A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessioncslbseatukat1dt5ie1ovdo202oi4bjh): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Undefined array key "choices"

Filename: controllers/Detail.php

Line Number: 249

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Trying to access array offset on value of type null

Filename: controllers/Detail.php

Line Number: 249

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Trying to access array offset on value of type null

Filename: controllers/Detail.php

Line Number: 249

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Trying to access array offset on value of type null

Filename: controllers/Detail.php

Line Number: 249

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: 8192

Message: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated

Filename: models/Detail_model.php

Line Number: 71

Backtrace:

File: /var/www/html/application/models/Detail_model.php
Line: 71
Function: strpos

File: /var/www/html/application/controllers/Detail.php
Line: 252
Function: insertAPISummary

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: 8192

Message: str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated

Filename: helpers/my_audit_helper.php

Line Number: 8919

Backtrace:

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 8919
Function: str_replace

File: /var/www/html/application/controllers/Detail.php
Line: 255
Function: formatAIDetailSummary

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Undefined array key "choices"

Filename: controllers/Detail.php

Line Number: 256

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 256
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Trying to access array offset on value of type null

Filename: controllers/Detail.php

Line Number: 256

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 256
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Trying to access array offset on value of type null

Filename: controllers/Detail.php

Line Number: 256

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 256
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Undefined array key "usage"

Filename: controllers/Detail.php

Line Number: 257

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 257
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Trying to access array offset on value of type null

Filename: controllers/Detail.php

Line Number: 257

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 257
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Undefined array key "usage"

Filename: controllers/Detail.php

Line Number: 258

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 258
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Trying to access array offset on value of type null

Filename: controllers/Detail.php

Line Number: 258

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 258
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Undefined array key "usage"

Filename: controllers/Detail.php

Line Number: 259

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 259
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Trying to access array offset on value of type null

Filename: controllers/Detail.php

Line Number: 259

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 259
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Undefined array key "usage"

Filename: controllers/Detail.php

Line Number: 260

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 260
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Trying to access array offset on value of type null

Filename: controllers/Detail.php

Line Number: 260

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 260
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Trying to access array offset on value of type null

Filename: controllers/Detail.php

Line Number: 260

Backtrace:

File: /var/www/html/application/controllers/Detail.php
Line: 260
Function: _error_handler

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests

Filename: helpers/my_audit_helper.php

Line Number: 143

Backtrace:

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 143
Function: file_get_contents

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 209
Function: simplexml_load_file_from_url

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3098
Function: getPubMedXML

File: /var/www/html/application/controllers/Detail.php
Line: 574
Function: pubMedSearch_Global

File: /var/www/html/application/controllers/Detail.php
Line: 488
Function: pubMedGetRelatedKeyword

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Attempt to read property "Count" on bool

Filename: helpers/my_audit_helper.php

Line Number: 3100

Backtrace:

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3100
Function: _error_handler

File: /var/www/html/application/controllers/Detail.php
Line: 574
Function: pubMedSearch_Global

File: /var/www/html/application/controllers/Detail.php
Line: 488
Function: pubMedGetRelatedKeyword

File: /var/www/html/index.php
Line: 316
Function: require_once

7 Tesla MRI with a transmit/receive loopless antenna and B1-insensitive selective excitation. | LitMetric

7 Tesla MRI with a transmit/receive loopless antenna and B1-insensitive selective excitation.

Magn Reson Med

Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland, USA; Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, Maryland, USA.

Published: July 2014

AI Article Synopsis

Article Abstract

Purpose: Use of external coils with internal detectors or conductors is challenging at 7 Tesla (T) due to radiofrequency (RF) field (B1 ) penetration, B1 -inhomogeneity, mutual coupling, and potential local RF heating. The present study tests whether the near-quadratic gains in signal-to-noise ratio and field-of-view with field-strength previously reported for internal loopless antennae at 7T can suffice to perform MRI with an interventional transmit/receive antenna without using any external coils.

Methods: External coils were replaced by semi-rigid or biocompatible transmit/receive loopless antennae requiring only a few Watts of peak RF power. Slice selection was provided by spatially selective B1 -insensitive composite RF pulses that compensate for the antenna's intrinsically nonuniform B1 -field. Power was adjusted to maintain local temperature rise ≤1°C. Fruit, intravascular MRI of diseased human vessels in vitro, and MRI of rabbit aorta in vivo are demonstrated.

Results: Scout MRI with the transmit/receive antennae yielded a ≤10 cm cylindrical field-of-view, enabling subsequent targeted localization at ∼100 μm resolution in 10-50 s and/or 50 μm MRI in ∼2 min in vitro, and 100-300 μm MRI of the rabbit aorta in vivo.

Conclusion: A simple, low-power, one-device approach to interventional MRI at 7T offers the potential of truly high-resolution MRI, while avoiding issues with external coil excitation and interactions at 7T.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4113325PMC
http://dx.doi.org/10.1002/mrm.24910DOI Listing

Publication Analysis

Top Keywords

mri transmit/receive
8
transmit/receive loopless
8
external coils
8
loopless antennae
8
mri
8
mri rabbit
8
rabbit aorta
8
μm mri
8
tesla mri
4
transmit/receive
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!