38 months (range 4-142). The HPVα-7, HPVα-9 and negative groups showed the 3-year overall survival (OS; 59.3%, 80.4% and 72.2% [P = 0.25]); local control (LC; 67.5%, 81% and 80% [P = 0.78]); pelvic control (PC) (50%, 81% and 72.7% [P = 0.032]); pelvic lymph node (PLN) control (78.7%, 95% and 92.3% [P = 0.012]); distant metastasis free (DMF) survival (50%, 75.4% and 42.8% [P = 0.098]); and progression free survival (PFS) rate of patients (30%, 66.7% and 38.9% [P = 0.085]), respectively. Patients with HPVα-7 showed statistically significant poorer PC than the HPVα-9 group, in multivariate analysis. This result is consistent with previous studies for HPV positive patients. The HPV negativity rate was higher in this study than in other studies and further work on this may be needed for clinical use.

Patterns and predictors of site-specific recurrence in cervical cancer after radical hysterectomy.

AIM: This study examines patterns and predictors of site-specific recurrence to explore the causes of local recurrence of cervical cancer. METHODS: Radical hysterectomy was performed in 121 patients (stage IB-IIB). Nerve-sparing was performed whenever possible. The first recurrence in local, regional, and distant areas was examined. We investigated the possibility of nerve involvement in local recurrence, focusing on paravaginal tissues containing the pelvic plexus. We provide Supporting Information on local recurrence in the paravaginal area. RESULTS: Local recurrence was an independent event from regional or distant recurrence. Local recurrence was seen only in high-risk patients, while regional and distant recurrences were not or less related to the risk category. The independent risk factors by logistic regression for local, regional, and distant recurrence were parametrial invasion, vaginal invasion, and lymph node metastasis, respectively. Local recurrence showed a comparable or more significant negative impact on survival than distant recurrence. Among seven patients with local recurrences, five had a recurrence in the paravagina. The rate of paravaginal recurrence was one in 76 early-stage and four in 45 locally advanced diseases. Four sites of paravaginal recurrence occurred on the nerve-sparing side and two on the non-nerve-sparing side. Supporting Information demonstrated histological evidence of perineural spread into the pelvic plexus and perineural invasion of the primary tumor. CONCLUSIONS: A high percentage of local recurrences are in paravaginal tissue containing the pelvic plexus. The causal association of nerve-sparing surgery and perineural invasion with local recurrence needs to be investigated in large prospective studies.

Imaging findings of ovarian metastasis of primary renal cell carcinoma: A case report and literature review.

A 62-year-old woman presented with a tumor in the right kidney. A right partial nephrectomy was performed, and the tumor was diagnosed as clear cell renal cell carcinoma (RCC) on histopathological examination. A right ovarian tumor was detected on follow-up computed tomography (CT) 5 years after partial nephrectomy and pathology proved RCC metastasis. RCC rarely metastasizes to the ovaries. There is limited information on the radiological features of ovarian metastasis in RCC. In this case report, we presented the CT and magnetic resonance images of ovarian metastasis of RCC. In addition, we also presented a literature review with special emphasis on the imaging features of ovarian metastasis of RCC.

Radiological tumor classification across imaging modality and histology.

Radiomics refers to the high-throughput extraction of quantitative features from radiological scans and is widely used to search for imaging biomarkers for prediction of clinical outcomes. Current radiomic signatures suffer from limited reproducibility and generalizability, because most features are dependent on imaging modality and tumor histology, making them sensitive to variations in scan protocol. Here, we propose novel radiological features that are specially designed to ensure compatibility across diverse tissues and imaging contrast. These features provide systematic characterization of tumor morphology and spatial heterogeneity. In an international multi-institution study of 1,682 patients, we discover and validate four unifying imaging subtypes across three malignancies and two major imaging modalities. These tumor subtypes demonstrate distinct molecular characteristics and prognoses after conventional therapies. In advanced lung cancer treated with immunotherapy, one subtype is associated with improved survival and increased tumor-infiltrating lymphocytes compared with the others. Deep learning enables automatic tumor segmentation and reproducible subtype identification, which can facilitate practical implementation. The unifying radiological tumor classification may inform prognosis and treatment response for precision medicine.

A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer.

