Case Illustration of the Natural History of Left Dominant Arrhythmogenic Cardiomyopathy.

Background: Arrhythmogenic left ventricular cardiomyopathy is an increasingly recognized cause of recurrent myocarditis, a mimicker of acute coronary syndrome, and an important cause of malignant ventricular arrythmias and heart failure. Desmoplakin is a protein that is critical to maintaining the structural integrity of the myocardium. Disruption of desmoplakin leads to fibrofatty infiltration of the myocardium which leads to congestive heart failure, cardiac arrhythmias, and sudden cardiac death. However, desmoplakin cardiomyopathy is often misdiagnosed, resulting in significant morbidity and mortality. We report 2 contrasting cases illustrating the natural history-hot and cold phases-of arrhythmogenic left ventricular cardiomyopathy. Case Series: The first case demonstrates a common phenotypic presentation of desmoplakin cardiomyopathy manifested as recurrent myocarditis and myocardial injury representing the hot phase. The second case is an undulating course of chronic systolic heart failure and ventricular arrhythmias representing the cold phase. Conclusion: Arrhythmogenic cardiomyopathy manifests as a spectrum of disease processes that involve the right, left, or both ventricles. Mutations in the desmoplakin gene are often associated with a left dominant ventricular cardiomyopathy. Diagnosis remains difficult as the condition has no signature clinical presentation, and imaging findings are variable.

ECG-gated cardiac CT angiography using 64-MDCT for detection of patent foramen ovale.

OBJECTIVE: The purpose of our study was to show the feasibility of ECG-gated, 64-MDCT cardiac angiography for the detection of patent foramen ovale (PFO). MATERIALS AND METHODS: Chart review was performed on 214 consecutive patients referred for clinically indicated 64-MDCT angiography. The study cohort consisted of 20 patients who had previously undergone transesophageal echocardiography (TEE). Blinded consensus review of each CT angiography was performed by two experienced cardiac radiologists and results were compared with TEE, which served as a reference standard. CT criteria for the diagnosis of PFO were distinct left atrial "flap" in the expected location of the septum primum, continuous column of contrast material connecting this flap to the right atrium, and a "jet" of contrast material from the column into the right atrium. RESULTS: Of the 20 patients who underwent both TEE and cardiac CT angiography, six (30%) were found to have a PFO by TEE. Using the presence of a left atrial flap as the only diagnostic criterion, all six cases of PFO were detected using CT (sensitivity = 100%). Of the 14 patients with no PFO seen on TEE, 12 of these were correctly identified using CT (specificity = 86%). Using all three criteria together, the sensitivity decreased to 66% and the specificity increased to 100%. CONCLUSION: ECG-gated cardiac CT angiography performed with a 64-MDCT scanner can be used to reliably detect PFO.

Tumefactive cysts: a delayed complication following radiosurgery for cerebral arterial venous malformations.

We report five cases of symptomatic delayed cyst formation after radiosurgery for intracranial arterial venous malformations. Median time to discovery of the cysts following most recent radiosurgery was 59 months (range, 34-89 months). In all five patients, the radiation therapy-induced cysts exhibited tumefactive characteristics, including vasogenic edema, mass effect, and nodular enhancement. Despite these malignant features, these cystic lesions should be recognized as a benign complication of radiosurgery so that proper treatment (i.e., cystoperitoneal shunt surgery or excision) can be initiated.

Spontaneous adrenal hemorrhage during pregnancy: a review of the literature and a case report of successful conservative management.

Spontaneous adrenal hemorrhage is an acute hemorrhage of the adrenal gland that occurs in the absence of trauma or anticoagulant therapy. The incidence of this condition in pregnancy is unknown. We describe a patient with spontaneous unilateral adrenal hemorrhage that occurred during the third trimester of pregnancy. She was successfully managed conservatively with complete resolution of symptoms and had an uncomplicated perinatal outcome. We review the literature on spontaneous adrenal hemorrhage, including clinical signs and symptoms, diagnostic tests, and management of spontaneous adrenal hemorrhage, to help other practitioners to recognize and appropriately treat this rare condition.

Prospective comparison of echocardiography versus cardiac magnetic resonance imaging in patients with Ebstein's anomaly.

Ebstein's anomaly (EA) is primarily diagnosed by echocardiography. The purpose of this study was to compare echocardiography and magnetic resonance imaging (MRI) in EA. Data from cardiac MRI and echocardiography were prospectively collected from 16 patients with EA. Imaging data also were compared with intraoperative findings. Information provided by MRI and echocardiography were comparable for left ventricular size and function, tricuspid valve repairability, qualitative assessment of right-sided cavities, and visibility of septal and anterior tricuspid valve leaflets. The posterior tricuspid valve leaflet and tricuspid valve fenestrations were better visualized with MRI; associated heart defects were equally recognized, apart from small shunts that tended to be more readily diagnosed with echocardiography. Quantification of right-cavity size and right ventricular ejection fraction was possible only with cardiac MRI. The degree of tricuspid valve regurgitation was underestimated by echocardiography (2 patients) and by MRI (4 patients) when compared with intraoperative assessment. When evaluating EA, echocardiography and MRI provide complementary data. For visualization of the posterior tricuspid valve leaflet and quantitative assessment of right ventricular size and function, MRI is preferable. For appropriate risk stratification in EA, both MRI and echocardiography should be performed before cardiac surgery.

