Palindrome Partitioning

Given a string s, partition s such that every substring of the partition is a palindrome.

Return all possible palindrome partitioning of s.

For example, given s = “aab”,
Return

  [
    ["aa","b"],
    ["a","a","b"]
  ]

#include <vector>
#include <string>
#include <iostream>

using namespace std;
class Solution {
public:
	vector<vector> partition(string s) {
		// Start typing your C/C++ solution below
		vector tempp;
		vector temp;
		vector<vector> result;
		int nStart = 0;
		int nEnd = 1;

		for(int i=0;i<s.length();i++){
			string strtemp;
			strtemp = s.substr(i,1);
			temp.push_back(strtemp);
			if (nEnd==s.length()){
				string str;
				str = s.substr(nStart,nEnd-nStart);
				tempp.push_back(str);
				continue;
			}
			if(s.at(nStart)!=s.at(nEnd)){
				string str;
				str = s.substr(nStart,nEnd-nStart);
				tempp.push_back(str);

				nStart=nEnd;
				nEnd++;
			}
			else{
				nEnd++;
			}
		}
		result.push_back(tempp);
		result.push_back(temp);
		return result;
	}
};
void main()
{
	string s = "aabccbbb"; //for test
	vector<vector<string>> vecResults;
	Solution sol;
	vecResults = sol.partition(s);
	for(int i=0;i<vecResults.size();i++){
		for(int j=0;j<vecResults.at(i).size();j++){
			cout<<vecResults.at(i).at(j);
			cout<<" ";
		}
		cout<<"\n";
	}	
}

MRI hardware components

A typical MRI system include following components:

• Magnet
• RF coils
• Gradient coils
• Shim coils
• Magnet coils
• Magnet power supply
• Shim power supply
• Gradient amplifiers
• RF transmitter
• RF receivers
• Digitizer
• Host computer
• Operators console
• Image processor

Flow quantification

Susceptibility Weighted Imaging and Mapping

Imaging Traumatic Brain Injury

Sequence: Spin Echo

T1 weighted images (T1WI) are achieve using a short TE and short TR
T2 weighted images (T2WI) are achieve using a long TE and long TR
Proton Density images (PD) are achieve using a short TE and long TR

MRI and Nobel

A brief historical account of the Nobel Prize Laureates clearly shows the track of the discovery, development, and applications of NMR spectroscopy.

Otto Stern, USA: Nobel Prize in Physics 1943, “for his contribution to the development of molecular ray method and his discovery of the magnetic moment of the proton”
Isidor I. Rabi, USA: Nobel Prize in Physics 1944, “for his resonance method for recording the magnetic properties of atomic nuclei”
Felix Bloch, USA and Edward M. Purcell, USA: Nobel Prize in Physics 1952, “for their discovery of new methods for nuclear magnetic precision measurements and discoveries in connection therewith”
Richard R. Ernst, Switzerland: Nobel Prize in Chemistry 1991, “for his contributions to the development of the methodology of high resolution nuclear magnetic resonance (NMR) spectroscopy
Kurt Wüthrich, Switzerland: Nobel Prize in Chemistry 2002, “for his development of nuclear magnetic resonance spectroscopy for determining the three-dimensional structure of biological macromolecules in solution”
Paul C. Lauterbur, USA and Peter Mansfield, United Kingdom: Nobel Prize in Physiology or Medicine 2003, “for their discoveries concerning magnetic resonance imaging”

Find your file in the folder

If you want to search a file under the MFC programming environment, the below source code may help you.

///… Search File
HANDLE hFile;
WIN32_FIND_DATA    FindFileData;
CString szFileMask;  //file search path and file wildcard
hFile = FindFirstFile(szFileMask,&FindFileData);
while(hFile != INVALID_HANDLE_VALUE)
{
if(!FindNextFile(hFile,&FindFileData))
break;
}
FindClose(hFile);
///…End Search File

“Unable to Attach to the Process” visual studio 2008 error

Problem: It’s really weird. when I try debug the program as usual, there is an error box jump up “Unable to Attach to the Process”.
Solution: Project propeties->debugging->Attach set to NO.
The function of Attach is specifies whether to start or attach to the application. Default setting is No. I don’t know why mine is set to yes.

MRI take home point 4

• The data in the center of k-space determine SNR.
• The spin-echo pulse sequence consists of a 90-TE/2-180-TE/2-ADC.
• Total scan time for 2D spin-echo imaging is determined by the product of TR, the number of phase-encoding steps, and the number of excitations per phase-encoding step.
• In multislice SE, many slices are collected in the same scan time as a single slice. The maximum number of slices is determined by TR and TE, the longer TR and the shorter TE, the more slices that can be acquired.
• Gradient-echo pulse sequences speed image acquisitions by using partial flip angles (less than 90 degree) and gradient-reversal to form a signal echo.
• Fast spin-echo (FSE) sequences provide similar contrast weighting to SE sequences, but with reduced scan times.
• The echo train length (ETL) in FSE describes the number of echoes acquired after each excitation; each echo corresponds to a different phase-encoding view (or line in k-space).
• Echo planar imaging (EPI) acquires extremely fast images but at limited spatial resolution and contrast weighting; more sensitive to chemical shift artifacts.
• Short TI inversion recovery (STIR) sequences provide fat suppression by selection of a TI value that nulls the signal from fat; STIR is a useful substitute for fat-suppressed T2W SE or FSE sequences.
• “Fast STIR” imaging collects multiple phase-encoding views (or lines in k-space) for each
• 180-TI-90-TE/2-180-TE/2-ADC pulse train, making it a practical alternative
• to FSE for obtaining fat-suppressed T2-weighted images.
• Noise is best measured as the standard deviation in the background of an MRI.
• Image SNR increases approximately linearly with static magnetic field strength above 0.5 tesla.
• Image SNR increases linearly with pixel size.
• When two similarly acquired images are added or subtracted, the resulting image has a noise level that is square root of 2 higher than that in either image.
• The larger the lesion area or contrast, and the lower the noise, the easier the lesion is to detect.
• The rose model describes the relationship between lesion area, contrast, and noise for lesion detection; the larger the lesion area or contrast, and the lower the noise, the easier the lesion is to detect.
• Artifacts can be caused by imperfection of hardware including B0, B1, gradients, shielding, RF coils.
• Cross-talking in multi-slice MRI. Partial-volume artifacts.
• Most artifacts in PE direction (such as motion) but chemical shift artifact which in FE direction.
• Ringing artifacts by insufficient sample points, Wraparound artifacts by insufficient FOV.
• Gd-chelates’ primary effect is marked shortening of T1; thus heavily T1-weighted sequences are essential for high sensitivity to cancer.
• Gd-chelate contrast agents have the potential to cause a new, potentially serious disease (nephrogenic systemic fibrosis or NSF) in patients who have moderate to end-stage kidney disease at the time of administration of contrast agent