BACKGROUND AND PURPOSE: Urethra-sparing radiation therapy for localized prostate cancer can reduce the risk of radiation-induced genitourinary toxicity by intentionally underdosing the periurethral transitional zone. We aimed to compare the clinical impact of a urethra-sparing intensity-modulated proton therapy (US-IMPT) plan with that of conventional clinical plans without urethral dose reduction. MATERIALS AND METHODS: This study included 13 patients who had undergone proton beam therapy. The prescribed dose was 63 GyE in 21 fractions for 99% of the clinical target volume. To compare the clinical impact of the US-IMPT plan with that of the conventional clinical plan, tumor control probability (TCP) and normal tissue complication probability (NTCP) were calculated with a generalized equivalent uniform dose-based Lyman-Kutcher model using dose volume histograms. The endpoints of these model parameters for the rectum, bladder, and urethra were fistula, contraction, and urethral stricture, respectively. RESULTS: The mean NTCP value for the urethra in US-IMPT was significantly lower than that in the conventional clinical plan (0.6% vs. 1.2%, p < 0.05). There were no statistically significant differences between the conventional and US-IMPT plans regarding the mean minimum dose for the urethra with a 3-mm margin, TCP value, and NTCP value for the rectum and bladder. Additionally, the target dose coverage of all plans in the robustness analysis was within the clinically acceptable range. CONCLUSIONS: Compared with the conventional clinically applied plans, US-IMPT plans have potential clinical advantages and may reduce the risk of genitourinary toxicities, while maintaining the same TCP and NTCP in the rectum and bladder.

Herpes zoster infection mimicking pelvic lymph node metastasis on FDG-PET/CT in a patient with cervical cancer.

Although 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) is an established method for the staging of malignancies, benign lesions (e.g, active inflammatory lesions) often show increased metabolic activity. Herpes zoster is the clinical manifestation of the activation and replication of dormant varicella-zoster virus (VZV) in individuals with decreased cell-mediated immunity. Although the diagnosis of herpes zoster is clinical, it is sometimes observed incidentally during imaging for another disease. We describe the case of a 67-year-old Japanese female patient diagnosed with cervical cancer in whom FDG-PET/CT revealed herpes zoster manifestations: hypermetabolic cutaneous lesions in the buttock and pelvic lymph node involvement. The resected lymph nodes showed no malignant lesions but revealed lymphoid follicle formation, probably related to viral infection. There has been no report comparing FDG-PET findings of lymph nodes with histologic findings; the present findings are compatible with a clinically VZV-induced inflammatory reaction in regional lymph nodes, which increased FDG accumulation. Active infection with VZV displays increased FDG uptake in regional lymph nodes and may lead to incorrect malignant disease management in oncology. Misdiagnoses can be avoided by a careful interpretation by experienced nuclear medicine physicians as well as proper clinical evaluation.

Visualizing the urethra by magnetic resonance imaging without usage of a catheter for radiotherapy of prostate cancer.

The urethra position may shift due to the presence/absence of the catheter. Our proposed post-urination-magnetic resonance imaging (PU-MRI) technique is possible to identify the urethra without catheter. We aimed to verify the inter-operator difference in contouring the urethra by PU-MRI. The mean values of the evaluation indices of dice similarity coefficient, mean slice-wise Hausdorff distance, and center coordinates were 0.93, 0.17 mm, and 0.36 mm for computed tomography, and 0.75, 0.44 mm, and 1.00 mm for PU-MRI. Therefore, PU-MRI might be useful for identifying the prostatic urinary tract without using a urethral catheter. Clinical trial registration: Hokkaido University Hospital for Clinical Research (018-0221).

Characteristics of MR Imaging for Staging and Survival Analysis of Neuroendocrine Carcinoma of the Endometrium: A Multicenter Study in Japan.

PURPOSE: This study aimed to examine MRI features and staging of neuroendocrine carcinoma (NEC) of the endometrium and evaluate survival. METHODS: Clinical data, pathological, and preoperative pelvic MRI findings in 22 patients with histologically surgery-proven endometrial NEC were retrospectively reviewed. Tumors were pure NEC (n = 10) or mixed histotype (n = 12), with 13 large and nine small cell type. RESULTS: International Federation of Gynecology and Obstetrics (FIGO) staging was I, II, III, and IV in 6, 2, 12, and 2 patients, respectively. In 13 (76.4%) of 17 patients with pathological deep myometrial invasion, MRI showed abnormal diffusely infiltrative high T2 signal intensity throughout the myometrium with loss of normal uterine architecture. All tumors had restricted diffusion (apparent diffusion coefficient map low signal intensity, diffusion weighted imaging high signal intensity). Accuracy of T staging by MRI for all cases was 81.8%, with reference to pathology staging, while patient-based sensitivity, specificity, and accuracy for detecting metastatic pelvic lymph nodes was 60.0%, 100%, and 77.8%, respectively. Two intrapelvic peritoneal dissemination cases were detected by MRI. During follow-up (mean 30.4, range 3.3-138.4 months), 16 patients (72.7%) experienced recurrence and 12 (54.5%) died of disease. Two-year disease-free and overall survival rates for FIGO I, II, III, and IV were 66.7% and 83.3%, 50% and 100%, 10% and 33.3%, and 0% and 0%, respectively. CONCLUSION: Abnormal diffusely infiltrative high T2 signal intensity throughout the myometrium with normal uterine architecture loss and obvious restricted diffusion throughout the tumor are suggestive features of endometrial NEC. Pelvic MRI is reliable for intrapelvic staging of affected patients.