Nonlinearity of FMRI responses in human auditory cortex.

An investigation was made into the nature of the nonlinearity observed in auditory functional magnetic resonance imaging (fMRI) experiments associated with increases in total duration of acoustic imaging noise [e.g., Edmister et al., 1999; Shah et al., 1999]. A two-stimulus, four-condition paradigm was used to evaluate four acoustic conditions involving: (1) the presence or absence of a desired broadband music stimulus; and (2) two possible durations of trains of acoustic noise associated with image acquisition. Responses observed while increasing the duration of acoustic imaging noise were consistent with previous work (Talavage et al. [1999]: Hum Brain Mapp7:79-88) but the response to combined stimulation did not exhibit variation as a function of the acoustic imaging noise duration. These results suggest that spectral overlap of the stimuli produced colocalized responses that did not add linearly. This conclusion has implications for conducting both blocked and rapid-presentation event-related auditory fMRI experiments. The cortical activity induced by the stimulus may not reflect the activation, in spatial extent or magnitude of signal change, occurring in the absence of other acoustic noise.

Invasive lobular carcinoma: spectrum of enhancement and morphology on magnetic resonance imaging.

Invasive lobular carcinoma (ILC) may be a difficult tumor to detect early by physical examination, mammography, or ultrasound. We undertook this study to describe the spectrum of gadolinium enhancement and morphologic features of ILC on magnetic resonance imaging (MRI). Nineteen patients with ILC who presented with a palpable mass, a mammographically visible abnormality, or an unknown primary underwent preoperative MRI of both breasts using a T1-weighted high-resolution gradient echo sequence (pre- and postcontrast), and an echoplanar sequence during the administration of gadolinium. Using a quantitative measure of gadolinium uptake over time, called the extraction flow (EF) product, and a normal tissue threshold EF level of 25 or less, enhancement for 15 of the 19 cancers was characterized. By consensus, three radiologists categorized the morphologic features of the lesions. For the 15 cases of ILC that had echoplanar data, analysis showed peak EFs ranging between 25 and 120, and the majority showed EFs in the 30s. A substantial portion of two tumors enhanced in a similar fashion to normal breast tissue, with EFs in the low 20s. Morphologically MRI showed a focal mass in eight cases, regional enhancement in five, segmental enhancement in one, segmental enhancement with multiple small nodules in one, a mixture of a focal mass and regional enhancement in one, diffuse enhancement in one, multiple small nodules in one, and bilateral disease in one. Of the focal masses, seven were irregular in shape and one was round; six had ill-defined margins and two had spiculated margins. All eight enhanced heterogeneously. Four cases had multifocal disease and one case had unsuspected contralateral disease discovered only on MRI. MRI using a combination of morphology and a quantitative measure of gadolinium uptake was able to detect the majority of cases of ILC. However, there was a variable morphologic appearance and contrast enhancement pattern on MRI. A few lesions were difficult to distinguish from normal tissue. This suggests that some cases of ILC may be difficult to detect on MRI.

The lactating breast: MRI findings and literature review.

Normal physiologic changes in the breast related to pregnancy and lactation can reduce the sensitivity of imaging modalities, such as mammography. This is likely to be true for other breast imaging techniques such as magnetic resonance imaging (MRI). Although malignancy is relatively uncommon in lactating breasts, patients may develop palpable abnormalities that require imaging evaluation. Physiologic changes from pregnancy and lactation can complicate breast imaging. We report the MRI appearance of the lactating breast and address potential difficulties that may be encountered in this clinical situation.

Occult contralateral breast carcinoma incidentally detected by breast magnetic resonance imaging.

The incidence of synchronous bilateral breast cancers has been reported to be between 3.4% and 7.4%, as detected on mammography, physical examination, or both. We undertook a study to determine how often magnetic resonance (MR) imaging detects a contralateral abnormality in patients with known breast carcinoma. As part of an institutional review board (IRB) -approved research protocol, 17 patients with pathologically proven invasive carcinoma underwent preoperative MR imaging of both breasts using a T1-weighted, high-resolution gradient echo sequence (precontrast and postcontrast), an echo-planar sequence during administration of gadolinium, and a T2-weighted, fast-spin echo sequence. The morphology and dynamic enhancement of lesions in both breasts were assessed. Biopsy was recommended for any lesion meeting set criteria. MR imaging identified all 17 known invasive cancers in the breast of concern on mammography or physical examination. Five of 17 patients (29%) had 10 contralateral lesions identified on MR, for which biopsy was recommended. One of these lesions proved to represent a fibroadenoma. The other 9 lesions proved to represent a malignancy (6 invasive lobular, 2 infiltrating ductal, and 1 tubular). Four of the 17 patients (24%) with invasive cancer had contralateral synchronous cancers occult to physical examination, mammography, and ultrasonography. In this series, breast MR imaging of the breasts was more sensitive than mammography or physical examination in the detection of early breast cancer. Breast MR imaging of the contralateral breast may be of value as a routine screen in those patients with a known or suspected malignancy.