Neuroendocrine carcinoma of uterine cervix findings shown by MRI for staging and survival analysis - Japan multicenter study.

OBJECTIVES: To investigate neuroendocrine carcinoma (NEC) of the uterine cervix cases for MRI features and staging, as well as pathological correlations and survival. RESULTS: FIGO was I in 42, II in 14, III in 1, and IV in 5 patients. T2-weighted MRI showed homogeneous slightly high signal intensity and obvious restricted diffusion (ADC map, low intensity; DWI, high intensity) throughout the tumor in most cases, and mild enhancement in two-thirds. In 50 patients who underwent a radical hysterectomy and lymphadenectomy without neoadjuvant chemotherapy (NAC), intrapelvic T staging by MRI overall accuracy was 88.0% with reference to pathology staging, while patient-based sensitivity, specificity, and accuracy for metastatic pelvic lymph node detection was 38.5%, 100%, and 83.3%, respectively. During a mean follow-up period of 45.6 months (range 4.3-151.0 months), 28 patients (45.2%) experienced recurrence and 24 (38.7%) died. Three-year progression-free and overall survival rates for FIGO I, II, III, and IV were 64.3% and 80.9%, 50% and 64.3%, 0% and 0%, and 0% and 0%, respectively. MATERIALS AND METHODS: Sixty-two patients with histologically surgery-proven uterine cervical NEC were enrolled. Twelve received NAC. Clinical data, pathological findings, and pretreatment pelvic MRI findings were retrospectively reviewed. Thirty-two tumors were pure NEC and 30 mixed with other histotypes. The NECs were small cell type (41), large cell type (18), or a mixture of both (3). CONCLUSIONS: Homogeneous lesion texture with obvious restricted diffusion throughout the tumor are features suggestive of cervical NEC. Our findings show that MRI is reliable for T staging of cervical NEC.

Improvement of image quality on low-dose dynamic myocardial perfusion computed tomography with a novel 4-dimensional similarity filter.

The aim of this study was to evaluate the effect of a novel 4-dimensional similarity filter (4DSF) on quantitative and qualitative parameters of low-dose dynamic myocardial computed tomography perfusion (CTP) images.In this retrospective study, medical records of 32 patients with suspected or known coronary artery disease who underwent dynamic myocardial CTP at 80 kV were included. The 4DSF reduces noise by averaging voxels that have similar dynamic behavior after adaptive iterative dose reduction 3D (AIDR3D) and deformable image registration were applied. Qualitative (artefact, contour sharpness, and myocardial homogeneity [1 = poor; 2 = intermediate; 3 = good]) and quantitative measurement (standard deviation [SD] and signal-to-noise ratio [SNR]) were compared between the 4DSF and AIDR3D. Contrast-to-noise ratio (CNR) between ischemic and normal remote myocardium was also assessed using myocardial perfusion magnetic resonance imaging as the reference standard in seven patients.The 4DSF was successfully applied to all the images. Improvement in subjective image quality yielded by 4DSF was higher than that yielded by AIDR3D (homogeneity, 1.0 [3 vs 2]; artefact, 1.5 [3 vs 1.5]; P < .001) in all patients. The 4DSF significantly decreased the SD by 59% (AIDR3D vs 4DSF: 33.5 ±â€Š0.4 vs 13.8 ±â€Š0.4, P < .001), increased the SNR by 134% (AIDR3D vs 4DSF: 4.4 ±â€Š0.2 vs 10.3 ±â€Š0.2, P < .001), and increased the CNR by 131% (AIDR3D vs 4DSF: 1.6 ±â€Š0.2 vs 3.7 ±â€Š0.2, P < .001).The 4DSF improved the qualitative and quantitative parameters of low-dose dynamic myocardial CTP images.

Predicting metastasis in clinically negative axillary lymph nodes with minimum apparent diffusion coefficient value in luminal A-like breast cancer.

BACKGROUND: We investigated the usefulness of the minimum ADC value of primary breast lesions for predicting axillary lymph node (LN) status in luminal A-like breast cancers with clinically negative nodes in comparison with the mean ADC. METHODS: Forty-four luminal A-like breast cancers without axillary LN metastasis at preoperative clinical evaluation, surgically resected with sentinel LN biopsy, were retrospectively studied. Mean and minimum ADC values of each lesion were measured and statistically compared between LN positive (n = 12) and LN negative (n = 32) groups. An ROC curve was drawn to determine the best cutoff value to differentiate LN status. Correlations between mean and minimum ADC values and the number of metastatic axillary LNs were investigated. RESULTS: Mean and minimum ADC values of breast lesions with positive LN were significantly lower than those with negative LN (mean 839.9 ± 110.9 vs. 1022.2 ± 250.0 × 10- 6 mm2/s, p = 0.027, minimum 696.7 ± 128.0 vs. 925.0 ± 257.6 × 10- 6 mm2/s, p = 0.004). The sensitivity and NPV using the best cutoff value from ROC using both mean and minimum ADC were 100%. AUC of the minimum ADC (0.784) was higher than that of the mean ADC (0.719). Statistically significant negative correlations were observed between both mean and minimum ADCs and number of positive LNs, with stronger correlation to minimum ADC than mean ADC. CONCLUSIONS: The minimum ADC value of primary breast lesions predicts axillary LN metastasis in luminal A-like breast cancer with clinically negative nodes, with high sensitivity and high NPV.

Effects of menstrual cycle on background parenchymal enhancement and detectability of breast cancer on dynamic contrast-enhanced breast MRI: A multicenter study of an Asian population.

PURPOSE: To evaluate the effect of the menstrual cycle on BPE and cancer detectability in an Asian population. MATERIAL AND METHODS: 266 premenopausal patients with regular menstrual cycles from 24 centers were included, and 176 of them were diagnosed by pathology as having breast cancer. Thirty-five patients were examined in the menstrual phase (days 1-4), 105 in the proliferative phase (days 5-14), and 126 in the secretory phase (days 15-30). Measurement of the following signal intensities (SIs) were obtained: breast tissue on the unaffected side on a pre-contrast image (SI1) and an early-phase image (SI2); the SIs of breast tissue on the affected side on a pre-contrast image (SI3) and an early-phase image (SI4); and the SIs of breast cancer on a pre-contrast image (SI5) and an early-phase image (SI6). We calculated the BPE ratio, i.e., (SI2- SI1)/SI1 and the cancer/background enhancement ratio (C/B) ratio, i.e., (SI6- SI5) / (SI4- SI3). The BPE was classified as minimal, mild, moderate, or marked, and the cancer detectability was classified as excellent, good, or poor independently by two radiologists. RESULTS: The average C/B ratio was 20.1, 15.7, and 9.1 at the menstrual, proliferative, and secretory phases (p < 0.001). BPE was determined as moderate or marked in 0% and 5.4% at the menstrual phase, 10.3% and 11.0% at the proliferative phase, and 17.5% and 21.7% at the secretory phase by the two observers, respectively (p = 0.01, p = 0.01). The detectability of breast cancer was classified as poor in 0% and 0%, 1.4% and 13.0%, and 8.0% and 22.1% at the menstrual, proliferative, and secretory phases by the two observers, respectively (p = 0.07, p = 0.02). CONCLUSION: The menstrual phase and the proliferative phase seem to be suitable for breast MRI of Asian women.

Assessment of Coronary Flow Velocity Reserve in the Left Main Trunk Using Phase-contrast MR Imaging at 3T: Comparison with 15O-labeled Water Positron Emission Tomography.

PURPOSE: The aim of this study was to verify coronary flow velocity reserve (CFVR) on the left main trunk (LMT) in comparison with myocardial flow reserve (MFR) by 15O-labeled water positron emission tomography (PET) (MFR-PET) in both the healthy adults and the patients with coronary artery disease (CAD), and to evaluate the feasibility of CFVR to detect CAD. METHODS: Eighteen healthy adults and 13 patients with CAD were evaluated. CFVR in LMT was estimated by 3T magnetic resonance imaging (MRI) with phase contrast technique. MFR-PET in the LMT territory including anterior descending artery and circumflex artery was calculated as the ratio of myocardial blood flow (MBF)-PET at stress to MBF-PET at rest. RESULTS: There was a significant positive relationship between CFVR and MFR-PET (R = 0.45, P < 0.0001). Inter-observer calculations of CFVR showed good correlation (R2 = 0.93, P < 0.0001). The CFVR in patients with CAD was significantly lower than that in healthy adults (1.90 ± 0.61 vs. 2.77 ± 1.03, respectively, P = 0.01), which were similar to the results of MFR-PET (2.23 ± 0.84 vs. 3.96 ± 1.04, respectively, P < 0.0001). For the detection of patients with CAD, the area under the curve was 0.78 (P = 0.01). The sensitivity was 0.77 and specificity was 0.72 when a cut-off of 2.15 was used. CONCLUSION: CFVR by 3T was validated with MFR-PET. CFVR could detect the patients with CAD. This method is a simple and reliable index without radiation or contrast material.

IgG4-related Cardiovascular Disease from the Aorta to the Coronary Arteries: Multidetector CT and PET/CT.

Immunoglobulin G4 (IgG4)-related disease can affect the cardiovascular system, including the coronary arteries and pericardium and especially the walls of large and medium-sized vessels. The presence of coronary involvement is critical, as this condition can cause myocardial ischemia or sudden cardiac death. Although histopathologic examination remains the reference standard for detecting organ involvement and diagnosing IgG4-related disease, obtaining biopsy or surgical specimens from the vessel wall is still challenging. Because patients may be only mildly symptomatic, noninvasive imaging evaluation of IgG4-related cardiovascular disease (CVD) has an essential role in not only the diagnosis but also the management of this condition. Multidetector CT is a useful noninvasive examination for establishing the primary diagnosis and defining anatomic landmarks and their relationships. The spectrum of vessel involvement is vast, with varied manifestations. Radiologists should be familiar with inflammatory vasculitis, aneurysmal change, and pseudotumor formation in all vessels and the distribution of these conditions throughout the body. Electrocardiographically gated CT enables accurate, fast, and noninvasive characterization of coronary pathologic conditions and thus has an important advantage over catheter angiography. Combined PET/CT can depict inflammatory processes and help distinguish IgG4-related CVD from atherosclerosis. Familiarity with the PET/CT and CT findings of inflammatory processes involved in IgG4-related CVD is important for accurate diagnosis and evaluation of therapeutic response during follow-up. The multidetector CT and PET/CT characteristics of IgG4-related CVD, such as aortitis, periaortitis, arteritis, and periarteritis and including coronary artery involvement and pericarditis, are reviewed. In addition, the inflammatory process, quantification of active inflammation, and therapeutic response during follow-up associated with IgG4-related CVD are described. Online DICOM image stacks are available for this article. ©RSNA, 2018.

Heterogeneity of longitudinal and circumferential contraction in relation to late gadolinium enhancement in hypertrophic cardiomyopathy patients with preserved left ventricular ejection fraction.

PURPOSE: To evaluate heterogeneity of myocardial contraction in relation to extensive late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) patients with preserved left ventricular ejection fraction, using fast strain-encoded magnetic resonance imaging. MATERIALS AND METHODS: Twenty-two HCM patients and 24 age-matched control subjects were included in this retrospective study. The regional and global peak values of longitudinal and circumferential strain (LSregional, LSglobal, CSregional, CSglobal), and their regional heterogeneities were evaluated using coefficients of variation (LSCoV, CSCoV) in relation to LGE. Receiver operating characteristic curve analysis was performed to identify patients with a total left ventricular myocardial LGE ≥ 15%. RESULTS: LSglobal in HCM patients was significantly decreased compared to that in controls (- 14.4 ± 2.4% vs - 17.2 ± 2.0%; p = 0.0004), while CSglobal was not (p = 1.0). Negative LGE segments demonstrated decreased LSregional in HCM patients compared to in controls (p < 0.0001), while CSregional was not decreased. CSCoV demonstrated the largest area under the curve (AUC) (0.91), with high sensitivity (83%) and specificity (94%) for detection of HCM patients with extensive LGE, while the AUC of LSCoV was low (0.49). CONCLUSION: The heterogeneity in CSregional has a high diagnostic value for detection of HCM patients with extensive LGE.

Sudden maternal hypoxemia during elective cesarean section in a woman with placenta previa.

There have been no reports regarding imaging-documented bronchospasm in patients with amniotic fluid embolism (AFE). In a woman with scheduled cesarean section for placenta previa, transient bronchospasm and pulmonary hypertension were documented explaining a sudden drop in SpO2. Mild AFE was the most likely diagnosis in this patient.